Method and device for transmitting and receiving compressed sound signal frames with priority messages for digital sound broadcasting

FIELD: encoding technologies.

SUBSTANCE: method includes generating digital information, characterizing sound signal, estimating number of bits, distributed for digital information in modem frame, encoding digital information in estimated number of bits to produce encoded information, selected bits are deleted from encoded information, bits, appropriate for digital messages, are added to encoded information for generation of composition modem frame, bits of said composition modem frame are formatted to produce formatted bits of composition modem frame and said formatted bits of composition modem frame are transmitted.

EFFECT: higher efficiency of sound frames encoding.

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The technical field to which the invention relates.

This invention relates to methods and apparatus for transmitting and receiving digital data, and in particular to such methods and devices for use in digital audio broadcasting.

The level of technology

Digital audio broadcasting (CSV) is a means of providing digital audio signal quality, superior formats analog broadcast of the prior art. CSV signals DM and FM, you can pass in a hybrid format in which the past digital modulation signal coexists with the broadcast at this time, the analog AM or FM signal, or entirely in digital format without the analog signal. For band - in-ear (UPVC) systems CSV not require new spectrum allocations because each CSV signal simultaneously transmit in the same spectral pattern of the existing distribution of DM or FM channels. UPVC CSV helps conserve spectrum and simultaneously provides broadcasters the opportunity to provide their audience audio digital signal quality. To date, proposed several solutions UPVC CSV. One solution, according to U.S. patent No. 5558022, offers a way of simultaneously broadcasting analog and digital signals in a standard channel, AM broadcast. Soglashaetsa the decision of the first broadcast of the radio-frequency amplitude-modulated signal, having the first frequency spectrum. Amplitude-modulated radio frequency signal includes the first carrier, the modulated analog signal program. At the same time certain set of past digital modulation of the carrier signals broadcast within a bandwidth which encompasses the first frequency spectrum. Every last digital modulation of the carrier signal modulate some part of the digital signal of the program. The first group underwent digital modulation of the carrier signals is within the first frequency spectrum, and its modulate in quadrature with the first carrier signal. The second and third groups of the past digital modulation of the carrier signals outside the first frequency spectrum, and their and modulate in-phase and in quadrature with the first carrier signal. To accommodate the reported information use multiple bearing due to orthogonal multiplexing frequency division (OMCR).

Broadcasting system UPVC CSV with FM are the subject of several U.S. patents, including: No. 5465396; 5315/583; 5278844; 5278826. One hybrid signal UPVC CSV with FM combines analog modulated carrier with a certain set of orthogonal multiplexed (OMCR) frequency division subcarriers placed in the range of 129 kHz to 199 kHz, approximately, in the direction from the center of InEU FM frequency as above, and bottom of the spectrum occupied by the analog modulated main FM carrier. Fully digital UPVC CSW system eliminates analog modulated main signal, while leaving the upper subcarriers and adding additional subcarriers in the range of 100 kHz to 129 kHz, approximately, from the Central FM frequency. These additional carriers can transmit back a signal that can be used to obtain the output signal receivers in case of loss of the main, or indigenous, signal.

Digital audio broadcasting, which uses a single-frequency network or a method of filling gaps, described in "Radio Broadcasting Systems; Digital Audio Broadcasting (DAB) To Mobile, Portable And Fixed Receivers", European Telecommunications Standard ETS 300 401, Second Edition, May 1997 (1997-05). This standard describes a method of encoding a signal for a digital sound broadcasting in CSV system SFN.

One of the distinguishing features of digital transmission systems is its inherent ability to simultaneously transmit and the digital audio signal, and data. The digital audio information are often compressed for transmission over a channel with limited bandwidth. For example, it is possible to compress the digital source information stereo compact disc (CD) with approximately 1.5 MB/s 96 KB/s, while maintaining the sound quality of the evidence is automatic as the KD for UPVC CSV the world Cup. Further compression of up to 48 kbps and below can still provide a good quality stereo sound signal, which is useful for system CSV with AM or system ZZV the world Cup with a backup channel with low delay and channel settings.

Efficient compression techniques applied AC source coding with variable speed, according to which fixed time segments of the audio signal to encode digital packets of variable length, i.e. audio segments, changing “complexity” is converted into frames of the audio signal of variable length.

Frames of the audio signal generated by a standard audio coders have formats that are inefficient for transmission as signal UPVC CSV. There is a need for an effective method of transmitting and receiving compressed frames of the audio signal for a digital sound broadcasting.

The invention

This invention provides a method of transmitting compressed data for digital audio broadcasting, namely, that accept digital information characterizing the audio signal, allocate a number of bits of digital information in a modem frame encode digital information within a distributed number of bits to obtain coded data and take cyfrowy the message, characterized in that a digital message according to the priority select bits of the digital message with the highest priority, to add to the existing bits in the modem frame, add the selected bits of the digital message to the encrypted data to form a composite modem frame format bits composite modem frame for receiving the formatted bits composite modem frame and transmit the formatted bits composite modem frame.

Transmitters that transmit digital audio broadcasting signals in accordance with the above method, is also included in this invention.

The invention also includes the formats modem frame obtained by the above method, and transmitters carrying out it. Formats modem frame contain some combination of the back fields of the indigenous audio signal, the extended field of audio signal data and a header field. Each backing field of the indigenous sound signal contains a frame of the indigenous sound signal, bits control the cyclic redundancy code, the redundant header field and the bits of the alignment.

List of figures

Fig 1 - block diagram of a receiver for use in a system for digital sound broadcasting made with the possibility re the ACI signals, formatted according to this invention.

Figure 2 - functional block diagram illustrating a method of multiplexing and coding packets of audio signals and located in accordance with the priority data in accordance with this invention.

Figure 3 - block diagram of the receiver is made with the possibility of signal processing according to this invention.

4 is a block diagram illustrating part of the signal processing performed depicted in figure 3 receiver.

5 is a schematic representation of the preferred embodiments of the format of the modem frame used in accordance with this invention.

6 is a schematic representation of the preferred embodiments the backup format audio/additional frame used in accordance with this invention.

7 is a schematic representation of the preferred embodiments of the backup frame of the native sound format modem frame used in accordance with this invention.

Fig - schematic representation of the preferred embodiments of the extended field of audio signal data format modem frame used in accordance with this invention.

Fig.9 is a schematic representation of the preferred embodiments redundant header fields format m is nemnogo frame, used according to this invention.

Figure 10 - schematic representation of the preferred embodiments of the format of the indigenous modem frame used in accordance with this invention for use in the system CSV AM.

11 is a schematic representation of the preferred embodiments of the frame format of the indigenous unit of the audio signal used in accordance with this invention for use in the system CSV with DM.

Fig - schematic representation of the preferred embodiments the extended format of modem frame used in accordance with this invention for use in the system CSV AM.

Fig - block diagram of the interfaces of the data signal that can be used when applying the present invention in a receiver for use in a system for digital sound broadcasting.

Fig - block diagram of interface signal data, which can be used when applying this invention in the transmitter in the system digital audio broadcasting.

Information confirming the possibility of carrying out the invention

Referring to the drawings: figure 1 is a block diagram of the transmitter 10 ZSW made with the possibility of broadcasting digital audio broadcasting signals according to this invention. The signal source 12 provides transferable signal. IP is odny signal can take many forms, for example, the analog signal of the program, which may represent voice or music signal, and/or digital information signal, which may represent the message data, such as information graphics. The modulator 14 on the basis of the digital signal processor (PDB) processes the raw signal in accordance with various known methods of signal processing, such as source coding, interleaving and forward error correction, to obtain in-phase and quadrature components of the complex baseband signal on lines 16 and 18. Components of the signal are offset in frequency upwards, filtered and interpolate to a higher sampling rate in block 20 of the Converter with increasing frequency. Thereby receive the digital sampling frequency fson the signal of the intermediate frequency fifon line 22. D / a Converter 24 converts this signal to an analog signal on line 26. The filter 28 intermediate frequency suppresses the frequency of the spurious signal to obtain a signal fifintermediate frequency on line 30. The local oscillator 32 generates a signal floon line 34, which is mixed with the intermediate frequency signal on line 30 mixer 36 to receive the sum and difference signals on line 38. The total signal and the other of unnecessary intermodulation the e components and the noise suppressing filter 40 suppress the mirror side of the band, to obtain a modulated signal fccarrier on the line 42. The amplifier 44 high power then sends the signal to the antenna 46.

The method according to this invention provides an efficient and reliable multiplexing the compressed digital audio signal together with the data messages that must meet different requirements. the priority or urgency. The main transmission unit CSW signal is a modem frame, which lasts about one second. This duration is needed to ensure that a sufficiently long periods of alternation was able to mitigate the effects of fading or brief communication breakdowns or bursts of noise that can be expected in the system digital audio broadcasting. The delay for the main channel digital peremienko alarm can only be not less than the duration of the modem frame. But this delay is not a significant drawback, since one system UPVC CSV, which may use the present invention, already applies the method of delay diversity, which intentionally delays the digital signal for a few seconds with respect to the analog signal. CSW system using a temporary separation, is described in U.S. patent No. 6178317. Analog or digital signal with a time spacing provide for capture signal through would be the Troy settings. Therefore, the main digital audio signal is processed in blocks of modem frames, and any processing of the audio signal, the smoothing errors and coding techniques should use this relatively significant time modem frame without additional losses.

The format Converter you can use to Repack compressed frames of the digital audio signals more efficiently and securely send and receive UPVC signal over the air. Standard commercially available encoder audio signals may first form a compressed frames of the digital audio signals. Converter input format removes unnecessary information from the frames of the digital audio signals generated by the encoder of the audio signals. This unnecessary information includes timing information frame and also any other information that can be deleted or modified for the transmission of audio signals CSV, without compromising the sound information. Assembler modem frame UPVC CSV reintroduces timing information in a way that is more efficient and reliable for delivery CSV. The format Converter in the receiver restored original frames of the audio signals to be decoded by a standard decoder beeps.

Both systems UPVC CSV and FM, and AM once escaut digital audio signal and data in blocks of modem frames. Both systems are simplified and improved by assigning a fixed number of frames of audio signals each modem frame. The scheduler determines the total number of bits allocated for the frames of the audio signals in each modem frame. The coder of the audio signal and then encodes frames of audio signals by allocating bits for this modem frame. Other bits in the modem frame are multiplexed data and additional bits.

Functional block diagram of the process of compiling the modem frame is presented in figure 2. Depicted in figure 2 functions can be performed in block 14, depicted in figure 1. In this embodiment, the implementation of this invention, the left and right audio programming signals CSV served by lines 50 and 52. Data messages (also called “auxiliary data”) with different levels of priority are served on lines 54, 56 and 58 and memorize the buffers 60, 62 and 64. The algorithm 66 dynamic scheduling or scheduler coordinates the preparation of the modem frame to the encoder 68 of the audio signal. The number of auxiliary data that can be transmitted is determined by several factors. In a preferred implementation, the encoder of the audio signals of first looking at the audio content of the audio information in the buffer 70 frames of the audio signal is fishing, which stores audio information transmitted in the next cycle modem. This view do for the purpose of evaluation or “entropy” of audio information for this modem frame as illustrated by block 72. This estimation of entropy can be used to predict the number of bits required to provide the desired sound quality. Using this estimate of the entropy on line 74, together with the number and prioritized data message buffers 60, 62 and 64, the dynamic scheduling algorithm allocates the bits in the modem frame between the data and an audio signal.

After allocating a certain number of bits for the next modem frame encoder encodes audio signals all frames of audio signals (e.g., 64 frames of audio signals) for the next modem frame, and transmits its result to the inverter 76 of the frame format of the audio signals. The actual number of bits used by the frame of the audio signals represent the scheduler on line 78 so that he could best use of unused allocation of bits, if any. The format Converter frame of the audio signals removes all header information and additional bits and sends thus obtained processed frames of the audio signals in the block 0 of the function, format and preparation of the modem frame.

The dynamic scheduling algorithm, or the scheduler can generally work as follows. First, if any of the data message is not received, the scheduler distributes the entire capacity of the regular modem frame for compressed audio signal. The result often turns out a greater number of bits than required to provide the desired sound quality. Secondly, if you have only messages of low priority, then the capacity of the modem frame more than the required number of bits for the audio signal to distribute messages (data). In the result, no loss of sound quality compared with the desired quality. Thirdly, if you have messages of high priority, the scheduler must make a compromise between quality of the audio signal and timely delivery of messages high priority. This compromise can be estimated using the cost function given the implied importance of the message, in relation to a possible reduction in sound quality. The transmitted messages can be choose by sending a signal on line 82 to the multiplexer 84 data packets.

From the point of view of broadcasters messages with a higher priority is associated with a gradual increase in the cost, because the quality of the audio signal m which may gradually get worse. From the point of view of the user data or message prioritization of messages may also be based on cost functions to compensate for broadcasters loss in the quality of the audio signal. This cost function can be the actual cost. For example, the actual custom shipping cost of the package can be doubled for each increase priority class. This can be an effective tool to increase the fees charged to users who agree to pay for the higher rated if the message data is considered to be urgent. Or prioritization can be based on the type of messages that are generated by the broadcaster. And in fact, in another case, the assignment of priorities is self-regulating, and higher priority is prescribed with caution because it has been some increase in cost to the user, and for broadcasters. Of course, the broadcaster will assign rules and the relevant cost function to its net profit, while providing its users and listeners most efficient service.

Function format and preparation of the modem frame and places the information frame of the audio signal in data packets in a modem frame. Header information includes the size and location of the frames of audio signals, which was only removed in the Converter frame format sounds, again enter into the modem frame is redundant, but effective, way. This re-formatting improves the reliability of the signal UPVC CSV transmitted over the air, which is less than reliable. For transmission in a fully digital mode UPVC CSV also form a backup frames according to the data received on line 86. Reserve personnel can provide spaced in time, the excess signal in order to reduce the likelihood of interruption of transmission, disappears if the main signal. During normal operation, the backup frames are combined using the code from the main channel to provide a more reliable transmission of data in terms of fading. Analog signal (AM or FM) is used instead of reserve personnel in hybrid UPVC system.

The receiver performs the conversion of some of the features described in relation to the transmitter. Figure 3 is a block diagram of a radio receiver 88, made with the possibility of signal processing according to this invention. CSV-the signal is received by the antenna 90. Band-pass filter 92 preliminary selection skips the desired band of frequencies including the desired signal at frequency fwithbut suppresses the mirror sideband frequencies fc-2fif(for lo, which introduces low side lobe). Low noise at elitel 94 amplifies the signal. The amplified signal is mixed in the mixer 96 with the signal flolo, directed along the line 98 tunable local oscillator 100. This creates total (fc+flo) and difference (fc-flosignals on line 102. The filter 104 intermediate frequency passes a signal fifintermediate frequency and attenuates frequencies outside the bandwidth of the desired modulated signal. Analog-to-digital Converter 106 operates using a clock signal fsto obtain digital samples on line 108 with the sampling frequency fs. Digital Converter 110 with decreasing frequency shifts the frequency filters and thins signal to obtain in-phase and quadrature signals with a lower frequency of sampling on lines 112 and 114. The demodulator 116 on the basis of the digital signal processor then performs additional signal processing to produce an output signal on line 118 to the output device 120.

Figure 4 is a block diagram illustrating demodulation modem frame of the audio signal and the data performed in the receiver 3. Inverse assembler 122 frames takes to be processed, the signal on line 124 and performs all necessary operations of the inverse interleave, combining codes, decoding with direct error correction (PIO), and flag errors audio information and info the information data in each modem frame. Data, if any, is treated in a separate tract on the line 126 from the sound signal on line 128. Then route data, as shown in block 130, the corresponding data service. Queuing priority data is a function of the transmitter, not the receiver. Sound information from each modem frame is processed by Converter 132 format, which places the sound data in the frame format of the audio signals that are compatible with the corresponding decoder 134 audio signal, which provides left and right output audio signals 136 and 138.

In one type of hybrid system CSV with FM: analog modulated carrier combined with a set of orthogonal multiplexed (OMCR) frequency division subcarriers in the range from 129 kHz to 199 kHz, approximately, from the Central FM frequencies above and below the spectrum occupied by the analog modulated main FM carrier. According to a fully digital version of the analog modulated main signal is removed, leaving the upper subcarriers and adding additional subcarriers in the range from approximately 100 kHz to 129 kHz above and below the Central FM frequency. These additional carriers can transmit back a signal that can be used to obtain the output signal is Ramnicu in case of loss of principal, or indigenous, signal.

To ensure efficient and reliable communication system UPVC CSV are different formats of frames. Moreover, the formatting of frames provides an important indication of this technical solution, including the passing time, rapid setup channel, multi-level combining codes PIO between the main and backup channels, redundant header information (one of the types of unequal error) and flexible bandwidth allocation between frames of the audio signal and the message data. Many signs of frame formats designed for fully digital system UPVC CSV the world Cup. FM formats hybrid frames are designed so that they are compatible with a fully digital FM formats.

According to figure 5 modem frame 140 of the main channel consists of a set of 8 backup fields 142 indigenous beep (Sah), additional extended field 144 of the audio signal data (EAD) and redundant fields 146 header (RH). Modem frame of the main channel contains audio information for 64 frames of audio signals, together with some capacity dynamic data. According to a preferred variant implementation of the invention, the size of the modem frame is 18432 bytes after encoding with reed-Solomon code (PC). The number of input b is itov for variants encoding the RS(144100), RS(144136) and RS(144132) is 17920, 17408, and 16896 bytes, respectively.

This modem frame is first processed by the encoder reed-Solomon and then treated using functions forward error correction (PIO) and alternations. The frequency steps of the encoder reed-Solomon determines the exact number of bytes that make up the modem frame before encoding PIO. It should be noted that according to a preferred variant of this invention, the code word reed-Solomon code to encode systematically in such a way that the parity symbols are at the front of information symbols. Due to this byte alignment (absolutely zero) remains as the last byte, the present inner convolutional encoder. Redundant header field is at the end of the modem frame, so you can encode a separate code word reed-Solomon code.

The format for backup audio/additional frame 148 is fully digital UPVC system CSV depicted in Fig.6. Each backup audio/additional frame contains backing field 150 of the audio signal, additional field data 152, 154 bytes control the cyclic redundancy code and byte 156 alignment. Apply two modes of action: backup mode indigenous audio signal with a data rate of 24 kbps and backup mode indigenous sound the new signal with a rate of 48 KB/s Although each frame Sah contains 8 fields of the audio signal of variable length, but the total length of the combined fields Sah is constant.

8 back[ fields SAO - USA indigenous beep modem frame of the main channel are redundant with the same fields 142 backup/sound extra frame (BAS) 148. But back frames fully digital system UPVC CSV passed a few seconds after transmission of the corresponding modem frame. Reserve personnel deliberately delayed in order to introduce temporary explode. This delay is temporary spacing is an integer modem frames. In contrast, the receiver processes the backup footage with speed, need for quick settings. The receiver aligns in time field Sah in modem frame with redundant fields Sah back in the frame by the appropriate delay audio information in a modem frame.

After alignment of fields Sah in modem frame and fields Sah back in the frame aligned to the time field of ICA combined with convolutional codes in the decoder of the receiver. According to one implementation options of the receiver using the signal processing in accordance with this invention the outer PIO using reed-Solomon code is used for a digital signal, then vypolnyayutsya convolutional PIO to interleave and subsequent transfer. It is important that the field of ICA was coded exactly in the same sequence using codes and external, and internal PIO to provide the possibility of combining the code with the division. This ensures reliable performance tuning and backup channel, even when the modem frame, and backup audio/additional frames partially destroyed. According to a preferred variant implementation of the invention field of the ICA contain native backup audio signal having a data rate equal to or 24 kbit/s or 48 KB/s on the choice of broadcasters.

Backup audio/auxiliary frame Wash passed on back of subcarriers of the channel during each of a pair of blocks of the interleaver for the duration of the modem frame. Additional field data bytes control the cyclic redundancy code and alignment transfer only in the standby mode indigenous sound signal with a speed of 24 KB/s Additional data field to replace the additional audio information in the backup mode of the indigenous audio signal with a rate of 48 KB/s According to a preferred implementation variant, the frame BASx contains 1152 bytes (after encoding with reed-Solomon code) 8 code reed-Solomon's words. Each field Sah contains 576 bytes (after encoding with reed-Solomon code) on the I-mode with a speed of 24 KB/s, 4 code words reed-Solomon, or 1152 bytes (after encoding with reed-Solomon code) for a mode with a speed of 48 kbps, 8 code reed-Solomon's words. Additional data field contains 576 bytes (after encoding with reed-Solomon code) for a mode with a speed of 24 KB/s, 4 code reed-Solomon's words. Mode with a speed of 48 kbit/s additional data field is absent. Bytes control the cyclic redundancy code and the alignment used in the modes at 24 KB/s, but not in the mode with a speed of 48 KB/s Backup mode of the audio signal at 24 KB/s allows you to enter additional data field with a capacity of about 24 KB/s This field is intended for use as an independent service broadcasting messages or delivery of packet data. Timesync at this level provides bandwidth for additional data, which will have its own format/Protocol in the additional data field.

The format for backing field 142 indigenous beep (Sah) is shown in Fig.7. The length of this field is determined by the choice of two backup modes. Backup mode with a speed of 24 KB/s is designed to provide a mono backing of a sound signal with a bandwidth of about 6 kHz, while the alarm is in the backup mode with a speed of 48 kbps is stereo or mono with a bandwidth of about 10 kHz. Field Sah contains 8 frames 158 audio signals, each of which has a variable length field 160 header (NSA), 162 bytes alignment and possibly a spare box 164. Spare field contains any bytes remaining after the distribution of frames of the audio signals. Each frame of the audio signal contains a frame 166 (Sakh) indigenous digital audio signals and byte 168 control the cyclic redundancy code. But the total length field 142 Sah is constant. Therefore, the coder of the audio signal to assign a fixed number of bytes to encode each group of 8 frames (Sakh) indigenous audio signals.

One of the back fields Sah indigenous sound signals (x=0 to x=7) redundantly transmit to the backup sub-channel for each block (0 to 7) of the modem interleaver frame. 8 frames Sah also passed as part of the modem frame. According to a preferred implementation variant of the present invention, each field Sah contains 576 bytes (after encoding with reed-Solomon code) for a mode with a speed of 24 KB/s, 4 code words of reed-Solomon and 1152 bytes (after encoding reed-Solomon) mode with a speed of 48 kbps, 8 code words. Frame Sakh indigenous sound signal contains a certain number of frames of the audio signals of variable length of bytes (up to coding using the code reed-Solo is she in the fields of Sah, these fields Sakh headers, ordered to better hide errors. Also contains a one-byte (before encoding with reed-Solomon code) control the cyclic redundancy code, and single-byte (before encoding with reed-Solomon code) field alignment to perform alignment in the Viterbi decoder. Title NSA is 8 bytes (before encoding with reed-Solomon code) and specifies the size of each of the 8 fields Sah.

Advanced format sound field signal/data (EAD) 170 presents on Fig. EAD is passed into the modem frame and it contains information expansion of the audio signal for 64 frames of the audio signal. EAD contains a field 172 header, a set of extended field 174 of the audio signal, each of which contains an enhanced audio (Eax) 176 and 178 bytes control the cyclic redundancy code field 180 data, one byte 182 control the cyclic redundancy code and 184 bytes alignment. In a preferred embodiment, the implementation of EAD contains 13680 bytes (PC after encoding) backup mode with a speed of 24 KB/s with 95 PC code words and 9072 bytes (PC after encoding) backup mode with a speed of 48 KB/s 63 of the code words. 64-byte (to PC-encoding) header 166 specifies the size of each of the 64 fields Eax 168. Field Eax contain inform the widespread expansion of the audio signal to improve the quality/increase the speed of the native signal. The number of bytes (up to PC-coding) in each field Eax specified in the header, x=0, 1, 14, ... (7*l mod 64) for k=0 to 63, and they are ordered to mask errors. Each extended field of the sound signal contains a portion 170 with the data and byte 172 control the cyclic redundancy code. If the scheduler determines that the data are bytes, then the data can be placed in field 174 data byte 178 control the cyclic redundancy code. Single-byte (to PC-encoding) box 178 zero alignment is used to align the Viterbi decoder. Field EAD contains additional audio information, and therefore, in combination with the fields of the indigenous sound signal corresponding modem frame provides the sound quality is actually at the level of the compact disc (CD).

Extended field of audio signal data contains a field 172 header, a set of extended Field 174 of the Audio Signal, each of which contains the audio portion (Eax) 176 and 178 bytes control the cyclic redundancy code field 180 data and 184 bytes alignment. Format 146 redundant header fields (RH) is shown in Fig.9. This field contains redundant information about the size (or location) field of the sound signal. It contains redundant field 172 header (NEA), headers (Nsah) 186 indigenous sound signal, byte 188 to the control of the cyclic redundancy code and byte 190 alignment. Redundant header field contains header information for 64 frames of the audio signal in this modem frame. According to a preferred implementation variant of the present invention redundant header field contains 144 bytes (after encoding with reed-Solomon code) in a code word. NEA contains 64 bytes (before encoding with reed-Solomon code)indicating the size of each of the 64 fields Eax, and is redundant with the field of NEA in the frame EAD. The title of the indigenous sound signal contains 64 bytes (before encoding with reed-Solomon code) 8 headers, duplicate of the ICA. Single-byte control the cyclic redundancy code include all headers. Field alignment contains 15-R zero byte (before encoding with reed-Solomon code), where P is an even number of bytes for the implementation of the alignment Viterbi decoder. This redundancy provides additional protection from damage important header information. Extended headers (NEA) 166 audio signals transmit in two locations in this modem frame (i.e. the field of RH and 8 fields NSA). Headers 182 indigenous audio signal passed at three locations (i.e. RH and 8 fields NSA in this modem frame, in addition to the 8 fields NSA back in extra frames (BAS) audio signal completely is the or system UPVC CSV). Header information NEA contains 64 bytes (up to PC-encoding)specifies the size of each of the 64 fields Eax excessively field with NEA in the frame EAD. Headers indigenous beep contain 64 bytes (up to PC-encoding) with eight titles, duplicate of the ICA. Field RH contains 144 bytes after PC-encoding with one PC-a code word. Field RH also contains 184 bytes control the cyclic redundancy code field 186 alignment. The number of bytes field alignment depends on the number of parity bytes (R) encoding with reed-Solomon code. In particular, the number of bytes alignment is 15-R.

According to a variant implementation of the invention, is particularly appropriate systems CSV AM, share data on Indigenous Data or Data Extensions, depending on the requirements for good reception. Modem Frame 192 CSV AM, illustrated in figure 10, contains a set of 8 Backup fields 194 Indigenous Audio Signal, the Extended field 196 Audio Signal Data and field 198 Redundant Header according to the scheme of figure 10. Each Backing field of the Indigenous Sound Signal contains a group of 4 Frames Indigenous Sound Signal, and each field of ICA allocated a fixed maximum size. Full Modem Frame is sent to the Encoder SRTCM, and then treated with funk the s alternation.

The format of the Block 194 Indigenous Beep (CAB) Indigenous Modem presents figure 11. Each CAB contains the header 200, four frame 202 Indigenous Audio Signal, each of which has a byte 204 control the cyclic redundancy code, a spare block 206 and field 208 alignment. Eight frame Sawh passed as part of the indigenous modem frame. According to a preferred implementation variant, each field Sawh until the coding is 460 bytes. Title NSA has four bytes indicating the size of each of the four fields of the Mar. Frame Sakh indigenous sound signal contains specified in the header Sakh a certain number of bytes of frames of the audio signal of variable length. Control the cyclic redundancy code is a single byte. Block 206 represents the remaining spare bytes (if any) after the distribution of frames of the audio signal. Block 208 alignment represents six bits zero data used for alignment in the Viterbi decoder.

The Audio encoder Signals, depicted in figure 3, assign a certain number of bits for the next Modem Frame (Indigenous or Extended). This Encoder Audio Signals encodes all Frames of Audio Signals (e.g., 32 frame audio signals) for the next Modem Frame, and sends its result is Converted into Atwater Frame Format of the Audio Signals.

Indigenous Modem format CSV with DM contains information indigenous sound signal for 32 frames of the audio signal, together with a certain amount of dynamic data. Indigenous Modem Frame comprises spaced in time primary and backup components. In the preferred implementation according to this invention the size of the Native Modem Frame is 30000 bits (3750 bytes) to encode. Sawh (from x=0 to x=7) is the indigenous blocks of the audio signal from CSBO to CSB7, each of which contains 460 bytes.

Eight fields of the Indigenous Audio Signal from SAVO on SAV Modem Frame transmit redundantly as posted in time Main and Backup components. These Main and Backup elements form during PIO and alternations. Reserve component Fully Digital UPVC system passed a few seconds after transmission of the corresponding Primary component of the Indigenous Modem Frame. Reserve component intentionally delayed in order to introduce explode in time. This delay diversity is an integer of Indigenous Modem Frames (e.g., 3). In contrast, the receiver processes the Backup component with the appropriate speed to provide quick setting. The receiver does the reverse alternation Back and the Main composition of the managing Indigenous Modem Frame, resulting in these components, if any, are combined using the code, taking advantage of the increased diversity and metric evaluation.

The format of the extended Modem Frame (EMF) 210 presents on Fig. Each frame EMF contains the header 212, the combination of the Extended fields of the Sound (Eax), each. of which is 216 bytes control the cyclic redundancy code, a spare block 218 and field 220 alignment. This frame contains additional audio information, with the result that he, in conjunction with Indigenous Sound Signal corresponding Indigenous Modem Frame provides higher quality sound signal than in the case when using only Indigenous Beep.

Advanced modem frame contains extended information of the audio signal for 32 frames of the audio signal plus data, if any. In the preferred implementation of advanced modem frame contains 22800 bits (3360 bytes). The header 212 NEA contains 32 bytes indicating the size of each of the 32 fields Eax. Field Eax contain extended information of the audio signal to improve the quality of indigenous beep and have a variable size. Provide single-bit control the cyclic redundancy code. Block 218 contains spare bytes, studies the after distribution of frames of the audio signals. A one-byte field alignment, consisting of zeros, is provided to align in the Viterbi decoder.

The scheduler arranges the incoming received priority and packaged in accordance with predetermined rules. The simplest algorithm simply places the packets of the message with the highest priority queue in chronological order for each priority class. This algorithm ensures that messages with a higher priority will be given to any messages of lower priority waiting in the queue, and that the chronological order will ensure justice in each priority class. It also ensures that the message with the highest priority will be sent with the shortest possible delay of the current planning algorithm. But this planning algorithm does not guarantee that messages will be delivered in guaranteed terms for each priority class. It is also possible that the message of any priority, not the highest, will be in the queue indefinitely, will continue until the formation of a new message with the highest priority.

To ensure efficient and reliable communication system UPVC CSV are different formats of frames. Moreover, the formatting of frames provides an important indication of this technical solution, including temporary posted the e, quick setting of channel, multi-level combination code PIO between the main and backup channels, and flexible bandwidth allocation between frames of the audio signal and the message data. Many signs of frame formats designed for fully digital system UPVC CSV the world Cup. Hybrid formats frame with AM also compatible with all digital formats with AM.

Fig is a block diagram of the interfaces, advanced audio encoding signal (AAS) UPVC CSV in the receiver made in accordance with this invention. The incoming signal supplied from terrestrial sink interface on line 122. Inverse assembler 224 modem frame separates the data from the coded edge information of the frame and audio information. Data is sent through line 226 to the router 228 data, which sends data at various destinations along the line 230. Boundary and sound information is available on lines 232 and 234 in the Converter 236 format, which converts the signal into a standard bit stream AAS on line 238. Then the standard AAC decoder 240 decodes the sample audio signal.

Fig is a block diagram of the interface AAS/UPVC CSV in the transmitter made in accordance with this invention. The stream audio signals of the modem frame serves on line 242 in the AAC encoder 244. First, the AAC encoder generates C is cash entropy on line 246 to the distributor 248 data modem frame. The scheduler 250 data delivers data with different priorities in the dispenser data modem frame lines 252. Then the distributor 248 data modem frame generates a signal distribution of the bits on lines 254, and then the AAC encoder generates a bit stream audio signals of the AAS on line 256. The Converter 258 format converts a standard bit stream AAC encoded in the boundary information of the cycle frame 260, and encoded audio information frame on line 262. On line 264 also provide a signal to change distribution, which allows the dispenser data modem frame to distribute the data on line 266 in accordance with the signal changes of the distribution. Assembler 268 modem frame accepts coded edge information of the frame encoded audio information frame and the data distributed in accordance with signal changes in the distribution to get the modem frame, which derive in the ether interface on line 270.

The scheduler arranges the incoming received priority and packetized messages according to certain rules. The simplest algorithm simply places the packets of the message with the highest priority queue in chronological order for each priority class. This algorithm ensures that messages with a higher priority will be lane is given to any messages of lower priority, waiting in the queue, and that the chronological order will ensure justice in each priority class. It also ensures that the message with the highest priority will be sent with the shortest possible delay of the current planning algorithm. But this planning algorithm does not guarantee that messages will be delivered in guaranteed terms for each priority class. It is also possible that the message of any priority, not the highest, will be in the queue indefinitely, will continue until the formation of a new message with the highest priority.

In order to guarantee the delivery time for each priority class, you can use more sophisticated algorithms for dynamic scheduling. Some mechanism flow control can also exclude the reception of messages in the queue of a given priority class if it is full. At least the user knows, guaranteed or not delivery time. If a specific priority class is full, the user can schedule your message in a different priority class for a different cost. One of the advantages of this algorithm is that it eliminates the hang of messages of a lower priority, when continuously form the messages of higher priority. In addition, the user pays only for the service, to the / establishment, which he receives. Therefore, there is considerable flexibility in the choice of the planning algorithm with the corresponding value functions that allow broadcasters to optimize their services.

This invention provides a reliable method of Multiplexing and transmitting compressed frames of the digital audio signal together with the packet of digital data in a modem frame systems in-band co-channel (UPVC) digital audio broadcasting (CSV). This method is designed so that minimal negative impact on the quality of the digital audio signal, and this leads to maximum throughput according to many posts with different assigned priorities. This invention provides a mechanism for flow control with optimal compromise assigned priority class of the data packets in relation to the quality of the audio signal. Planning algorithm for different packet priorities multiplexes the data packets together with the coded packets of the audio signal when the modem frame. In addition, the converters of the frame format of a sound signal are used to provide transmission reformatted total compressed frames of the audio signal in a modem frame CSV understandable to the decoder of the audio signal. But on the encoder SV is the same signal, certain restrictions apply. These restrictions encoder relate to the allocation of bits to different groups of frames of the audio signal. The new formatting of frames enables transfer with separation in time of the sound information and also combining codes PIO spaced in time of the audio segments in a fully digital system. This characteristic, related to the passing of time, and its compatibility also provide a hybrid system that uses an analog signal as spaced in time backup signal in accordance with the application for U.S. patent No. 08/947902 from 09 October 1997, assigned to the assignee of this invention.

This invention provides the ability to use standard encoder for advanced encode the audio signal (AAS) in the transmitter of the digital audio signals. In the illustrated preferred embodiment, the implementation of the transmitter perform individual formatting modem frame out of the encoder. Similarly, in accordance with a preferred implementation of the receiver perform reverse-engineer, disassemble modem frame to use standard AAC decoder for decoding samples of the audio signal.

Although this invention is described relative to preferred embodiments, the specialists in this area and equipment will be clear, in the disclosed embodiment, the implementation can be done in various modifications without going beyond the scope of the invention expressed in the claims.

1. The mode of transmission of compressed data for a broadcasting system for digital audio signals, namely, that accept digital information characterizing the audio signal, allocate a number of bits of digital information in a modem frame, encode digital information in a distributed number of bits to obtain coded data, and receive digital messages containing auxiliary data, characterized in that

remove unnecessary bits of information from coded data

feature in accordance with the priority digital messages

choose the bits of the digital message with the highest priority, to add them to the available bits in the specified modem frame,

add the selected bits of the specified digital messages with the highest priority, to the specified encoded data to form a composite modem frame,

introduce additional redundant data frame bits in the specified composite modem frame for receiving the formatted bits composite modem frame and

transmit the formatted bits composite modem frame.

2. The method according to claim 1, trichosis fact, when allocating a number of bits of digital information in a modem frame additionally

remember the specified digital information in the buffer and

estimate the entropy of a specified digital information.

3. The method according to claim 1, characterized in that it further multiplexers these digital messages and enter multiplexed digital messages in the specified data of a composite frame.

4. The method according to claim 1, characterized in that the specified modem frame further comprises a fixed number of frames of the digital audio signals, in this case frames of the digital audio signals have a variable length.

5. The method according to claim 1, characterized in that in the encoding specified digital information in the estimated number of bits to obtain coded data is additionally placed bits of digital information in the aggregate backup frame and extended frame of the audio signals.

6. The method according to claim 5, characterized in that the bits of digital information in the backup frame and extended frame of the audio signal is additionally placed for the next code combination.

7. The transmitter (10) digital sound broadcasting containing means (14) for receiving digital data characterizing the audio signal, allocating a number of bits for digital devices with the new information in a modem frame, encoding digital information in a distributed number of bits to obtain coded data and receive digital messages containing auxiliary data, characterized in that it contains

means (76) remove unnecessary bits of information from coded data

means (66) the location of the digital messages in accordance with priority

means (84) selection bits of the digital message with the highest priority, to add them to the available bits in the specified modem frame,

means (80) to add selected with the highest priority, these bits of digital messages to the specified coded information, for forming a composite modem frame for the insertion of additional redundant data frame bits in the specified composite modem frame for receiving the formatted bits composite modem frame, and

means (46) transmitting the formatted bits composite modem frame.

8. The transmitter according to claim 7, characterized in that the means of receiving digital information further comprises

means (70) for storing digital information in the buffer, and means (72) to evaluate the entropy of digital information.

9. The transmitter according to claim 7, characterized in that it further comprises means (84) for multiplexing digital messages and is edenia multiplexed digital messages in the specified data of a composite frame.

10. The transmitter according to claim 7, characterized in that the specified modem frame further comprises a fixed number of frames of the audio signal, while the frames of the audio signals have a variable length.

11. The transmitter according to claim 7, characterized in that the means of encoding the specified digital information in the estimated number of bits to obtain the encoded data further comprises means for placing reserve personnel specified digital information for transmission in the specified composite modem frame.

12. The transmitter according to claim 11, characterized in that the bits of digital information in the backup frame and extended frame of the audio signal is additionally posted for next code combination.



 

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