WO2013023600A1

WO2013023600A1 - Method and device for transmitting and receiving service description information in digital audio broadcasting system

Info

Publication number: WO2013023600A1
Application number: PCT/CN2012/080183
Authority: WO
Inventors: 邹峰; 李锦文; 申红兵; 杨明; 邢观斌; 高鹏; 雷文; 冯昂
Original assignee: 国家广播电影电视总局广播科学研究院; 北京泰美世纪科技有限公司
Priority date: 2011-08-17
Filing date: 2012-08-15
Publication date: 2013-02-21
Also published as: CN102957650B; CN102957650A

Abstract

Disclosed are a method and device for transmitting and receiving service description information in a digital audio broadcasting system. When transmitting, a code scrambling, forward error correction coding, bit interleaving, and constellation mapping are performed in sequence on the service description information to acquire a modulation symbol. The modulation symbol is placed in accordance to the distribution pattern thereof on a predetermined symbol and a carrier thereof in the residual capacity of a system on the basis of the structure of a system frame, and is multiplexed with other signal elements into a frequency-domain signal, then the frequency-domain signal is converted into a time-domain signal for transmission. When receiving, the time-domain signal is converted into the frequency-domain signal while an effective carrier is demultiplexed therefrom, then a service description information symbol distributed is extracted from the effective carrier on the basis of the structure of the system frame, and a demapping, deinterleaving, forward error correction decoding, and descrambling are performed in sequence to acquire the service description information. Employment of the present invention improves the credibility of transmitting the service description information symbol in the residual capacity, and provides the digital audio broadcasting system with an enhanced guarantee in supporting rich program contents and flexible service modes.

Description

Method and device for transmitting and receiving service description information in digital audio broadcasting system

The present invention relates to the field of digital audio broadcasting technologies, and in particular, to a method and a transmitting and receiving apparatus for transmitting and receiving service description information in a digital audio broadcasting system. Background technique

The digital audio broadcasting system has the characteristics of high spectrum utilization, wide coverage, and rich program content. In order to provide better quality of service and user experience, digital audio broadcasting typically supports multiple business models including data services and audio services. Therefore, only efficient and reliable service description information symbol transmission mechanism can meet the needs of multi-channel audio data multiplex broadcasting. Different from the main service data, the error-free probability of the service description information symbol is higher, and the service description information symbol also occupies part of the transmission channel of the main service data, thereby reducing the transmission efficiency of the main service data.

Currently, existing digital broadcasting systems, such as DAB-T, DRM, HD-Radio, and CMMB, have their service description information symbols placed in the residual capacity of the primary service rate matching, which effectively solves the service description information symbols and The problem of sharing the transmission channel between the main services.

However, in the current systems, the service description information symbols are in a centralized manner, and time and frequency diversity cannot be effectively utilized, and the reliability of the service description information symbols is not high.

Summary of the invention

In view of this, it is a primary object of the present invention to provide a method and apparatus for transmitting and receiving service description information in a digital audio broadcasting system, which improves the reliability of transmitting service description information symbols within a residual capacity.

To achieve the above objective, the technical solution of the present invention is implemented as follows: The following steps are included on the transmitting end: A. The service description information to be sent is sequentially subjected to scrambling processing, forward error correction coding processing, bit interleaving processing, and constellation mapping. Processing, obtaining a modulation symbol of the service description information; B, according to the system frame structure, placing the modulation symbol of the service description information in a distributed manner on a predetermined symbol and a carrier thereof in the residual capacity of the system; C, step B The processed symbol sequence and other signals of the system The elements are multiplexed to form a frequency domain signal of an Orthogonal Frequency Division Multiplexing (OFDM) structure, and then the frequency domain signal is converted into a time domain signal for transmission.

Specifically, the system frame structure includes a superframe, a frame, a subframe, and an OFDM symbol; each superframe is divided into 4 frames, each frame is divided into 4 subframes, and each subframe is divided into 57 OFDM symbols. Each OFDM symbol has 242 effective carriers; or, each superframe is divided into 4 frames, and each frame is divided into 4 frames.

II

Each subframe is divided into 112 OFDM symbols, and each OFDM symbol has 122 effective carriers; or, each superframe is divided into 4 frames, each frame is divided into 4 subframes, and each subframe is divided into 4 subframes. There are 62 OFDM symbols, and each OFDM symbol has 242 active carriers.

The step B specifically includes: Step B1, constructing a subcarrier matrix M with a row number of ⁴ * and a column number of *, wherein the V is the number of OFDM symbols in each subframe, and the number of valid subcarriers is ^Λ ^ is the number of interleaved blocks; the number of rows and the number of columns of the subcarrier matrix are counted from 1; the subcarrier matrix is equally divided into rows from top to bottom and left to right as ^ V , number of columns For the submatrix", ie:

M" = (m ,

·> Among them. _{w X} w

= l, 2, - - - S _N , b Step B2, in the subcarrier matrix M, starting from the submatrix 1 of the first column on the left, placing the service in order from the top to the bottom of each column a modulation symbol describing the information; wherein, for any sub-matrix ^Μ ", the modulation symbols of the service description information are all placed in the 1st to Ns _DISn rows of the ^M ", in the +1st row of the ¹ " The modulation symbol of the service description information is placed in the second to ^^^ column, and the sum ^N SD is a system setting value.

The receiving end includes the following steps: a, converting the time domain signal into a frequency domain signal; b, extracting distributed service description information symbols from the effective carrier of the frequency domain signal according to the system frame structure, and generating the existing information in the constellation space Demodulating the signal; c. sequentially de-mapping, de-interleaving, forward error-correcting decoding, and descrambling the demodulated signal to obtain service description information.

In step b, the effective carrier is detected by using a diversity method including frequency domain diversity and time domain diversity, and distributed service description information symbols are extracted from the system frame structure, and generated in the constellation space. Demodulated signal.

The step c specifically includes: sequentially de-mapping and de-interleaving the demodulated signal to obtain Soft information of frequency diversity and time diversity; decoding the soft information by forward error correction decoding, aggregating frequency diversity and time diversity into system gain, outputting a decoded bit stream; descrambling the decoded bit stream to obtain Business description information.

The device for transmitting service description information in the digital audio broadcasting system of the present invention includes: a scrambler configured to perform scrambling processing on the service description information to be transmitted and output the information bit stream to the encoder; and an encoder for inputting The information bit stream is encoded, and the encoded bit stream is output to the interleaver; the interleaver is configured to reorder the input encoded bit stream according to a predetermined rule and output the same to the mapper; the constellation mapper is configured to pass the encoded bit stream through the constellation Mapping the modulated symbols and outputting them to the multiplexer; the multiplexer is configured to: according to the system frame structure, the modulation symbols of the service description information are placed in a distributed manner on a predetermined symbol and a carrier thereof in the residual capacity of the system, and It is multiplexed with other signal elements of the system to generate a frequency domain signal and output to a frequency-time domain converter; a frequency-time domain converter is used to obtain a time domain signal by frequency-time domain transform of the frequency domain signal.

The apparatus for receiving service description information in the digital audio broadcasting system of the present invention comprises: a time-frequency converter for converting a time domain signal into a frequency domain signal and outputting to the signal detector; and a signal detector for using the system frame The structure extracts distributed service description information symbols from the effective carrier of the frequency domain signal, generates a demodulated signal existing in the constellation space, and outputs the demodulated signal to the demapper; the demapper is configured to demap the demodulated signal and Outputting a coded bit stream to a deinterleaver; deinterleaving, deinterleaving the coded bit stream to obtain soft information including frequency diversity and time diversity, and outputting the soft information to a decoder; and decoding, for using the soft information Decoding, frequency diversity and time diversity are aggregated into system gain, and the decoded bit stream is outputted to the descrambler. The descrambler is configured to descramble the decoded bit stream to obtain service description information.

Compared with the prior art, the present invention proposes a low complexity bit interleaving coding modulation scheme for the low-complexity bit interleaving coding modulation scheme for the low symbol rate of the service description information, but the service description information is distributedly distributed within the residual capacity. Symbol, thereby increasing the credibility of transmitting the service description information symbols within the residual capacity. On the other hand, the system frame structure scheme of the present invention takes into consideration factors such as transmission efficiency and anti-interference ability, and multi-service support, and is also compatible with major audio coding formats. The invention can provide powerful guarantee for the digital audio broadcasting system to support rich program content and flexible service mode, and the invention can be widely applied to various digital audio broadcasting fields such as satellite audio broadcasting, terrestrial wireless audio broadcasting, ground handheld audio broadcasting, etc., in particular, Applied to Fourier transform, Walsh transform, or wavelet transform Multi-carrier system. DRAWINGS

1 is a schematic diagram of a device for transmitting service description information in a digital audio broadcasting system according to the present invention;

2 is a schematic diagram of a device for receiving service description information in a digital audio broadcasting system according to the present invention;

3 is a linear feedback shift register for generating a scrambling code according to the present invention;

Figure 4 is a convolutional code encoder of the present invention;

Figure 5 is a QPSK constellation map according to the present invention;

6 is a 16QAM constellation map according to the present invention;

Figure 7 is a 64QAM constellation map of the present invention;

8 is a schematic diagram of a logical frame structure and a physical layer signal frame structure according to the present invention;

9 is a schematic structural diagram of a subframe according to the present invention;

FIG. 10 is a schematic diagram of distribution of service information description symbols and other symbols according to the present invention; FIG. 11 is a schematic diagram of padding of a subcarrier matrix according to the present invention.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

The digital audio broadcasting system according to the embodiment of the present invention is an OFDM system.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic diagram of a device for transmitting service description information in a digital audio broadcasting system according to the present invention. Referring to FIG. 1, the transmitting device includes:

The scrambler, in one embodiment, is a pseudo-random sequence scrambler for scrambling the service description information (SDIS) to be transmitted to generate an information bit stream having a binary random sequence feature, and outputting the information bit stream Give the encoder

The encoder, in one embodiment, is a forward error correction encoder for encoding the input information bit stream, searching for a corresponding coded code word in the codeword set, obtaining an encoded bit stream, and outputting the encoded bit stream Give an interleaver; An interleaver, configured to reorder the input encoded bit stream according to a predetermined rule and output the same to the mapper;

a constellation mapper for mapping the encoded bit stream through the constellation to obtain a modulation symbol and outputting the same to the multiplexer;

a multiplexer, configured to: according to a system frame structure, the modulation symbols of the service description information are placed in a predetermined manner on a predetermined symbol and a carrier thereof in a residual capacity of the system main service rate matching, and other signal elements of the system Generating a frequency domain signal and outputting it to a frequency-time domain converter, such as a load, a discrete pilot, and a continuous pilot multiplex;

A frequency-time domain converter for performing a frequency-time domain transform on a frequency domain signal to obtain a time domain signal for transmission.

Figure 2 is a schematic diagram of a device for receiving service description information in the digital audio broadcasting system of the present invention. Referring to FIG. 2, the receiving device includes:

a time-frequency converter for converting a time domain signal into a frequency domain signal and outputting to a signal detector; a signal detector, corresponding to a demultiplexer, for using an effective carrier from the frequency domain signal according to a system frame structure Extracting distributed service description information symbols, generating demodulated signals existing in the constellation space and outputting them to the demapper;

a demapper, configured to demap the demodulated signal and output the encoded bit stream to the deinterleaver; and a deinterleaver, configured to deinterleave the encoded bit stream to obtain soft information including frequency diversity and time diversity. Output to the decoder;

a decoder, configured to decode the soft information, using message passing forward error correction decoding including SOVA and BCJR, searching for maximum likelihood probability or maximum a posteriori probability decoding by message passing, and Frequency diversity and time diversity are aggregated into system gain, and the output decoded bit stream is sent to the descrambler;

And a descrambler, configured to descramble the decoded bitstream to obtain service description information.

Based on the transmitting and receiving apparatus described in Figs. 1 and 2, a method of transmitting and receiving service description information in the digital audio broadcasting system of the present invention will be described below.

The method for sending the service description information of the present invention includes:

Step 101: Perform the scrambling process and the forward error correction coding process on the service description information to be transmitted in sequence to generate an encoded bit stream. Step 102: Perform bit interleaving processing and constellation mapping processing on the encoded bit stream to obtain a modulation symbol of the service description information.

Step 103: According to a system frame structure, the modulation symbols of the service description information are placed in a predetermined manner on a predetermined symbol and a carrier thereof in a residual capacity of the system main service rate matching.

Step 104: The symbol sequence processed in step 103 is multiplexed with other signal elements of the system, such as a load, a discrete pilot, and a continuous pilot, to form a frequency domain signal of the OFDM structure;

Step 105: Convert the frequency domain signal into a time domain signal for transmission.

In step 101, the upper layer service description information (the input data byte stream is in the MSB preceding manner) is scrambled by a binary pseudo random sequence. Generated by a linear feedback shift register, as shown in Figure 3, the corresponding generator polynomial is: x ¹² + x ^u + x ⁸ + x ⁶ + l. The initial value of the shift register is 000000000001, and the linear feedback shift register is reset at the beginning of each logical frame.

The scrambling code processing is implemented by performing modulo-2 addition of a sequence of input bit information and a binary pseudo-random sequence, as shown in equation (1):

y( ) = X()® ) (!) where:

- pre-scrambling information bits

γ^——bit after scrambling

The service description information after scrambling is a 1/4 convolutional code with a constraint length of 7. The encoder of the convolutional code is shown in Figure 4. The corresponding octal generator polynomial is: 133, 171, 145, 133, shift The initial value of the register is all "0". The service description information resets the linear feedback shift register at the beginning of each logical frame.

In the step 102, the convolutionally encoded service description information will be processed by bit interleaving, and the interleaving is performed in units of interleaved blocks. The interleaving algorithm is as follows:

Let the input sequence before interleaving be ^ζ = ^(ζ ., , ^ζ "..., -ι) , where N _MUX is the length of the interleaved block, and the output sequence after interleaving is: ^: ,^,^,...^^ ^) , then _=3⁄4 „) , where ^) can be obtained according to the following algorithm: For(i = 0,n = 0;i <s;i + +)

{

If (p(i)<N _MUX )

{

R(n) = p(i);

n + +;

Where _ρ (0) = 0, p(i) = (5x p(il) + q)mods,(i≠0) _{? s} = 2 ^{l 2} , q = s/4-l Service description information in various The lengths of the interleaving blocks corresponding to different modulation modes in the transmission mode are shown in Table 1, and one logical block includes an interleaving block.

Table 1

In step 102, the encoded bit stream is constellated by quadrature phase shift keying (QPSK), 16-symbol quadrature amplitude modulation (16QAM), and 64-symbol quadrature amplitude modulation (64QAM). Figure 5, Figure 6 Corresponding constellation maps are given separately from Figure 7. The coded bit stream is input to the constellation mapper in the most significant bit (MSB) first manner, and the mapper outputs the modulation symbol sequence of the service description information by the sequence number generated by each group of bits.

In step 103, the system frame structure of the present invention includes a superframe, a frame, a subframe, and an OFDM symbol 4 layer. 8 is a schematic diagram of a logical frame structure and a physical layer signal frame structure according to the present invention, and FIG. 9 is a schematic diagram of a subframe structure according to the present invention. Referring to FIG. 8 and FIG. 9, the superframe length of the present invention is 2560 ms, and each superframe is composed of four physical layer signal frames of length 640 ms, and each physical layer signal frame includes four subframes having a length of 160 ms. Each subframe includes 1 beacon and OFDM symbols. Each physical layer signal frame carries data for one logical frame.

The invention is divided into three transmission modes. In transmission mode 1, each superframe is divided into 4 frames, each frame is divided into 4 subframes, each subframe is divided into 57 OFDM symbols, and each symbol has 242 effective carriers. The first OFDM symbol of each subframe is used as a beacon for system synchronization and demodulation preprocessing, and the other 56 OFDM symbols include payload, discrete pilot, continual pilot, and virtual subcarrier. In transmission mode 2 Each superframe is divided into 4 frames, each frame is divided into 4 subframes, each subframe is divided into 112 OFDM symbols, and each symbol has 122 effective carriers. The first OFDM symbol of each subframe serves as a beacon, and the 111 OFDM symbols include a payload, a scattered pilot, a continual pilot, and a virtual subcarrier. In transmission mode 3, each superframe is divided into 4 frames, each frame is divided into 4 subframes, each subframe is divided into 62 OFDM symbols, and each symbol has 242 effective carriers. The first OFDM symbol of each subframe is used as a beacon, and the other 61 OFDM symbols include a payload, a discrete pilot, a continuous pilot, and a virtual subcarrier. Each OFDM symbol is prefixed by a guard interval to reduce OFDM intersymbol interference. The subcarrier spacing of transmission mode 1 and transmission mode 3 is the same, but the guard interval length is different, and the subcarrier spacing of transmission mode 2 is twice that of the foregoing two modes. Define the unit time T = 1/816000 seconds, system parameters such as subcarrier spacing, symbol interval, and guardian interval are shown in Table 2:

Table 2

The OFDM signal consists of up to 8 subbands with a nominal bandwidth of 100 kHz. The frequency pattern specifies the number of subbands, as well as the locations of the effective subbands and the virtual subbands. In some frequency patterns, some valid subbands All subcarriers in the upper half subband or the lower half subband are virtual subcarriers. Within a valid subband, each

The OFDM symbol includes effective subcarriers composed of contiguous pilots, discrete pilots, and data subcarriers (when the subcarriers of the upper half subband and the lower half of the subband are not all virtual subcarriers), or ^/2 are consecutive A valid subcarrier consisting of a pilot, a scattered pilot, and a data subcarrier (when the subcarriers of the upper half or the lower half of the subband are all virtual subcarriers). For each frequency mode, the subcarriers except the virtual subcarrier, the contiguous pilot subcarrier, and the scattered pilot subcarrier in the OFDM symbol are data subcarriers, and the data subcarriers are placed with service description information symbols and service data symbols. Contains ( ⁴ * )* (a valid subcarrier in a logical frame, the minimum value is 1 and the maximum value is 8. The specific value is set by the system.

According to the above system frame structure, the step 103 specifically includes the following steps 131 to 132:

Step 131: Construct a subcarrier matrix Μ whose number of rows is ⁴ * and whose number of columns is *, where ^ is the number of OFDM symbols in each subframe, and the number of effective subcarriers is the number of interleaved blocks; The number of rows and the number of columns of the subcarrier matrix are counted from 1. The elements in the subcarrier matrix are divided into system information elements, discrete pilot elements, and data elements. The subcarrier matrix is divided into a number of sub-matrices ^^" from top to bottom and left to right, ie:

Where M _si = (m _a , _wX w _v ,

m _a = l, Uw, b = l, 2, '", N _v ) represents an element in the sub-matrix. Step 132: The modulation symbol of the service description information is transmitted in units of one logical frame, and the step is performed. scrambled modulation symbols 101 and 102 of the service description information code, coding, interleaving, and constellation mapping needs to be placed in a distributed manner in the matrix M sub-carriers, the sub-matrix ^{Μ ι} first column from the left, iota started, at every The sub-matrix of the column from top to bottom sequentially places the modulation symbols of the service description information; wherein, for any sub-matrix ^, ', the service description information is all placed in the first to the ^^ lines of the ^^" The modulation symbol, the modulation symbol of the service description information is placed in the 1st to ^^ columns in the + ^1th row of the ^, the ^^ and ^^^^ are system setting values.

The following is a more specific description of the step 132: The modulation symbols of the service description information after scrambling, encoding, interleaving and constellation mapping are respectively placed in the data elements specified on ^M ", ^M " is placed in the data elements of the SDIS The location is shown in Table 3. Transmission mode 1 transmission mode 2 transmission mode 3

M N N N M N

2 0 3 72 1 128

The data elements in the first to the first row are all SDIS, and the data element from the 1st to the ^1st line in ^M " is SDIS. The SDIS sub-matrix is first from left to right and top to bottom.

After the data elements specified in Table 3 of M 1,1 are filled, the corresponding data elements in each sub-carrier sub-matrix are sequentially filled in the direction indicated by the arrow of FIG. 10, that is, starting from the sub-matrix ^M u of the first column on the left, according to each The sub-matrices of the column from top to bottom sequentially place the modulation symbols of the SDIS. The distribution of the placed SDIS and other symbols within the system frame is shown in Figure 11, which presents distributed features at the sub-frame and sub-band locations, increasing the likelihood that SDIS will acquire time diversity and frequency diversity.

The subcarrier matrix M of the present invention removes the data elements other than the SDIS and places the main service data (MSIS) within a logical frame, that is, the SDIS is placed in the residual capacity of the system main service rate matching. The four subcarrier sub-matrices in each transmission mode are given in Table 4 below.

The number of data elements in the MSIS and the number of data elements in which the SDIS is placed.

Table 4

After the processing of the above step 103, the SDIS and MSIS from the upper layer are processed into a symbol sequence, and then the steps 104 and 105 are performed to multiplex the symbol sequence with other signal elements of the system such as load, discrete pilot and continuous pilot. And constituting a frequency domain signal of the OFDM structure, converting the frequency domain signal into a time domain signal for transmission.

At the signal receiving end, the method for receiving service description information in the digital audio broadcasting system of the present invention includes: Step 201: Convert the time domain signal into a frequency domain signal.

Step 202: Extract distributed service description information symbols from the effective carrier of the frequency domain signal according to a system frame structure, and generate a demodulated signal existing in the constellation space. In this step, the effective carrier is detected by using a diversity method including frequency domain diversity and time domain diversity, and distributed service description information symbols are extracted from the system frame structure, and generated in the constellation space. Demodulated signal

Step 203: Demap the demodulated signal to obtain an encoded bit stream.

Step 204: Deinterleave the encoded bit stream to obtain soft information including frequency diversity and time diversity.

Step 205: Decode the soft information, use message passing forward error correction decoding including SOVA and BCJR, search for maximum likelihood probability or maximum a posteriori probability decoding by message transmission, and divide the frequency. And time diversity is aggregated into system gain, and the decoded bit stream is output.

Step 206: De-scramble the decoded bit stream outputted in step 205 to obtain service description information. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalents, improvements, etc., which are made within the spirit and principles of the present invention, should be included in the present invention. Within the scope of protection.

Claims

A method for transmitting service description information in a digital audio broadcasting system, the method comprising:

A. The service description information to be sent is sequentially subjected to scrambling processing, forward error correction coding processing, bit interleaving processing, and constellation mapping processing to obtain a modulation symbol of the service description information;

B. Configuring, according to a system frame structure, a modulation symbol of the service description information according to a distribution pattern on a predetermined symbol and a carrier thereof in a residual capacity of the system;

C. The symbol sequence processed in step B is multiplexed with other signal elements of the system to form a frequency domain signal of the OFDM structure, and then the frequency domain signal is converted into a time domain signal for transmission.

2. The transmitting method according to claim 1, wherein the system frame structure in step B comprises a superframe, a frame, a subframe, and an OFDM symbol;

Each superframe is divided into 4 frames, each frame is divided into 4 subframes, each subframe is divided into 57 OFDM symbols, and each OFDM symbol has 242 effective carriers;

Or, each superframe is divided into 4 frames, each frame is divided into 4 subframes, each subframe is divided into 112 OFDM symbols, and each OFDM symbol has 122 effective carriers;

Or, each superframe is divided into 4 frames, each frame is divided into 4 subframes, each subframe is divided into 62 OFDM symbols, and each OFDM symbol has 242 effective carriers.

The transmitting method according to claim 1, wherein the step B specifically includes: step B1, constructing a subcarrier matrix M having a row number of ⁴ * and a column number of *, wherein the V is within each subframe The number of OFDM symbols, the number of effective subcarriers, the number of interleaved blocks; the number of rows and the number of columns of the subcarrier matrix are counted from 1; the subcarrier matrix is pressed from top to bottom, from left To the right, the sub-matrix ^^" with the number of rows is ^ V and the number of columns is ^, that is:

m _a = l, Uw, b = l, 2, '", N _v ) represent the elements in the submatrix;

Step B2, in the subcarrier matrix M, starting from the submatrix ^1 of the first column on the left, placing the modulation symbols of the service description information in order from the top to the bottom of each column; a sub-matrix ^, ', in the first to the first line of the ^ ^ " the business description information The modulation symbol, the modulation symbol of the service description information is placed in the first to the ^1 columns in the row of the ^M ", and the N _SDISn and N _SDISvaUd are system setting values.

The transmitting method according to claim 1, wherein in the step A, the scrambling code processing is specifically a pseudo random sequence scrambling code processing;

The forward error correction coding process is specifically a convolutional coding process;

The constellation mapping process is specifically processed by a QPSK mapping mode, a 16QAM mapping mode, or a 64QAM mapping mode.

The method according to any one of claims 1 to 4, characterized in that the digital audio broadcasting system is a multi-carrier system employing Fourier transform, Walsh transform, or wavelet transform.

A method for receiving service description information in a digital audio broadcasting system, comprising:

a, converting the time domain signal into a frequency domain signal;

b. extracting distributed service description information symbols from the effective carrier of the frequency domain signal according to a system frame structure, and generating a demodulated signal existing in the constellation space;

c. Demodulating, deinterleaving, forward error correction decoding, and descrambling are sequentially performed on the demodulated signal to obtain service description information.

The receiving method according to claim 6, wherein in step b, the effective carrier is detected by using a diversity method including frequency domain diversity and time domain diversity, and is extracted according to a system frame structure. Deriving a distributed service description information symbol to generate a demodulated signal existing in a constellation space;

The step c specifically includes: sequentially de-mapping and de-interleaving the demodulated signal to obtain soft information including frequency diversity and time diversity; decoding the soft information by using forward error correction decoding, and performing frequency diversity and time diversity. Aggregating into a system gain, outputting a decoded bit stream; descrambling the decoded bit stream to obtain service description information.

The receiving method according to claim 6, wherein the forward error correction decoding is specifically: message-based forward error correction decoding including SOVA and BCJR.

A device for transmitting service description information in a digital audio broadcasting system, characterized in that the transmitting device comprises:

a scrambler, configured to perform scrambling processing on the service description information to be sent and output information ratio Special flow to the encoder;

An encoder, configured to encode an input information bit stream, and output the encoded bit stream to the interleaver;

An interleaver, configured to reorder the input encoded bit stream according to a predetermined rule and output the image to the mapper;

a constellation mapper, configured to map the encoded bit stream through the constellation to obtain a modulation symbol and output the modulation symbol to the multiplexer;

a multiplexer, configured to: according to a system frame structure, the modulation symbols of the service description information are placed in a predetermined manner on a predetermined symbol and a carrier thereof in a residual capacity of the system, and are multiplexed with other signal elements of the system to generate a frequency The domain signal is output to the frequency-time domain converter;

A frequency-time domain converter is used to obtain a time domain signal by frequency-time domain transform of a frequency domain signal.

A device for receiving service description information in a digital audio broadcasting system, characterized in that the receiving device comprises:

a time-frequency converter for converting a time domain signal into a frequency domain signal and outputting to a signal detector; a signal detector for extracting distributed service description information symbols from an effective carrier of the frequency domain signal according to a system frame structure Generating a demodulated signal existing in the constellation space and outputting it to the demapper;

a decoder, configured to decode the soft information, aggregate frequency diversity and time diversity into a system gain, and output a decoded bit stream to the descrambler;