CN103780561A - Transmission method of anti-noise mobile digital broadcasting signals - Google Patents

Abstract

The invention discloses an anti-noise mobile digital broadcasting signal transmission method, which is a frame modulation scheme mixed in time domain and frequency domain. The training sequence optimization design, signal generation mode and signal selection method of the anti-noise mobile digital broadcast signal transmission method of the present invention are easy to process and recover the original signal of the OFDM signal at the receiver end, and have low peak-to-average power ratio, short synchronization time, Anti-channel fading, controllable multi-service and other advantages.

Description

Anti-noise mobile digital broadcasting signal transmission method

technical field

The invention belongs to the field of wireless communication, and more specifically relates to a noise-resistant mobile digital broadcasting signal transmission method.

Background technique

At present, television broadcasting has gradually developed from analog to digital. Digital TV mobile digital broadcasting transmission system, as an important part of digital TV mobile digital broadcasting, the development of its related technologies is closely related to people's quality of life, and therefore has received extensive attention from people. Digital TV, mobile digital broadcasting related technologies and related industries are industries with rapid development and good market prospects in the field of communication and computer. In terms of technologies related to digital TV anti-noise mobile digital broadcasting, countries are currently focusing on how to provide low-cost, reliable and high-speed mobile implementation solutions for digital TV anti-noise mobile digital broadcasting in a complex wave propagation environment. The anti-noise mobile digital broadcast signal transmitter transmission technology is the key technology of the digital TV anti-noise mobile digital broadcast system, which plays a decisive role in the performance of the whole system and is the object of everyone's key research.

Due to the rapid development of digital signal processing technology and integrated circuit technology, the system realization of Orthogonal Frequency Division Multiplexing (OFDM) technology becomes easier and easier. Because OFDM multi-carrier transmission technology has many advantages such as simple structure, high spectrum utilization rate, and anti-frequency selectivity and channel time variation, it has attracted much attention and has been deeply researched and applied in Xdsl, broadband mobile communication, broadband wireless local area network, It is widely used in many fields such as digital TV anti-noise, mobile digital broadcasting, etc.

The high peak-to-average power ratio (PAPR) of OFDM signals has high requirements on the linear range of amplifiers and digital-to-analog converters. If the linear range of the system cannot meet the signal changes, it will cause signal distortion and signal spectrum changes. , resulting in the destruction of the orthogonality between sub-channels, resulting in mutual interference and deteriorating system performance. Therefore, it is necessary to consider how to reduce the occurrence probability of high peak power signals in OFDM signals and reduce the impact of nonlinear distortion.

Channel coding is an important part of digital communication systems. With the rapid development of modern information technology, channel coding technology has become an indispensable technology in the field of modern communication. Redundant code elements are embedded in the information sequence, and channel coding technology reduces signal errors during transmission through the role of redundant code elements, thereby improving the reliability of the communication system. Low Density Parity Check (LDPC) code is an error correction code used to transmit information in a noisy transmission channel and perform forward error correction (FEC, Forward Error Correction). LDPC coding is a coding scheme that can make the data transmission rate close to the theoretical maximum, which is the Shannon limit.

In the actual communication environment, the performance of the digital TV mobile digital broadcasting communication system is affected by factors such as synchronization time, clock jitter, channel fading, and channel interference. The transmission method of anti-noise mobile digital broadcasting signal transmitter is the key technology to realize reliable digital television anti-noise mobile digital broadcasting.

Using the digital TV mobile digital broadcast transmission system to provide controllable multi-services such as free TV broadcast, paid TV broadcast, confidential information transmission, and multimedia value-added services is the embodiment of the new generation of digital TV mobile digital broadcast transmission system to meet social needs.

Based on the above background, the present invention proposes an anti-noise mobile digital broadcast signal transmission method for the actual communication environment, which can meet the needs of high data rate controllable multi-service digital TV anti-noise mobile digital broadcast transmission.

For a more in-depth understanding of the patent background, please refer to the following literature:

R.V.Nee.R.Prasad.“OFDM for wireless multimedia communications”.

Boston: Artech House, 2000.

Y. Wu, S. Hirakawa, U.H. Reimers, and J. Whitaker. "Overview of digital television development," Proceedings of the IEEE, Special Issue on Global Digital Television: Technology and Emerging Services, pp.8-21, Jan.2006.

M.S. Richer, G. Reitmeier, T. Gurley, G.A. Jones, J. Whitaker, and R.

Rast. "The ATSC digital television system," Proceedings of the IEEE, Special Issue on Global Digital Television: Technology and Emerging Services, pp.37-43, Jan.2006.

U.Ladebusch and C.A.Liss. "Terrestrial DVB (DVB-T): A broadcast technology for stationary portable and mobile use," Proceedings of the IEEE, Special Issue on Global Digital Television: Technology and Emerging Services, pp.183-194, .2006.

M. Takada and M. Saito. "Transmission systems for ISDB-T," Proceedings of the IEEE, Special Issue on Global Digital Television: Technology and Emerging Services, pp.251-256, Jan.2006.

Contents of the invention

Aiming at the problem of high data rate controllable multi-service digital TV anti-noise mobile digital broadcasting, the invention proposes a noise-resistant mobile digital broadcasting signal transmission method.

A kind of anti-noise mobile digital broadcasting signal transmission method that the present invention proposes is characterized in that it comprises the following steps:

1) The anti-noise mobile digital broadcast signal transmitter converts the multimedia data stream into a bit stream through the media data processor, and uses the scrambling code sequence generated by the feedback shift register to perform scrambling processing to form the input data bit stream;

2) The anti-noise mobile digital broadcast signal transmitter forms an FFT encoded data block in the frequency domain after its input data bit stream undergoes LDPC encoding, symbol modulation and symbol rotation. LDPC means low-density parity check, and FFT encoded data The length of the block is K, and the value of K is an even number;

3) The anti-noise mobile digital broadcast signal transmitter uses IFFT to transform the FFT coded data block into a time-domain discrete coded data sample block D _total = [d ₀ , d ₁ ,..., d _K-2 , d _K-1 ];

4) The anti-noise mobile digital broadcasting signal transmitter demultiplexes the time-domain discrete coded data sample blocks and sequentially separates and generates time-domain discrete coded data sample odd sub-blocks according to the order of each time-domain discrete coded data sample. _Dodd =[d ₀ , d ₂ ,..., d _K-4 , d _K-2 ] and time-domain discrete coded data sample even sub-block _Deven =[d ₁ , d ₃ ,...,d _K-3 , dK _-1 ];

生成模式3为

生成模式4为

生成模式5为

生成模式6为

生成模式7为D_new＝[D^* _奇，D_偶]，生成模式8为生成模式9为

生成模式10为

生成模式11为

生成模式12为

生成模式13为D_new＝[D_奇，D^* _偶]，生成模式14为

生成模式15为

生成模式16为生成模式17为生成模式18为

比较18种生成模式合成的时域离散编码数据样值块D_new，选取其中具有最低峰均功率比的降峰均功率比时域离散编码数据样值块

并将降峰均功率比时域离散编码数据样值块

所对应采用的生成模式信息发送给业务指标序列设置单元，其中，D^* _奇表示对时域离散编码数据样值奇子块D_奇的各时域离散编码数据样值进行共轭运算处理而得到的时域离散编码数据样值子块；D^* _偶表示对时域离散编码数据样值偶子块D_偶的各时域离散编码数据样值进行共轭运算处理而得到的时域离散编码数据样值子块；5) The anti-noise mobile digital broadcast signal transmitter adjusts the signal power of the odd sub-block Dodd of time-domain discretely coded data samples and _{the even} sub-block D of time-domain discretely coded data samples through the peak- _to-average power ratio adjustment unit and the corresponding signal Process and re-synthesize a new time-domain discretely coded data sample block _Dnew , the new time-domain discretely coded data sample block _Dnew is obtained using the following generation mode, generation mode 1 is _Dnew =[ _Dodd , _Deven ], generate mode 2

Generate schema 3 as

Generate schema 4 as

Generate schema 5 as

Generate schema 6 as

Generation mode 7 is D _new = [D ^* _odd , D _even ], generation mode 8 is Generate schema 9 as

Generate schema 10 as

Generate schema 11 as

Generate schema 12 as

Generation mode 13 is D _new = [D _odd , D ^* _even ], generation mode 14 is

Generate schema 15 as

Generate schema 16 as Generate schema 17 as Generate schema 18 as

Compare the time-domain discrete-coded data sample block D _new synthesized by 18 generation modes, and select the time-domain discrete-coded data sample block with the lowest peak-to-average power ratio

and reduce the peak-to-average power ratio time-domain discretely coded data sample block

The generated mode information correspondingly adopted is sent to the service indicator sequence setting unit, wherein, D ^* _odd means that the time-domain discrete-coded data samples of the odd sub-block Dodd of _the time-domain discrete-coded data samples are conjugated and processed to obtain The time-domain discretely coded data sample sub-block; D ^* _even represents the time-domain discretely coded data obtained by performing conjugate operation on _each time-domain discretely coded data sample of the time-domain discretely coded data sample even sub-block Deven sample sub-block;

6) The anti-noise mobile digital broadcast signal transmitter inserts the service index sequence behind the training sequence to form a time-domain embedded training sequence discrete sample block in the time domain. The service index sequence contains and uniquely expresses the anti-noise mobile digital broadcast signal transmitter Each system parameter and business mode information; the length of the time-domain embedded training sequence discrete sample block is numerically equal to the length of the peak-to-average power ratio time-domain discrete coded data sample block;

7) The anti-noise mobile digital broadcasting signal transmitter directly superimposes the time-domain discrete coded data sample block with reduced peak-to-average power ratio and the discrete sample value block of the time-domain embedded training sequence to form a time-domain embedded training sequence with reduced peak-to-average power ratio time-domain discrete coded data sample blocks as frame bodies;

8) The anti-noise mobile digital broadcasting signal transmitter uses the cyclic prefix as a guard interval, that is, the frame header is inserted into the time domain embedding training sequence to reduce the peak-to-average power ratio, and the time domain discretely encoded data sample block is the frame body to form a signal frame. length is C;

9) The anti-noise mobile digital broadcast signal transmitter adopts the square root raised cosine roll-off filter to shape the signal pulse of the signal frame;

10) The anti-noise mobile digital broadcast signal transmitter up-converts the baseband signal to the carrier to form a radio frequency signal and transmit it to the air wireless channel;

11) The anti-noise mobile digital broadcast signal receiver detects and receives the radio frequency signal sent by the anti-noise mobile digital broadcast signal transmitter and down-converts it to form a baseband signal, and uses the characteristics of the training sequence and the structural characteristics of the signal frame to receive and process the baseband signal.

According to the above-mentioned anti-noise mobile digital broadcasting signal transmission method, it is characterized in that: the peak-to-average power ratio of the anti-noise mobile digital broadcasting signal transmitter is decomplexed by the time-domain discretely encoded data sample block Using and sequentially separating the generated time-domain discrete-coded data sample odd sub-block and time-domain discrete-coded data sample even-sub-block according to the sequence parity of each time-domain discrete coded data sample value to perform signal power adjustment and corresponding signal processing and It is re-synthesized through 18 specially designed generation modes; the training sequence of the anti-noise mobile digital broadcasting signal transmitter is composed of the first training sequence and the second training sequence; the first training sequence is composed of constant envelope zero autocorrelation CAZAC sequence B and Each symbol of the pseudo-random PN sequence A is alternately inserted into a new sequence and a cyclic prefix of length G; the second training sequence is composed of a constant envelope zero autocorrelation CAZAC sequence-B ^* and each of the pseudo-random PN sequence A ^* A new sequence generated by alternate insertion of a symbol and a cyclic prefix of length G; B ^* means to perform conjugate operation processing on each symbol of B, A ^* means to perform conjugate operation processing on each symbol of A, B and A has the same symbol length L; the cyclic prefix length G of the first training sequence and the second training sequence is 1/8 of the symbol length L of the first training sequence and the second training sequence; anti-noise mobile digital broadcast signal transmitter signal The cyclic prefix length C of the frame is 1/16 of the length K of the FFT encoded data block; the service index sequence of the anti-noise mobile digital broadcasting signal transmitter has pseudo-random characteristics, and is realized by a set of shifted m sequences; the anti-noise mobile digital broadcasting signal Each different service index sequence of the transmitter contains and uniquely expresses the system parameters and business mode information of the anti-noise mobile digital broadcast signal transmitter; the FFT coded data block of the anti-noise mobile digital broadcast signal transmitter is composed of subcarriers, subcarriers The frequency interval of the carrier is one of 2KHz, 4KHz, and 1KHz; the symbol modulation is one of QPSK, 16QAM, 64QAM, and 256QAM, and the symbol constellation mapping method of the symbol modulation adopts Gray code mapping; the symbol rotation passes The rotation angle of the symbol constellation diagram is realized by rotating a certain angle. The rotation angle of the symbol constellation diagram of QPSK is 22.5 degrees. The rotation angle of the symbol constellation diagram of 16QAM is 11.25 degrees. The rotation angle of the symbol constellation diagram of 64QAM is 5.626 degrees. The meta-constellation rotation angle is 2.8125 degrees. The anti-noise mobile digital broadcast signal receiver can make full use of the characteristics of the training sequence and the structural characteristics of the signal frame for baseband signal reception processing, including joint iterative separation processing of the time-frequency domain of the signal frame header and signal frame body.

Features of the present invention:

The invention is a framing modulation scheme of mixing time domain and frequency domain. In the present invention, the time-domain discretely coded data sample blocks are demultiplexed and sequentially separated to generate time-domain discretely coded data sample odd sub-blocks and time-domain discretely coded data samples according to the order of each time-domain discretely coded data sample. Even sub-blocks and their corresponding signal power adjustment and signal processing, generation mode of 18 kinds of time-domain discrete coded data sample blocks with reduced peak-to-average power ratio through specific design and reduced peak-to-average power ratio with the lowest peak-to-average power ratio The time-domain discrete coded data sample block selection method can not only make full use of the maximum peak power of the OFDM signal, but the probability of the high peak power signal is very low, and the real part (or imaginary part) of the OFDM signal when the number of subcarriers is large It is a complex Gaussian random process and the amplitude obeys the characteristics of Rayleigh distribution, so as to effectively change the power distribution law of the framed signal with low complexity to achieve the purpose of reducing the peak-to-average power ratio. The original signal of the OFDM signal is obtained by processing and recovering at the receiver, and at the same time, the orthogonality characteristic of the sub-carrier signal will not be destroyed and additional nonlinear distortion will not be generated. The training sequence in the signal frame of the anti-noise mobile digital broadcast signal transmitter is obtained by the constant envelope zero autocorrelation CAZAC sequence and the pseudo-random PN sequence through specific optimization design, and the time domain embedded training sequence of the anti-noise mobile digital broadcast signal transmitter The reduced peak-to-average power ratio time-domain discrete coded data sample block is formed by directly superimposing the reduced peak-to-average power ratio time-domain discrete coded data sample block and the time-domain embedded training sequence discrete sample block, which guarantees the anti-noise movement Digital broadcast signal receivers can achieve fast and accurate frame synchronization, frequency synchronization, time synchronization, estimation of channel transmission characteristics, and reliable tracking of phase noise and channel transmission characteristics. Inserting the cyclic prefix as a guard interval into the time-domain embedding training sequence to reduce the peak-to-average power ratio time-domain discretely coded data sample blocks to form a signal frame can reduce the interference between adjacent signal frames. Channel coding the input data with LDPC codes provides error correction performance close to the Shannon limit. Symbol modulation and constellation rotation provide diversity effects for mobile digital broadcasting signals. Each different service index sequence of the anti-noise mobile digital broadcast signal transmitter contains and uniquely expresses the system parameters and business mode information of the anti-noise mobile digital broadcast signal transmitter, which can make the digital TV anti-noise mobile digital broadcast transmission system able to Provide controllable multi-services such as free TV broadcasting, paid TV broadcasting, confidential information transmission, and multimedia value-added services to meet social needs. The transmission method of the present invention has many advantages such as low peak-to-average power ratio, short synchronization time, small clock jitter, anti-channel fading, anti-channel interference, high data rate, controllable multi-service digital TV, anti-noise mobile digital broadcast transmission, and the like.

Description of drawings

Fig. 1 is a schematic diagram of an embodiment of signal transmission between a certain transmitter and a receiver according to the noise-resistant mobile digital broadcasting signal transmission method of the present invention.

Fig. 2 is a schematic diagram of an embodiment of signal frame formation during signal transmission between a transmitter and a receiver according to the anti-noise mobile digital broadcasting signal transmission method of the present invention.

Detailed ways

Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

According to the schematic diagram of an embodiment of signal transmission between a transmitter and a receiver of the anti-noise mobile digital broadcasting signal transmission method proposed by the present invention, as shown in Figure 1, the following steps are carried out:

1) The certain anti-noise mobile digital broadcast signal transmitter converts the multimedia data stream into a bit stream through a media data processor, and uses the scrambling code sequence generated by the feedback shift register to perform scrambling processing to form an input data bit stream;

2) The certain anti-noise mobile digital broadcast signal transmitter forms an FFT coded data block in the frequency domain after its input data bit stream undergoes LDPC encoding, symbol modulation and symbol rotation, LDPC means low-density parity check, The length of the FFT encoded data block is K, and the value of K is an even number; the encoding rate of LDPC encoding is one of 1/4, 1/2, 5/8, 3/4 and 7/8 for the input data; the symbol The modulation is one of QPSK, 16QAM, 64QAM and 256QAM. The symbol constellation mapping method of symbol modulation adopts Gray code mapping; the symbol rotation is realized by rotating the symbol constellation at a certain angle. The QPSK symbol constellation The rotation angle is 22.5 degrees, the rotation angle of the symbol constellation diagram of 16QAM is 11.25 degrees, the rotation angle of the symbol constellation diagram of 64QAM is 5.626 degrees, and the rotation angle of the symbol constellation diagram of 256QAM is 2.8125 degrees;

3) The certain anti-noise mobile digital broadcast signal transmitter uses IFFT to transform the FFT coded data block into a time-domain discrete coded data sample block D _total = [d ₀ , d ₁ ,..., d _K-2 , d _{K- 1} ];

4) The certain anti-noise mobile digital broadcast signal transmitter demultiplexes the time-domain discretely coded data sample blocks and sequentially separates and generates time-domain discretely coded data samples according to the sequence parity of each time-domain discretely coded data sample Odd sub-block _Dodd =[d ₀ , d ₂ ,...,d _K-4 ,d _K-2 ] and even sub-block D _even of time-domain discrete coded data samples=[d ₁ ,d ₃ ,...,d _{K -3} , dK _-1 ];

生成模式3为

生成模式4为

生成模式5为

生成模式6为

生成模式7为D_new＝[D^* _奇，D_偶]，生成模式8为生成模式9为

生成模式10为

生成模式11为

生成模式12为

生成模式13为D_new＝[D_奇，D^* _偶]，生成模式14为

生成模式15为

生成模式16为

生成模式17为生成模式18为

比较18种生成模式合成的时域离散编码数据样值块D_new，选取其中具有最低峰均功率比的降峰均功率比时域离散编码数据样值块

并将降峰均功率比时域离散编码数据样值块

所对应采用的生成模式信息发送给业务指标序列设置单元，其中，D^* _奇表示对时域离散编码数据样值奇子块D_奇的各时域离散编码数据样值进行共轭运算处理而得到的时域离散编码数据样值子块；D^* _偶表示对时域离散编码数据样值偶子块D_偶的各时域离散编码数据样值进行共轭运算处理而得到的时域离散编码数据样值子块；5) The certain anti-noise mobile digital broadcasting signal transmitter performs signal power adjustment on the odd sub-block Dodd of time-domain discretely encoded data samples and _{the even} sub-block Deven of time-domain discretely encoded data samples through the peak- _to -average power ratio adjustment unit And the corresponding signal processing and re-synthesis of a new time-domain discrete coded data sample block _Dnew , the new time-domain discrete coded data sample block _Dnew is obtained by the following generation mode, generation mode 1 is _Dnew = [ _Dodd , Dnew _Even ], the generation mode 2 is

Generate schema 3 as

Generate schema 4 as

Generate schema 5 as

Generate schema 6 as

Generation mode 7 is D _new = [D ^* _odd , D _even ], generation mode 8 is Generate schema 9 as

Generate schema 10 as

Generate schema 11 as

Generate schema 12 as

Generation mode 13 is D _new = [D _odd , D ^* _even ], generation mode 14 is

Generate schema 15 as

Generate schema 16 as

Generate schema 17 as Generate schema 18 as

Compare the time-domain discrete-coded data sample block D _new synthesized by 18 generation modes, and select the time-domain discrete-coded data sample block with the lowest peak-to-average power ratio

and reduce the peak-to-average power ratio time-domain discretely coded data sample block

The generated mode information correspondingly adopted is sent to the service indicator sequence setting unit, wherein, D ^* _odd means that the time-domain discrete-coded data samples of the odd sub-block Dodd of _the time-domain discrete-coded data samples are conjugated and processed to obtain The time-domain discretely coded data sample sub-block; D ^* _even represents the time-domain discretely coded data obtained by performing conjugate operation on _each time-domain discretely coded data sample of the time-domain discretely coded data sample even sub-block Deven sample sub-block;

6) The certain anti-noise mobile digital broadcast signal transmitter inserts the service index sequence behind the training sequence to form a time-domain embedded training sequence discrete sample block in the time domain. The service index sequence contains and uniquely expresses the anti-noise mobile digital broadcasting The system parameters and business mode information of the signal transmitter; the length of the time-domain embedded training sequence discrete sample block is numerically equal to the length of the peak-to-average power ratio time-domain discrete coded data sample block;

7) The anti-noise mobile digital broadcasting signal transmitter directly superimposes the peak-to-average power ratio time-domain discrete coded data sample block and the time-domain embedded training sequence discrete sample block to form a time-domain embedded training sequence with a reduced peak-to-average power ratio Discretely coded data sample blocks in the time domain, as a frame body;

8) The certain anti-noise mobile digital broadcasting signal transmitter inserts the cyclic prefix as the guard interval, that is, the frame header, into the time domain embedding training sequence to reduce the peak-to-average power ratio time domain discretely encoded data sample block, that is, the frame body, to form a signal frame, The length of the cyclic prefix is C;

9) The certain anti-noise mobile digital broadcast signal transmitter adopts a square root raised cosine roll-off filter to shape the signal pulse of the signal frame;

10) The certain anti-noise mobile digital broadcast signal transmitter up-converts the baseband signal to the carrier to form a radio frequency signal and transmits it to the wireless channel in the air;

11) The certain anti-noise mobile digital broadcast signal receiver detects and receives the radio frequency signal sent by the anti-noise mobile digital broadcast signal transmitter and down-converts it to form a baseband signal, and uses the characteristics of the training sequence and the structural characteristics of the signal frame to perform baseband signal The receiving process includes joint iterative separation processing of the time-frequency domain of the signal frame header and the signal frame body.

According to the schematic diagram of an embodiment of signal frame formation in the process of signal transmission between a certain transmitter and receiver according to the anti-noise mobile digital broadcast signal transmission method of the present invention, as shown in Figure 2, the specific implementation is as follows:

The certain anti-noise mobile digital broadcast signal transmitter converts the multimedia data stream into a bit stream through a media data processor, and uses the scrambling code sequence generated by the feedback shift register to perform scrambling processing to form an input data bit stream.

This certain anti-noise mobile digital broadcasting signal transmitter forms FFT coded data blocks in the frequency domain after its input data bit stream undergoes LDPC encoding, symbol modulation and symbol rotation. LDPC means low-density parity check, and then passes through IFFT transforms it into a discretely coded data sample block in the time domain, and generates and selects the time domain discretely coded data sample block with the lowest peak-to-average power ratio through the peak-to-average power ratio adjustment unit. The generation mode information of is sent to the business indicator sequence setting unit.

The FFT encoded data block of this certain anti-noise mobile digital broadcasting signal transmitter is made up of subcarriers, and the frequency interval of subcarriers is taken as one of 2KHz, 4KHz, and 1KHz; the encoding rate of LDPC encoding for input data is 1/4, One of 1/2, 5/8, 3/4, and 7/8; the symbol modulation is one of QPSK, 16QAM, 64QAM, and 256QAM, and the symbol constellation mapping method of symbol modulation adopts Gray code mapping; The symbol rotation is realized by rotating the symbol constellation diagram by a certain angle. The rotation angle of the symbol constellation diagram of QPSK is 22.5 degrees, the rotation angle of the symbol constellation diagram of 16QAM is 11.25 degrees, and the rotation angle of the symbol constellation diagram of 64QAM is 5.626 degrees. , the rotation angle of the symbol constellation diagram of 256QAM is 2.8125 degrees.

The training sequence of this certain anti-noise mobile digital broadcast signal transmitter is made up of the first training sequence and the second training sequence; the first training sequence is composed of each symbol of the constant envelope zero autocorrelation CAZAC sequence B and the pseudo-random PN sequence A The new sequence generated by alternate insertion and its cyclic prefix of length G; the second training sequence is a new sequence generated by alternately inserting each symbol of the constant envelope zero autocorrelation CAZAC sequence-B ^* and the pseudo-random PN sequence A ^* and Its length is composed of cyclic prefixes of G; B ^* means to perform conjugate operation processing on each symbol of B, A ^* means to perform conjugate operation processing on each symbol of A, and B and A have the same symbol length L; The cyclic prefix length G of the first training sequence and the second training sequence is 1/8 of the symbol length L of the first training sequence and the second training sequence.

The certain anti-noise mobile digital broadcasting signal transmitter inserts a service index sequence behind the training sequence to form a time domain embedded training sequence discrete sample value block in the time domain.

The service index sequence of the certain anti-noise mobile digital broadcasting signal transmitter has a pseudo-random characteristic, and is realized by a group of shifted m sequences; each different service index sequence of the certain anti-noise mobile digital broadcasting signal transmitter contains and It uniquely expresses the system parameters and business mode information of the anti-noise mobile digital broadcasting signal transmitter.

The length of the time-domain embedded training sequence discrete sample value block of this certain anti-noise mobile digital broadcasting signal transmitter is numerically equal to the length of the peak-to-average power ratio time-domain discrete coded data sample block; the certain anti-noise mobile The digital broadcast signal transmitter directly superimposes the time-domain discrete coded data sample blocks with reduced peak-to-average power ratio and time-domain embedded training sequence discrete sample blocks to form time-domain embedded training sequence reduced peak-to-average power ratio time-domain discrete coded data sample blocks , as the frame body; the anti-noise mobile digital broadcast signal transmitter uses the cyclic prefix as a guard interval, that is, the frame header is inserted into the training sequence in the time domain to reduce the peak-to-average power ratio, and the discretely encoded data sample block in the time domain is the frame body, to form For the signal frame, the length of the cyclic prefix is C; the length C of the cyclic prefix of the signal frame of the certain anti-noise mobile digital broadcasting signal transmitter is 1/16 of the length K of the FFT coded data block.

The certain noise-resistant mobile digital broadcast signal transmitter uses a square root raised cosine roll-off filter to pulse shape the signal of the signal frame.

The certain anti-noise mobile digital broadcast signal transmitter converts the baseband signal up to the carrier to form a radio frequency signal and transmits it to the wireless channel in the air.

The anti-noise mobile digital broadcast signal receiver detects and receives the radio frequency signal sent by the anti-noise mobile digital broadcast signal transmitter and converts it down to form a baseband signal, and uses the characteristics of the training sequence and the structural characteristics of the signal frame to receive and process the baseband signal , including joint iterative separation processing of the time-frequency domain of the signal frame header and the signal frame body.

The specific embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and those skilled in the art can make various modifications without departing from the spirit and scope of the claims of the application modify or remodel.

Claims (6)

1. An anti-noise mobile digital broadcasting signal transmission method is characterized in that it comprises the following steps: 1) The anti-noise mobile digital broadcast signal transmitter converts the multimedia data stream into a bit stream through the media data processor, and uses the scrambling code sequence generated by the feedback shift register to perform scrambling processing to form the input data bit stream; 2) The anti-noise mobile digital broadcast signal transmitter forms an FFT encoded data block in the frequency domain after its input data bit stream undergoes LDPC encoding, symbol modulation and symbol rotation. LDPC means low-density parity check, and FFT encoded data The length of the block is K, and the value of K is an even number; the symbol modulation is one of QPSK, 16QAM, 64QAM and 256QAM, and the symbol constellation mapping method of the symbol modulation adopts Gray code mapping; The constellation diagram is realized by rotating a certain angle. The rotation angle of the symbol constellation diagram of QPSK is 22.5 degrees, the rotation angle of the symbol constellation diagram of 16QAM is 11.25 degrees, the rotation angle of the symbol constellation diagram of 64QAM is 5.626 degrees, and the rotation angle of the symbol constellation diagram of 256QAM The rotation angle is 2.8125 degrees; 3) The anti-noise mobile digital broadcast signal transmitter uses IFFT to transform the FFT coded data block into a time-domain discrete coded data sample block D _total = [d ₀ , d ₁ ,..., d _K-2 , d _K-1 ]; 4) The anti-noise mobile digital broadcasting signal transmitter demultiplexes the time-domain discrete coded data sample blocks and sequentially separates and generates time-domain discrete coded data sample odd sub-blocks according to the order of each time-domain discrete coded data sample. _Dodd =[d ₀ , d ₂ ,..., d _K-4 , d _K-2 ] and time-domain discrete coded data sample even sub-block _Deven =[d ₁ , d ₃ ,...,d _K-3 , dK _-1 ]; 5) The anti-noise mobile digital broadcast signal transmitter adjusts the signal power of the odd sub-block Dodd of time-domain discretely coded data samples and _{the even} sub-block D of time-domain discretely coded data samples through the peak- _to-average power ratio adjustment unit and the corresponding signal Process and re-synthesize a new time-domain discretely coded data sample block _Dnew , the new time-domain discretely coded data sample block _Dnew is obtained using the following generation mode, generation mode 1 is _Dnew =[ _Dodd , _Deven ], Generate schema 2 as

Generate schema 3 as

Generate schema 4 as

Generate schema 5 as

Generate schema 6 as Generation mode 7 is D _new = [D ^* _odd , D _even ], generation mode 8 is

Generate schema 9 as

Generate schema 10 as

Generate schema 11 as

Generate schema 12 as

Generation mode 13 is D _new = [D _odd , D ^* _even ], generation mode 14 is

Generate schema 15 as

Generate schema 16 as

Generate schema 17 as

Generate schema 18 as Compare the time-domain discrete-coded data sample block D _new synthesized by 18 generation modes, and select the time-domain discrete-coded data sample block with the lowest peak-to-average power ratio

and reduce the peak-to-average power ratio time-domain discretely coded data sample block

The generated mode information correspondingly adopted is sent to the service indicator sequence setting unit, wherein, D ^* _odd means that the time-domain discrete-coded data samples of the odd sub-block Dodd of _the time-domain discrete-coded data samples are conjugated and processed to obtain The time-domain discretely coded data sample sub-block; D ^* _even represents the time-domain discretely coded data obtained by performing conjugate operation on _each time-domain discretely coded data sample of the time-domain discretely coded data sample even sub-block Deven sample sub-block; 6) The anti-noise mobile digital broadcast signal transmitter inserts the service index sequence behind the training sequence to form a time-domain embedded training sequence discrete sample block in the time domain. The service index sequence contains and uniquely expresses the anti-noise mobile digital broadcast signal transmitter Each system parameter and business mode information; the length of the time-domain embedded training sequence discrete sample block is numerically equal to the length of the peak-to-average power ratio time-domain discrete coded data sample block; 7) The anti-noise mobile digital broadcasting signal transmitter directly superimposes the time-domain discrete coded data sample block with reduced peak-to-average power ratio and the discrete sample value block of the time-domain embedded training sequence to form a time-domain embedded training sequence with reduced peak-to-average power ratio time-domain discrete coded data sample blocks as frame bodies; 8) The anti-noise mobile digital broadcasting signal transmitter uses the cyclic prefix as a guard interval, that is, the frame header is inserted into the time domain embedding training sequence to reduce the peak-to-average power ratio, and the time domain discretely encoded data sample block is the frame body to form a signal frame. length is C; 9) The anti-noise mobile digital broadcast signal transmitter adopts the square root raised cosine roll-off filter to shape the signal pulse of the signal frame; 10) The anti-noise mobile digital broadcast signal transmitter up-converts the baseband signal to the carrier to form a radio frequency signal and transmit it to the air wireless channel; 11) The anti-noise mobile digital broadcast signal receiver detects and receives the radio frequency signal sent by the anti-noise mobile digital broadcast signal transmitter and down-converts it to form a baseband signal, and uses the characteristics of the training sequence and the structural characteristics of the signal frame to receive and process the baseband signal. 2. by the anti-noise mobile digital broadcast signal transmission method of claim 1, it is characterized in that: described training sequence is made up of the first training sequence and the second training sequence; The first training sequence is by constant envelope zero autocorrelation CAZAC sequence B The new sequence generated by alternately inserting each symbol of the pseudo-random PN sequence A and its cyclic prefix of length G; the second training sequence is composed of the constant envelope zero autocorrelation CAZAC sequence-B ^* and the pseudo-random PN sequence A ^* Each symbol is alternately inserted into a new sequence and a cyclic prefix of length G; B ^* means to perform conjugate operation processing on each symbol of B, A ^* means to perform conjugate operation processing on each symbol of A, and B Has the same symbol length L as A. 3. The anti-noise mobile digital broadcasting signal transmission method according to claim 1, characterized in that: said C is 1/16 of K; said G is 1/8 of L. 4. The anti-noise mobile digital broadcast signal transmission method according to claim 1, characterized in that: said service index sequence has a pseudo-random property and is realized by a group of shifted m sequences. 5. by the anti-noise mobile digital broadcasting signal transmission method of claim 1, it is characterized in that: said FFT coded data block is made up of subcarrier, and the frequency interval of subcarrier gets a kind of in 2KHz, 4KHz, 1KHz; Data is LDPC-encoded at one of 1/4, 1/2, 5/8, 3/4, and 7/8. 6. by the anti-noise mobile digital broadcast signal transmission method of claim 1, it is characterized in that: the baseband signal receiving process that described anti-noise mobile digital broadcast signal receiver carries out, one of the steps is signal frame header and signal frame body The time-frequency domain joint iterative separation process.

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