JP6348802B2 - Delay time measuring device, delay time measuring system and program - Google Patents

Description

  The present invention relates to a delay time measuring apparatus, a delay time measuring system, and a program for measuring a delay time of signal propagation when a digital signal is transmitted from a transmitter to a receiver via a transmission line.

  Conventionally, 8K Super Hi-Vision (SHV) ultra-high-definition video service with 16 times the number of pixels of Hi-Vision (registered trademark) has been researched and developed with the aim of starting test broadcasting by satellite in 2016. (See Non-Patent Document 1).

  In addition, as the research and development of ultra-high-definition video services progresses, the Information and Communication Council decided that “Technical Conditions for Satellite Core Broadcasting and General Satellite Broadcasting” in “Technical Conditions for Ultra-High-Definition Television Broadcasting Systems”. ”Was submitted, and a satellite broadcasting transmission system for distributing SHV signals equivalent to about 100 Mbps was formulated in March 2014. The ministerial ordinances and notifications related to the above technical conditions have been revised (see Non-Patent Document 2).

  In order to rebroadcast the SHV signal on cable television, it is necessary to transmit a large amount of data. As a method for transmitting large-capacity data, a method for extending an existing cable television transmission system and transmitting a large-capacity MPEG-2 TS signal with a plurality of carriers has been proposed (see Non-Patent Documents 3 and 4). ).

  Assuming that ultra-high-definition video services will be launched as satellite test broadcasts in 2016, transmission systems will become more sophisticated and large-capacity in order to be able to provide equivalent services even on cable TV. In order to respond to the standardization, standardization activities are being conducted with the aim of standardizing the transmission system. In JCTEA (Japan CATV Technology Association), a demonstration experiment of the proposed method is scheduled within 2014.

  When introducing a new broadcasting system (super high-definition broadcast cable television transmission system) to realize ultra-high definition video services, the transmission path coding parameters (interleave depth, FEC coding rate, etc.) Accordingly, it is necessary to actually measure the delay time of signal propagation from the transmitter to the receiver via the transmission path. This is due to the delay in signal propagation when the satellite broadcast is received directly by the parabolic antenna and when it is rebroadcast (retransmitted) by cable television (when it is retransmitted by a retransmission system with a cable television station). This is because if the time difference becomes large, there will be a trouble in realizing a broadcast service or the like based on time information. Therefore, the delay time is measured in advance and measures are taken to absorb the delay time.

  For example, in a service such as live broadcasting, when the difference in delay time increases, it may be difficult to engage between the relay site and the studio. Therefore, by measuring the delay time, it is necessary to select transmission path encoding parameters within a range that does not hinder and reflect them in the actual operation regulations.

  Conventionally, various methods have been disclosed for measuring a delay time of signal propagation when a digital signal is transmitted from a transmitter to a receiver via a transmission line. For example, a technique (first technique) for embedding time data in a transmission signal is known. This method is based on the difference between the transmission time embedded in the packet on the transmission side and the arrival time of the packet, with the transmission time embedded in the packet with the transmission side and reception time synchronized. And delay time of signal propagation is measured.

  Also, a technique (second technique) is known in which a signal propagation delay time from a broadcasting station studio to each transmitting station is measured using a control line (see, for example, Patent Document 1). In this method, a broadcast station studio and each transmitting station are connected by a control line, and a time for returning a signal transmitted from the broadcast station studio through the control line is measured as a signal propagation delay time. .

  Also, a technique (third technique) for measuring a signal propagation delay time by obtaining a delay profile of an OFDM signal at each transmitting station is known (see, for example, Patent Document 2). This method analyzes the difference between the ideal arrangement of SP (scattered pilot) included in the OFDM signal and the arrangement of the actually received SP, performs inverse Fourier transform of the frequency characteristics, and performs a delay profile on the time axis. By calculating the relative delay time between different paths.

Japanese Patent No. 4416905 Japanese Patent No. 4212403

E. Nakasu, “Super Hi-vision on the Horizon”, IEEE Consumer Electronics Magazine, 1, 2, pp. 36-42 (Apr. 2012) Technical conditions for ultra-high-definition television broadcasting system, [online], published by the Ministry of Internal Affairs and Communications, March 2012, [searched July 16, 2014], Internet <URL: http: //www.soumu. go.jp/menu_news/s-news/01ryutsu08_02000095.html> Y.Hakamada, N.Nakamura, T.Kurakake, T.Kusakabe, and K.Oyamada, “UHDTV (8K) Distribution Technology and Field Trial on Cable Television Networks”, ITE Trans.on MTA, 2,1, pp.2 -7 (Jan.2014) Y. Hakamada, N. Nakamura, K. Oyamada, T. Kurakake, and T. Kusakabe, “An UHDTV Cable Television Distribution in Combinations of Multiple 64 and 256 QAM Channels”, IEEE ICCE2013, 2, pp. 488-489 (Jan .2013)

  However, in the first method of embedding time data in a transmission signal, when transmission line characteristics deteriorate and BER (Bit Error Ratio) deteriorates, an error occurs in time data and it is difficult to measure the delay time. There was a problem of becoming.

  In the second method using a control line, it is necessary that a control line be connected between the broadcasting station studio and each transmitting station. This second method is based on the premise that a control line is installed. When the control line is not installed, it is possible to easily realize the delay time measurement such as a new construction is required. There was a problem that I could not.

  In addition, the third method for obtaining the delay profile of the OFDM signal has a problem that the broadcasting system (modulation system) for measuring the delay time is limited, a complicated configuration is required, and the signal processing load is high.

  Therefore, the present invention has been made to solve the above-described problems, and the object of the present invention is to transmit from a transmitter by a simple method that does not need to lay a control line in a transmission line and does not depend on a broadcasting system. It is an object of the present invention to provide a delay time measuring apparatus, a delay time measuring system, and a program capable of measuring a delay time of signal propagation between a receiver and a receiver.

  In order to achieve the object, the delay time measuring apparatus according to claim 1 performs a predetermined transmission process on data to be transmitted, and transmits the signal subjected to the transmission process via a transmission line, the transmission A delay time measuring apparatus for measuring a delay time of signal propagation to a receiver that performs predetermined reception processing on data of a signal received through a transmission line and the transmission path, generating periodic data repeated at a constant period, A periodic data generator for storing periodic data in a first buffer; a transmission processor for inputting the periodic data generated by the periodic data generator; and outputting the periodic data to the transmitter; and the transmission processor And a reception processing unit that inputs the periodic data output from the transmitter, the transmission path, and the receiver, and stores the periodic data in a second buffer, and the first buffer. A delay time measuring unit that calculates a time difference from a timing at which the periodic data stored in the fa and the periodic data stored in the second buffer are synchronized, and measures a delay time of the signal propagation based on the time difference And.

  The delay time measuring device according to claim 2 is the delay time measuring device according to claim 1, further comprising: an output terminal from which the transmission processing unit outputs the periodic data; and the reception processing unit, which receives the periodic data. An internal processing time measuring unit that measures the delay time measured by the delay time measuring unit as an internal processing time when the input terminal is directly connected to the input terminal, the delay time measuring unit from the time difference, The internal processing time measured by the internal processing time measurement unit is subtracted, and the result of the subtraction is measured as the signal propagation delay time.

  The delay time measuring device according to claim 3 is the delay time measuring device according to claim 1 or 2, wherein the delay time of the signal propagation is measured by the two delay time measuring devices on the transmitting side and the receiving side. In this case, the transmission processing unit provided in the transmission-side delay time measuring device inputs the periodic data generated by the periodic data generation unit provided in the transmission-side delay time measuring device and inputs the transmitter. The reception processing unit provided in the delay time measuring device on the receiving side outputs the periodic data output by the transmission processing unit provided in the delay time measuring device on the transmitting side to the transmitter and the transmission And the period data is stored in the second buffer provided in the delay time measuring device on the receiving side, and the delay time provided in the delay time measuring device on the receiving side. Measuring part The period data stored in the first buffer included in the delay time measuring apparatus on the receiving side and the period data stored in the second buffer included in the delay time measuring apparatus on the receiving side are synchronized. A time difference is calculated from the timing, and a delay time of the signal propagation is measured based on the time difference.

  Furthermore, the delay time measurement system according to claim 4 performs a predetermined transmission process on data to be transmitted, and transmits the signal subjected to the transmission process via a transmission path, the transmission path, and the transmission path. In a delay time measurement system for measuring a delay time of signal propagation to a receiver that performs predetermined reception processing on data of a signal received via a signal, periodic data that is repeated at a constant period is generated, and the periodic data is transmitted to the transmitter The first delay time measuring device to output to the first delay time measuring device and the period data output from the first delay time measuring device are input via the transmitter, the transmission path and the receiver, and the signal propagation delay A second delay time measuring device for measuring time, wherein the first delay time measuring device has a common time in the first delay time measuring device and the second delay time measuring device. A first clock unit having an internal clock set, a first cycle data generation unit that generates the cycle data from a predetermined measurement start time at which measurement of the signal propagation delay time is started, and the first A transmission processing unit that inputs the periodic data generated by the periodic data generation unit and outputs the periodic data to the transmitter, and the second delay time measuring device has an internal clock to which the common time is set. A second clock unit having a second clock data generating unit that generates the cycle data from the predetermined measurement start time and stores the cycle data in a first buffer; and the first delay time measurement. The reception processing unit that inputs the periodic data output by the transmission processing unit of the apparatus through the transmitter, the transmission path, and the receiver, and stores the periodic data in a second buffer; and the first Store in the buffer A delay time measuring unit that calculates a time difference from a timing at which the periodic data stored and the periodic data stored in the second buffer are synchronized, and measures a delay time of the signal propagation based on the time difference; It is characterized by having.

  The delay time measurement system according to claim 5 is the delay time measurement system according to claim 4, wherein a delay time measurement unit provided in the second delay time measurement device is connected to the first delay time measurement device. A processing time from when the transmission processing unit provided includes the periodic data input from the first periodic data generation unit to output to the transmitter; and the reception provided in the second delay time measuring device An internal processing time corresponding to a time obtained by adding a processing time until the processing unit inputs the periodic data from the receiver and stores it in the second buffer is set in advance, and the internal processing is determined from the time difference. The time is subtracted, and the result of the subtraction is measured as a delay time of the signal propagation.

  Furthermore, a delay time measuring program according to a sixth aspect causes a computer to function as the delay time measuring apparatus according to any one of the first to third aspects.

  The delay time measurement program according to claim 7 is a transmitter for performing a predetermined transmission process on data to be transmitted and transmitting the signal subjected to the transmission process via a transmission path, the transmission path, and the transmission path. A program for measuring a delay time of signal propagation for a receiver that performs predetermined reception processing on data of a signal received via a first data that generates periodic data repeated at a constant period and outputs the data to the transmitter The delay time measuring device and the period data output by the first delay time measuring device are input via the transmitter, the transmission path, and the receiver, and the signal propagation delay time is measured. In the delay time measuring program by the delay time measuring system, the first delay time measuring device includes the first delay time measuring device and the second delay time measuring device. A first clock unit having an internal clock in which a common time is set in the extended time measuring device, wherein the second delay time measuring device matches the time by the internal clock of the first delay time measuring device; A second clock unit having an internal clock for generating the period data from a predetermined measurement start time for starting measurement of the signal propagation delay time in a computer constituting the first delay time measuring device; And a second step of outputting the periodic data to the transmitter, and causing a computer constituting the second delay time measuring device to perform the measurement from the predetermined measurement start time. A third step of generating periodic data and storing the periodic data in a first buffer; and the periodic data output in the first step, the transmitter, the transmission line, and the receiver The fourth step of storing the periodic data in the second buffer, the periodic data stored in the first buffer, and the periodic data stored in the second buffer are synchronized. A fifth step of calculating a time difference from timing and a sixth step of measuring a delay time of the signal propagation based on the time difference are executed.

  As described above, according to the present invention, there is no need to lay a control line in the transmission line, and the signal between the transmitter and the receiver through the transmission line is a simple method that does not depend on the broadcasting system. Propagation delay time can be measured.

1 is a schematic diagram illustrating an overall configuration of a delay time measuring system including a delay time measuring apparatus according to a first embodiment. It is a block diagram which shows the structure of the delay time measuring apparatus of Example 1. FIG. 3 is a flowchart illustrating processing of the delay time measuring apparatus according to the first embodiment. 6 is a time chart for explaining processing of the delay time measuring apparatus according to the first embodiment. It is a figure explaining a signal speed and measurable delay time. It is a figure explaining the header structure of TS packet. It is the schematic which shows the whole structure of the delay time measuring system containing the delay time measuring apparatus of Example 2. FIG. FIG. 10 is a block diagram illustrating a configuration of a transmission side delay time measuring apparatus according to a second embodiment. 10 is a flowchart illustrating processing of a transmission-side delay time measuring apparatus according to the second embodiment. FIG. 10 is a block diagram illustrating a configuration of a delay time measuring apparatus on the reception side according to the second embodiment. 10 is a flowchart illustrating processing of a delay time measuring apparatus on the reception side according to the second embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The first embodiment (Example 1) uses one delay time measuring device. The delay time measuring apparatus outputs periodic data having a predetermined pattern that is repeated at a constant period, and inputs the periodic data via a transmitter, a transmission path, and a receiver. Then, the delay time measuring device measures the delay time of signal propagation from the transmitter to the receiver via the transmission path by pattern matching and calculation processing between the output periodic data and the input periodic data. .

  In addition, the second embodiment (Example 2) uses two delay time measuring devices on the transmission side and the reception side, and uses a GPS (Global Positioning System) clock to The clock time is synchronized in advance. The delay time measuring apparatus on the transmission side generates and outputs periodic data of a predetermined pattern that is repeated at a constant period, with the synchronized predetermined time as a start time. The delay time measurement device on the reception side generates periodic data with the same predetermined time as the start time as the start time, and the periodic data output from the delay time measurement device on the transmission side is transmitted via the transmitter, the transmission path, and the receiver. input. Then, the delay time measuring device on the receiving side performs a signal matching delay time from the transmitter to the receiver through the transmission path by pattern matching and calculation processing between the generated periodic data and the input periodic data. Measure.

  In the embodiment of the present invention, the modes for measuring the delay time include the stand-alone mode of the first embodiment and the remote mode of the second embodiment. In the stand-alone mode, the signal propagation delay time for a signal passing through the device under test (DUT) from the transmitter to the receiver via the transmission path using one delay time measuring device. Is a mode for measuring. This mode has application in measurements when the transmitter and receiver are in close proximity, for example in a laboratory. On the other hand, the remote mode is a mode in which the delay time of signal propagation is measured using two delay time measuring devices provided at remote locations. This mode has application in measurements when the transmitter and receiver are at a long distance.

[Example 1]
First, Example 1 will be described. As described above, the first embodiment measures the delay time in the stand-alone mode using one delay time measuring device.

  FIG. 1 is a schematic diagram illustrating an overall configuration of a delay time measuring system including the delay time measuring apparatus according to the first embodiment. The delay time measuring system 9-1 includes a delay time measuring device 1, a transmitter 2, a transmission path 3, and a receiver 4. The transmitter 2, the transmission path 3, and the receiver 4 are measurement objects whose delay time is measured by the delay time measuring device 1.

  The delay time measuring apparatus 1 stores periodic data of a predetermined pattern repeated at a constant period in an MPEG-2 TS packet (hereinafter referred to as TS packet) and outputs it to the transmitter 2 to generate an initial value of the periodic data. At the time of output (measurement start time).

  The delay time measuring apparatus 1 inputs the output TS packet via the transmitter 2, the transmission path 3, and the receiver 4, extracts the period data from the input TS packet, and makes the extracted period data self-run. The delay time is measured by pattern matching with periodic data, and the measured delay time is output.

  In the delay time measuring apparatus 1, an input / output interface for outputting TS packets to the transmitter 2 and inputting TS packets from the receiver 4 is, for example, DVB-SPI (Digital Video Broadcasting-Synchronous Parallel Interface) or DVB. ASI (Digital Video Broadcasting-Asynchronous Serial Interface) is used.

Moreover, as periodic data stored in the TS packet, for example, PRBS23 data (Pseudo Random Bit Sequence 23: 23rd order M-sequence pseudo-random signal (random number bit sequence signal)) or PRBS31 data (Pseudo Random Bit Sequence 31: 31st-order M sequence) A pseudo-random signal (random bit sequence signal)) is used. The PRBS23 data is data of a pattern composed of different unique data every 23 bits, and the pattern length is 2 ²³ −1 (8388607) bits. The PRBS31 data is a pattern signal composed of unique and different data every 31 bits, and the pattern length is 2 ³¹ −1 (2147483647) bits. The PRBS23 data and the PRBS31 data are configured by periodic data having a predetermined pattern that is repeated at a constant period.

  The delay time measuring device 1 may be a single device that measures only the delay time or may be incorporated as a part of a device that measures the BER of a digital signal.

  The transmitter 2 performs predetermined transmission processing (such as error correction coding processing and modulation processing) on data such as a video / audio signal to be transmitted, and transmits the transmission signal to the receiver 4 via the transmission path 3. It is a device that transmits. The receiver 4 receives the transmission signal transmitted from the transmitter 2 via the transmission path 3, and supports transmission processing (such as error correction coding processing and modulation processing) in the transmitter 2 for the received data. This is a device that performs predetermined reception processing (demodulation processing, error correction decoding processing, etc.) to restore data such as the original video / audio signal.

  When the delay time measuring apparatus 1 measures the delay time, the transmitter 2 receives the TS packet from the delay time measuring apparatus 1 and transmits the same transmission process (error correction encoding process and Modulation processing or the like is performed, and the transmission signal is transmitted to the receiver 4 via the transmission path 3. The receiver 4 receives the transmission signal transmitted from the transmitter 2 via the transmission path 3, and performs the same reception processing (demodulation processing and error correction decoding processing) as the original data is restored with respect to the received data. Etc.) and the TS packet is output to the delay time measuring apparatus 1.

[Configuration of Delay Time Measuring Apparatus 1 / Example 1]
Next, the delay time measuring apparatus 1 shown in FIG. 1 will be described. FIG. 2 is a block diagram showing a configuration of the delay time measuring apparatus 1. The delay time measuring apparatus 1 includes a calibration processing unit (internal processing time measuring unit) 10, a PRBS data (period data) generating unit 11, a transmitting unit 12 and a receiving unit 13. The transmission unit 12 includes a transmission processing unit (output (transmission) interface) 14, and the reception unit 13 includes buffers 15 and 17, a reception processing unit (input (reception) interface) 16, and a delay time measurement unit 18. .

  Prior to the measurement of the delay time, the calibration processing unit 10 performs a calibration process of the delay time measuring apparatus 1 by an operator's operation. Specifically, the calibration processing unit 10 will be described later in a state where the transmission processing unit 14 of the transmission unit 12 and the reception processing unit 16 of the reception unit 13 are connected (in a state where an input / output terminal (not shown) is connected). The delay time measured by the delay time measuring unit 18 is measured as the internal processing time. The internal processing time is a time obtained by adding the processing time of the reception processing unit 16 to the processing time of the transmission processing unit 14. Then, the calibration processing unit 10 outputs the measured internal processing time to the delay time measuring unit 18 of the receiving unit 13. The input / output terminals are connected by an operator who operates the delay time measuring apparatus 1.

  The processing time of the transmission processing unit 14 is a time from when PRBS data (PRBS23 data or PRBS31 data) is input to when the transmission processing is performed on the PRBS data and the TS packet is output to the transmitter 2. The processing time of the reception processing unit 16 is the time from when the TS packet is input until the TS packet is subjected to reception processing and the PRBS data is stored in the buffer 17.

  When the measurement of the delay time is started by the operation of the operator, the PRBS data generation unit 11 inputs a reset signal indicating the measurement start timing of the delay time, selects either the PRBS23 data or the PRBS31 data, and receives a predetermined signal A clock speed for outputting the PRBS data from the transmission processing unit 14 is set at a speed, and is generated as PRBS data at the set clock speed. Then, the PRBS data generation unit 11 sequentially outputs the generated PRBS data to the transmission processing unit 14 of the transmission unit 12 and sequentially stores it in the buffer 15 of the reception unit 13. As a result, the PRBS data is stored in the buffer 15 as self-running data from the time (measurement start time) when the PRBS data generation unit 11 generates the initial value of the PRBS data and the transmission processing unit 14 outputs it. The The time when the reset signal is input by the PRBS data generation unit 11 is the measurement start time.

  The reset signal is input when the measurement of the delay time is started by the operation of the operator. However, the reset signal may be input at a predetermined time or intermittently at a predetermined cycle timing. You may make it input into.

  The transmission processing unit 14 of the transmission unit 12 receives the PRBS data from the PRBS data generation unit 11, stores the PRBS data in the payload of the TS packet, and outputs the TS packet including the PRBS data at a predetermined signal speed.

  The reception processing unit 16 of the reception unit 13 inputs a TS packet including PRBS data, extracts PRBS data from the payload of the TS packet, and sequentially stores the extracted PRBS data in the buffer 17.

  The delay time measuring unit 18 of the receiving unit 13 receives the internal processing time from the calibration processing unit 10 and compares the PRBS data pattern sequentially stored in the buffer 15 with the PRBS data pattern sequentially stored in the buffer 17. Then, the time until both PRBS data are synchronized is calculated. That is, the delay time measurement unit 18 calculates the time until the PRBS data pattern stored in the buffer 17 matches the PRBS data pattern stored in the buffer 15. Then, the delay time measurement unit 18 subtracts the input internal processing time from the calculated time to obtain a delay time, and outputs the delay time.

  Thereby, the delay time measuring apparatus 1 measures the delay time of signal propagation in the measurement object of the transmitter 2, the transmission path 3, and the receiver 4.

[Processing of Delay Time Measuring Apparatus 1 / Example 1]
Next, processing of the delay time measuring apparatus 1 shown in FIG. 2 will be described. FIG. 3 is a flowchart showing processing of the delay time measuring apparatus 1, and FIG. 4 is a time chart explaining processing of the delay time measuring apparatus 1.

  First, the calibration processing unit 10 of the delay time measuring apparatus 1 performs a calibration process by an operator's operation in a state where the input / output terminals of the transmission processing unit 14 and the reception processing unit 16 are connected by the operator. Is measured (step S301). Specifically, the calibration processing unit 10 causes the PRBS data generation unit 11, the transmission processing unit 14, the reception processing unit 16, and the delay time measurement unit 18 to perform the same processing as the processing for measuring the delay time, The delay time measured by the delay time measuring unit 18 is measured as the internal processing time. The internal processing time is a time obtained by adding the processing time of the reception processing unit 16 to the processing time of the transmission processing unit 14, and is a delay time in a state where the input / output terminals of the transmission processing unit 14 and the reception processing unit 16 are connected.

  Here, the state where the input / output terminals are connected refers to a state where the TS packet output from the transmission processing unit 14 is input as it is by the reception processing unit 16. Further, the PRBS data used by the PRBS data generation unit 11 is selected in advance by an operator's operation, and PRBS data used when measuring the internal processing time, PRBS data used when measuring the delay time, Are the same. That is, the PRBS data used when measuring the internal processing time is assumed to be the same data as the PRBS data selected in step S302 described later. The delay time measurement unit 18 compares the PRBS data pattern stored in the buffer 15 with the PRBS data pattern stored in the buffer 17 when the calibration processing unit 10 measures the internal processing time. A time difference is calculated from the timing at which both PRBS data are synchronized, and this time difference is measured as a delay time. The delay time measured by the delay time measuring unit 18 is treated as the internal processing time.

  When the measurement of the delay time is started by the operator's operation, the PRBS data generation unit 11 inputs a reset signal, and PRBS data (PRBS23 data or PRBS31 data) that is already set according to the operator's operation is received. select. Then, the PRBS data generation unit 11 sets a clock speed for outputting TS packets from the transmission processing unit 14 at a predetermined signal speed, and generates PRBS data at the set clock speed (step S302).

  FIG. 5 is a diagram for explaining signal speed and measurable delay time. In FIG. 5, the signal speed indicates the speed of the TS packet output from the transmission processing unit 14, and the period indicates the reciprocal of the signal speed. The minimum value of the signal speed and period of the TS packet is 0.01 Mbps and 0.1 msec, respectively, and the maximum value is 210 Mbps and 4.8 nsec, respectively. For example, the signal speed for outputting the TS packet of the SHV signal from the transmission processing unit 14 is 100 Mbps, and the cycle is 10 nsec.

  The data series indicates the PRBS data to be used. When the data sequence is PRBS23 data, the bit length of one cycle is 8388607, and when the data sequence is PRBS31 data, the bit length of one cycle is 2147483647. The measurable delay time corresponds to the period of PRBS data corresponding to the upper signal speed. This is because the delay time measurement unit 18 measures the delay time by the matching process within the range of one period of the PRBS data.

  For example, when the PRBS data generation unit 11 selects PRBS23 data as random data and sets the clock rate for outputting TS packets from the transmission processing unit 14 at a signal rate of 0.01 Mbps, the delay time measurement unit 18 The delay time that can be measured by is 838861 sec (838860.7 msec). This 83.8861 sec corresponds to a period of PRBS23 data that is periodically repeated when a TS packet is output at a signal rate of 0.01 Mbps.

  Similarly, when the PRBS data generation unit 11 selects PRBS23 data and sets the clock rate for outputting TS packets at a signal rate of 210 Mbps, the delay time measurable by the delay time measurement unit 18 is 0. .040 sec (39.9 msec). Further, when the PRBS data generation unit 11 selects the PRBS31 data and sets the clock rate for outputting TS packets at the signal rates of 0.01 Mbps and 210 Mbps, respectively, the delay that can be measured by the delay time measurement unit 18 The times are 214748 sec (214748834.7 msec) and 10 sec (1026.1 msec), respectively.

  Furthermore, when outputting the TS packet of the SHV signal from the transmission processing unit 14, the PRBS data generation unit 11 selects PRBS23 data and PRBS31 data, respectively, and sets the clock speed for outputting the TS packet at a signal rate of 100 Mbps. When set, the delay times measurable by the delay time measuring unit 18 are 0.084 sec (83.9 msec) and 21 sec (21474.8 msec), respectively.

  Thus, from FIG. 5, when outputting the TS packet of the SHV signal from the transmission processing unit 14, that is, when outputting the TS packet at a signal rate of 100 Mbps, if PRBS23 data is used, 0.084 sec or less is used. Although the delay time can be measured, it can be seen that the delay time exceeding 0.084 sec cannot be measured. Therefore, when the delay time exceeds 0.084 sec, it is necessary to use PRBS31 data.

  3 and 4, the PRBS data generation unit 11 outputs the PRBS data generated in step S302 to the transmission processing unit 14 of the transmission unit 12 and transmits the PRBS data as transmission PRBS data to the buffer 15 of the reception unit 13. Store (step S303). The transmission PRBS data stored in the buffer 15 is handled as data self-run by the delay time measuring apparatus 1 and is used for calculating the delay time together with reception PRBS data stored in the buffer 17 described later.

  Referring to FIG. 4, transmission PRBS data is stored in buffer 15 as periodic data for each period from the measurement start time.

  The delay time measurement unit 18 starts the counter from the measurement start time when the reset signal is input to the PRBS data generation unit 11 and the transmission PRBS data starts to be stored in the buffer 15 (step S304). The count value of this counter increases in accordance with the amount of transmission PRBS data stored in the buffer 15 and is a value corresponding to the elapsed time from the measurement start time. The amount of PRBS data output from the transmission processing unit 14 It is also a value that increases according to. As shown in FIG. 5, for example, when PRBS23 data is selected and a clock speed for outputting TS packets of an SHV signal is set at a signal speed of 100 Mbps, one period of PRBS23 data is stored in the buffer 15. Every time it is stored, the count value corresponding to 0.084 sec increases.

  Referring to FIG. 4, the count value is reset to 0 at the measurement start time and increases, and is reset to 0 when it reaches a predetermined value. The count value increases from 0 to a predetermined value according to the amount of transmission PRBS data stored in the buffer 15.

  The transmission processing unit 14 generates header information of the TS packet by setting data for identifying the PRBS data in a program ID (PID). Then, the transmission processing unit 14 stores the header information in the header of the TS packet, and also generates the TS packet by storing the PRBS data generated by the PRBS data generation unit 11 in the payload of the TS packet. Is output (step S305). Thus, the TS packet including the PRBS data is output to the transmitter 2 and input to the reception processing unit 16 via the transmission path 3 and the receiver 4.

  Here, the header size of the MPEG-2 TS packet (TS packet) is 4 bytes, and the payload size is 184 bytes. Therefore, the size of the TS packet is 188 bytes.

  FIG. 6 is a diagram for explaining the header configuration of a TS packet. The TS packet header includes a synchronization word (sync), a transport error indicator, a payload unit start indicator, a transport priority, a program ID (PID), and a transport. It consists of areas for scramble control and adaptation field control. The data and bit length of these header information are as shown in FIG. As the program ID, arbitrary data designated by the outside is set. In the first embodiment, the transmission processing unit 14 stores data indicating the type of PRBS data (data for identifying PRBS23 data or PRBS31 data) in the program ID area.

  Returning to FIG. 3 and FIG. 4, the reception processing unit 16 inputs the TS packet output from the transmission processing unit 14 via the transmitter 2, the transmission path 3, and the receiver 4, and receives PRBS data from the TS packet. Extract (step S306). Specifically, the reception processing unit 16 extracts the program ID stored in the header of the TS packet, and when the program ID indicates the type of PRBS data currently used, the PRBS data is extracted from the payload of the TS packet. To extract.

  Thus, the PRBS data can be filtered by the program ID stored in the header of the TS packet, the TS packet storing the PRBS data can be specified, and the PRBS data can be extracted from the TS packet.

  The reception processing unit 16 stores the PRBS data extracted from the TS packet in the buffer 17 as reception PRBS data (step S307). Referring to FIG. 4, received PRBS data is stored in buffer 17 as periodic data corresponding to the transmitted PRBS data, delayed by a delay time (α in FIG. 4) from the measurement start time.

  The delay time measuring unit 18 reads out the transmitted PRBS data that has been self-run from the buffer 15 and also reads out the received PRBS data from the buffer 17, compares the pattern of the transmitted PRBS data with the pattern of the received PRBS data, and Matching determination is performed between the pattern and the received PRBS data (step S308). When the delay time measurement unit 18 determines that matching has been performed by the matching determination (when it is determined that the pattern of the transmission PRBS data and the reception PRBS data are synchronized), the delay time measurement unit 18 calculates a time difference based on the count value at that time. (Step S309).

  For example, when the PRBS data is PRBS23 data, the delay time measurement unit 18 at the timing when the first 23 bits of data in the transmission PRBS data (the hatched portion of the transmission PRBS data in FIG. 4) is stored in the buffer 15. The count value at that time (c1 in FIG. 4) is stored. Then, the delay time measurement unit 18 counts the current count value (in FIG. 4) at the timing when the first 23 bits of the received PRBS data (in FIG. 4, the hatched portion of the received PRBS data) is stored in the buffer 17. The time difference is calculated based on the difference between c2) and the already stored count value (c1 in FIG. 4).

  As a result, the first 23 bits of data in the transmitted PRBS data and the first 23 bits of data in the received PRBS data delayed by the delay time are determined for matching, and a time difference is calculated. The reason why the 23-bit data is subjected to the matching determination is that the PRBS23 data is composed of unique and different data for each 23 bits.

  The target of the matching determination is not necessarily the first 23 bits of data in the transmission PRBS data and the reception PRBS data, but is data at any same position in the transmission PRBS data and the reception PRBS data that are periodically repeated. And 23-bit data may be used. When the PRBS data is PRBS31 data, the first 31-bit data in the transmission PRBS data and the reception PRBS data, or data at any same position and 31-bit data is subjected to matching determination. . The target of the matching determination may be one cycle data.

  When the count value indicates the number of bits of transmission PRBS data stored in the buffer 15, the delay time measurement unit 18 calculates the difference between the count values when it is determined that the matching is performed by the matching determination, The difference between the count values may be divided by the signal speed corresponding to the clock speed set in step S302 to obtain the division result.

  The delay time measurement unit 18 subtracts the internal processing time measured by the calibration processing unit 10 in step S301 from the time difference calculated in step S309, and the subtraction results are transmitted to the transmitter 2, the transmission path 3 and the receiver 4. This is obtained as the delay time of signal propagation in the measurement object (step S310). Then, the delay time measuring unit 18 outputs the delay time (step S311).

  The delay time measured by the delay time measuring device 1 is displayed on the screen and stored in the memory. In this case, when displaying the delay time on the screen, the delay time measuring apparatus 1 calculates the maximum value, the minimum value, and the average value and displays the calculated value. Further, the delay time measured by the delay time measuring apparatus 1 is analyzed off-line using a device other than the delay time measuring apparatus 1. For example, another device reads a predetermined number of delay times stored in the memory by the delay time measuring device 1 in the CSV file format or the TXT file format, and performs offline analysis.

  As described above, according to the delay time measuring apparatus 1 of the first embodiment, the calibration processing unit 10 measures the internal processing time that is the processing time of the transmission processing unit 14 and the buffer 15 by the calibration process, and generates PRBS data. The unit 11 sets a clock speed for outputting TS packets from the transmission processing unit 14 at a predetermined signal speed, generates PRBS data at the set clock speed, and receives the PRBS data as transmission PRBS data. The data is stored in the buffer 15. The transmission processing unit 14 stores the PRBS data in the TS packet and outputs the TS packet including the PRBS data to the transmitter 2.

  Then, the reception processing unit 16 inputs the TS packet output from the transmission processing unit 14 via the transmitter 2, the transmission path 3, and the receiver 4, extracts PRBS data from the TS packet, and extracts the extracted PRBS data. Is stored in the buffer 17 as received PRBS data. Then, the delay time measurement unit 18 compares the pattern of the transmission PRBS data stored in the buffer 15 with the pattern of the reception PRBS data stored in the buffer 17, and calculates a time difference from the timing at which both data are synchronized. The delay time was obtained by subtracting the internal processing time from the time difference.

  Thereby, the delay time of signal propagation in the measurement object of the transmitter 2, the transmission line 3 and the receiver 4 is measured without laying a control line in the transmission line 3 and without storing time information in the TS packet. The Further, since the delay time is measured by comparing the pattern of the transmission PRBS data stored in the buffer 15 with the pattern of the reception PRBS data stored in the buffer 17, this delay time can be measured by any method. Applicable to broadcasting system. That is, the delay time can be measured with a simple configuration and processing without depending on a broadcasting system such as the OFDM system or the QAM modulation system.

  In addition, according to the delay time measuring apparatus 1 of the first embodiment, it is only necessary to establish synchronization between transmission PRBS data and reception PRBS data that are repeated at a constant period. Compared to the technique, the delay time can be measured even when the characteristics of the transmission path 3 are deteriorated and the BER is deteriorated.

  Further, according to the delay time measuring apparatus 1 of the first embodiment, the time difference is calculated from the timing at which the transmission PRBS data and the reception PRBS data are synchronized, and the internal processing measured by the calibration processing unit 10 from the time difference in the configuration process. The time was subtracted to obtain the delay time. Thereby, the difference in the processing time by the input-output interface of the transmission processing part 14 and the reception processing part 16 for every delay time measuring apparatus 1 can be absorbed, and a highly accurate delay time can be measured.

[Example 2]
Next, Example 2 will be described. As described above, in the second embodiment, the delay time is measured in the remote mode using two delay time measuring apparatuses.

  FIG. 7 is a schematic diagram illustrating an overall configuration of a delay time measuring system including the delay time measuring apparatus according to the second embodiment. This delay time measuring system 9-2 includes delay time measuring devices 1-1 and 1-2, a transmitter 2, a transmission path 3, a receiver 4, a GPS satellite 5, and GPS receivers 6-1 and 6-2. Is done. The transmitter 2, the transmission path 3, and the receiver 4 are measurement objects whose delay times are measured by the delay time measuring apparatuses 1-1 and 1-2. For example, in a re-transmission system that re-broadcasts (re-transmits) on cable television, the delay time is measured by the delay time measuring devices 1-1 and 1-2.

  The delay time measuring device 1-1 inputs time information from the GPS receiver 6-1, sets an internal clock, and obtains periodic data of a predetermined pattern that is repeated at a predetermined period at a predetermined measurement start time by the internal clock. The data is stored in a TS packet and output to the transmitter 2.

  The delay time measuring device 1-2 receives the same time information as the time information input by the delay time measuring device 1-1 from the GPS receiver 6-2, sets the internal clock, and starts a predetermined measurement of the internal clock. At the time, the same period data as that of the delay time measuring device 1-1 is allowed to self-run. Then, the delay time measuring device 1-2 extracts period data from the input TS packet, and synchronizes both period data by pattern matching between the extracted period data and the self-running period data. taking measurement.

  The transmitter 2, the transmission path 3, and the receiver 4 are the same as those in the first embodiment shown in FIG.

  The GPS satellite 5 transmits GPS time and orbit information. The GPS receiver 6-1 receives GPS time and orbit information from the GPS satellite 5, and outputs the time information of the GPS time to the delay time measuring device 1-1. Similar to the GPS receiver 6-1, the GPS receiver 6-2 receives GPS time and orbit information from the GPS satellite 5, and outputs the time information of the GPS time to the delay time measuring device 1-2. Thereby, the delay time measuring apparatuses 1-1 and 1-2 can input the time information of the same GPS time from the GPS receivers 6-1 and 6-2, and the respective internal clocks are set to the same time. Is done.

[Configuration of Delay Time Measuring Apparatus 1-1 / Example 2]
Next, the delay time measuring apparatus 1-1 shown in FIG. 7 will be described. FIG. 8 is a block diagram showing the configuration of the delay time measuring apparatus 1-1. The delay time measuring device 1-1 includes a calibration processing unit 10, a PRBS data generation unit 11, a transmission unit 12, a reception unit 13, and a clock unit 19. The transmission unit 12 includes a transmission processing unit 14, and the reception unit 13 includes buffers 15 and 17, a reception processing unit 16, and a delay time measurement unit 18.

  The delay time measuring apparatus 1-1 uses the calibration processing unit 10, the PRBS data generation unit 11, the transmission unit 12, and the clock unit 19 without using the reception unit 13 among these components, and performs calibration processing, PRBS. Data generation processing, TS packet output processing, and processing for setting time by inputting time information of GPS time are performed. The delay time measuring apparatus 1-1 does not perform TS packet input processing and delay time measurement processing by the receiving unit 13.

  Comparing the delay time measuring apparatus 1 of the first embodiment shown in FIG. 2 with the delay time measuring apparatus 1-1 of the second embodiment shown in FIG. Although the same in that the calibration processing unit 10, the PRBS data generation unit 11, the transmission unit 12, and the reception unit 13 are provided, the delay time measuring device 1-1 according to the second embodiment further includes a clock unit 19. This is different from the delay time measuring apparatus 1 of the first embodiment.

  Further, when compared from the viewpoint of processing, the delay time measuring devices 1 and 1-1 are the same in that they perform calibration processing, PRBS data creation processing, and TS packet output processing, but the delay time measuring device 1 of the second embodiment. -1 is different from the delay time measurement apparatus 1 of the first embodiment in that the time information of GPS time is input and the time is set, but the TS packet input process and the delay time measurement process are not performed.

  In FIG. 8, the calibration processing unit 10, the PRBS data generation unit 11, and the transmission processing unit 14 of the transmission unit 12 are the same as the components of the delay time measuring apparatus 1 of the first embodiment shown in FIG. Then, explanation is omitted.

  The clock unit 19 receives GPS time information from the GPS receiver 6-1, and sets the time of the internal clock (the internal clock provided in the clock unit 19) of the delay time measuring device 1-1 to the GPS time. Thereby, the internal clock of the delay time measuring device 1-1 is set to the GPS time acquired from the GPS satellite 5, and the time is used as the reference time. Similarly, since the internal clock of the delay time measuring device 1-2 described later is set to the GPS time acquired from the GPS satellite 5, the times of the internal clocks of the delay time measuring devices 1-1 and 1-2 coincide. Used as a common reference time.

  When the time of the internal clock reaches a preset time, the clock unit 19 outputs a reset signal to the PRBS data generation unit 11 in order to start measuring the delay time. Similarly, the clock unit 19 of the delay time measuring device 1-2 to be described later is reset to the same time as the delay time measuring device 1-1 because the internal clock is the same in the delay time measuring devices 1-1 and 1-2. The signal is output to the PRBS data generation unit 11.

  The PRBS data generation unit 11 receives a reset signal from the clock unit 19, sets a clock speed for outputting PRBS data from the transmission processing unit 14 at a predetermined signal speed, and outputs PRBS data at the set clock speed. The generated PRBS data is output to the transmission processing unit 14 of the transmission unit 12 and stored in the buffer 15 of the reception unit 13. In this case, the PRBS data stored in the buffer 15 is not used.

  The transmission processing unit 14 of the transmission unit 12 receives the PRBS data from the PRBS data generation unit 11, stores the PRBS data in a TS packet, and outputs the TS packet.

[Processing of delay time measuring apparatus 1-1 / Example 2]
Next, processing of the delay time measuring apparatus 1-1 shown in FIG. 8 will be described. FIG. 9 is a flowchart showing processing of the delay time measuring apparatus 1-1. The processes in steps S901 to S904 shown in FIG. 9 correspond to the processes in steps S301 to S303 and S305 in the first embodiment shown in FIG.

  First, the calibration processing unit 10 of the delay time measuring device 1-1 performs a calibration process by an operator's operation in a state where the input / output terminals of the delay time measuring device 1-1 are connected by the operator. The internal processing time of 1-1 is measured. In addition, the clock unit 19 sets the time of the internal clock to the GPS time using the time information of the GPS time input from the GPS receiver 6-1 (step S901).

  Specifically, the calibration processing unit 10 causes the PRBS data generation unit 11, the transmission processing unit 14, and the reception processing unit 16 to perform the same processing as the processing for measuring the delay time during the calibration processing, The processing time of the transmission processing unit 14 and the reception processing unit 16 is measured as the internal processing time. Then, when the time of the internal clock reaches a preset time, the clock unit 19 outputs a reset signal for starting the measurement of the delay time to the PRBS data generation unit 11.

  Note that the calibration processing by the calibration processing unit 10 of the delay time measuring apparatus 1-1 is not always necessary. This is because the internal processing time measured by the calibration processing unit 10 of the delay time measuring apparatus 1-1 is not used for measuring the delay time.

  The PRBS data generation unit 11 receives a reset signal from the clock unit 19 and selects the PRBS data (PRBS23 data or PRBS31 data) that has already been set according to the operator's operation. Then, the PRBS data generation unit 11 sets a clock speed for outputting TS packets from the transmission processing unit 14 at a predetermined signal speed, and generates PRBS data at the set clock speed (step S902).

  The PRBS data generation unit 11 outputs the PRBS data generated in step S902 to the transmission processing unit 14 of the transmission unit 12 and stores it as transmission PRBS data in the buffer 15 of the reception unit 13 (step S903). In this case, the PRBS data stored in the buffer 15 is not used.

  The transmission processing unit 14 generates header information of the TS packet by setting data for identifying the PRBS data in a program ID (PID). Then, the transmission processing unit 14 stores the header information in the header of the TS packet, and also generates the TS packet by storing the PRBS data generated by the PRBS data generation unit 11 in the payload of the TS packet. Is output (step S904). Thereby, the TS packet including the PRBS data is output to the transmitter 2 and input to the delay time measuring device 1-2 via the transmission path 3 and the receiver 4.

  As described above, in the delay time measuring apparatus 1-1, the GPS time is set in the internal clock as in the delay time measuring apparatus 1-2, and the measurement of the delay time is started at a predetermined time based on the internal clock. . Thereby, the delay time measuring apparatuses 1-1 and 1-2 can start the measurement of the delay time at the same time.

[Configuration of Delay Time Measuring Device 1-2 / Example 2]
Next, the delay time measuring apparatus 1-2 shown in FIG. 7 will be described. FIG. 10 is a block diagram showing a configuration of the delay time measuring apparatus 1-2. Similar to the delay time measuring device 1-1, the delay time measuring device 1-2 includes a calibration processing unit 10, a PRBS data generation unit 11, a transmission unit 12, a reception unit 13, and a clock unit 19. The transmission unit 12 includes a transmission processing unit 14, and the reception unit 13 includes buffers 15 and 17, a reception processing unit 16, and a delay time measurement unit 18.

  The delay time measuring apparatus 1-2 uses the calibration processing unit 10, the PRBS data generation unit 11, the reception unit 13, and the clock unit 19 without using the transmission unit 12, and uses the calibration processing, PRBS, and the like. Data creation processing, TS packet input processing, delay time measurement processing, and processing for setting time by inputting time information of GPS time are performed. The delay time measuring device 1-2 does not perform TS packet output processing by the transmission unit 12.

  When the delay time measuring apparatus 1 of the first embodiment shown in FIG. 2 and the delay time measuring apparatus 1-2 of the second embodiment shown in FIG. 10 are compared in terms of configuration, the delay time measuring apparatuses 1 and 1-2 are: Although the same in that the calibration processing unit 10, the PRBS data generation unit 11, the transmission unit 12, and the reception unit 13 are provided, the delay time measuring device 1-2 of the second embodiment further includes a clock unit 19. This is different from the delay time measuring apparatus 1 of the first embodiment.

  Further, when compared from the viewpoint of processing, the delay time measuring apparatuses 1 and 1-2 are the same in that they perform calibration processing, PRBS data creation processing, TS packet input processing, and delay time measurement processing. The delay time measuring apparatus 1-2 performs the process of setting the time by inputting the time information of the GPS time, but does not perform the TS packet output process from the transmission processing unit 14, so that the delay time measurement of the first embodiment is performed. Different from the device 1.

  In FIG. 10, the calibration processing unit 10, the PRBS data generation unit 11, the buffers 15 and 17 of the reception unit 13, the reception processing unit 16, and the delay time measurement unit 18 are the delay time measurement apparatus according to the first embodiment shown in FIG. Since the configuration is the same as that of the first component, the description thereof is omitted here. The clock unit 19 is the same as the clock unit 19 shown in FIG.

  The internal clock of the delay time measuring device 1-2 is set by the clock unit 19 to the GPS time acquired from the GPS satellite 5, and the time is used as the reference time. Similarly, since the internal clock of the delay time measuring device 1-1 is set to the GPS time acquired from the GPS satellite 5, the times of the internal clocks of the delay time measuring devices 1-1 and 1-2 coincide. Used as a common reference time. Therefore, the clock unit 19 of the delay time measuring apparatuses 1-1 and 1-2 outputs a reset signal to the PRBS data generation unit 11 at the same time.

  The PRBS data generation unit 11 receives a reset signal from the clock unit 19 and sets a clock speed for outputting the PRBS data from the transmission processing unit 14 at a predetermined signal rate, similarly to the delay time measuring device 1-1. Then, PRBS data is generated at the set clock speed, and the PRBS data is output to the transmission processing unit 14 of the transmission unit 12 and stored in the buffer 15 of the reception unit 13. In this case, the PRBS data output to the transmission processing unit 14 is not used.

  As a result, the PRBS data generating unit 11 of the delay time measuring apparatus 1-1 generates an initial value of PRBS data and the transmission processing unit 14 of the delay time measuring apparatus 1-1 outputs the buffer 15 (measurement start). From the time), the PRBS data is stored as self-running data. The time when the reset signal is input by the PRBS data generation unit 11 of the delay time measuring apparatuses 1-1 and 1-2 is the measurement start time.

[Processing of Delay Time Measuring Device 1-2 / Example 2]
Next, the processing of the delay time measuring apparatus 1-2 shown in FIG. 10 will be described. FIG. 11 is a flowchart showing the processing of the delay time measuring apparatus 1-2. 11 corresponds to the processing of step S301 to step S304 in the first embodiment shown in FIG. 3, and the processing of step S1105 to step S1110 shown in FIG. 11 is shown in FIG. This corresponds to the processing in steps S306 to S311 of the first embodiment.

  First, the calibration processing unit 10 of the delay time measuring device 1-2 performs a calibration process by an operator's operation while the input / output terminal of the delay time measuring device 1-2 is connected by the operator, and the delay time measuring device 1 -2 measure internal processing time. In addition, the clock unit 19 sets the time of the internal clock to the GPS time using the time information of the GPS time input from the GPS receiver 6-2 (step S1101). The processing of the calibration processing unit 10 and the clock unit 19 of the delay time measuring device 1-2 is the same as the processing of the calibration processing unit 10 and the clock unit 19 of the delay time measuring device 1-1. When the time of the internal clock reaches a preset time, the clock unit 19 outputs a reset signal for starting measurement of the delay time to the PRBS data generation unit 11.

  The internal processing time measured by the calibration processing unit 10 of the delay time measuring device 1-2 is used when measuring the delay time by the delay time measuring unit 18. The internal processing time is a time obtained by adding the processing times in the transmission processing unit 14 and the reception processing unit 16 included in the delay time measuring device 1-2, but the internal processing time used when measuring the delay time is: Essentially, the time should be the sum of the processing times of the transmission processing unit 14 provided in the delay time measuring apparatus 1-1 and the reception processing unit 16 provided in the delay time measuring apparatus 1-2. Therefore, when the specifications of the delay time measuring device 1-1 and the delay time measuring device 1-2 are the same, the processing time of the transmission processing unit 14 included in the delay time measuring device 1-2 and the delay time measuring device 1-1. Assuming that the processing time of the transmission processing unit 14 provided is equivalent, the internal processing time measured by the calibration processing unit 10 of the delay time measuring device 1-2 is used when measuring the delay time.

  The PRBS data generation unit 11 receives a reset signal from the clock unit 19 and selects the PRBS data (PRBS23 data or PRBS31 data) that has already been set according to the operator's operation. Then, the PRBS data generation unit 11 sets a clock speed for outputting TS packets from the transmission processing unit 14 at a predetermined signal speed, and generates PRBS data at the set clock speed (step S1102).

  The PRBS data generation unit 11 outputs the PRBS data generated in step S1102 to the transmission processing unit 14 of the transmission unit 12 and stores it as transmission PRBS data in the buffer 15 of the reception unit 13 (step S1103). In this case, the PRBS data output to the transmission processing unit 14 is not used. The transmission PRBS data stored in the buffer 15 is handled as data self-run by the delay time measuring device 1-2, and is used for calculating the delay time together with reception PRBS data stored in the buffer 17 described later. It is done.

  As described above, in the delay time measuring device 1-2, the GPS time is set in the internal clock as in the delay time measuring device 1-1, and the measurement of the delay time is started at a predetermined time based on the internal clock. . Thereby, the delay time measuring apparatuses 1-1 and 1-2 can start the measurement of the delay time at the same time.

  The delay time measurement unit 18 starts the counter from the measurement start time when the reset signal is input to the PRBS data generation unit 11 and the transmission PRBS data starts to be stored in the buffer 15 (step S1104).

  The reception processing unit 16 inputs the TS packet output from the transmission processing unit 14 of the delay time measuring apparatus 1-1 through the transmitter 2, the transmission path 3, and the receiver 4, and is stored in the header of the TS packet. If the program ID indicates the type of PRBS data currently used, the PRBS data is extracted from the payload of the TS packet (step S1105). Then, the reception processing unit 16 stores the PRBS data extracted from the TS packet in the buffer 17 as reception PRBS data (step S1106).

  The delay time measurement unit 18 reads out the transmitted PRBS data that has been self-run from the buffer 15, reads out the received PRBS data from the buffer 17, compares the pattern of the transmitted PRBS data with the pattern of the received PRBS data, and transmits the transmitted PRBS data. Is matched with the received PRBS data (step S1107). When the delay time measurement unit 18 determines that matching has been performed by the matching determination (when it is determined that the pattern of the transmission PRBS data and the reception PRBS data are synchronized), the delay time measurement unit 18 calculates a time difference based on the count value at that time. (Step S1108).

  The delay time measurement unit 18 subtracts the internal processing time measured by the calibration processing unit 10 in step S1101 from the time difference calculated in step S1108, and the subtraction results are transmitted to the transmitter 2, the transmission path 3 and the receiver 4. Is obtained as a delay time of signal propagation in the measurement target (step S1109). Then, the delay time measurement unit 18 outputs a delay time (step S1110).

  As described above, according to the delay time measuring apparatus 1-1 of the second embodiment, the calibration processing unit 10 measures the internal processing time by the calibration process, and the clock unit 19 sets the time of the internal clock to the GPS time. I tried to do it. Then, when the time of the internal clock in the clock unit 19 reaches a preset time, the PRBS data generation unit 11 sends a TS packet from the transmission processing unit 14 at a predetermined signal speed in order to start measuring the delay time. A clock speed for output is set, PRBS data is generated at the set clock speed, and the transmission processing unit 14 stores the PRBS data in the TS packet and outputs the TS packet including the PRBS data to the transmitter 2. I did it.

  Further, according to the delay time measuring apparatus 1-2 of the second embodiment, the calibration processing unit 10 measures the internal processing time by the calibration process, and the clock unit 19 sets the time of the internal clock to the GPS time. did. Then, when the time of the internal clock in the clock unit 19 reaches a preset time (the same time as the delay time measuring device 1-1), the PRBS data generation unit 11 starts measuring the delay time. The clock speed for outputting the TS packet from the transmission processing unit 14 is set at the signal speed, PRBS data is generated at the set clock speed, and the PRBS data is stored in the buffer 15 of the receiving unit 13 as transmission PRBS data. I did it. Then, the reception processing unit 16 inputs the TS packet output from the transmission processing unit 14 of the delay time measuring apparatus 1-1 through the transmitter 2, the transmission path 3, and the receiver 4, and the PRBS data from the TS packet. And the extracted PRBS data is stored in the buffer 17 as received PRBS data. Then, the delay time measurement unit 18 compares the pattern of the transmission PRBS data stored in the buffer 15 with the pattern of the reception PRBS data stored in the buffer 17, and calculates a time difference from the timing at which both data are synchronized. The delay time was obtained by subtracting the internal processing time from the time difference.

  As a result, in the two delay time measuring devices 1-1 and 1-2 provided at distant locations, the times of the internal clocks of the respective clock units 19 coincide with each other. Measurement can be started at the same time, and the same effect as in the first embodiment can be obtained. Therefore, even when the transmitter 2 and the receiver 4 are located at a distance from each other, it is not necessary to lay a control line in the transmission line 3 and the transmitter can be used with a simple method that does not depend on the broadcasting system. It becomes possible to measure the delay time of signal propagation between 2 and the receiver 4 via the transmission line 3.

  As hardware configurations of the delay time measuring device 1 according to the first embodiment and the delay time measuring devices 1-1 and 1-2 according to the second embodiment, a normal computer can be used. The delay time measuring apparatuses 1, 1-1, 1-2 are configured by a computer including a volatile storage medium such as a CPU and a RAM, a nonvolatile storage medium such as a ROM, an interface, and the like. The functions of the calibration processing unit 10, the PRBS data generation unit 11, the transmission processing unit 14 of the transmission unit 12, and the reception processing unit 16 and the delay time measurement unit 18 of the reception unit 13 included in the delay time measuring device 1 are as follows. Each is realized by causing the CPU to execute a program describing the function. The same applies to the delay time measuring apparatuses 1-1 and 1-2. These programs are stored in the storage medium and read out and executed by the CPU. These programs can also be stored and distributed on a storage medium such as a magnetic disk (floppy (registered trademark) disk, hard disk, etc.), optical disk (CD-ROM, DVD, etc.), semiconductor memory, etc. You can also send and receive.

  The present invention has been described with reference to the first and second embodiments. However, the present invention is not limited to the first and second embodiments, and various modifications can be made without departing from the technical idea thereof. In the first and second embodiments, PRBS data (PRBS23 data or PRBS31 data) has been described as an example of a random signal. However, the present invention is not limited to PRBS data, and is repeated at a constant period. Any period data of a predetermined pattern may be used.

  In the first embodiment, the calibration processing unit 10 measures the internal processing time in the calibration processing, and the delay time measuring unit 18 subtracts the internal processing time measured by the calibration processing unit 10 from the calculated time difference. The delay time was calculated. Moreover, in the said Example 2, the calibration process part 10 of the delay time measuring apparatus 1-2 measured the internal processing time by the calibration process, and the delay time measuring part 18 of the delay time measuring apparatus 1-2 calculated. The delay time is obtained by subtracting the internal processing time measured by the calibration processing unit 10 from the time difference. On the other hand, the delay time measuring unit 18 may use an internal processing time preset by the operator. That is, the delay time measurement unit 18 subtracts a preset internal processing time from the calculated time difference to obtain a delay time. In this case, the delay time measurement unit 18 may treat the internal processing time measured by the calibration processing unit 10 as a preset internal processing time. In the case of the second embodiment, the internal processing times set in advance are the internal processing time of the transmission processing unit 14 provided in the delay time measuring device 1-1 and the reception processing unit 16 provided in the delay time measuring device 1-2. This corresponds to the time obtained by adding the internal processing time.

  In the second embodiment, the internal clocks of the delay time measuring apparatuses 1-1 and 1-2 are set by the GPS time acquired from the GPS satellite 5, but the present invention is not limited to this. For example, the time of the internal clock may be set using the standard time transmitted from the standard radio wave transmission station, or information on the standard time is received via the Internet, and the time of the internal clock is used by using this information. You may make it set.

  Further, the calibration processing unit 10, the PRBS data generation unit 11, and the transmission processing unit 14 of the transmission unit 12 included in the delay time measurement device 1 according to the first embodiment and the delay time measurement devices 1-1 and 1-2 according to the second embodiment, In addition, the buffers 15 and 17, the reception processing unit 16, and the delay time measurement unit 18 of the reception unit 13 may be mounted on the IC chip as hardware or software.

DESCRIPTION OF SYMBOLS 1 Delay time measuring apparatus 2 Transmitter 3 Transmission path 4 Receiver 5 GPS satellite 6 GPS receiver 9 Delay time measuring system 10 Calibration processing part 11 PRBS data generation part 12 Transmission part 13 Reception part 14 Transmission processing part 15, 17 Buffer 16 Reception processing unit 18 Delay time measuring unit 19 Clock unit

Claims (7)

A predetermined transmission process is performed on the data to be transmitted, and a transmitter that transmits the signal subjected to the transmission process via a transmission path, the transmission path, and a signal received via the transmission path are predetermined. In a delay time measuring apparatus for measuring a delay time of signal propagation to a receiver that performs processing,
A periodic data generating unit that generates periodic data repeated at a constant period and stores the periodic data in a first buffer;
A transmission processor that inputs the periodic data generated by the periodic data generator and outputs the periodic data to the transmitter;
The period data output by the transmission processing unit is input via the transmitter, the transmission path, and the receiver, and the reception processing unit stores the period data in a second buffer;
A time difference is calculated from the timing at which the periodic data stored in the first buffer and the periodic data stored in the second buffer are synchronized, and the delay time of the signal propagation is measured based on the time difference. A delay time measurement unit;
A delay time measuring apparatus comprising: In the delay time measuring device according to claim 1,
Further, when the transmission processing unit directly connects the output terminal that outputs the periodic data and the input terminal that inputs the periodic data, the delay time measured by the delay time measuring unit is obtained. An internal processing time measurement unit that measures internal processing time
The delay time measurement unit includes:
The delay time measuring apparatus, wherein the internal processing time measured by the internal processing time measuring unit is subtracted from the time difference, and the subtracted result is measured as a delay time of the signal propagation. In the delay time measuring device according to claim 1 or 2,
When measuring the delay time of the signal propagation by the two delay time measuring devices on the transmission side and the reception side,
The transmission processing unit provided in the delay time measuring device on the transmission side inputs the periodic data generated by the periodic data generation unit provided in the delay time measuring device on the transmission side, and outputs to the transmitter,
The reception processing unit provided in the delay time measuring device on the reception side uses the transmitter, the transmission path, and the reception of the periodic data output by the transmission processing unit provided in the delay time measurement device on the transmission side. The period data is stored in the second buffer provided in the delay time measuring device on the receiving side,
The delay time measuring unit provided in the delay time measuring device on the receiving side includes the period data stored in the first buffer provided in the delay time measuring device on the receiving side, and the delay time measuring device on the receiving side. A delay time measuring device, wherein a time difference is calculated from a timing at which the periodic data stored in the second buffer provided for synchronization is synchronized, and a delay time of the signal propagation is measured based on the time difference . A predetermined transmission process is performed on the data to be transmitted, and a transmitter that transmits the signal subjected to the transmission process via a transmission path, the transmission path, and a signal received via the transmission path are predetermined. In a delay time measurement system for measuring a delay time of signal propagation to a receiver to be processed,
A first delay time measuring device that generates periodic data repeated at a constant period and outputs the periodic data to the transmitter;
A second delay time measuring device for inputting the period data output by the first delay time measuring device via the transmitter, the transmission line and the receiver, and measuring the delay time of the signal propagation; With
The first delay time measuring device includes:
A first clock unit having an internal clock in which a common time is set in the first delay time measuring device and the second delay time measuring device;
A first period data generation unit that generates the period data from a predetermined measurement start time for starting measurement of the delay time of the signal propagation;
A transmission processing unit that inputs the cycle data generated by the first cycle data generation unit and outputs the cycle data to the transmitter;
The second delay time measuring device includes:
A second clock unit having an internal clock in which the common time is set;
A second period data generation unit configured to generate the period data from the predetermined measurement start time and store the period data in a first buffer;
Reception in which the periodic data output by the transmission processing unit of the first delay time measuring device is input via the transmitter, the transmission path, and the receiver, and the periodic data is stored in a second buffer. A processing unit;
A time difference is calculated from a timing at which the periodic data stored in the first buffer and the periodic data stored in the second buffer are synchronized, and the delay time of the signal propagation is measured based on the time difference. A delay time measuring system comprising: a delay time measuring unit. The delay time measurement system according to claim 4,
The delay time measuring unit provided in the second delay time measuring device,
A processing time from when the transmission processing unit provided in the first delay time measuring device inputs the periodic data from the first periodic data generation unit to output to the transmitter; and the second An internal processing time corresponding to a time obtained by adding the processing time until the reception processing unit provided in the delay time measuring apparatus inputs the periodic data from the receiver and stores it in the second buffer in advance. Set,
A delay time measuring system, wherein the internal processing time is subtracted from the time difference, and the subtraction result is measured as a delay time of the signal propagation.   A delay time measuring program for causing a computer to function as the delay time measuring device according to any one of claims 1 to 3. A predetermined transmission process is performed on the data to be transmitted, and a transmitter that transmits the signal subjected to the transmission process via a transmission path, the transmission path, and a signal received via the transmission path are predetermined. A program for measuring a signal propagation delay time for a receiver to be processed,
A first delay time measuring apparatus that generates periodic data repeated at a constant period and outputs the periodic data to the transmitter;
A second delay time measuring device for inputting the period data output by the first delay time measuring device via the transmitter, the transmission line and the receiver, and measuring the delay time of the signal propagation; In the delay time measurement program by the delay time measurement system comprising
The first delay time measuring device includes a first clock unit having an internal clock in which a common time is set in the first delay time measuring device and the second delay time measuring device,
The second delay time measuring device includes a second clock unit having an internal clock that matches the time of the internal clock of the first delay time measuring device,
In the computer constituting the first delay time measuring device,
A first step of generating the periodic data from a predetermined measurement start time for starting measurement of the delay time of the signal propagation;
Performing the second step of outputting the periodic data to the transmitter;
In the computer constituting the second delay time measuring device,
A third step of generating the periodic data from the predetermined measurement start time and storing the periodic data in a first buffer;
A fourth step of inputting the periodic data output in the first step via the transmitter, the transmission path and the receiver, and storing the periodic data in a second buffer;
A fifth step of calculating a time difference from a timing at which the periodic data stored in the first buffer and the periodic data stored in the second buffer are synchronized;
And a sixth step of measuring a delay time of the signal propagation based on the time difference.

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