JP3842450B2 - Receiving device for hierarchical synthesis - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to hierarchical synthesis for hierarchical transmission used in broadcasting and communication systems, and relates to a receiving apparatus for reproducing the transmission signal.
[0002]
[Prior art]
In recent years, instead of analog broadcasting, digital broadcasting has been put into practical use. For example, some digital terrestrial broadcasting systems employ a layered transmission system for transmission. In such a transmission system, data processing is performed for each of a plurality of hierarchies. However, since the data generation is not uniform and is input in a burst form, the data is temporarily stored in a hierarchical storage means. The control in this method is complicated.
[0003]
In general data processing, a hierarchical structure of memory and storage (for example, a structure such as a high-speed buffer memory) according to the data rate (transmission speed) is adopted by controlling the program. Even if possible, it is a complicated control system because of the program.
[0004]
Normally, this is always required for modules used in digital television broadcasts implemented in the above-mentioned hierarchical transmission system, such as a tuner circuit of a television receiver, a decoder (digital demodulation circuit), or an attached adapter. A means for accumulating such hierarchical inputs is required.
[0005]
In particular, when hierarchical transmission is performed in a digital terrestrial broadcasting system, the receiving device on the receiving side receives a signal subjected to demodulation processing, for example, demapping or time deinterleaving, for each layer. There is a need for so-called “hierarchical synthesis” in which a series of signals (for example, a TS (Transport Stream) signal) is synthesized.
[0006]
Currently used in broadcasting and communication systems as a method of outputting such signals as signals in a predetermined packet unit (ie, Transport Stream Packets (TSP)) in each layer in an accumulated order. Several techniques have been proposed for the configuration for hierarchical transmission.
[0007]
As an example, FIG. 6 shows the configuration of modules in a receiving apparatus that performs hierarchical synthesis. For example, a circuit module such as a tuner or a decoder that constitutes this type of receiving apparatus accumulates input signals for each layer by layer and connects to the storage unit 10 to monitor the accumulation state for each layer. The output control unit 20 is configured. The storage means 10 is composed of four storage buffers 11 to 14 for each of the layers 1 to 4, and the output control unit 20 is connected to the storage buffers 11 to 14 for output control.
[0008]
As described above, in the techniques proposed so far, in general, when TSP packets are output in the order in which they are accumulated in each layer, it can be easily realized as shown in FIG. 6 and is not quantitatively constant in each layer. The packet data input in a burst form is sequentially accumulated in the TSP accumulation buffers 11 to 14 for the data, and if data for one TSP packet data is accumulated in any of the layers, Data is output as packet data TSP.
[0009]
[Problems to be solved by the invention]
However, the hierarchical transmission method in the digital terrestrial broadcasting system has the following conditions. That is,
(1) When TSPs are stored in two or more layers, the TSP of the layer stored earlier is output.
(2) If there is no TSP stored in all layers, a null packet is output.
[0010]
The null packet is a packet defined in, for example, an MPEG2 transport stream, and is composed of a predetermined header and a predetermined unit of data string.
In order to satisfy each of these conditions, it is impossible to realize it only by the configuration of the conventional receiving apparatus shown in FIG. This is because, since detailed monitoring is not performed regarding the storage status in each TSP storage buffer 11 to 14 and the storage order thereof, control that satisfies the above conditions for each layer cannot be performed.
[0011]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a module of a receiving apparatus that can correctly perform hierarchical synthesis and output on the receiving side in the hierarchical transmission system of a digital terrestrial broadcasting system.
[0012]
[Means for Solving the Problems]
The present invention has been made in view of the above-described present situation, and the following measures are taken in order to solve the above problems and achieve the object. In other words, the receiving apparatus is configured to output a storage means for storing a plurality of storage spaces for storing the input signal for each hierarchy, and an output for controlling the output of the accumulated signal for each hierarchy by connecting to this storage means. A control means, and a monitoring means connected to the output control means and the storage means for monitoring the storage state of the storage means for each hierarchy, the monitoring means includes memory means that can be stored in a queue, When input signal data is accumulated in the storage space of a certain hierarchy, a flag indicating that it has been accumulated in that storage space is issued and sequentially stored in the memory means. When the output control means is notified to sequentially read out the storage contents of the corresponding storage space, the output control means is configured to control the storage means so as to be combined into a series of output signals.
[0013]
In other words, one method of layer synthesis performed by the receiving apparatus proposed by the present invention is that when signals are transmitted in a layered transmission system in a terrestrial digital broadcasting system, signals separated in each layer are received by a predetermined module on the receiving side. This was born out of the need to hierarchically synthesize one TS signal, and in particular, this is a technique for outputting the hierarchically synthesized TSPs by recombining them in the order temporarily stored in the module.
[0014]
For this reason, a monitoring unit for monitoring the storage area for each layer is provided so that when one TSP of data is stored from each layer, a flag indicating that is generated, and these flag outputs for each layer are output. The data is stored in a queue memory and the flag is read at 1 TSP cycle. At this time, if TSPs are accumulated in two or more layers, a time difference occurs at the end of the accumulation. Therefore, when the burst-like data stored for each layer is input to the storage region for a certain layer, the same data is not input to the storage region for any other layer, and therefore at the same time. TSPs are not stored in more than one hierarchy. The present invention provides a receiving apparatus that uses this to perform hierarchical synthesis.
[0015]
[Action]
In the receiving apparatus of the present invention, the following operation is achieved by the above means. That is, according to the present invention, by reading the accumulation flag sequentially from the FIFO in the monitoring unit, it is possible to read the TSP of the previously accumulated hierarchy. If no TSP exists in any hierarchy, no accumulation flag is output from any hierarchy, and the FIFO in the monitoring unit is also empty. In this case, the above-described null packet is generated and output instead. it can. Therefore, a series of transport stream packets (TSP), for example, in units of packets in each layer are output in the correct order.
[0016]
According to the aspects described in the above claims, it is possible to realize a receiving apparatus capable of layer synthesis that satisfies predetermined specifications and conditions of the layered transmission method in the digital terrestrial broadcasting system.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
First, an overview of a digital television receiver (hereinafter abbreviated as “digital television”) according to the receiving apparatus of the present invention will be described with reference to FIG.
As a basic configuration of a digital television as a receiving apparatus, a tuner circuit 2 following the antenna 1, a digital demodulation circuit 3, a video data decoding circuit 4, a screen format conversion circuit 5, an audio data decoding circuit 6, It is mainly composed of a display 7 and outputs not only audio and video but also various information such as characters and graphics from a series of received digital data streams.
[0018]
The video data decoding circuit 4 performs a decompression process of video data sent in correspondence with a predetermined compression method (for example, MPEG), while the audio data decoding circuit 6 performs a decompression process of the audio data. Do. These decoding circuits 4 and 6 employ a chip set composed of a dedicated LSI.
[0019]
The screen format conversion circuit 5 is a circuit for converting video data in accordance with the number of pixels that can be displayed on a predetermined display 7. For example, a display corresponding to interlaced scanning for video and audio center playback, Then, format conversion suitable for the number of screen pixels, scanning method, frame / field frequency, etc. based on a display that supports non-interlaced scanning that reproduces characters (teletext) and graphics multiplexed in the video signal is also performed.
[0020]
Hereinafter, a module of a receiving apparatus that performs hierarchical synthesis according to the present invention will be described in detail with reference to a plurality of exemplary embodiments and modifications thereof.
(First embodiment)
FIG. 2 conceptually shows the structure of a module of a receiving apparatus that performs hierarchical synthesis as a first embodiment of the present invention.
[0021]
Basically, the module according to the first embodiment includes, as shown in the figure, storage means 10 for storing input signals for each hierarchy, and storage from storage means for each hierarchy connected to the storage means 10. An output control means 20 for controlling the output of the content, and a monitoring means 30 connected to the output control means 20 and the storage means 10 for monitoring the storage state of the storage means 10 on a hierarchical basis based on a predetermined condition; Consists mainly of.
[0022]
The storage means 10 has a plurality of storage spaces for each hierarchy, and is configured so that it can be output for each hierarchy in response to a command from the output control means 20. The monitoring means 30 includes a memory capable of storing a queue. When input data is stored in a storage space of a certain level, a predetermined storage flag indicating that the input data is stored is issued. It is configured to sequentially store in a memory.
[0023]
(Operation effect 1)
When the reception signal formed and transmitted according to the hierarchical transmission method is input to the input terminal of this module on the receiving side, the storage means 10 stores this input signal for each hierarchy. On the other hand, the monitoring means 30 recognizes how and in which hierarchy a series of input signals (hereinafter referred to as data) are stored while individually monitoring the accumulated state of each hierarchy in the accumulation means 10. To do. Then, when the monitoring unit 30 sends a command to the output control unit 20 so that the reproduction is performed in the correct order, the output control unit 20 causes the storage unit 10 to generate an output signal (data stream) in the correct order.
[0024]
Specifically, for example, the monitoring unit 30 generates an accumulation flag based on a predetermined signal every time data is accumulated in the accumulation unit 10 in a certain hierarchy, and stores this in a memory in a predetermined queue form. Since the contents of this memory are stored in chronological order from the oldest to the newest accumulation flag, the order in which the series of data streams are divided and stored can be understood from the contents of this memory. Therefore, the monitoring means 30 recognizes the oldest accumulation flag in this memory and the hierarchy to which the memory belongs in the hierarchy synthesis before output, takes out the data in the accumulation means 10 of the hierarchy first, and then the next oldest Recognizing the accumulation flag and its attribute, the corresponding data is taken out one by one. If no data is stored in the storage space, a null code (“00”) is generated and output instead.
[0025]
By such control, the data separated into a plurality of layers is hierarchically synthesized into one continuous data stream, that is, a carrier signal (TS signal), and the series of the hierarchically synthesized series from the output terminal of this module. As TS signals, they are output in the correct order.
Therefore, according to the illustrated first embodiment, it is possible to provide a module that realizes hierarchical synthesis that satisfies the specifications and conditions of the digital hierarchical transmission scheme described above.
[0026]
The form illustrated in the first embodiment can be implemented as in the second embodiment described below.
(Second Embodiment)
FIG. 3 illustrates a further configuration of a module relating to the receiving apparatus of the present invention. As shown in the figure, the feature of the present embodiment is that the TSP storage buffers 11 to 14 are configured by, for example, RAM for each of the four layers 1 to 4 as storage means, and the memory for the queue is, for example, FIFO ( One monitoring unit 30 having a shift register such as First In First Out) is provided.
[0027]
Specifically, the structure of the storage means 10 includes a TSP storage buffer 11 dedicated to the first hierarchy (hereinafter abbreviated as hierarchy 1) and a TSP storage buffer 12 dedicated to hierarchy 2 as a plurality of hierarchical storage spaces. And a TSP accumulation buffer dedicated to the hierarchy 3, and a TSP accumulation buffer 14 dedicated to the hierarchy 4. Each of the TSP storage buffers 11, 12, 13, and 14 of each layer is configured by a plurality of RAMs, for example, so as to temporarily store packet data of each layer. The output control unit 20 serving as the output control unit is connected to a monitoring unit 30 serving as a monitoring unit, and controls the TSP accumulation buffers 11, 12, 13, and 14.
[0028]
FIG. 4 shows the structure of the TSP accumulation buffer, and FIG. 5 shows the structure of the FIFO.
As shown in FIG. 4, since the input data stream in units of packets is encoded with 8 bits in the case of byte multiplexing, a TSP storage area having a predetermined packet length (for example, 204 byte length) with this width, Corresponding to the byte counter of the first 1 byte, a TSP counter is added for counting the length of the TSP and the like.
[0029]
Further, as shown in FIG. 5, the monitoring unit 30 as the monitoring means has a memory for sequentially storing an accumulation flag for managing in which of the TSP accumulation buffers 11 to 14 the data classified by hierarchy is accumulated. As a means, a FIFO shift register is provided.
[0030]
In this shift register, the accumulation flag generated at the same time as the data is accumulated in the accumulation buffer of a certain hierarchy enters from the direction of the arrow IN sequentially to form a queue, but the oldest accumulation flag is changed to the arrow according to the read signal. The data is extracted in the direction of OUT, temporarily stored in a fixed register, and its contents (for example, hierarchy attributes) can be read.
[0031]
(Operation effect 2)
The second embodiment is realized by the above-described configuration and the following operation. That is, when data for 1 TSP is accumulated in each of the layers 1 to 4, a flag (storage flag) indicating the situation is generated. The monitoring unit 30 accumulates the flag output of each layer in a shift register such as a FIFO, for example, and reads the flag from the FIFO in 1 TSP cycle. At this time, if TSPs are accumulated in two or more layers, a time difference naturally occurs at the end of the accumulation. However, burst data that is not quantitatively input to the TSP storage buffers 11 to 14 of each layer is stored in any other storage buffer when the data is input to the storage buffer of a certain layer. Not entered. Therefore, TSPs are not accumulated in two or more layers at the same time. Therefore, the TSP data divided and accumulated for a plurality of hierarchies can be re-synthesized into a series of TSPs correctly following the time series, that is, “hierarchical synthesis”.
[0032]
Utilizing this fact, when the monitoring unit 30 notifies the output control unit 20 of the contents of the accumulation flag read from the FIFO, the output control unit 20 instructs to take out data from the corresponding TSP accumulation buffer according to this notification. .
[0033]
In this way, by reading the accumulation flag in order from the FIFO in the monitoring unit 30, it is possible to read the TSP of the previously accumulated hierarchy. Also, if there is no TSP in any hierarchy, no accumulation flag is output from any hierarchy and the FIFO becomes empty, so only in this case, a null packet is output as a TS signal as described above.
[0034]
As described above, according to the second embodiment, it is possible to realize layered composition that satisfies the specifications and conditions of the digital layered transmission method described above.
Further, it is possible to provide a module capable of performing hierarchical synthesis that can cope with packet data generated in a burst state by a relatively simple device operation that is not controlled by a program or the like.
[0035]
As mentioned above, although it demonstrated based on several example of embodiment, the following invention is also contained in this specification. That is,
[A] In a digital terrestrial broadcasting system that performs hierarchical transmission,
A module of a receiving apparatus that combines an input signal that has been subjected to predetermined processing for each layer into a series of transport stream signals (TS signals)
Transport stream packet (TSP) to be transmitted / conveyed ・ Storage means having a plurality of TSP storage buffers for temporarily storing data in a predetermined hierarchical unit;
Monitoring means for monitoring the storage means, setting and storing an accumulation flag indicating that data has been accumulated therein, and monitoring and managing the storage means of each corresponding hierarchy based on the contents of the accumulation flag When,
An output control means for controlling the data stored in the corresponding storage means to be output as an output signal based on a predetermined condition, based on a command from the monitoring means;
It is a module characterized by comprising.
[0036]
[B] The storage means synthesizes and outputs the TSP that has been stored separately in each hierarchy by combining the continuous TS signals by the monitoring and control of the monitoring means and the output control means. The module according to [A], which is characterized.
[C] The module according to [A], wherein the monitoring unit includes a FIFO (First In First Out) as a queuing memory.
[D] The module according to [C], wherein the queuing memory includes a shift register capable of arranging information of at least the number of layers of the TSP accumulation buffer.
[E] The TSP accumulation buffer includes a RAM,
It has at least a TSP storage area of one packet length, a byte counter that counts the byte length of actual data stored in the packet, and a TSP counter that counts the number of stored packets. It is a module as described in [A].
[0037]
[F] The flag described in [A], wherein the flag includes at least an attribute representing a storage space constituting the storage means and information indicating the presence / absence of signals / data stored in the storage space. Module.
[G] A module that performs hierarchical composition constituting a receiver used for digital television broadcasting in a hierarchical transmission system is
The module according to [A], which is at least a tuner circuit, a decoder (that is, a digital demodulation circuit), or an adapter attached to the receiver.
[0038]
[H] When performing hierarchical transmission in a digital terrestrial broadcasting system,
On the receiving side, a module that inputs a demodulated signal that has been subjected to at least demapping or time deinterleaving for each layer,
In order to output the signals in the order in which they are accumulated as signals of a predetermined unit (for example, Transport Stream Packet (TSP) signals) in each layer, a predetermined time each time one TSP is accumulated in each layer Decoding processing circuit for generating a flag, storing it in a queue, and synthesizing TSP of each layer into one continuous transport stream (TS) signal while monitoring this flag when outputting It is characterized by being.
[0039]
[I] The module for performing the demodulation process is a digital demodulation circuit,
The decoding processing circuit is at least a video data decoding circuit for hierarchically synthesizing and decoding input video data and an audio data decoding circuit for hierarchically synthesizing and decoding input audio data. The module according to [H].
[0040]
(Other variations)
In addition to the above-described embodiments, the present invention can be variously modified without departing from the spirit of the present invention. For example,
The transmission method employed by the receiving apparatus according to the present invention can be applied to the “hierarchical (orthogonal) frequency division multiplexing (OFDM)” transmission method.
Similarly, the modulation / demodulation method employed by the receiving apparatus according to the present invention can be applied to the “hierarchical (orthogonal) modulation / demodulation (OFDM)” method.
[0041]
In addition, even in the “frequency division multiplexing (FDM)” communication method, the “time division multiplexing (TDM)” communication method, the “frequency division multiplexing (FDM)” method, and the “time division multiplexing (TDM)” method, The basic method of hierarchical synthesis is applicable.
[0042]
In addition, the specifications of each component module related to the exemplified receiving device, the number of registers and memories to be used, the storage capacity, the actual device chip, etc. can be increased or decreased as necessary and various changes can be made. Any suitable combination with others is possible.
Furthermore, the combination of the receiving apparatus of the present invention and the existing broadcasting technology, the equipment used for this, etc. are not limited to those illustrated, and can be arbitrarily set and used.
[0043]
【The invention's effect】
As described above, as described based on a plurality of exemplary embodiments and modifications, according to the present invention, by sequentially reading the flag from the queue memory in the monitoring unit, the TSP of the previously accumulated hierarchy can be used. In this case, when there is no TSP in any hierarchy, no flag is output from any hierarchy, and the queue memory in the monitoring unit becomes empty. Hierarchical synthesis is performed while generating a null packet, and a series of TSPs are output. Thus, according to the receiving apparatus of the present invention, the following effects can be obtained.
(1) It is possible to provide a receiver having a module capable of hierarchical synthesis that satisfies a predetermined condition in the hierarchical transmission method of the digital terrestrial broadcasting system.
(2) Since a queue can be set and managed without requiring an exaggerated control system such as a program, the control function can be provided with a relatively simple configuration.
(3) Therefore, it is possible to reduce the size of a module that requires hierarchical synthesis and reduce its manufacturing cost, and also to easily realize structural simplification, size reduction, and weight reduction of the receiving device itself by making this module into a chip. it can.
[0044]
As described above, according to the present invention, it is possible to provide a module of a receiving apparatus capable of correctly performing hierarchical synthesis and outputting on the receiving side in the hierarchical transmission method of the digital terrestrial broadcasting system.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram illustrating a basic configuration of a receiving apparatus (digital television receiver) according to an embodiment of the present invention.
FIG. 2 is a schematic block configuration diagram showing a basic configuration of a module of a receiving apparatus that performs hierarchical synthesis as a first embodiment of the present invention.
FIG. 3 is a block configuration diagram showing a configuration of a module of a receiving apparatus that performs hierarchical synthesis as a second exemplary embodiment of the present invention.
FIG. 4 is also an explanatory diagram showing the structure of a TSP accumulation buffer of this module.
FIG. 5 is also an explanatory view showing the structure of the FIFO of this module.
FIG. 6 is a block configuration diagram showing a configuration of a module of a receiving apparatus that performs related hierarchical synthesis;
[Explanation of symbols]
1 ... antenna,
2 ... tuner circuit,
3 ... Digital demodulation circuit,
4 ... Video data decoding circuit,
5. Screen format conversion circuit,
6 ... Audio data decoding circuit,
7 ... Display,
10: Accumulation means,
11 ... TSP accumulation buffer (for layer 1 only),
12 ... TSP accumulation buffer (for layer 2 only),
13 ... TSP accumulation buffer (only for layer 3),
14 ... TSP accumulation buffer (for layer 4 only),
20 ... Output control means (output control unit),
30: Monitoring means (monitoring unit).

Claims (3)

In a receiving apparatus that is used in a digital terrestrial broadcasting system that distributes signal data to a plurality of layers and performs hierarchical transmission, and combines the signal data demodulated separately for each of the plurality of layers into a series of signal data by layer combining ,
A plurality of hierarchical spaces for storing the signal data demodulated for each of the plurality of layers by layer, and storing means for outputting the signal data from the storage space of the designated layer and performing layer synthesis ;
Output control means for outputting signal data stored in a hierarchical space of an arbitrary hierarchy from the storage means;
Monitoring means for monitoring the storage state of a plurality of hierarchical spaces in the storage means for each hierarchy ;
Comprising
The monitoring means includes memory means that can be stored in a queuing manner, and when signal data is accumulated in a storage space of a certain hierarchy, this is detected, and a predetermined meaning that it is accumulated in the storage space of the hierarchy It is configured to issue a flag and store it sequentially in the memory means. When synthesizing a hierarchy, it determines the hierarchy accumulated from the flag stored in the memory means, and the signal data of the corresponding accumulation space Notify the output control means to output sequentially ,
The receiving apparatus for performing hierarchical synthesis, wherein the output control means outputs the signal data of the storage space from the storage means based on the notification from the monitoring means . When the signal data conforms to MPEG2 ( Moving Picture Expert Group phase 2 ),
The storage means includes a plurality of storage spaces for storing the signal data by layer in units of transport stream packets defined by MPEG2.
The monitoring means outputs a data string of a predetermined unit defined as a null packet in the MPEG2 transport stream when the signal data is not accumulated in the accumulation space of all layers of the accumulation means. The receiving apparatus according to claim 1, wherein the output control means is instructed. The storage means synthesizes signal data in a plurality of storage spaces that have been stored separately for each hierarchy into continuous output signals under the control of the output control means accompanying monitoring from the monitoring means. When there is a period in which the storage space of all layers of the storage means is empty, a null data string having a predetermined unit length corresponding to this period is generated and output instead. Item 4. The receiving device according to Item 1.

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