CN103763241A - Anti-noise mobile signal transmission method for digital broadcast single frequency network - Google Patents

Abstract

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

Description

Transmission method of anti-noise mobile signal in digital broadcasting single frequency network

technical field

The invention belongs to the field of wireless communication, and more specifically relates to a digital broadcast single frequency network anti-noise mobile signal transmission method.

Background technique

As an important part of digital TV wireless digital broadcasting, the single frequency network wireless transmission system of digital TV 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 wireless 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 related technologies of digital TV wireless digital broadcasting, countries are currently focusing on how to provide low-cost, reliable and high-speed mobile implementation solutions for digital TV wireless digital broadcasting in a complex wave propagation environment. The framing modulation technology of the anti-noise mobile signal transmitter of the digital broadcast single frequency network is the key technology of the digital TV wireless digital broadcasting system.

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 wireless digital broadcasting.

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.

The networking mode of single frequency network (that is, several transmitting stations transmit the same signal on the same frequency at the same time to achieve reliable coverage of a certain service area) can greatly improve the wireless transmission system of digital TV digital broadcasting single frequency network. Spectrum utilization. In the actual SFN communication environment, the performance of the digital TV digital broadcasting SFN wireless communication system is affected by factors such as synchronization time, clock jitter, channel fading, and channel interference. The transmission method of each digital broadcast anti-noise mobile signal transmitter in the single frequency network is a key technology for realizing reliable digital television digital broadcast single frequency network wireless transmission.

Using the digital TV digital broadcast single frequency network wireless 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 digital broadcast single frequency network wireless transmission system to meet social needs. .

Based on the above background, the present invention proposes a digital broadcasting single frequency network anti-noise mobile signal transmission method for the actual communication environment, which can meet the needs of high data rate controllable multi-service digital television digital broadcasting single frequency network wireless 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 high data rate controllable multi-service digital television digital broadcasting single frequency network wireless problem, the invention proposes a digital broadcasting single frequency network anti-noise mobile signal transmission method.

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

1) The central data manager of the single frequency network 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 an input data bit stream;

2) The network data manager of the single frequency network forms an FFT encoded data block in the frequency domain after the input data bit stream undergoes LDPC encoding, symbol modulation and symbol rotation. LDPC means low-density parity check, and the FFT encoded data block The length is K, and the value of K is an even number;

3) The network data manager of the single frequency network uses a space-frequency encoder with a code rate of 1 to modulate the FFT coded data block formed in the frequency domain to each digital broadcast anti-noise mobile signal transmitter branch in the single frequency network to form Space-frequency modulation FFT coded data blocks, and adjust the time synchronization of each digital broadcast single frequency network anti-noise mobile signal transmitter branch to ensure that all transmitters in the network process the space-frequency modulated FFT coded data blocks at the same time;

4) Each digital broadcast anti-noise mobile signal transmitter in the single frequency network uses IFFT to transform the space-frequency modulation FFT coded data block into a space-frequency modulation time-domain discrete coded data sample block D _total = [d ₀ , d ₁ ,  … , d _K-2 , d _K-1 ];

5) Each digital broadcast anti-noise mobile signal transmitter in the single frequency network demultiplexes the space-frequency modulation time-domain discrete-coded data sample block and performs the parity sequence according to the sequence of each space-frequency modulation time-domain discrete-coded data sample Separately generate space-frequency modulation time-domain discretely coded data sample odd sub-block _Dodd =[d ₀ , d ₂ ,...,d _K-4 , d _K-2 ] and space-frequency modulation time-domain discretely coded data sample even sub-block Block D _even = [d ₁ , d ₃ , . . . , d _K-3 , d _K-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种生成模式合成的空频调制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空频调制时域离散编码数据样值块

并将降峰均功率比空频调制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^*奇表示对空频调制时域离散编码数据样值奇子块D_奇的各空频调制时域离散编码数据样值进行共轭运算处理而得到的空频调制时域离散编码数据样值子块；D^*偶表示对空频调制时域离散编码数据样值偶子块D_偶的各空频调制时域离散编码数据样值进行共轭运算处理而得到的空频调制时域离散编码数据样值子块；6) Each digital broadcast anti-noise mobile signal transmitter in the single frequency network uses the peak-to-average power ratio adjustment unit to space-frequency modulated time-domain discretely coded data sample odd sub-block D _odd , space-frequency modulated time-domain discretely coded data sample The even sub-block D _even performs signal power adjustment and corresponding signal processing and re-synthesizes a new space-frequency modulation time-domain discrete-coded data sample block _Dnew , and the new space-frequency modulation time-domain discrete-coded data sample block _Dnew is generated as follows The pattern is obtained, the generation pattern 1 is D _new =[D _odd , D _even ], and the generation pattern 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 space-frequency modulation time-domain discrete-coded data sample block D _new synthesized by 18 generation modes, and select the space-frequency modulation time-domain discrete-coded data sample block with the lowest peak-to-average power ratio among them

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

The generated mode information correspondingly adopted is sent to the service index sequence setting unit, wherein, D ^* odd means that each space-frequency modulated time-domain discrete-coded data sample value of the odd sub-block D _odd is performed The space-frequency modulation time-domain discretely coded data sample sub-blocks obtained by the conjugate operation; D ^* even represents each space-frequency modulation time-domain discretely coded data of the space-frequency modulation time-domain discretely coded data sample _even sub-block Deven Space-frequency modulated time-domain discretely coded data sample sub-blocks obtained by performing conjugate operation on the samples;

7) Each digital broadcast anti-noise mobile signal transmitter in the single frequency network inserts a service index sequence behind the training sequence to form a time domain training sequence discrete sample value block in the time domain. The service index sequence contains and uniquely expresses the single frequency network Each system parameter and business mode information of each digital broadcast anti-noise mobile signal transmitter in ;

8) Each digital broadcast anti-noise mobile signal transmitter in the single frequency network inserts the cyclic prefix as a guard interval into the time-domain discrete coded data sample block of the reduced peak-to-average power ratio space-frequency modulation to form a reduced peak-to-average power ratio space-frequency modulation The domain cyclic prefix discretely coded data sample block is used as the frame body, and the length of the cyclic prefix is C;

9) Each digital broadcast anti-noise mobile signal transmitter in the single frequency network inserts the time-domain training sequence discrete sample value block, that is, the frame header, into the peak-to-average power ratio space-frequency modulation time-domain cyclic prefix discrete coded data sample block, that is, the frame body to form a signal frame;

10) Each digital broadcast anti-noise mobile signal transmitter in the single frequency network uses a square root raised cosine roll-off filter to shape the signal pulse of the signal frame;

11) Each digital broadcast anti-noise mobile signal transmitter in the single frequency network up-converts the baseband signal to the carrier to form a radio frequency signal and transmit it to the wireless channel in the air;

12) The digital broadcast anti-noise mobile signal receiver in the single frequency network detects and receives the radio frequency signal sent by each digital broadcast anti-noise mobile signal transmitter in the single frequency network and down-converts it to form a baseband signal, using the characteristics of the training sequence and The structural characteristics of the signal frame are used for baseband signal reception processing.

According to the above-mentioned digital broadcast single frequency network anti-noise mobile signal transmission method, it is characterized in that: the peak-to-average power ratio of each digital broadcast anti-noise mobile signal transmitter in the single frequency network The space-frequency modulation time-domain discrete-coded data sample odds are generated by demultiplexing the space-frequency modulation time-domain discrete-coded data sample block and sequentially separating the odd-even sequence of each space-frequency-modulated time-domain discrete-coded data sample Block and space-frequency modulation time-domain discrete coded data sample even sub-blocks for signal power adjustment and corresponding signal processing and re-synthesis through 18 specifically designed generation modes; each digital broadcast anti-noise mobile signal transmitter in the single frequency network The training sequence is composed of the first training sequence and the second training sequence; the first training sequence is a new sequence whose length is G The cyclic prefix is composed of; the second training sequence is composed of a constant envelope zero autocorrelation CAZAC sequence-B ^* and a new sequence generated by alternately inserting each symbol of the pseudo-random PN sequence A ^* and its cyclic prefix of length G; B ^* Indicates that the conjugate operation is performed on each symbol of B, A ^* indicates that the conjugate operation is performed on each symbol of A, B and A have the same symbol length L; the cyclic prefix of the first training sequence and the second training sequence The length G is 1/8 of the symbol length L of the first training sequence and the second training sequence; the cyclic prefix length C of the signal frame of each digital broadcast anti-noise mobile signal transmitter in the single frequency network is 1/8 of the length K of the FFT coded data block 1/16; The service index sequence of each digital broadcast anti-noise mobile signal transmitter in the single frequency network has pseudo-random characteristics, and is realized by a set of shifted m sequences; each digital broadcast anti-noise mobile signal transmitter in the single frequency network Each different service index sequence contains and uniquely expresses the system parameters and business mode information of each digital broadcast anti-noise mobile signal transmitter in the single frequency network; each digital broadcast anti-noise mobile signal transmitter in the single frequency network The FFT encoded data block is composed of subcarriers, and the frequency interval of subcarriers is one of 2KHz, 4KHz, 1KHz; the encoding rate of LDPC encoding for input data is 1/4, 1/2, 5/8, 3/4 and one of 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 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 is 2.8125 degrees degree; the code rate of the space frequency coder is 1. The digital broadcast anti-noise mobile signal receiver in the single frequency network can make full use of the characteristics of the training sequence and the structural characteristics of the signal frame to receive and process the baseband signal, including the joint iterative separation of the time-frequency domain of the signal frame header and the signal frame body.

Features of the present invention:

The invention is a framing modulation scheme in which space domain, time domain and frequency domain are mixed. In the present invention, the space-frequency modulation time-domain discrete-coded data sample block is demultiplexed, and the odd-even sequence of each space-frequency-modulated time-domain discrete-coded data sample is sequentially separated to generate space-frequency modulated time-domain discrete-coded data sample odds Block and space-frequency modulation time-domain discrete coded data sample even sub-blocks and the corresponding signal power adjustment and signal processing, through specially designed 18 kinds of reduced peak-to-average power ratio space-frequency modulation time-domain discrete coded data sample block The generation mode and the reduced peak-to-average power ratio space-frequency modulation with the lowest peak-to-average power ratio have a time-domain discrete coded data sample block selection method, which can not only make full use of the maximum peak power of the OFDM signal, but the probability of high peak power signals is very low, When the number of subcarriers is large, the real part (or imaginary part) of the OFDM signal is a complex Gaussian random process and the amplitude obeys the characteristics of Rayleigh distribution, thereby effectively changing the power distribution law of the framed signal with low complexity to reduce the peak-to-average power ratio For the purpose of the generation mode, the amount of additional information required to be sent is small, and it is easy to process and restore the original signal of the OFDM signal at the receiver without destroying the orthogonality characteristics of the subcarrier signal and generating additional nonlinearity distortion. The training sequence in the signal frame of each digital broadcast anti-noise mobile signal transmitter in the single frequency network is obtained by a specific optimization design of the constant envelope zero autocorrelation CAZAC sequence and the pseudo-random PN sequence. The signal frame of the anti-noise mobile signal transmitter is formed by inserting the discrete sample block of the time domain training sequence, that is, the frame header, into the discrete coded data sample block, that is, the frame body, of the time domain cyclic prefix of the space-frequency modulation with reduced peak-to-average power ratio. The digital broadcast single frequency network anti-noise mobile signal receiver can realize fast and accurate frame synchronization, frequency synchronization, time synchronization, estimation of channel transmission characteristics, and reliable tracking of phase noise and channel transmission characteristics. The cyclic prefix is inserted as a guard interval into the time-domain discrete coded data sample block with reduced peak-to-average power ratio space-frequency modulation to form a signal frame body, which can reduce the interference effect between the signal frame header and frame body data. Channel coding the input data with LDPC codes provides error correction performance close to the Shannon limit. Symbol modulation and symbol rotation provide diversity effects for mobile digital broadcasting signals. Each different service index sequence of each digital broadcast anti-noise mobile signal transmitter in the single frequency network contains and uniquely expresses each system parameter and business mode information of each digital broadcast anti-noise mobile signal transmitter in the single frequency network, It can make the digital TV digital broadcast single frequency network wireless transmission system able to provide controllable multi-services such as free TV broadcast, paid TV broadcast, 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, and can provide high data rate controllable multi-service digital television digital broadcast single frequency network wireless transmission.

Description of drawings

FIG. 1 is a schematic diagram of an embodiment of signal transmission between a transmitter and a receiver in a method for transmitting a noise-resistant mobile signal in a digital broadcast single frequency network according to the present invention.

Fig. 2 is a schematic diagram of an embodiment of signal frame formation during the signal transmission process between the transmitter and the receiver of the digital broadcast single frequency network anti-noise mobile signal transmission method according to 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 embodiment diagram of the signal transmission between the transmitter and the receiver of the digital broadcast single frequency network anti-noise mobile signal transmission method proposed by the present invention, as shown in Figure 1, carry out according to the following steps:

1) The central data manager of the single frequency network 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 an input data bit stream;

2) The network data manager of the single frequency network forms an FFT encoded data block in the frequency domain after the input data bit stream undergoes LDPC encoding, symbol modulation and symbol rotation. LDPC means low-density parity check, and the FFT encoded data block The length is K, and the value of K is an even number; the encoding rate of LDPC encoding for input data is one of 1/4, 1/2, 5/8, 3/4, and 7/8; the symbol modulation is QPSK, 16QAM One of , 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 by a certain angle, and the symbol constellation rotation angle 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 is 2.8125 degrees;

3) The network data manager of the single frequency network uses a space-frequency encoder with a code rate of 1 to modulate the FFT coded data block formed in the frequency domain to each digital broadcast anti-noise mobile signal transmitter branch in the single frequency network to form Space-frequency modulation FFT coded data blocks, and adjust the time synchronization of each digital broadcast single frequency network anti-noise mobile signal transmitter branch to ensure that all transmitters in the network process the space-frequency modulated FFT coded data blocks at the same time;

4) Each digital broadcast anti-noise mobile signal transmitter in the single frequency network uses IFFT to transform the space-frequency modulation FFT coded data block into a space-frequency modulation time-domain discrete coded data sample block D _total = [d ₀ , d ₁ ,  … , d _K-2 , d _K-1 ];

5) Each digital broadcast anti-noise mobile signal transmitter in the single frequency network demultiplexes the space-frequency modulation time-domain discrete-coded data sample block and performs the parity sequence according to the sequence of each space-frequency modulation time-domain discrete-coded data sample Separately generate space-frequency modulation time-domain discretely coded data sample odd sub-block _Dodd =[d ₀ , d ₂ ,...,d _K-4 , d _K-2 ] and space-frequency modulation time-domain discretely coded data sample even sub-block Block D _even = [d ₁ , d ₃ , . . . , d _K-3 , d _K-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种生成模式合成的空频调制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空频调制时域离散编码数据样值块

并将降峰均功率比空频调制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^*奇表示对空频调制时域离散编码数据样值奇子块D_奇的各空频调制时域离散编码数据样值进行共轭运算处理而得到的空频调制时域离散编码数据样值子块；D^*偶表示对空频调制时域离散编码数据样值偶子块D_偶的各空频调制时域离散编码数据样值进行共轭运算处理而得到的空频调制时域离散编码数据样值子块；6) Each digital broadcast anti-noise mobile signal transmitter in the single frequency network uses the peak-to-average power ratio adjustment unit to space-frequency modulated time-domain discretely coded data sample odd sub-block D _odd , space-frequency modulated time-domain discretely coded data sample The even sub-block D _even performs signal power adjustment and corresponding signal processing and re-synthesizes a new space-frequency modulation time-domain discrete-coded data sample block _Dnew , and the new space-frequency modulation time-domain discrete-coded data sample block _Dnew is generated as follows The pattern is obtained, the generation pattern 1 is D _new =[D _odd , D _even ], and the generation pattern 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 space-frequency modulation time-domain discrete-coded data sample block D _new synthesized by 18 generation modes, and select the space-frequency modulation time-domain discrete-coded data sample block with the lowest peak-to-average power ratio among them

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

The generated mode information correspondingly adopted is sent to the service index sequence setting unit, wherein, D ^* odd means that each space-frequency modulated time-domain discrete-coded data sample value of the odd sub-block D _odd is performed The space-frequency modulation time-domain discretely coded data sample sub-blocks obtained by the conjugate operation; D ^* even represents each space-frequency modulation time-domain discretely coded data of the space-frequency modulation time-domain discretely coded data sample _even sub-block Deven Space-frequency modulated time-domain discretely coded data sample sub-blocks obtained by performing conjugate operation on the samples;

7) Each digital broadcast anti-noise mobile signal transmitter in the single frequency network inserts a service index sequence behind the training sequence to form a time domain training sequence discrete sample value block in the time domain. The service index sequence contains and uniquely expresses the single frequency network Each system parameter and business mode information of each digital broadcast anti-noise mobile signal transmitter in ;

8) Each digital broadcast anti-noise mobile signal transmitter in the single frequency network inserts the cyclic prefix as a guard interval into the time-domain discrete coded data sample block of the reduced peak-to-average power ratio space-frequency modulation to form a reduced peak-to-average power ratio space-frequency modulation The domain cyclic prefix discretely coded data sample block is used as the frame body, and the length of the cyclic prefix is C;

9) Each digital broadcast anti-noise mobile signal transmitter in the single frequency network inserts the time-domain training sequence discrete sample value block, that is, the frame header, into the peak-to-average power ratio space-frequency modulation time-domain cyclic prefix discrete coded data sample block, that is, the frame body to form a signal frame;

10) Each digital broadcast anti-noise mobile signal transmitter in the single frequency network uses a square root raised cosine roll-off filter to shape the signal pulse of the signal frame;

11) Each digital broadcast anti-noise mobile signal transmitter in the single frequency network up-converts the baseband signal to the carrier to form a radio frequency signal and transmit it to the wireless channel in the air;

12) The digital broadcast anti-noise mobile signal receiver in the single frequency network detects and receives the radio frequency signal sent by each digital broadcast anti-noise mobile signal transmitter in the single frequency network and down-converts it to form a baseband signal, using the characteristics of the training sequence and The structural characteristics of the signal frame are used for baseband signal reception processing.

According to the embodiment of the signal frame formation (assuming that there are N transmitters in the single frequency network) in the signal transmission process between the transmitter and the receiver of the digital broadcast single frequency network anti-noise mobile signal transmission method of the present invention, as shown in Figure 2 , the specific implementation is as follows:

The central data manager of the single frequency network 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.

The network data manager of the single frequency network forms an FFT encoded data block in the frequency domain after the input data bit stream undergoes LDPC encoding, symbol modulation and symbol rotation. LDPC means low-density parity check; The frequency coder modulates the FFT encoded data blocks formed in the frequency domain to each digital broadcast anti-noise mobile signal transmitter branch in the single frequency network to form space-frequency modulation FFT encoded data blocks, and adjusts the anti-noise of each digital broadcast single frequency network The time synchronization of the noise-moving signal transmitter branch ensures that all transmitters in the network process the space-frequency modulation FFT coded data block at the same time; and then transform it into space-frequency modulation time-domain discrete coded data samples by IFFT block, the peak-to-average power ratio adjustment unit is used to generate and select the reduced peak-to-average power ratio space-frequency modulation time-domain discrete-coded data sample block with the lowest peak-to-average power ratio, and at the same time, the corresponding generated mode information is sent to the service index sequence Set up the unit.

The FFT encoded data block of each digital broadcast anti-noise mobile signal transmitter in the single frequency network is composed of subcarriers, and the frequency interval of the subcarriers is one of 2KHz, 4KHz, and 1KHz; the encoding rate of LDPC encoding for input data is 1 One of /4, 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; symbol rotation is realized by rotating the symbol constellation diagram at 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, and the symbol constellation rotation angle of 256QAM is 2.8125 degrees.

The training sequence of each digital broadcast anti-noise mobile signal transmitter in the single frequency network is made up of the first training sequence and the second training sequence; Each symbol is alternately inserted into a new sequence and a cyclic prefix of length G; the second training sequence is generated by alternately inserting each symbol of the constant envelope zero autocorrelation CAZAC sequence-B ^* and the pseudo-random PN sequence A ^* The new sequence and its cyclic prefix whose length is G; B ^* means to perform conjugate operation processing on each symbol of B, and 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.

Each digital broadcast anti-noise mobile signal transmitter in the single frequency network inserts a service index sequence behind the training sequence to form a time domain training sequence discrete sample block in the time domain.

The service index sequence of each digital broadcast anti-noise mobile signal transmitter in the single frequency network has pseudo-random characteristics, and is realized by a set of shifted m sequences; each digital broadcast anti-noise mobile signal transmitter in the single frequency network has different The service index sequence contains and uniquely expresses the system parameters and service mode information of each digital broadcast anti-noise mobile signal transmitter in the single frequency network.

Each digital broadcast anti-noise mobile signal transmitter in the single frequency network inserts the cyclic prefix as a guard interval into the time-domain discrete coded data sample block with reduced peak-to-average power ratio space-frequency modulation to form a time-domain cycle with reduced peak-to-average power ratio space-frequency modulation Prefix discrete coded data sample block, as the frame body, the length of the cyclic prefix is C; each digital broadcast anti-noise mobile signal transmitter in the single frequency network inserts the discrete sample value block of the time domain training sequence, that is, the frame header, into the peak-average Power ratio space-frequency modulation time-domain cyclic prefix discrete coded data sample block is the frame body to form a signal frame; the cyclic prefix length C of each digital broadcast anti-noise mobile signal transmitter signal frame in the single frequency network is an FFT coded data block 1/16 of the length K.

Each digital broadcast anti-noise mobile signal transmitter in the single frequency network uses a square root raised cosine roll-off filter to pulse-shape the signal of the signal frame.

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

The digital broadcast anti-noise mobile signal receiver in the single frequency network detects and receives the radio frequency signal sent by each digital broadcast anti-noise mobile signal transmitter in the single frequency network and down-converts it to form a baseband signal, using the characteristics of the training sequence and the signal frame Based on the structural characteristics of the baseband signal receiving process, including the time-frequency domain joint iterative separation process of the signal frame header and 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. a noise-resistance mobile signal transmission method for digital broadcasting single frequency network, is characterized in that it comprises the following steps:

1) the centre data manager of single frequency network converts the multi-medium data media data processor of flowing through to bit stream, and the scrambler sequence of utilizing feedback shift register to produce is carried out scrambling processing to form input data bit flow;

2) the network data management device of single frequency network is flowed through input data bit after LDPC coding, code element modulation are rotated with code element and on frequency domain, is formed FFT coded data block, LDPC represents low-density checksum, the length of FFT coded data block is K, and the numerical value of K is got even number; Code element is modulated to the one in QPSK, 16QAM, 64QAM and 256QAM, and the symbol constellations figure mapping mode of code element modulation adopts Gray code mapping; Code element is rotated by symbol constellations figure is rotated to an angle and realized, the symbol constellations figure anglec of rotation of QPSK is 22.5 degree, the symbol constellations figure anglec of rotation of 16QAM is 11.25 degree, the symbol constellations figure anglec of rotation of 64QAM is 5.626 degree, and the symbol constellations figure anglec of rotation of 256QAM is 2.8125 degree;

3) to adopt code check be 1 to the network data management device of single frequency network that space-frequency coding device is modulated to the FFT coded data block forming on frequency domain in each digital broadcasting antinoise movable signal transmitter branches in single frequency network and forms empty frequency modulation FFT coded data block processed, and the time synchronized of adjusting each digital broadcast single-frequency network antinoise movable signal transmitter branches is all processed empty frequency modulation FFT coded data block processed at one time with all transmitters in assurance network;

4) each digital broadcasting antinoise movable signal transmitter in single frequency network adopts IFFT that FFT coded data block processed empty frequency modulation is transformed to sky frequency modulation time domain discrete coded data processed sample value piece D _total=[d ₀, d ₁..., d _k-2, d _k-1];

5) each digital broadcasting antinoise movable signal transmitter in single frequency network separates successively and generates the strange sub-block D of empty frequency modulation time domain discrete coded data processed sample value by time domain discrete coded data sample value piece demultiplexing processed empty frequency modulation and according to the sequencing odd even of each empty frequency modulation time domain discrete coded data processed sample value _very=[d ₀, d ₂..., d _k-4, d _k-2] and the even sub-block D of empty frequency modulation time domain discrete coded data processed sample value _even=[d ₁, d ₃..., d _k-3, d _k-1];

6) each digital broadcasting antinoise movable signal transmitter in single frequency network passes through peak-to-average power ratio adjustment unit to the strange sub-block D of empty frequency modulation time domain discrete coded data processed sample value _very, the even sub-block D of empty frequency modulation time domain discrete coded data processed sample value _evencarry out signal power adjustment and corresponding signal and process also synthetic new empty frequency modulation time domain discrete coded data processed sample value piece D again _new, new empty frequency modulation time domain discrete coded data processed sample value piece D _newadopt following generate pattern to obtain, generate pattern 1 is D _new=[D _very, D _even], generate pattern 2 is

generate pattern 3 is generate pattern 4 is

generate pattern 5 is

generate pattern 6 is

generate pattern 7 is D _new=[D ^* _very, D _even], generate pattern 8 is

generate pattern 9 is

generate pattern 10 is

generate pattern 11 is

generate pattern 12 is

generate pattern 13 is D _new=[D _very, D ^* _even], generate pattern 14 is

generate pattern 15 is

generate pattern 16 is

generate pattern 17 is

generate pattern 18 is

relatively 18 kinds of empty frequency modulation time domain discrete coded data processed sample value piece D that generate pattern is synthetic _new, choose wherein there is minimum peak-to-average power ratio the empty frequency modulation of peak-to-average power ratio time domain discrete coded data processed sample value piece falls

and the empty frequency modulation of peak-to-average power ratio time domain discrete coded data processed sample value piece will fall the corresponding generate pattern information adopting send to operational indicator sequence setting unit, wherein, D ^*very represent the strange sub-block D of empty frequency modulation time domain discrete coded data processed sample value _veryeach empty frequency modulation time domain discrete coded data processed sample value carry out conjugate operation processing and the empty frequency modulation time domain discrete coded data processed sample value sub-block that obtains; D ^* _evenexpression is to the even sub-block D of empty frequency modulation time domain discrete coded data processed sample value _eveneach empty frequency modulation time domain discrete coded data processed sample value carry out conjugate operation processing and the empty frequency modulation time domain discrete coded data processed sample value sub-block that obtains;

7) each digital broadcasting antinoise movable signal transmitter Insert service index series after training sequence in single frequency network forms time-domain training sequence discrete sample block in time domain, and operational indicator sequence is comprising and unique each system parameters and business model information of expressing each digital broadcasting antinoise movable signal transmitter in single frequency network;

8) each digital broadcasting antinoise movable signal transmitter in single frequency network inserts using Cyclic Prefix as protection interval and falls the empty frequency modulation of peak-to-average power ratio time domain discrete coded data processed sample value piece, the discrete coded data sample value of the empty frequency modulation time domain cyclic prefix processed of peak-to-average power ratio piece falls in formation, as frame, the length of Cyclic Prefix is C;

9) each digital broadcasting antinoise movable signal transmitter in single frequency network is that frame head is inserted into that to fall the discrete coded data sample value of the empty frequency modulation time domain cyclic prefix processed of peak-to-average power ratio piece be frame by time-domain training sequence discrete sample block, to form signal frame;

10) each digital broadcasting antinoise movable signal transmitter in single frequency network adopts square root raised cosine filter to be shaped to the signal pulse of signal frame;

11) each digital broadcasting antinoise movable signal transmitter in single frequency network forms emission of radio frequency signals to on-air radio channel by baseband signal up-conversion to carrier wave;

12) radiofrequency signal that each digital broadcasting antinoise movable signal transmitter in the detection of the digital broadcasting antinoise movable signal receiver in single frequency network reception single frequency network sends also forms baseband signal by its down-conversion, utilizes the architectural characteristic of training sequence characteristic and signal frame to carry out baseband signal reception & disposal.

2. by the noise-resistance mobile signal transmission method for digital broadcasting single frequency network of claim 1, it is characterized in that: described training sequence is comprised of the first training sequence and the second training sequence; The Cyclic Prefix that the first training sequence is G by each symbol new sequence that alternately insertion produces and the length thereof of permanent envelope zero auto-correlation CAZAC sequence B and pseudorandom PN sequence A forms; The second training sequence is by permanent envelope zero auto-correlation CAZAC sequence-B ^*with pseudorandom PN sequence A ^*each symbol alternately insert the Cyclic Prefix composition that the new sequence that produces and length thereof are G; B ^*expression is carried out conjugate operation processing, A to each symbol of B ^*expression is carried out conjugate operation processing to each symbol of A, and B has identical symbol lengths L with A.

3. by the noise-resistance mobile signal transmission method for digital broadcasting single frequency network of claim 1, it is characterized in that: described C gets 1/16 of K; Described G gets 1/8 of L.

4. by the noise-resistance mobile signal transmission method for digital broadcasting single frequency network of claim 1, it is characterized in that: described operational indicator sequence has pseudo-random characteristics, by one group of Phase shift m sequence, realized.

5. by the noise-resistance mobile signal transmission method for digital broadcasting single frequency network of claim 1, it is characterized in that: described FFT coded data block is comprised of subcarrier, and the frequency interval of subcarrier is got the one in 2KHz, 4KHz, 1KHz; The described encoding rate that carries out LDPC coding to inputting data is in 1/4,1/2,5/8,3/4 and 7/8.

6. by the noise-resistance mobile signal transmission method for digital broadcasting single frequency network of claim 1, it is characterized in that: the baseband signal reception & disposal that described digital broadcast single-frequency network antinoise movable signal receiver carries out, one of them step is the time domain and frequency domain combined alternate analysis processing of signal frame head and signal frame body.

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