CN101420410A - Interference resistant modulation method for digital television terrestrial broadcast transmitter - Google Patents
Interference resistant modulation method for digital television terrestrial broadcast transmitter Download PDFInfo
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Abstract
The present invention discloses a method for modulating digital television ground broadcasting transmitter based on insertion training sequence and LDPC code, wherein the method comprises the following steps: 1) forming data block with the input bit flow through BCH encoding, bit interweaving, LDPC encoding, code modulating and code interweaving; 2) modulating with a space-frequency coder and adjusting time synchronization; 3) switching the data block to time domain discrete data sample block through IFFT; 4) forming a complex training sequence block with a mode that a training sequence is used as a real part sequence and an operational indicator sequence is used as an imaginary part sequence; 5) continuously repeating the complex training sequence for four times to form a time domain insertion training sequence discrete sample block; 6) directly overlapping the space-frequency modulation time domain discrete data sample block and the time domain insertion training sequence discrete sample block for forming space-frequency modulation time domain insertion training sequence data block; 7) inserting a circulating prefix for forming a signal frame; 8) forming a signal pulse with a square-root raised cosine roll-off filter; and 9) upconverting the baseband signal to the carrier.
Description
Technical field
The invention belongs to wireless communication field, relate more specifically to a kind of based on embedding training sequence and cascade interweaved code modulated digital television ground broadcast transmitter space-frequency modulation method.
Background technology
At present, ground TV broadcast develops to the digitlization direction gradually from simulation.Digital television ground broadcast transmission system, as the important component part of Digital Television Terrestrial Broadcasting, its development of technologies, closely bound up with people's quality of life, and therefore be subjected to people's extensive concern especially.Digital Television Terrestrial Broadcasting correlation technique and related industry thereof are that development is very fast in the Communications And Computer field, the industry of good market prospect.On the Digital Television Terrestrial Broadcasting correlation technique, the emphasis of various countries' concern at present is that the Digital Television Terrestrial Broadcasting how to pass under the environment for complex wave provides the implementation of reliable high-speed mobile cheaply.The digital television ground broadcast transmitter modulation technique is the key technology of digital tv ground broadcasting, for whole system performance decisive role, is the object of everybody primary study.
Because the develop rapidly of Digital Signal Processing and integrated circuit technique, the system of OFDM (OFDM) technology realizes becoming more and more easier.Because of OFDM multi-carrier transmission technology has simple in structure, the availability of frequency spectrum high plurality of advantages such as becomes and extremely everybody concern and obtain deep research and the extensive use in numerous areas such as Xdsl, wide-band mobile communication, wideband wireless local area network, Digital Television Terrestrial Broadcasting in the time of can resisting frequency selectivity and channel.
In the practical communication environment, the ofdm communication system performance is subjected to the influence of factors such as lock in time, clock jitter, channel fading, multi-user's common-channel interference.Channel coding technology and modulator approach are to realize the key technology of reliable ofdm communication.
Chnnel coding is the important component part of digital communication system.Along with the develop rapidly of modern information technologies, channel coding technology has become the indispensable technology in modern communications field.Embed redundancy symbol in information sequence, the effect of channel coding technology by redundancy symbol reduces signal and makes a mistake in transmission course, thereby improves the reliability of communication system.
Under multidiameter fading channel, can be by coding, interweave and the cascade optimal design of modulation scheme reaches big as far as possible signal diversifying exponent number, so that in equaling or exceeding the symbol sebolic addressing of minimum free distance, obtain independent decline.The different coding form of cascade can make full use of the advantage of different coding technology; Between coding and code element modulation, insert bit interleaver, can be so that coding be relatively independent with modulated process and expand diversity order to different binary bits number from different multi-system symbolic numbers, thus make diversity order be improved significantly and under multidiameter fading channel, have the bit error performance of getting well.
Multiple antenna communication uses a plurality of (N
tIndividual) transmitting antenna and one or more (N
rIndividual) reception antenna carries out transfer of data, and it is by with N
tIndividual transmitting antenna sends different data and improves system throughput or improve the reliability of communication by send data redundantly.Transmit diversity utilizes in the space, the redundant transmission of the enterprising line data of combination of frequency, time or these dimensions, handle by simple transmit diversity, thereby the reliability that can improve the communication system data transmission makes communication system obtain stronger performance at the transmitter and receiver place.Simultaneously, the networking model of employing single frequency network (that is, the same time of several transmitting stations is launched same signal to realize the reliable covering to certain coverage on same frequency) can improve the availability of frequency spectrum of digital television ground broadcast transmission system greatly.
Utilizing digital television ground broadcast transmission system that may command multi-services such as free television broadcasting, paid television broadcasting, security information transmission, multimedia value-added service are provided is embodiments that digital television ground broadcast transmission system of new generation satisfies social needs.
Just be based on above background, it is a kind of based on embedding training sequence and cascade interweaved code modulated digital television ground broadcast transmitter space-frequency modulation method to the present invention is directed to the proposition of practical communication environment, can satisfy the needs of single frequency network High Data Rate may command multi-service Digital Television Terrestrial Broadcasting transmission.
Desire is done more deep understanding to the patent background can be with reference to following documents and materials:
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Summary of the invention
The present invention is directed to single frequency network High Data Rate may command multi-service Digital Television Terrestrial Broadcasting, proposed a kind of based on embedding training sequence and cascade interweaved code modulated digital television ground broadcast transmitter space-frequency modulation method.
What the present invention proposed is a kind of based on embedding training sequence and cascade interweaved code modulated digital television ground broadcast transmitter space-frequency modulation method, it is characterized in that it comprises the following steps:
1) the network data management device of single frequency network will be imported data bit flow Bose-Chaudhuri-Hocquenghem Code (the BoseChaudhuri Hocquenghem that flows through, BCH), Bit Interleave, LDPC coding (Low Density Parity Check, LDPC), further on frequency domain, form the cascade interweaved coding modulation data piece of FFT (length (symbol numbers) of the cascade interweaved coding modulation data piece of FFT is K) after the code element modulation, symbol interleave;
2) to adopt code check be that the cascade interweaved coding modulation data piece of FFT that 1 space-frequency coding device will form on frequency domain is modulated to form on each digital television ground broadcast transmitter branch road in the single frequency network and emptyly frequently modulates the cascade interweaved coding modulation data piece of FFT (empty length (symbol numbers) of modulating the cascade interweaved coding modulation data piece of FFT frequently is K) to the network data management device of single frequency network, and the time synchronized of adjusting each digital television ground broadcast transmitter branch road is all modulated the cascade interweaved coding modulation data piece of FFT frequently to sky at one time and handled to guarantee all transmitters in the network;
3) each digital television ground broadcast transmitter in the single frequency network adopts IFFT (fast discrete Fourier inverse transformation) that sky is modulated the cascade interweaved coding modulation data piece of FFT frequently and is transformed to the empty cascade interweaved coding modulation data sample value of the time domain discrete piece of frequently modulating;
4) each digital television ground broadcast transmitter in the single frequency network as the real part sequence of sequence of plural training, with the imaginary part sequence of operational indicator sequence as sequence of plural training, constitutes the discrete sample block (length of the discrete sample block of training sequence, operational indicator sequence, sequence of plural training all is X) of sequence of plural training with training sequence on time domain;
5) each digital television ground broadcast transmitter in the single frequency network will repeat to form for 4 times time domain continuously in the discrete sample block of the sequence of plural training that constitutes on the time domain and embed training sequence discrete sample block (length that time domain embeds training sequence discrete sample block is K, K=4 * X) on time domain;
6) each digital television ground broadcast transmitter in the single frequency network is modulated the cascade interweaved coding modulation data sample value of time domain discrete piece, time domain frequently with sky and is embedded training sequence discrete sample block and directly superpose and form the empty time domain of frequently modulating and embed the cascade interweaved coding modulation data piece of training sequence, as frame;
7) each digital television ground broadcast transmitter in the single frequency network inserts the empty time domain of frequently modulating with Cyclic Prefix (length of Cyclic Prefix is C) as protection interval (frame head) and embeds the cascade interweaved coding modulation data piece of training sequence (frame), with the formation signal frame;
8) each digital television ground broadcast transmitter in the single frequency network adopts square root raised cosine filter that the signal pulse of signal frame is shaped;
9) each digital television ground broadcast transmitter in the single frequency network with the baseband signal up-conversion to carrier wave.
, it is characterized in that based on embedding training sequence and cascade interweaved code modulated digital television ground broadcast transmitter space-frequency modulation method according to above-mentioned: have periodic time domain in the signal frame of digital television ground broadcast transmitter and embed training sequence discrete sample block; The length X of the training sequence of digital television ground broadcast transmitter is in 512,1024,2048, the length K (sub-carrier number) of the cascade interweaved coding modulation data piece of corresponding FFT is respectively 2048,4096,8192, the frequency interval of corresponding subcarrier is respectively 4KHz, 2KHz, 1KHz, and corresponding circulating prefix-length C is respectively 1/4,1/8,1/16 of the cascade interweaved coding modulation data block length of FFT K size; The training sequence of digital television ground broadcast transmitter, operational indicator sequence are formed by a series of 1 or-1, have pseudo-random characteristics; The training sequence of digital television ground broadcast transmitter, operational indicator sequence have orthogonality each other; The different operational indicator sequence of each of digital television ground broadcast transmitter is comprising and unique each system parameters and business model information of expressing digital television ground broadcast transmitter; The code check of space-frequency coding device is 1; The encoding rate that the input data are carried out the LDPC coding that Bose-Chaudhuri-Hocquenghem Code, Bit Interleave, LDPC coding, code element modulation, symbol interleave handle is in 1/4,1/2,5/8,3/4 and 7/8, Bit Interleave adopts the random interleaving mode, code element is modulated to a kind of among QPSK, 16 QAM, 32 QAM and 64 QAM, symbol constellations figure mapping mode adopts the Gray code mapping, and symbol interleave adopts the random interleaving mode.
Characteristics of the present invention:
The present invention is the modulation scheme that a kind of spatial domain time-domain and frequency-domain mixes.Have periodic time domain in the signal frame of digital television ground broadcast transmitter and embed training sequence discrete sample block, the training sequence of digital television ground broadcast transmitter, the operational indicator sequence has pseudo-random characteristics, the training sequence of digital television ground broadcast transmitter, the operational indicator sequence has orthogonality each other, the cascade interweaved coding modulation data piece of time domain embedding training sequence of digital television ground broadcast transmitter is the discrete cascade interweaving encoding modulating data sample value piece by time domain, time domain embeds training sequence discrete sample block and directly superposes and form, and these have guaranteed that digital television ground broadcast transmitter can realize frame synchronization fast and accurately, Frequency Synchronization, time synchronized, channel transfer characteristic is estimated, and phase noise and channel transfer characteristic reliably followed the tracks of.Cyclic Prefix is inserted time domain at interval as protection embed the cascade interweaved coding modulation data piece of training sequence, can reduce the interference effect between the adjacent signals frame to form signal frame.Adopt cascade interweaved coded modulation that the input data are carried out chnnel coding error-correcting performance near shannon limit is provided.The different operational indicator sequence of each of digital television ground broadcast transmitter is comprising and unique each system parameters and business model information of expressing digital television ground broadcast transmitter, digital television ground broadcast transmission system can satisfy social needs so that can provide may command multi-services such as free television broadcasting, paid television broadcasting, security information transmission, multimedia value-added service.Adopt empty modulation frequently to make whole digital tv ground broadcasting obtain stronger performance.Space-frequency modulation method of the present invention have lock in time short, clock jitter is little, anti-channel fading, anti-channel disturbance, can provide the plurality of advantages such as high cascade interweaving encoding modulation data rate may command multi-service Digital Television Terrestrial Broadcasting transmission in the single frequency network.
Description of drawings
Fig. 1 is according to the embodiment schematic diagram based on the single frequency network transmitter that embeds training sequence and cascade interweaved code modulated digital television ground broadcast transmitter space-frequency modulation method of the present invention.
Fig. 2 is the embodiment schematic diagram that forms signal frame based on the single frequency network transmitter that embeds training sequence and cascade interweaved code modulated digital television ground broadcast transmitter space-frequency modulation method according to of the present invention.
Embodiment
Below in conjunction with accompanying drawing specific embodiments of the invention are described in detail.
Embodiment according to the present invention's proposition based on the single frequency network transmitter (supposing has N transmitter in the single frequency network) that embeds training sequence and cascade interweaved code modulated digital television ground broadcast transmitter space-frequency modulation method, as shown in Figure 1, follow these steps to carry out:
1) the network data management device of single frequency network will be imported data bit flow Bose-Chaudhuri-Hocquenghem Code (the BoseChaudhuri Hocquenghem that flows through, BCH), Bit Interleave, LDPC coding (Low Density Parity Check, LDPC), (length (symbol numbers) of the cascade interweaved coding modulation data piece of FFT is K further to form the cascade interweaved coding modulation data piece of FFT after the code element modulation, symbol interleave on frequency domain; When X got 512, the length K (sub-carrier number) of the cascade interweaved coding modulation data piece of corresponding FFT got 2048, and the frequency interval of corresponding subcarrier is got 4KHz; When X got 1024, the length K (sub-carrier number) of the cascade interweaved coding modulation data piece of corresponding FFT got 4096, and the frequency interval of corresponding subcarrier is got 2KHz; When X got 2048, the length K (sub-carrier number) of the cascade interweaved coding modulation data piece of corresponding FFT got 8192, and the frequency interval of corresponding subcarrier is got 1KHz);
2) to adopt code check be that the cascade interweaved coding modulation data piece of FFT that 1 space-frequency coding device will form on frequency domain is modulated to form on each digital television ground broadcast transmitter branch road in the single frequency network and emptyly frequently modulates the cascade interweaved coding modulation data piece of FFT to the network data management device of single frequency network, and the time synchronized of adjusting each digital television ground broadcast transmitter branch road is all modulated the cascade interweaved coding modulation data piece of FFT frequently to sky at one time and handled to guarantee all transmitters in the network;
3) each digital television ground broadcast transmitter in the single frequency network adopts IFFT (fast discrete Fourier inverse transformation) that sky is modulated the cascade interweaved coding modulation data piece of FFT frequently and is transformed to the empty cascade interweaved coding modulation data sample value of the time domain discrete piece of frequently modulating;
4) each digital television ground broadcast transmitter in the single frequency network with training sequence as the real part sequence of sequence of plural training, with the imaginary part sequence of operational indicator sequence as sequence of plural training, on time domain, constitute the discrete sample block (length of the discrete sample block of training sequence, operational indicator sequence, sequence of plural training all is X, and X gets in 512,1024,2048) of sequence of plural training;
5) each digital television ground broadcast transmitter in the single frequency network will repeat to form for 4 times time domain continuously in the discrete sample block of the sequence of plural training that constitutes on the time domain and embed training sequence discrete sample block (length that time domain embeds training sequence discrete sample block is K, K=4 * X) on time domain;
6) each digital television ground broadcast transmitter in the single frequency network is modulated the cascade interweaved coding modulation data sample value of time domain discrete piece, time domain frequently with sky and is embedded training sequence discrete sample block and directly superpose and form the empty time domain of frequently modulating and embed the cascade interweaved coding modulation data piece of training sequence, as frame;
7) (length of Cyclic Prefix is C to each digital television ground broadcast transmitter in the single frequency network with Cyclic Prefix; When X got 512, corresponding C got 1/4 of the cascade interweaved coding modulation data block length of FFT K size; When X got 1024, corresponding C got 1/8 of the cascade interweaved coding modulation data block length of FFT K size; When X gets 2048, corresponding C get the cascade interweaved coding modulation data block length of FFT K size 1/16) as protection at interval (frame head) insert the empty time domain of frequently modulating and embed the cascade interweaved coding modulation data piece of training sequence (frame), to form signal frame;
8) each digital television ground broadcast transmitter in the single frequency network adopts square root raised cosine filter that the signal pulse of signal frame is shaped;
9) each digital television ground broadcast transmitter in the single frequency network with the baseband signal up-conversion to carrier wave.
According to the embodiment (supposing to have in the single frequency network N transmitter) (supposing to have in the single frequency network N transmitter) that forms signal frame based on the single frequency network transmitter that embeds training sequence and cascade interweaved code modulated digital television ground broadcast transmitter space-frequency modulation method of the present invention, as shown in Figure 2, specifically implement as follows:
The network data management device of single frequency network will be imported data bit flow Bose-Chaudhuri-Hocquenghem Code (the Bose ChaudhuriHocquenghem that flows through, BCH), Bit Interleave, LDPC coding (Low Density Parity Check, LDPC), further on frequency domain, form the cascade interweaved coding modulation data piece of FFT after the code element modulation, symbol interleave.
The cascade interweaved coding modulation data piece of FFT is made up of subcarrier.The length (symbol numbers) of the cascade interweaved coding modulation data piece of FFT is K; When X got 512, the length K (sub-carrier number) of the cascade interweaved coding modulation data piece of corresponding FFT got 2048, and the frequency interval of corresponding subcarrier is got 4KHz; When X got 1024, the length K (sub-carrier number) of the cascade interweaved coding modulation data piece of corresponding FFT got 4096, and the frequency interval of corresponding subcarrier is got 2KHz; When X got 2048, the length K (sub-carrier number) of the cascade interweaved coding modulation data piece of corresponding FFT got 8192, and the frequency interval of corresponding subcarrier is got 1KHz.
It is that the cascade interweaved coding modulation data piece of FFT that 1 space-frequency coding device will form on frequency domain is modulated to form on each digital television ground broadcast transmitter branch road in the single frequency network and emptyly frequently modulates the cascade interweaved coding modulation data piece of FFT that the network data management device of single frequency network adopts code check, and the time synchronized of adjusting each digital television ground broadcast transmitter branch road is all modulated the cascade interweaved coding modulation data piece of FFT frequently to sky at one time and handled to guarantee all transmitters in the network.
Each digital television ground broadcast transmitter in the single frequency network adopts IFFT (fast discrete Fourier inverse transformation) that sky is modulated the cascade interweaved coding modulation data piece of FFT frequently and is transformed to the empty cascade interweaved coding modulation data sample value of the time domain discrete piece of frequently modulating.Each digital television ground broadcast transmitter in the single frequency network with training sequence as the real part sequence of sequence of plural training, with the imaginary part sequence of operational indicator sequence as sequence of plural training, on time domain, constitute the discrete sample block of sequence of plural training, on time domain, it is repeated 4 times continuously again and form time domain embedding training sequence discrete sample block.The length of the discrete sample block of training sequence, operational indicator sequence, sequence of plural training all is X, and X gets in 512,1024,2048, and the length that time domain embeds training sequence discrete sample block is K, K=4 * X.Training sequence, operational indicator sequence as digital television ground broadcast transmitter are formed by a series of 1 or-1, have pseudo-random characteristics, and training sequence, operational indicator sequence have orthogonality each other.The training sequence that satisfies above-mentioned feature can be by realizing as one group of displacement m sequence of a kind of specific type of pseudo-random number sequence with as the walsh sequence of orthogonal sequence, Hadamard sequences or by the orthogonal sequence that other modes produce.Each different operational indicator sequence is comprising and unique each system parameters and business model information of expressing digital television ground broadcast transmitter.
Each digital television ground broadcast transmitter in the single frequency network is modulated the cascade interweaved coding modulation data sample value of time domain discrete piece, time domain frequently with sky and is embedded training sequence discrete sample block and directly superpose and form the empty time domain of frequently modulating and embed the cascade interweaved coding modulation data piece of training sequence, as frame; Frequently modulate time domain at sky and embed and to insert Cyclic Prefix in the cascade interweaved coding modulation data piece of training sequence at interval, form signal frame as protection.
Length as protection Cyclic Prefix at interval is C; When X got 512, corresponding C got 1/4 of the cascade interweaved coding modulation data block length of FFT K size; When X got 1024, corresponding C got 1/8 of the cascade interweaved coding modulation data block length of FFT K size; When X got 2048, corresponding C got 1/16 of the cascade interweaved coding modulation data block length of FFT K size.
Each digital television ground broadcast transmitter in the single frequency network adopts square root raised cosine filter that the signal of signal frame is carried out pulse shaping.When X got 512, the rolloff-factor that corresponding signal to signal frame carries out the square root raised cosine filter of pulse shaping got 0.1; When X got 1024, the rolloff-factor that corresponding signal to signal frame carries out the square root raised cosine filter of pulse shaping got 0.05; When X got 2048, the rolloff-factor that corresponding signal to signal frame carries out the square root raised cosine filter of pulse shaping got 0.025.
In conjunction with the accompanying drawings specific embodiments of the invention are had been described in detail above, but the present invention is not limited to the foregoing description, under the spirit and scope situation of the claim that does not break away from the application, those skilled in the art can make various modifications or remodeling.
Claims (9)
1, a kind of based on embedding training sequence and cascade interweaved code modulated digital television ground broadcast transmitter space-frequency modulation method, it is characterized in that it comprises the following steps:
1) the network data management device of single frequency network will be imported data bit flow Bose-Chaudhuri-Hocquenghem Code (the Bose ChaudhuriHocquenghem that flows through, BCH), Bit Interleave, LDPC coding (Low Density Parity Check, LDPC), further on frequency domain, form the cascade interweaved coding modulation data piece of FFT (length (symbol numbers) of the cascade interweaved coding modulation data piece of FFT is K) after the code element modulation, symbol interleave;
2) to adopt code check be that the cascade interweaved coding modulation data piece of FFT that 1 space-frequency coding device will form on frequency domain is modulated to form on each digital television ground broadcast transmitter branch road in the single frequency network and emptyly frequently modulates the cascade interweaved coding modulation data piece of FFT (empty length (symbol numbers) of modulating the cascade interweaved coding modulation data piece of FFT frequently is K) to the network data management device of single frequency network, and the time synchronized of adjusting each digital television ground broadcast transmitter branch road is all modulated the cascade interweaved coding modulation data piece of FFT frequently to sky at one time and handled to guarantee all transmitters in the network;
3) each digital television ground broadcast transmitter in the single frequency network adopts IFFT (fast discrete Fourier inverse transformation) that sky is modulated the cascade interweaved coding modulation data piece of FFT frequently and is transformed to the empty cascade interweaved coding modulation data sample value of the time domain discrete piece of frequently modulating;
4) each digital television ground broadcast transmitter in the single frequency network as the real part sequence of sequence of plural training, with the imaginary part sequence of operational indicator sequence as sequence of plural training, constitutes the discrete sample block (length of the discrete sample block of training sequence, operational indicator sequence, sequence of plural training all is X) of sequence of plural training with training sequence on time domain;
5) each digital television ground broadcast transmitter in the single frequency network will repeat to form for 4 times time domain continuously in the discrete sample block of the sequence of plural training that constitutes on the time domain and embed training sequence discrete sample block (length that time domain embeds training sequence discrete sample block is K, K=4 * X) on time domain;
6) each digital television ground broadcast transmitter in the single frequency network is modulated the cascade interweaved coding modulation data sample value of time domain discrete piece, time domain frequently with sky and is embedded training sequence discrete sample block and directly superpose and form the empty time domain of frequently modulating and embed the cascade interweaved coding modulation data piece of training sequence, as frame;
7) each digital television ground broadcast transmitter in the single frequency network inserts the empty time domain of frequently modulating with Cyclic Prefix (length of Cyclic Prefix is C) as protection interval (frame head) and embeds the cascade interweaved coding modulation data piece of training sequence (frame), with the formation signal frame;
8) each digital television ground broadcast transmitter in the single frequency network adopts square root raised cosine filter that the signal pulse of signal frame is shaped;
9) each digital television ground broadcast transmitter in the single frequency network with the baseband signal up-conversion to carrier wave.
2, by claim 1 based on embedding training sequence and cascade interweaved code modulated digital television ground broadcast transmitter space-frequency modulation method, it is characterized in that: the length X of the discrete sample block of the training sequence of described digital television ground broadcast transmitter, operational indicator sequence, sequence of plural training is got in 512,1024,2048.
3, by claim 2 based on embedding training sequence and cascade interweaved code modulated digital television ground broadcast transmitter space-frequency modulation method, it is characterized in that: described training sequence, operational indicator sequence have pseudo-random characteristics, and described training sequence, operational indicator sequence have orthogonality each other.
4, by claim 1 based on embedding training sequence and cascade interweaved code modulated digital television ground broadcast transmitter space-frequency modulation method, it is characterized in that: the cascade interweaved coding modulation data piece of described FFT is made up of subcarrier; When X got 512, sub-carrier number K got 2048; When X got 1024, sub-carrier number K got 4096; When X got 2048, sub-carrier number K got 8192.
5, by claim 4 based on embedding training sequence and cascade interweaved code modulated digital television ground broadcast transmitter space-frequency modulation method, it is characterized in that: when X got 512, the frequency interval of subcarrier was got 4KHz; When X got 1024, the frequency interval of subcarrier was got 2KHz; When X got 2048, the frequency interval of subcarrier was got 1KHz.
6, by claim 1 based on embedding training sequence and cascade interweaved code modulated digital television ground broadcast transmitter space-frequency modulation method, it is characterized in that: described signal frame is inserted into time domain by Cyclic Prefix and embeds the cascade interweaved coding modulation data piece of training sequence and form.
7, by claim 1 based on embedding training sequence and cascade interweaved code modulated digital television ground broadcast transmitter space-frequency modulation method, it is characterized in that: the length of described Cyclic Prefix is C; 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.
8, by claim 1 based on embedding training sequence and cascade interweaved code modulated digital television ground broadcast transmitter space-frequency modulation method, it is characterized in that: described to the input data carry out Bose-Chaudhuri-Hocquenghem Code, Bit Interleave, the LDPC coding, the code element modulation, the encoding rate of the LDPC coding that symbol interleave is handled is 1/4,1/2,5/8, in 3/4 and 7/8 one, Bit Interleave adopts the random interleaving mode, code element is modulated to QPSK, 16QAM, a kind of among 32QAM and the 64QAM, symbol constellations figure mapping mode adopts the Gray code mapping, and symbol interleave adopts the random interleaving mode.
9, by claim 1 based on embedding training sequence and cascade interweaved code modulated digital television ground broadcast transmitter space-frequency modulation method, it is characterized in that: described space-frequency coding device code check be 1.
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