JP4840574B2 - Radio transmission method and apparatus considering relay transmission - Google Patents

Description

  The present invention relates to a radio transmission method and radio transmission apparatus that take relay transmission in asynchronous serial communication into consideration, and more particularly to a radio transmission method and apparatus that enable reduction in transmission quality to be reduced.

  In the conventional wireless transmission system and its apparatus, when performing communication between the wireless transmission apparatuses in a one-to-one manner, an interface for asynchronous serial data signals represented by RS-232C in addition to main signal transmission Some have. In this case, the serial data signal is transmitted using a transmission band for auxiliary signals. The serial data signal input from the outside is often non-integer multiple and asynchronous with the clock signal generated according to the transmission band. As the serial data signal transmission system, the following two systems are known.

The first method is for example disclosed in JP-2000-115145 (see Patent Document 1). In this method, a start bit, a stop bit, a parity bit, and character data are once separated from an externally input serial data signal. When outputting, only the character data is taken into the arithmetic circuit, and the start bit, stop bit, and parity bit are added again by the arithmetic unit. Thereafter, the output signal is taken out as a synchronous system signal having a bearer speed slightly faster than the serial data signal input from the outside, and is transmitted after being subjected to multiplexing processing.

  In this method, in order to separate various bits and data signals from an externally input asynchronous serial data signal, in addition to a serial input / output circuit, a start bit, a stop bit, and a parity bit are added to a radio frame. An arithmetic circuit for synchronous conversion to the speed of the band allocated in advance is required. For this reason, an increase in circuit scale is inevitable.

  In order to avoid this, in the second method, an oversampling process and a stuff process are performed on the asynchronous serial data signal input from the outside with a clock signal of a band allocated in advance in the radio frame, and the radio frame is processed. Multiplexed and transmitted.

  This second method will be described with reference to FIGS. FIG. 12 is a functional block diagram illustrating an example of a configuration in which a transmission apparatus 110 on a transmission side and a transmission apparatus 120 on a reception side face each other and transmit and receive signals via a wireless transmission path.

  In the illustrated transmission apparatus 110 on the transmission side, an oversampling circuit 111 performs an oversampling process on a serial data signal input from an input interface from a transmission terminal with a clock signal corresponding to a transmission band assigned in advance in a radio frame. The stuff circuit 112 performs stuff synchronization processing for multiplexing in a radio frame. The frame multiplexing circuit 113 multiplexes the signal subjected to the stuff synchronization processing in the stuff circuit 112 into a radio frame and sends it to the radio transmission circuit 114. The wireless transmission circuit 114 modulates the received signal and transmits it to the reception side transmission apparatus via the wireless transmission path.

On the other hand, in the reception-side transmission device 120, the wireless reception circuit 121 demodulates the data signal received via the wireless transmission path, performs clock extraction, and outputs the result to the frame synchronization circuit 122 and the smoothing circuit 125. The frame synchronization circuit 122 establishes frame synchronization with the demodulated data signal and clock signal input from the wireless reception circuit 121, and generates a timing signal for separating the data multiplexed in the wireless frame. The data extraction circuit 123 extracts a data signal based on the timing signal input from the frame synchronization circuit 122. The destuffing circuit 124 performs destuffing processing on the data signal subjected to the stuff synchronization processing by the transmission side stuffing circuit 112 described above. The smoothing circuit 125 smoothes the destuffed data signal and clock signal, and outputs the data signal through the output interface to the receiving terminal.

  FIG. 13 is a diagram for explaining a case where the relay transmission station 100T is constructed using the transmission-side transmission device 110 and the reception-side transmission device 120 described above. In the illustrated configuration, the data signal is transmitted from the transmitting terminal station 200S to the receiving terminal station 200R via the relay transmission station 100T. That is, the transmission side transmission device 110 of the transmission terminal station 200S and the reception side transmission device 120 of the relay transmission station 100T connected to the transmission terminal have the relationship shown in FIG. Similarly, the relationship between the transmission-side transmission device 110 of the relay transmission station 100T and the reception-side transmission device 120 of the reception terminal station 200R is the same as shown in FIG.

  Here, a data signal transmitted from the reception-side transmission device 120 to the transmission-side transmission device 110 via the intra-station relay transmission line inside the relay transmission station 100T is transmitted by the transmission-side transmission device 110 via an input interface with a terminal. Since it is input, it is processed as an asynchronous serial data signal.

  With such a transmission path configuration, when a wireless transmission path passes through a plurality of relay transmission stations 100T, it passes through the same number of transmission-side transmission devices as the relay transmission station. That is, every time it passes through the transmission device on the transmission side of the relay transmission station, the oversampling circuit performs an asynchronous and non-integer multiple oversampling process on the serial data signal. When the sampling error is accumulated by this processing, the serial data signal cannot be reproduced.

JP 2000-115145 A

  The problem to be solved is that the second method avoids the problem of increasing the circuit scale by using the first method, but the second method uses a plurality of stages of wireless transmission devices for serialization. When data signal relay transmission is performed, the transmission quality of the serial data signal is inevitably deteriorated. The reason is that each relay transmission station performs asynchronous and non-integer multiple oversampling every time it passes through the transmission device on the transmission side, so that sampling errors are accumulated and serial data signals cannot be reproduced. It is.

  The main feature of the present invention is to eliminate the asynchronous oversampling process at the relay transmission station for the purpose of preventing deterioration of the transmission quality of the serial data signal by the relay transmission station.

  That is, the radio transmission method according to the present invention is a method for relay transmission in a relay transmission station inserted and arranged in a radio transmission path, and an input data signal is assigned in advance in a radio frame of the radio transmission path. The serial signal is synchronized with the clock signal in the specified band, and the synchronized serial signal and clock signal are transmitted via the intra-station relay transmission path of the relay transmission station.

  With such a configuration, in the relay transmission station, the serial signal and the clock signal transmitted through the intra-station relay transmission line are synchronized, so that an oversampling circuit for asynchronous input is unnecessary on the transmission side. Thereby, it is possible to prevent a decrease in transmission quality of the serial data signal.

  For this reason, when relay transmission is performed from the reception-side transmission device to the transmission-side transmission device in the relay transmission station, the transmission-side transmission device directly stuffs the synchronized serial signal and the clock signal transmitted from the intra-station relay transmission path. Multiple processes can be processed to form a radio frame. Further, the transmission apparatus includes oversampling processing means, and the serial signal and the clock signal that are transmitted when the input to the stuff processing is connected to the intra-station relay transmission path, or When connecting to the terminal input interface, it is preferable to switch and connect to the data signal sent through the oversampling processing means and its clock signal because it can be set in the wireless terminal station or relay transmission station with the same configuration.

  As specific wireless transmission devices, a reception-side transmission device and a transmission-side transmission device are provided.

  One receiving-side transmission apparatus has a radio receiving circuit, a frame synchronization circuit, a data extraction circuit, a destuffing circuit, and a smoothing circuit as a basic configuration. The wireless reception circuit performs demodulation and clock extraction on the received data signal. The frame synchronization circuit establishes frame synchronization from the signal demodulated by the wireless reception circuit and the extracted clock signal, and generates the operation timing of the subsequent circuit. The data extraction circuit extracts a data signal multiplexed in the radio frame at a timing input from the frame synchronization circuit. The destuffing circuit performs destuffing processing on the data signal input from the data extraction circuit at a timing input from the frame synchronization circuit. The smoothing circuit performs a smoothing process on the synchronized data signal and clock signal after the destuffing process input from the destuffing circuit, and outputs the synchronized data signal and clock signal after the smoothing process. To do.

  The other transmission side transmission apparatus includes a reference oscillator, a transmission timing generation circuit, a stuff circuit, a frame multiplexing circuit, and a radio transmission circuit as a basic configuration. The reference oscillator generates a transmission reference clock signal. The transmission timing generation circuit generates timing for transmission device circuit operation. The stuff circuit receives the data signal and the clock signal, and performs synchronous conversion according to the timing input from the transmission timing generation circuit in order to multiplex the radio signal to be transmitted and output. The frame multiplexing circuit multiplexes the stuff-processed data signal into a radio frame at a timing input from the transmission timing generation circuit. The radio transmission circuit modulates and transmits the radio frame corresponding to the output radio frame.

  The transmission-side wireless transmission device can further include an internal oscillator, an oversampling circuit, and a switching circuit. The internal oscillator generates a timing clock signal for oversampling. The oversampling circuit oversamples a serial data signal input from the outside. The switching circuit is provided between the oversampling circuit and the stuff circuit, receives a station setting notification of whether the input from the outside is a transmission terminal station or a relay transmission station, and in the case of a transmission terminal station, the oversampling circuit Or in the case of a relay transmission station, the synchronized data signal and clock signal received from the intra-station relay transmission path are switched and output to the stuff circuit. With such a configuration, one transmitting side wireless transmission device can be used for both a wireless wireless terminal station and a relay transmission station.

  Further, in the transmission-side wireless transmission device, the internal oscillator is a frequency dividing circuit, and the internal oscillator is generated by dividing the timing clock signal to be output from the transmission reference clock signal generated by the reference oscillator. Can be deleted.

  In addition, the receiving side transmission device and the sending side transmission device are provided in the wireless transmission station, and both the synchronized data signal and clock signal are transmitted by the relay transmission path, so that the transmission side wireless transmission device is overloaded. The configuration can be made without the sampling circuit.

  On the other hand, the oversampling circuit is further provided and a switching circuit for the relay transmission path from the receiving transmission device facing in the relay transmission station is provided, so that the single transmission device can be used for the wireless terminal station or the relay transmission station. Can do.

  The wireless transmission method and apparatus according to the present invention simultaneously transmit a synchronized serial data signal and a clock signal using a relay transmission interface between a reception-side transmission device and a transmission-side transmission device in a relay transmission station. Therefore, asynchronous oversampling processing in the transmission apparatus on the transmission side can be reduced. Thus, even if a reception-side transmission device and a transmission-side transmission device are combined to form a multi-stage relay transmission system, there is an advantage that it is possible to prevent a decrease in transmission quality of a serial data signal due to relay transmission.

  Furthermore, the wireless transmission device according to the present invention can be constructed in the same device in either a transmission terminal station or a relay transmission station by incorporating an oversampling circuit and switching use / nonuse of the oversampling circuit. .

  Oversampling circuit is eliminated by transmitting serial data signal and clock signal simultaneously synchronized with the transmission path in the relay transmission station for the purpose of preventing transmission quality degradation of serial data signal due to relay transmission in wireless transmission Realized. Further, since it can be used for both the wireless terminal station and the relay transmission station, the cost increase of the wireless transmission device can be suppressed.

  Next, embodiments will be described with reference to the drawings. In the drawing, the portion according to the present invention is described because of space, but some functions essential for the wireless transmission device and system are also omitted from the drawing. Moreover, although each embodiment is described, the configuration is free as long as the function described in the above means is exhibited, and the following description does not limit the present invention.

  A first embodiment of the present invention will be described with reference to FIG.

  FIG. 1 is a block diagram showing an embodiment when a radio transmission apparatus according to the present invention is installed in a radio transmission station 1. The wireless transmission station 1 can be set to either a transmission terminal station or a relay transmission station by switching setting.

  The illustrated radio transmission station 1 can accommodate and connect external transmission terminal stations 2S and reception terminal stations 2R in addition to accommodating and connecting wireless transmission paths. Inside, a transmission device 10 on the transmission side and a transmission device 20 on the reception side are provided as wireless transmission devices. The transmission-side transmission device 10 has the above-described conventional function of inputting a data signal through an interface from the transmission terminal station 2S and outputting the data signal to a wireless transmission path. The reception-side transmission device 20 has the above-described conventional function of inputting a data signal from the wireless transmission path and outputting the data signal through an interface to the reception terminal station 2R. By providing such a transmission apparatus 10 on the transmission side and a transmission apparatus 20 on the reception side, a wireless terminal station similar to the conventional one can be formed.

  The transmission device 10 on the transmission side and the transmission device 20 on the reception side of the present embodiment can be further connected to each other via an intra-station relay transmission path to form the wireless transmission station 1 as a relay transmission station. A serial data signal and its clock signal are transmitted from the reception side transmission device 20 to the transmission side transmission device 10 through the intra-station relay transmission path. Therefore, the receiving side transmission apparatus 20 outputs the synchronized serial data signal and its clock signal. The transmission-side transmission device 10 includes a switching circuit that switches between input from the transmission terminal station 2S and input from the intra-station relay transmission path.

  Further, the wireless transmission station 1 is further provided with a terminal relay station setting unit 30. The terminal relay station setting unit 30 sets in advance whether the station in which the wireless transmission device according to this embodiment is provided is a wireless terminal station or a relay transmission station. That is, when the wireless transmission station is used as a wireless terminal station, a station setting signal for terminal station setting is output to the transmission apparatus 10 on the transmission side. When the wireless transmission station is used as a relay transmission station, the station setting signal becomes the relay station setting. The transmission apparatus 10 on the transmission side receives the station setting signal and switches between the input from the transmission terminal station 2S and the input from the intra-station relay transmission path.

  Next, details of the transmission apparatus 10 on the transmission side and the transmission apparatus 20 on the reception side will be described with reference to FIG. FIG. 2 is a functional block diagram illustrating an aspect of each of the transmission device 10 on the transmission side and the transmission device 20 on the reception side according to the first embodiment.

  The transmission-side transmission device 10 includes an oversampling circuit 11, a switching circuit 12, a stuff circuit 13, a frame multiplexing circuit 14, a wireless transmission circuit 15, an internal oscillator 16 for oversampling, a device reference oscillator 17, and a transmission timing generation circuit 18. Composed.

  The oversampling circuit 11 oversamples the serial data signal 1a input from the terminal input interface with the oversampling clock signal 1c of the internal oscillator 16, and outputs an oversampling data signal 1b. The switching circuit 12 selects the oversampling clock signal 1c and the oversampling data signal 1b when the wireless transmission station 1 is set as a wireless terminal station according to the station setting signal 1f input from the outside, and also selects the relay transmission station. When set, the relay transmission data signal 1d and the relay transmission clock signal 1e input from the intra-station relay transmission path are selected and output to the stuff circuit 13 as a transmission data signal 1g and a transmission clock signal 1h, respectively.

  The stuff circuit 13 stuffs the transmission data signal 1g and the clock signal 1h input from the switching circuit 12 with the overhead transmission clock signal 1k generated by the transmission timing generation circuit 18, and the overhead multiplexed signal 1m to the frame multiplexing circuit 14. Output. The frame multiplexing circuit 14 multiplexes the overhead multiplexed signal 1m input from the stuff circuit 13 in the overhead area of the radio frame in accordance with the overhead multiplexed timing signal 1j output from the transmission timing generation circuit 18, and the radio frame transmission data signal 1n. Generate and output to the wireless transmission circuit 15.

  The wireless transmission circuit 15 modulates the wireless frame transmission data signal 1n input from the frame multiplexing circuit 14 and outputs the modulated data to the wireless transmission path. The internal oscillator 16 is for oversampling, and generates and outputs an overhead transmission clock signal 1k to the stuff circuit 13 and an overhead multiplexing timing signal 1j to the frame multiplexing circuit 14. The device reference oscillator 17 generates a device transmission reference clock signal 1 i and sends it to the transmission timing generation circuit 18. The transmission timing generation circuit 18 receives the apparatus transmission reference clock signal 1i from the apparatus reference oscillator 17, and generates an overhead multiplexing timing signal 1j and an overhead transmission clock signal 1k for multiplexing in the overhead area of the radio frame.

  The reception-side transmission device 20 includes a wireless reception circuit 21, a frame synchronization circuit 22, a data extraction circuit 23, a destuff circuit 24, and a smoothing circuit 25.

  The radio reception circuit 21 demodulates and extracts a clock from the radio data signal received from the radio transmission circuit 15 of the transmission apparatus 10 on the opposite side via the radio transmission path. As a result, the radio reception circuit 21 outputs the radio frame reception data signal 2a to the frame synchronization circuit 22 and the data extraction circuit 23, and outputs the radio frame reception clock signal 2b to the frame synchronization circuit 22 and the smoothing circuit 25.

  The frame synchronization circuit 22 establishes frame synchronization for the radio frame reception data signal 2 a input from the radio reception circuit 21, and outputs an overhead separation timing signal 2 c to the data extraction circuit 23 and the destuff circuit 24. The data extraction circuit 23 separates the data signal multiplexed in the overhead area of the wireless frame reception data 2a input from the wireless reception circuit 21 in accordance with the overhead separation timing signal 2c input from the frame synchronization circuit 22, and extracts the overhead. The signal 2d is output to the destuff circuit 24.

  The destuff circuit 24 performs destuff processing on the overhead extraction signal 2 d input from the data extraction circuit 23 and outputs the destuff data signal 2 e and the destuff clock signal 2 f to the smoothing circuit 25. The smoothing circuit 25 smoothes the destuffing data signal 2e and the destuffing clock signal 2f input from the destuffing circuit 24 using the radio frame reception clock signal 2b. As a result, the smoothing circuit 25 outputs the reception data signal 2g to the terminal station output interface and the intra-station relay transmission path, and outputs the reception clock signal 2h synchronized with the reception data signal 2g to the intra-station relay transmission path.

  As described above, each of the transmission apparatus 10 on the transmission side and the transmission apparatus 20 on the reception side can be used for either the wireless terminal station or the relay transmission station by setting the station in advance in the terminal relay station setting unit 30. .

  Next, referring to FIG. 3 in addition to FIG. 3, it is a functional block diagram showing an embodiment of the configuration of the oversampling circuit 11 and the switching circuit 12 in FIG. 2.

  The oversampling circuit 11 can be realized by a D-FF (D-type flip-flop circuit) 31. The D-FF 31 overshoots the serial data signal 1a input from the terminal input interface with the oversampling clock signal 1c of the internal oscillator 16. The oversampling data signal 1b is output after sampling.

  The switching circuit 12 can be composed of two SWs (switches) 32 and 33. The SWs 32 and 33 are simultaneously switched according to the station setting of either the transmission terminal station or the relay transmission station of the station setting signal 1f input from the outside. The SW 32 switches the oversampling data signal 1b and the relay transmission data signal 1d and outputs a transmission data signal 1g. The SW 33 switches between the oversampling clock signal 1c and the relay transmission clock signal 1e and outputs a transmission clock signal 1h. This switch configuration is an example, and the present invention can be implemented using any known means.

  Next, referring to FIG. 4 together with FIG. 2, a functional block diagram illustrating an embodiment of the configuration of the smoothing circuit 25 in FIG. 2 is shown.

  The illustrated smoothing circuit 25 includes a smoothing clock generation circuit 34 and a memory 35. The smoothing clock generation circuit 34 generates a reception clock signal 2h using the radio frame reception clock signal 2b. The memory 35 smoothes the destuffing data signal 2e and outputs a reception data signal 2g. That is, the destuffing data signal 2e is written as the destuffing clock signal 2f and is read out as the receiving clock signal 2h, so that the destuffing data signal 2e is output as a smoothed receiving data signal 2g in synchronization with the receiving clock signal 2h.

  Here, the operation of the input / output signals in the smoothing circuit 25 will be described with reference to FIGS.

  For example, one stuff period is set to X clocks for the overhead extraction signal 2d. When there is no stuff control, there are data bits for X bits in one stuff cycle, but when there is stuff control, there are data bits for "X-1" bits in one stuff cycle. Therefore, it is not necessary to perform smoothing when there is no staff control. However, when there is stuff control, it is necessary to smooth the data signal and the clock signal so that the bit width of the “X-1” bits in one stuff cycle is uniform. As a result, it is possible to suppress sampling errors and fluctuations corresponding to missing teeth due to staff control. Therefore, depending on the presence or absence of stuff control, the reception data signal 2g and the reception clock signal 2h after the smoothing process cause sampling errors and fluctuations for one clock in one stuff cycle with respect to the radio frame reception clock signal 2b. However, the sampling error and fluctuation generated in the smoothing circuit 25 are equivalent to one clock of the radio frame reception clock signal 2b, and with respect to the sampling error of one clock of the oversampling clock signal 1c generated in the oversampling circuit 11, It is small enough. The reception data signal 2g smoothed by the smoothing circuit 25 is output in two branches to the terminal station output interface and the intra-station relay transmission path. A reception clock signal 2h synchronized with the reception data signal 2g is output to the intra-station relay transmission path.

  Next, with reference to FIG. 7 together with FIG. 2, an embodiment of a configuration for wireless transmission from a transmitting terminal to a receiving terminal via one relay transmission station will be described. FIG. 7 is a block diagram showing an embodiment of a wireless transmission system that relays and transmits a transmission device 10 and a reception device 20 connected in two stages according to the present invention. As shown in the figure, the transmission side transmission device 10S of the transmission terminal station 2S is connected from the reception side transmission device 20 of the relay transmission station 1T to the reception side transmission device 20 of the reception terminal station 2R via the transmission side transmission device 10T. . Here, the configuration of the transmission apparatus 10S, 10T is the same as that of the transmission apparatus 10 shown in FIG. The receiving side transmission apparatus 20 has the same configuration as shown in FIG.

  The transmitting terminal station 2S is a transmitting side wireless terminal station, and the receiving terminal station 2R is a receiving side wireless terminal station. Therefore, as a wireless terminal station for connecting a terminal to a wireless transmission path, the transmitting terminal station 2S and the receiving terminal station 2R are constructed as one wireless transmission station. The transmission side transmission device 10S of the transmission terminal station 2S and the reception side transmission device 20 of the reception terminal station 2R are each set as a wireless terminal station by a station setting signal. Therefore, in the transmitting side transmission device 10S of the transmitting terminal station 2S, the serial data signal 1a is input from the terminal station input interface of the transmitting terminal via the oversampling circuit 11 and the switching circuit 12, and is output to the wireless transmission path. In the receiving side transmission device 20 of the receiving terminal station 2R, the smoothing circuit 25 is connected to the terminal output interface of the receiving terminal, and the received data signal 2g is output.

  The relay transmission station 1T is set as a relay transmission station by a station setting signal. Accordingly, in the transmission-side transmission device 10T of the relay transmission station 1T, the relay transmission data signal 1d and the relay transmission clock signal 1e input from the intra-station relay transmission path are input via the switching circuit 12 and output to the wireless transmission path. The In the receiving side transmission device 20 of the relay transmission station 1T, since the smoothing circuit 25 is connected to the intra-station relay transmission path, the reception data signal 2g and the reception clock signal 2h are output. As a result, the reception data signal 2g and the reception clock signal 2h output from the reception side transmission device 20 are input to the transmission side transmission device 10 as the relay transmission data signal 1d and the relay transmission clock signal 1e via the intra-station relay transmission path. The

  Next, with reference to FIG. 8, an embodiment of a configuration of a radio frame in a radio transmission path that connects the radio terminal station and the relay transmission station to each other will be described. The illustrated radio frame includes header bits added before and after, and payload bits and overhead bits sandwiched between the header bits.

  FIG. 9 shows an embodiment of a serial data signal in the intra-station relay transmission path of the relay transmission station. The serial data signal shown in the figure is composed of a start bit and a stop bit and a plurality of data bits and a parity bit sandwiched between the start bit and the stop bit, and is transmitted as a burst data signal including a group from the start bit to the stop bit.

  Next, with reference to FIG. 7 together with FIG. 2, the operation of the transmission apparatus centering on the flow of the data signal in the case of wireless transmission from the transmitting terminal to the receiving terminal via one relay transmission station will be described. . The configuration of the transmission apparatus has already been described above.

  First, in the transmitting side transmission device 10S of the transmitting terminal station 2S, the serial data signal 1a input from the transmitting terminal via the terminal station input interface is received by the oversampling circuit 11 by the oversampling clock signal 1c from the internal oscillator 16. The oversampling process is performed and output as an oversampling data signal 1b. The oversampling clock signal 1c from the internal oscillator 16 has a clock speed corresponding to the overhead capacity of the radio frame. The serial data signal 1a input from the transmitting terminal via the terminal input interface and the oversampling clock signal 1c generated from the internal oscillator 16 are asynchronous and non-integer multiples. Therefore, a sampling error corresponding to a maximum of one clock occurs with respect to the oversampling clock signal 1c between the serial data signal 1a and the oversampling data signal 1b.

  Since the switching circuit 12 is set to the wireless terminal station by the station setting signal 1f input from the outside, the oversampling data signal 1b and the oversampling clock signal 1c are selected by the switching circuit 12, and the transmission data signal 1g and the transmission are transmitted. The clock signal 1h is output to the stuff circuit 13. On the other hand, the transmission timing generation circuit 18 generates an overhead multiplex timing signal 1j and an overhead transmission clock signal 1k for multiplexing from the device transmission reference clock signal 1i of the device reference oscillator 17 to the overhead region of the radio frame.

  The transmission data signal 1g output from the switching circuit 12 is stored in the memory by the stuff circuit 13 using the transmission clock signal 1h. Next, the transmission data signal 1g stored in the stuff circuit 13 is output as an overhead multiplexed signal 1m that is stuff-synchronized with the overhead transmission clock signal 1k and multiplexed into a radio frame. The overhead multiplexed signal 1m is multiplexed in the overhead area of the radio frame by the overhead multiplexing timing signal 1j in the frame multiplexing circuit 14, and is output to the radio transmission circuit 15 as a radio frame transmission data signal 1n. The radio frame transmission data signal 1n is modulated by the radio transmission circuit 15 and transmitted to the radio transmission path.

  Subsequently, in the relay transmission station 1T, in the receiving side transmission apparatus 20, the radio frame transmission data signal 1n received from the radio transmission path is demodulated and extracted by the radio reception circuit 21, and the radio frame reception data signal 2a and the radio frame are extracted. The received clock signal 2b is output. The radio frame reception data signal 2a and the radio frame reception clock signal 2b establish frame synchronization by the frame synchronization circuit 22, and are output as an overhead separation timing signal 2c. On the other hand, in the radio frame reception data signal 2a, the data extraction circuit 23 separates the data signal multiplexed in the overhead area according to the overhead separation timing signal 2c from the frame synchronization circuit 22, and the separated signal is the overhead extraction signal. 2d is output to the destuffing circuit 24. The overhead extraction signal 2d is destuffed by the destuff circuit 24 in accordance with the overhead separation timing signal 2c from the frame synchronization circuit 22, and is output to the smoothing circuit 25 as the destuff data signal 2e and the destuff clock signal 2f. . The destuffing data signal 2e is temporarily stored in the memory by the smoothing circuit 25 by the destuffing clock signal 2f. On the other hand, the radio frame reception clock signal 2b output from the radio reception circuit 21 is frequency-divided by the smoothing circuit 25 and generated as a reception clock signal 2h. The stored destuffing data signal 2e is read as a reception data signal 2g by the reception clock signal 2h, and is sent to the intra-station relay transmission line together with the reception clock signal 2h.

  Subsequently, in the transmission-side transmission device 10T connected to the intra-station relay transmission line in the relay transmission station 1T, the reception data signal 2g is used as the relay transmission data signal 1d, and the reception clock signal 2h is used as the relay transmission clock signal 1e. , Respectively, to the switching circuit 12. In the transmission apparatus 10T, since the relay station is set by the station setting signal 1f, the relay transmission data signal 1d is transmitted as the transmission data signal 1g and the relay transmission clock signal 1e is transmitted via the switching circuit 12. The clock signal 1h is input to the stuff circuit 13. The operations related to the frame multiplexing circuit 14, the radio transmission circuit 15, and the transmission timing generation circuit 18 after the stuff circuit 13 are the same as the operations in the transmission side transmission device 10S of the transmission terminal station 2S described above, and the description thereof is omitted.

  The operation of the receiving side transmission device 20 of the subsequent receiving terminal station 2R is the same as described above because the receiving side transmission device 20 has the same configuration as the receiving side transmission device 20 of the relay transmission station 1T as described above. However, the receiving side transmission device 20 in the receiving terminal station 2R outputs a serial data signal using the terminal station output interface.

  Since the present invention has the configuration as described above, by setting the wireless terminal station and the relay transmission station in advance by the terminal relay station setting unit, the same transmission side transmission device 10 and reception side transmission device 20 are provided. The wireless transmission station constructed by using the wireless transmission station can be used as a wireless terminal station or a relay transmission station. In addition, when used as a relay transmission station, the transmission apparatus on the transmission side can be deleted from the transmission line by disconnecting the oversampling circuit. Therefore, it is possible to reduce the asynchronous oversampling process in the relay transmission station, and it is possible to reduce the transmission quality deterioration due to the asynchronous serial data signal.

  A second embodiment of the present invention will be described with reference to FIG.

  FIG. 10 shows a configuration in which the transmission side transmission apparatus 10 is changed to the transmission side transmission apparatus 10A in the configuration of FIG. In the transmission device 10A, a frequency divider 19 is provided instead of the internal oscillator 16 of the transmission device 10 in FIG. That is, the frequency dividing circuit 19 receives the device transmission reference clock signal 1i from the device reference oscillator 17 and divides it, and generates the same oversampling clock signal 1c when output from the internal oscillator 16 of FIG. Therefore, the oversampling clock signal 1c is output to the oversampling circuit 11 and the switching circuit 12. In this embodiment, since the oversampling clock signal 1c is generated from the device transmission clock signal 1i, the oversampling internal oscillator 16 can be eliminated.

  A third embodiment of the present invention will be described with reference to FIG. 11 and FIG. 2 and FIG.

  The difference between the transmission device 10B in FIG. 11 and FIGS. 2 and 10 is that the circuits related to the oversampling circuit 11 and the switching circuit 12 are deleted. Therefore, in the transmission side transmission apparatus 10B connected to the intra-station relay transmission path, the reception data signal 2g is directly input to the stuff circuit 13 as the transmission data signal 1g, and the reception clock signal 2h is input as the transmission clock signal 1h, respectively. As a result, a relay transmission station is exclusively constructed by this transmission apparatus.

  Therefore, since the asynchronous oversampling process at the relay transmission station is reduced, it is possible to reduce the transmission quality degradation. Furthermore, only the components are deleted from the conventional configuration, and no new circuit formation is required, so that resources can be reduced.

  When configuring a relay transmission station using a reception-side transmission device and a transmission-side transmission device connected to a wireless transmission path in a wireless transmission station, by separating a circuit for asynchronous oversampling processing from the transmission-side transmission device, Transmission quality degradation caused by relay transmission can be easily reduced. Therefore, resources can be reduced when a dedicated circuit is configured. Furthermore, by switching the circuit for asynchronous oversampling processing depending on whether it is a wireless terminal station or a relay transmission station, it is possible to set the transmission terminal station or the relay transmission station with the same circuit configuration, and the cost can be reduced. Therefore, in a wireless transmission system that requires asynchronous oversampling processing, it can be applied to applications that require a reduction in transmission quality and a reduction in cost or resources, such as when a plurality of relay transmission stations are provided.

It is the figure which showed one Embodiment of the radio transmission station by this invention with the block configuration. (Examples 1 and 2) It is the figure which showed one Embodiment of the radio transmission apparatus by this invention with the functional block. Example 1 It is the circuit diagram which showed one Embodiment of the partial detail based on this invention in the transmission side transmission apparatus of FIG. 2 with the functional block. Example 1 It is the circuit diagram which showed one Embodiment of the partial detail embodiment based on this invention in the receiving side transmission apparatus of FIG. 2 with the functional block. Example 1 FIG. 5 is a time chart showing an embodiment in the case of the stuffless operation in the smoothing circuit of FIG. 4. Example 1 FIG. 5 is a time chart showing an embodiment in the case of an operation with staff in the smoothing circuit of FIG. 4. Example 1 It is the figure which showed one Embodiment by the block structure containing the relay transmission station of the wireless transmission system by this invention. (Examples 1 and 2) It is the figure which showed one Embodiment of the radio | wireless frame transmitted to a radio transmission line by this invention by the flame | frame structure. Example 1 It is the figure which showed one Embodiment of the serial data signal transmitted to an intra-office relay transmission line by this invention with the time chart. Example 1 It is the figure which showed one Embodiment of the wireless transmission apparatus different from FIG. 2 with the functional block. (Example 2) It is the figure which showed one Embodiment of the wireless transmission apparatus different from FIG.2 and FIG.10 with the functional block. (Example 3) It is the figure which showed an example of the conventional radio | wireless transmission apparatus with the functional block. It is the figure which showed an example including the relay transmission station of the conventional radio transmission system with a block configuration.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Radio transmission station 1T Relay transmission station 2R Reception terminal station 2S Transmission terminal station 10, 10A, 10B, 10S, 10T Transmission side transmission apparatus 11 Oversampling circuit 12 Switching circuit 13 Staff circuit 14 Frame multiplexing circuit 15 Radio transmission circuit 16 Internal oscillator 17 Device Reference Oscillator 18 Transmission Timing Generation Circuit 19 Frequency Dividing Circuit 21 Radio Reception Circuit 22 Frame Synchronization Circuit 23 Data Extraction Circuit 24 Destuff Circuit 25 Smoothing Circuit 30 Terminal Relay Station Setting Unit 31 D-FF
32, 33 SW
34 Smoothing clock generation circuit 35 Memory

Claims (7)

A relay transmission station inserted and arranged in a wireless transmission path, which is included in a wireless data signal transmitted from a transmission terminal station, is oversampled by the transmission terminal station, and is a destination terminal station from the transmission terminal station The contents of the auxiliary signal that is asynchronous with the clock signal generated in accordance with the frequency band assigned as the predetermined transmission band in the radio frame and sent together with the main signal that is the content communicated toward In the wireless transmission method when relaying the data signal corresponding to
Intra-station relay transmission in the relay transmission station that connects a receiving-side transmission apparatus that performs processing for receiving a wireless data signal received from the wireless transmission path and a transmitting-side transmission apparatus that transmits the received wireless data signal to the wireless transmission path On the road
An oversampled data signal generated by the transmitting terminal station by performing oversampling processing obtained by performing demodulation processing on the wireless data signal received from the wireless transmission path by the receiving side transmission device, Destuffing and converting to a serial signal synchronized with the clock signal of the predetermined transmission band obtained by extracting from the wireless frame of the wireless transmission path, and converting the serial signal and the clock signal to the transmitting side in a synchronized state While transmitting to the transmission device,
After the stuff processing is performed by using the clock signal sent simultaneously with the serial signal sent by the transmission device on the transmission side without going through the oversampling processing, frame multiplexing processing is performed on the predetermined transmission band. A wireless transmission method for relaying an oversampled signal, wherein the wireless signal is formed into a wireless frame together with the main signal and wirelessly transmitted. The wireless transmission method according to claim 1,
Using a transmission band for auxiliary signals as a predetermined transmission band in the radio frame,
A radio signal having a non-integer multiple signal length longer than the clock signal is a data signal to be relayed that is asynchronous with the clock signal generated in accordance with the transmission band for the auxiliary signal. Transmission method. The wireless transmission method according to claim 1 or 2,
While comprising an oversampling processing means in the transmission device on the transmission side,
Input to the staff process
When connecting to the intra-station relay transmission path, the synchronized serial signal and the clock signal transmitted from the receiving side transmission device,
When using the own relay transmission station as the transmission terminal station by connecting to the terminal input interface, the data signal input to the terminal input interface and its clock signal transmitted via the oversampling processing means,
Connect to be switchable as used,
Based on the station setting signal, the local relay transmission station is a wireless terminal station, the data signal input to the terminal station input interface is oversampled, stuffed, and then frame-multiplexed into the predetermined transmission band A wireless transmission method characterized by forming a wireless frame and wirelessly transmitting. Received as a destination from the transmitting terminal station by being oversampled by the transmitting terminal station and included in the wireless data signal transmitted from the transmitting terminal station by being inserted in the wireless transmission path and carried on the wireless frame. Auxiliary signal that is asynchronous to the clock signal that is generated in accordance with the frequency band assigned as a predetermined transmission band in the radio frame, which is sent with the main signal that is the content communicated toward the terminal station. A wireless transmission station that relays data signals corresponding to the contents of
As a receiving side transmission device that performs processing for receiving a wireless data signal received from the wireless transmission path,
A radio reception circuit that performs demodulation and clock extraction on the received radio data signal;
A frame synchronization circuit that establishes frame synchronization from the data signal demodulated by the wireless reception circuit and the extracted clock signal, and generates operation timing of a subsequent circuit;
A data extraction circuit for extracting a desired data signal from the demodulated data signal at a timing input from the frame synchronization circuit;
A destuff circuit that performs destuffing processing on the data signal input from the data extraction circuit at a timing input from the frame synchronization circuit;
A smoothing process based on the clock signal extracted by the wireless reception circuit is performed on the synchronized data signal and clock signal after the destuffing process input from the destuffing circuit, and the synchronized data signal and the clock signal after the smoothing process are synchronized A smoothing circuit for separately transmitting the data signal and the clock signal to the transmission side of the same relay transmission station;
With
As a transmission device on the transmission side for sending the received wireless data signal to the wireless transmission path,
A reference oscillator for generating a reference clock signal for transmission;
A transmission timing generation circuit for generating timing for transmission device circuit operation from the transmission reference clock signal;
Synchronous conversion is performed according to the timing input from the transmission timing generation circuit in order to receive the synchronized data signal and clock signal transmitted separately from the receiving side transmission apparatus as inputs and multiplex them into a radio frame to be transmitted and output. Do the staff circuit,
A frame multiplexing circuit that multiplexes the data signal after the stuff processing into a radio frame at a timing input from the transmission timing generation circuit;
A wireless transmission circuit that modulates the wireless frame and transmits it to the wireless transmission path;
With
The synchronized data signal and the clock signal after the smoothing process in the smoothing circuit of the reception side transmission apparatus are respectively separated and connected to the stuff circuit of the transmission side transmission apparatus without going through an oversampling process. A radio transmission station that performs signal processing and constructs a relay transmission station that multiplexes frames into the predetermined transmission band after stuffing processing to form a radio frame and wirelessly transmits it. The wireless transmission station according to claim 4, wherein
The transmitting side transmission device further includes:
An internal oscillator that generates a timing clock signal for oversampling;
An oversampling circuit for oversampling an externally input serial data signal;
The oversampling circuit is additionally provided between the oversampling circuit and the stuff circuit, and in the case of a wireless terminal station setting notification according to a station setting notification whether the input from the outside is a wireless terminal station or a relay transmission station A switching circuit for switching the output to the stuff circuit to a synchronized data signal and clock signal transmitted from the receiving side transmission device and received from the intra-station relay transmission path in the case of relay transmission station setting notification ,
A wireless transmission station comprising: The wireless transmission station according to claim 5, wherein
The transmission device on the transmission side is:
The wireless transmission characterized in that the internal oscillator is a frequency divider, and the frequency divider divides and generates a timing clock signal to be output by receiving a transmission reference clock signal generated by the reference oscillator. Bureau. In the radio transmission station according to claim 6,
As the output of the smoothing circuit of the receiving side transmission device, a wireless terminal is formed by connecting only the data signal after the smoothing processing to the wireless transmission path to the receiving terminal, or in the relay transmission station A wireless transmission station is formed by connecting a synchronized data signal and a clock signal to a relay transmission path to an opposite transmission apparatus on the other side to form a relay transmission station.

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