CN102255855B - Anti-noise method for transmitting wireless digital broadcast signal - Google Patents

Abstract

The invention discloses an anti-noise wireless digital broadcasting signal transmission method, which is a time-domain and frequency-domain mixed transmission scheme. The anti-noise wireless digital broadcast signal transmission method of the invention has the advantages of low peak-to-average power ratio, short synchronization time, anti-noise influence, controllable multi-service and the like.

Description

An anti-noise wireless digital broadcasting signal transmission method

technical field

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

Background technique

At present, television broadcasting has gradually developed from analog to digital. Digital TV wireless digital broadcasting transmission system, as an important part of digital TV wireless 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 technologies related to digital TV anti-noise wireless digital broadcasting, countries are currently focusing on how to provide low-cost, reliable and high-speed mobile implementation solutions for digital TV anti-noise wireless digital broadcasting in a complex wave propagation environment. Anti-noise wireless digital broadcasting signal transmitter transmission technology is the key technology of digital TV anti-noise wireless digital broadcasting 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, Widely used in many fields such as digital TV anti-noise 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.

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 symbols are embedded in the information sequence, and the channel coding technology reduces the error in the signal transmission process through the role of redundant symbols, thereby improving the reliability of the communication system. Low Density Parity Check (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 wireless digital broadcasting communication system is affected by factors such as synchronization time, clock jitter, channel fading, and channel interference. The transmission method of the anti-noise wireless digital broadcasting signal transmitter is the key technology to realize the reliable digital television anti-noise wireless digital broadcasting.

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

Based on the above background, the present invention proposes an anti-noise wireless 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 wireless 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.183-1294, Jan. .

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.

Z.Li, L.Chen, L.Zeng, S.Lin, W.Fong, "Efficient encoding of quasi-cyclic low-density parity-check codes," IEEE Trans.Commun., vol.54, no.1, pp .71-81, Jan. 2006.

Contents of the invention

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

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

1) The anti-noise wireless 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 wireless digital broadcasting signal transmitter forms an FFT coded data block on the frequency domain through LDPC encoding of its own input data bit stream, FFT represents fast discrete Fourier transform, and the length of the FFT coded data block is K;

3) The anti-noise wireless digital broadcast signal transmitter uses IFFT to transform the FFT coded data block into a time-domain discrete coded data sample block D _total , and IFFT stands for Inverse Fast Discrete Fourier Transform;

4) The anti-noise wireless digital broadcast signal transmitter divides the time-domain discretely coded data sample block into two equally in sequence, the time-domain discretely coded data sample sub-block D ₁ and the time-domain discretely coded data sample sub-block D ₂ , D _total = [D ₁ , D ₂ ];

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^* ₁表示对时域离散编码数据样值子块D₁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 wireless digital broadcast signal transmitter performs signal addition, subtraction, and conjugate operations on the time-domain discrete coded data sample sub-block D ₁ and the time-domain discrete coded data sample sub-block D ₂ through the peak-to-average power ratio adjustment unit 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 = [D ₁ , D ₂ ], Generate schema 2 as ${\mathrm{D.}}_{\mathrm{new}}=[{\mathrm{D.}}_1,\sqrt{1/2}({\mathrm{D.}}_1+{\mathrm{D.}}_2)],$ Generate schema 3 as ${\mathrm{D.}}_{\mathrm{new}}=[{\mathrm{D.}}_1,\sqrt{1/2}({\mathrm{D.}}_1-{\mathrm{D.}}_2)],$ Generate schema 4 as ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({\mathrm{D.}}_1+{\mathrm{D.}}_2),{\mathrm{D.}}_2],$ Generate schema 5 as ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({\mathrm{D.}}_1-{\mathrm{D.}}_2),{\mathrm{D.}}_2],$ Generate schema 6 as ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({\mathrm{D.}}_1+{\mathrm{D.}}_2),\sqrt{1/2}({\mathrm{D.}}_1-{\mathrm{D.}}_2)],$ Generation mode 7 is D _new = [D ^* ₁ , D ₂ ], generation mode 8 is ${\mathrm{D.}}_{\mathrm{new}}=[{{\mathrm{D.}}^{*}}_1,\sqrt{1/2}({{\mathrm{D.}}^{*}}_1+{\mathrm{D.}}_2)],$ Generate schema 9 as ${\mathrm{D.}}_{\mathrm{new}}=[{{\mathrm{D.}}^{*}}_1,\sqrt{1/2}({{\mathrm{D.}}^{*}}_1-{\mathrm{D.}}_2)],$ Generate schema 10 as ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({{\mathrm{D.}}^{*}}_1+{\mathrm{D.}}_2),{\mathrm{D.}}_2],$ Generate schema 11 as ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({{\mathrm{D.}}^{*}}_1-{\mathrm{D.}}_2),{\mathrm{D.}}_2],$ Generate schema 12 as ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({{\mathrm{D.}}^{*}}_1+{\mathrm{D.}}_2),\sqrt{1/2}({{\mathrm{D.}}^{*}}_1-{\mathrm{D.}}_2)],$ Compare the time-domain discrete-coded data sample block D _new synthesized by 12 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 index sequence setting unit, wherein, D ^* ₁ means that the time domain discrete coded data samples of the time domain discrete coded data sample sub-block _D1 are conjugated and processed Time-domain discretely coded data sample sub-blocks;

6) The anti-noise wireless digital broadcast signal transmitter uses the training sequence as the real part sequence of the complex training sequence, and uses the service index sequence set by the service index sequence setting unit as the imaginary part sequence of the complex training sequence to form a complex training sequence in the time domain The discrete sample value blocks of the sequence, the length of the discrete sample value blocks of the training sequence, the service index sequence, and the complex training sequence are all X, and the service index sequence contains and uniquely expresses the system parameters and parameters of the anti-noise wireless digital broadcasting signal transmitter business model information;

7) The anti-noise wireless digital broadcasting signal transmitter repeats the discrete sample value block of the complex training sequence formed in the time domain continuously for 4 times in the time domain to form a time domain embedded training sequence discrete sample value block, and the time domain embedded training sequence is discrete The length of the sample value block is numerically equal to the length of the time-domain discretely encoded data sample block with reduced peak-to-average power ratio, that is, K=4×X;

8) The anti-noise wireless 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;

9) The anti-noise wireless 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, that is, the frame body, to form a signal frame, and the cyclic prefix length is C;

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

11) The anti-noise wireless 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;

12) The anti-noise wireless digital broadcast signal receiver detects and receives the radio frequency signal sent by the wireless digital broadcast signal transmitter and converts it down to form a baseband signal, and uses the cyclic prefix characteristics of the signal frame and the structural characteristics of the signal frame to perform baseband signal reception processing .

According to the above-mentioned anti-noise wireless digital broadcasting signal transmission method, it is characterized in that: the reduced peak-to-average power ratio of the anti-noise wireless digital broadcasting signal transmitter is determined by the time-domain discretely coded data sample sub-block through a specific 12 kinds of generation modes for signal addition, subtraction, conjugate operation processing and re-synthesis; anti-noise wireless digital broadcasting signal transmitter signal frame has periodic time-domain embedded training sequence discrete sample blocks; anti-noise wireless digital The length X of the training sequence of the broadcast signal transmitter is one of 512, 1024, and 2048, the length K of the corresponding FFT data block is 2048, 4096, and 8192 respectively, and the frequency intervals of the corresponding subcarriers are 4KHz and 2KHz respectively , 1KHz, and the corresponding cyclic prefix lengths C are 1/4, 1/8, and 1/16 of the size of the FFT data block length K respectively; the training sequence and service index sequence of the anti-noise wireless digital broadcasting signal transmitter consist of a series of Composed of 1 or -1, with pseudo-random characteristics; the training sequence and service index sequence of the anti-noise wireless digital broadcast signal transmitter are orthogonal to each other; each different service index sequence of the anti-noise wireless digital broadcast signal transmitter contains It expresses and uniquely expresses the system parameters and business mode information of the anti-noise wireless digital broadcasting signal transmitter; the encoding rate of LDPC encoding for input data is 1/4, 1/2, 5/8, 3/4 and 7/ One of 8. The anti-noise wireless digital broadcast signal receiver can make full use of the cyclic prefix characteristics of the signal frame 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 present invention is a mixed transmission scheme of time domain and frequency domain. The generation mode of the time-domain discrete coded data sample block with reduced peak-to-average power ratio and the method for selecting the time-domain discrete-coded data sample block with the lowest peak-to-average power ratio of the present invention can not only make full use of the OFDM signal The maximum peak power is very high but the probability of high peak power signal is very low. When the number of subcarriers is large, the real part (or imaginary part) of OFDM signal is a complex Gaussian random process and the amplitude obeys the characteristics of Rayleigh distribution. The generation mode adopted The amount of additional information required to be sent is small, and the original signal of the OFDM signal is easy to process and recover 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 signal frame of the anti-noise wireless digital broadcast signal transmitter has periodic time-domain embedded training sequence discrete sample blocks, the training sequence and service index sequence of the anti-noise wireless digital broadcast signal transmitter have pseudo-random characteristics, and the anti-noise wireless digital The training sequence and service index sequence of the broadcast signal transmitter are orthogonal to each other, and the time-domain embedding training sequence of the anti-noise wireless digital broadcast signal transmitter reduces the peak-to-average power ratio. The average power ratio time domain discrete coded data sample block and the time domain embedded training sequence discrete sample block are directly superimposed, which ensures that the anti-noise wireless digital broadcast signal receiver can achieve fast and accurate frame synchronization, frequency synchronization, and time synchronization. Synchronization, estimation of channel transfer characteristics, and reliable tracking of phase noise and channel transfer 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. Each different service index sequence of the anti-noise wireless digital broadcast signal transmitter contains and uniquely expresses each system parameter and business mode information of the anti-noise wireless digital broadcast signal transmitter, which can make the digital TV anti-noise wireless 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 wireless 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 anti-noise wireless 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 wireless digital broadcast 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 certain transmitter and a receiver of the anti-noise wireless digital broadcasting signal transmission method proposed by the present invention, as shown in Figure 1, proceed according to the following steps:

1) The certain anti-noise wireless 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) This certain anti-noise wireless digital broadcasting signal transmitter forms the FFT coded data block on the frequency domain with its input data bit stream through LDPC code, and FFT represents fast discrete Fourier transform, and the length of FFT coded data block is K; The encoding rate of input data for LDPC encoding is one of 1/4, 1/2, 5/8, 3/4 and 7/8;

3) The certain anti-noise wireless digital broadcast signal transmitter adopts IFFT to transform the FFT coded data block into a time-domain discrete coded data sample block D _total , and IFFT stands for Inverse Fast Discrete Fourier Transform;

4) The certain anti-noise wireless digital broadcasting signal transmitter divides the time-domain discretely coded data sample block equally into two blocks in sequence, the time-domain discretely coded data sample sub-block _D1 and the time-domain discretely coded data sample sub-block D ₂ , D _total = [D ₁ , D ₂ ];

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^* ₁表示对时域离散编码数据样值子块D₁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 wireless _digital broadcasting signal transmitter performs signal addition, _subtraction , The conjugate operation processes and re-synthesizes a new time-domain discretely coded data sample block D _new , and the new time-domain discretely coded data sample block D _new is obtained by the following generation mode, and the generation mode 1 is D _new =[D ₁ , D ₂ ], generating pattern 2 as ${\mathrm{D.}}_{\mathrm{new}}=[{\mathrm{D.}}_1,\sqrt{1/2}({\mathrm{D.}}_1+{\mathrm{D.}}_2)],$ Generate schema 3 as ${\mathrm{D.}}_{\mathrm{new}}=[{\mathrm{D.}}_1,\sqrt{1/2}({\mathrm{D.}}_1-{\mathrm{D.}}_2)],$ Generate schema 4 as ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({\mathrm{D.}}_1+{\mathrm{D.}}_2),{\mathrm{D.}}_2],$ Generate schema 5 as ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({\mathrm{D.}}_1-{\mathrm{D.}}_2),{\mathrm{D.}}_2],$ Generate schema 6 as ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({\mathrm{D.}}_1+{\mathrm{D.}}_2),\sqrt{1/2}({\mathrm{D.}}_1-{\mathrm{D.}}_2)],$ Generation mode 7 is D _new = [D ^* ₁ , D ₂ ], generation mode 8 is ${\mathrm{D.}}_{\mathrm{new}}=[{{\mathrm{D.}}^{*}}_1,\sqrt{1/2}({{\mathrm{D.}}^{*}}_1+{\mathrm{D.}}_2)],$ Generate schema 9 as ${\mathrm{D.}}_{\mathrm{new}}=[{{\mathrm{D.}}^{*}}_1,\sqrt{1/2}({{\mathrm{D.}}^{*}}_1-{\mathrm{D.}}_2)],$ Generate schema 10 as ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({{\mathrm{D.}}^{*}}_1+{\mathrm{D.}}_2),{\mathrm{D.}}_2],$ Generate schema 11 as ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({{\mathrm{D.}}^{*}}_1-{\mathrm{D.}}_2),{\mathrm{D.}}_2],$ Generate schema 12 as ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({{\mathrm{D.}}^{*}}_1+{\mathrm{D.}}_2),\sqrt{1/2}({{\mathrm{D.}}^{*}}_1-{\mathrm{D.}}_2)],$ Compare the time-domain discrete-coded data sample block D _new synthesized by 12 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 index sequence setting unit, wherein, D ^* ₁ means that the time domain discrete coded data samples of the time domain discrete coded data sample sub-block _D1 are conjugated and processed Time-domain discretely coded data sample sub-blocks;

6) The certain anti-noise wireless digital broadcast signal transmitter uses the training sequence as the real part sequence of the complex training sequence, and uses the service index sequence set by the service index sequence setting unit as the imaginary part sequence of the complex training sequence, in the time domain The discrete sample value blocks that constitute the complex training sequence, the length of the discrete sample value blocks of the training sequence, service index sequence, and complex training sequence are all X, and the service index sequence contains and uniquely expresses each of the anti-noise wireless digital broadcasting signal transmitters. System parameters and business mode information, X takes one of 512, 1024, and 2048;

7) The certain anti-noise wireless digital broadcasting signal transmitter repeats the discrete sample value blocks of the complex training sequence formed in the time domain continuously 4 times in the time domain to form a time domain embedded training sequence discrete sample value block, and the time domain embedding The length of the discrete sample value block of the training sequence is equal to the length of the time-domain discrete coded data sample value block with reduced peak-to-average power ratio, that is, K=4×X; when X is 512, K is 2048, and the corresponding sub The frequency interval of the carrier is 4KHz; when X is 1024, K is 4096, and the frequency interval of the corresponding subcarrier is 2KHz; when X is 2048, K is 8192, and the frequency interval of the corresponding subcarrier is 1KHz;

8) The certain anti-noise wireless digital broadcasting signal transmitter directly superposes 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 peak-to-average power ratio reduction Discretely coded data sample blocks in the time domain, as a frame body;

9) The certain anti-noise wireless 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; when X is 512, C is 1/4 of the size of K; when X is 1024, C is 1/8 of the size of K; when X is 2048, C is 1/4 of the size of K 16;

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

11) The certain anti-noise wireless 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;

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

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

The certain anti-noise wireless 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.

The certain anti-noise wireless digital broadcasting signal transmitter encodes its input data bit stream in the frequency domain through LDPC to form an FFT coded data block, and then transforms it into a discrete coded data sample block in the time domain through IFFT, and passes the peak The average power ratio adjustment unit generates and selects the time-domain discrete coded data sample block with reduced peak-to-average power ratio with the lowest peak-to-average power ratio, and sends the corresponding generation mode information to the service index sequence setting unit.

The FFT data block consists of subcarriers. The length of the FFT data block is K; when X is 512, the corresponding K is 2048, and the frequency interval of the corresponding subcarrier is 4KHz; when X is 1024, the corresponding K is 4096, and the corresponding subcarrier The frequency interval of the frequency is 2KHz; when X is 2048, the corresponding K is 8192, and the frequency interval of the corresponding subcarrier is 1KHz.

The certain anti-noise wireless digital broadcast signal transmitter uses the training sequence as the real part sequence of the complex training sequence, and uses the service index sequence as the imaginary part sequence of the complex training sequence to form discrete sample blocks of the complex training sequence in the time domain, Repeat it four times continuously in the time domain to form discrete sample blocks of time domain embedding training sequence. The length of the discrete sample block of the training sequence, the service index sequence, and the complex training sequence is X, where X is one of 512, 1024, and 2048, and the length of the discrete sample block of the time domain embedded training sequence is K, K=4× X.

As the anti-noise wireless digital broadcast signal transmitter, the training sequence and service index sequence are composed of a series of 1 or -1, which have pseudo-random characteristics, and the training sequence and service index sequence are orthogonal to each other. The training sequence satisfying the above characteristics can be realized by a special type of shifted m-sequence as a pseudo-random number sequence and Walsh sequence, Hadamard sequence or orthogonal sequence generated by other methods as an orthogonal sequence. Each different service index sequence contains and uniquely expresses various system parameters and service mode information of the anti-noise wireless digital broadcasting signal transmitter.

This certain anti-noise wireless 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 in the time domain The discrete coded data sample block is used as a frame body; a cyclic prefix is inserted into the time domain embedded training sequence peak-to-average power ratio time domain discrete coded data sample block as a guard interval to form a signal frame. The length of the cyclic prefix used as the guard interval is C; when X takes 512, the corresponding C takes 1/4 of the size of K; when X takes 1024, the corresponding C takes 1/8 of the size of K; when X takes When 2048, the corresponding C takes 1/16 of the size of K.

The certain anti-noise wireless digital broadcasting signal transmitter employs a square root raised cosine roll-off filter to pulse-shape the signal of the signal frame. When X is 512, the roll-off coefficient of the square root raised cosine roll-off filter corresponding to the pulse shaping of the signal frame is 0.1; when X is 1024, the corresponding pulse shaping of the signal frame is The roll-off coefficient of the square root raised cosine roll-off filter is 0.05; when X is 2048, the corresponding roll-off coefficient of the square root raised cosine roll-off filter for pulse shaping the signal frame is 0.025.

The anti-noise wireless digital broadcasting 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.

The anti-noise wireless digital broadcast signal receiver detects and receives the radio frequency signal sent by the wireless digital broadcast signal transmitter and converts it down to form a baseband signal, and uses the cyclic prefix characteristics of the signal frame and the structural characteristics of the signal frame to receive the baseband signal The processing includes 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 (8)

1. an anti-noise wireless digital broadcast signal transmission method is characterized in that it comprises the following steps:

1) anti-noise wireless digital broadcast signal transmitter 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 and handled to form the input data bit flow;

2) anti-noise wireless digital broadcast signal transmitter is coded in the input data bit of oneself LDPC that flows through on the frequency domain and forms the FFT coded data block, and LDPC represents low-density checksum, and the length of FFT coded data block is K;

3) anti-noise wireless digital broadcast signal transmitter adopts IFFT that the FFT coded data block is transformed to time domain discrete coded data sample value piece D _Total

4) anti-noise wireless digital broadcast signal transmitter is divided equally into two with time domain discrete coded data sample value piece in order, the sub-piece D of time domain discrete coded data sample value ₁With the sub-piece D of time domain discrete coded data sample value ₂, D _Total=[D ₁, D ₂];

5) anti-noise wireless digital broadcast signal transmitter passes through the peak-to-average power ratio adjustment unit to the sub-piece D of time domain discrete coded data sample value ₁, the sub-piece D of time domain discrete coded data sample value ₂Carry out that signal adds, subtracts, the operation independent of conjugation is handled or combinatorial operation is handled and synthetic new time domain discrete coded data sample value piece D again _New, new time domain discrete coded data sample value piece D _NewAdopt following generate pattern to obtain, generate pattern 1 is D _New=[D ₁, D ₂], generate pattern 2 is

Generate pattern 3 is $D_{\mathrm{new}}=[D_1,\sqrt{1/2}(D_1-D_2)],$ Generate pattern 4 is $D_{\mathrm{new}}=[\sqrt{1/2}(D_1+D_2),D_2],$ Generate pattern 5 is

Generate pattern 6 is $D_{\mathrm{new}}=[\sqrt{1/2}(D_1+D_2),\sqrt{1/2}(D_1-D_2)],$ Generate pattern 7 is D _New=[D ^* ₁, D ₂], generate pattern 8 is $D_{\mathrm{new}}=[{D^{*}}_1,\sqrt{1/2}({D^{*}}_1+D_2)],$ Generate pattern 9 is $D_{\mathrm{new}}=[{D^{*}}_1,\sqrt{1/2}({D^{*}}_1-D_2)],$ Generate pattern 10 is Generate pattern 11 is $D_{\mathrm{new}}=[\sqrt{1/2}({D^{*}}_1-D_2),D_2],$ Generate pattern 12 is $D_{\mathrm{new}}=[\sqrt{1/2}({D^{*}}_1+D_2),\sqrt{1/2}({D^{*}}_1-D_2)],$ Compare the synthetic time domain discrete coded data sample value piece D of 12 kinds of generate patterns _New, choose wherein have a minimum peak-to-average power ratio peak-to-average power ratio time domain discrete coded data sample value piece falls

And peak-to-average power ratio time domain discrete coded data sample value piece will fall

The corresponding generate pattern information that adopts send to the operational indicator sequence unit be set, wherein, D ^* ₁Expression is to the sub-piece D of time domain discrete coded data sample value ₁Each time domain discrete coded data sample value carry out that conjugate operation is handled and the sub-piece of time domain discrete coded data sample value that obtains;

6) anti-noise wireless digital broadcast signal transmitter with training sequence as the real part sequence of sequence of plural training, the operational indicator sequence is arranged the set operational indicator sequence in unit as the imaginary part sequence of sequence of plural training, constitute the discrete sample block of sequence of plural training in time domain, the length of the discrete sample block of training sequence, operational indicator sequence, sequence of plural training all is X, and the operational indicator sequence is comprising and unique each system parameters and business model information of expressing anti-noise wireless digital broadcast signal transmitter;

7) discrete sample block of the anti-noise wireless digital broadcast signal transmitter sequence of plural training that will constitute in time domain repeats to form time domains 4 times continuously and embeds training sequence discrete sample block on time domain, time domain embeds the length and the length numerically equal of falling peak-to-average power ratio time domain discrete coded data sample value piece, i.e. K=4 * X of training sequence discrete sample block;

8) anti-noise wireless digital broadcast signal transmitter will fall peak-to-average power ratio time domain discrete coded data sample value piece, time domain and embed training sequence discrete sample block and directly superpose and form time domain and embed training sequence and fall peak-to-average power ratio time domain discrete coded data sample value piece, as frame;

9) anti-noise wireless digital broadcast signal transmitter at interval is that frame head inserts time domain and embeds training sequence to fall peak-to-average power ratio time domain discrete coded data sample value piece be frame with Cyclic Prefix as protection, and to form signal frame, the length of Cyclic Prefix is C;

10) anti-noise wireless digital broadcast signal transmitter adopts square root raised cosine filter that the signal pulse of signal frame is shaped;

11) anti-noise wireless digital broadcast signal transmitter forms emission of radio frequency signals to the on-air radio channel with the baseband signal up-conversion to carrier wave;

12) the anti-noise wireless digital broadcasting signal receiver detect to receive radiofrequency signal that the wireless digital broadcasting signal transmitter sends and its down-conversion is formed baseband signal, utilizes the architectural characteristic of the Cyclic Prefix characteristic of signal frame and signal frame to carry out baseband signal and receives and handle.

2. by the anti-noise wireless digital broadcast signal transmission method of claim 1, it is characterized in that: the length X of the discrete sample block of the training sequence of described anti-noise wireless digital broadcast signal transmitter, operational indicator sequence, sequence of plural training is got in 512,1024,2048.

3. by the anti-noise wireless digital broadcast signal transmission method of claim 2, it is characterized in that: described training sequence, operational indicator sequence are formed by a series of 1 or-1, have pseudo-random characteristics.

4. by the anti-noise wireless digital broadcast signal transmission method of claim 2, it is characterized in that: described training sequence, operational indicator sequence have orthogonality each other.

5. by the anti-noise wireless digital broadcast signal transmission method of claim 1, it is characterized in that: described FFT data block is made up of subcarrier; When X got 512, sub-carrier number got 2048, and the frequency interval of subcarrier is got 4KHz; When X got 1024, sub-carrier number got 4096, and the frequency interval of subcarrier is got 2KHz; When X got 2048, sub-carrier number got 8192, and the frequency interval of subcarrier is got 1KHz.

6. by the anti-noise wireless digital broadcast signal transmission method of claim 1, it is characterized in that: the length C value of described Cyclic Prefix is relevant with the X value; When X got 512, C got 1/4 of K size; When X got 1024, C got 1/8 of K size; When X got 2048, C got 1/16 of K size.

7. by the anti-noise wireless digital broadcast signal transmission method of claim 1, it is characterized in that: the described encoding rate that the input data are carried out the LDPC coding is in 1/4,1/2,5/8,3/4 and 7/8.

8. press the anti-noise wireless digital broadcast signal transmission method of claim 1, it is characterized in that: the baseband signal that described anti-noise wireless digital broadcasting signal receiver carries out receives to be handled, and one of them step is that the time domain and frequency domain combined alternate analysis of signal frame head and signal frame body is handled.

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