A kind of single-frequency network anti-noise mobile multimedia broadcast signal framing modulator approach
Technical field
The invention belongs to moving communicating field, relate more specifically to a kind of single-frequency network anti-noise mobile multimedia broadcast signal framing modulator approach.
Background technology
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, broadband mobile LAN, Digital Television Mobile Multimedia Broadcasting in the time of can resisting frequency selectivity and channel.Peak-to-average power ratio (PAPR) pair amplifier that ofdm signal is higher and the range of linearity of digital to analog converter have very high requirement, if the system linearity scope can not satisfy the variation of signal, then can cause signal distortion, signal spectrum is changed, thereby cause the orthogonality between the subchannel to be destroyed, produce the phase mutual interference, make system performance degradation.Therefore, the solution that must consider how to reduce the probability of occurrence of big peak power signal in the ofdm signal and reduce the nonlinear distortion influence.
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.(Low Density Parity Check, LDPC) sign indicating number is a kind ofly to be used in noise transmission channel transmission information and to carry out the error correcting code of forward error correction (FEC, Forward Error Correction) to low-density checksum.LDPC coding be a kind of message transmission rate that can make near theoretical maximum, i.e. the encoding scheme of shannon limit.
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 Mobile Multimedia Broadcasting transmission system greatly.In actual single frequency network communication environment, Digital Television Mobile Multimedia Broadcasting communication system performance is subjected to the influence of factors such as lock in time, clock jitter, channel fading, channel disturbance.Single-frequency network anti-noise mobile multimedia broadcast signal transmitter framing modulator approach is to realize the key technology of reliable digit TV monochromatic network antinoise Mobile Multimedia Broadcasting.
Utilizing digital television single-frequency network antinoise Mobile Multimedia Broadcasting 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 Mobile Multimedia Broadcasting transmission system of new generation satisfies social needs.
Just be based on above background, the present invention is directed to the practical communication environment and propose a kind of single-frequency network anti-noise mobile multimedia broadcast signal framing modulator approach, can satisfy the needs of High Data Rate may command multi-service digital television single-frequency network antinoise Mobile Multimedia Broadcasting transmission.
Desire is done more deep understanding to the patent background can be with reference to following documents and materials:
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,Jan.2006.
M.Takada?and?M.Saito.“Transmission?systems?for?ISDB-T,”Proceedings?of?the?IEEE,Special?Issueon?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.
Summary of the invention
The present invention is directed to high coded data rate may command multi-service digital television single-frequency network antinoise Mobile Multimedia Broadcasting problem, proposed a kind of single-frequency network anti-noise mobile multimedia broadcast signal framing modulator approach.
A kind of single-frequency network anti-noise mobile multimedia broadcast signal framing modulator approach that the present invention proposes is characterized in that it comprises the following steps:
1) the network data management device of single frequency network will be imported flow through LDPC coding, code element modulation of data bit and form the FFT coded data block with code element rotation back on frequency domain, LDPC represents low-density checksum, FFT represents the fast discrete Fourier conversion, and the length of FFT coded data block is K; Code element is modulated to a kind of among QPSK, 16QAM, 64QAM and the 256QAM, and the symbol constellations figure mapping mode of code element modulation adopts the Gray code mapping; The code element rotation realizes by symbol constellations figure is rotated to an angle, 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;
2) to adopt code check be that FFT coded data block that 1 space-frequency coding device will form on frequency domain is modulated to form on each antinoise mobile multimedia broadcast signal transmitter branches in the single frequency network and emptyly frequently modulates the FFT coded data block to the network data management device of single frequency network, and the time synchronized of adjusting each antinoise mobile multimedia broadcast signal transmitter branches is all modulated the FFT coded data block frequently to sky at one time and handled to guarantee all transmitters in the network;
3) each antinoise mobile multimedia broadcast signal transmitter in the single frequency network adopts IFFT that sky is modulated the FFT coded data block frequently and is transformed to the empty time domain discrete coded data sample value piece t that frequently modulates
Otal, IFFT represents the fast discrete Fourier inverse transformation;
4) each antinoise mobile multimedia broadcast signal transmitter in the single frequency network is modulated sky frequently time domain discrete coded data sample value piece in order and is divided equally into two, the empty sub-piece D of time domain discrete coded data sample value that frequently modulates
1Frequently modulate the sub-piece D of time domain discrete coded data sample value with sky
2, D
Total=[D
1, D
2];
5) each antinoise mobile multimedia broadcast signal transmitter in the single frequency network is modulated the sub-piece D of time domain discrete coded data sample value by the peak-to-average power ratio adjustment unit frequently to sky
1, the empty sub-piece D of time domain discrete coded data sample value that frequently modulates
2Carry out that signal adds, subtracts, conjugate operation is handled and the synthetic new again empty time domain discrete coded data sample value piece D that frequently modulates
New, the new empty time domain discrete coded data sample value piece D that frequently modulates
NewAdopt following generate pattern to obtain, generate pattern 1 is D
New=[D
1, D
2], 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
* 1, D
2], generate pattern 8 is
Generate pattern 9 is
Generate pattern 10 is
Generate pattern 11 is
Generate pattern 12 is
Relatively 12 kinds of synthetic empty frequencies of generate pattern are modulated time domain discrete coded data sample value piece D
New, choose the empty frequency of peak-to-average power ratio that falls that wherein has minimum peak-to-average power ratio and modulate time domain discrete coded data sample value piece
And the empty time domain discrete coded data sample value piece of frequently modulating of peak-to-average power ratio will fall
The corresponding generate pattern information that adopts send to the operational indicator sequence unit be set, wherein, D
* 1Expression is modulated the sub-piece D of time domain discrete coded data sample value frequently to sky
1Each empty modulate that time domain discrete coded data sample value carries out that conjugate operation is handled frequently and the empty sub-piece of time domain discrete coded data sample value of frequently modulating that obtains;
6) each antinoise mobile multimedia broadcast signal transmitter in the single frequency network is with the real part sequence of training sequence as sequence of plural training, the operational indicator sequence is provided with the imaginary part sequence of the set operational indicator sequence in unit as sequence of plural training, on time domain, constitute the discrete sample block of sequence of plural training, training sequence, the operational indicator sequence, the length of the discrete sample block of 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 each antinoise mobile multimedia broadcast signal transmitter in the single frequency network;
7) each antinoise mobile multimedia broadcast signal transmitter in the single frequency network will repeat 4 times continuously and form time domain embedding training sequence discrete sample block on time domain in the discrete sample block of the sequence of plural training that constitutes on the time domain, time domain embeds the length of training sequence discrete sample block and falls the empty length numerically equal of frequently modulating time domain discrete coded data sample value piece of peak-to-average power ratio, i.e. K=4 * X;
8) each antinoise mobile multimedia broadcast signal transmitter in the single frequency network will fall the empty time domain discrete coded data sample value piece, time domain frequently modulated of peak-to-average power ratio and embed training sequence discrete sample block and directly superpose and form time domain and embed training sequence and fall that peak-to-average power ratio is empty frequently modulates time domain discrete coded data sample value piece, as frame;
9) each antinoise mobile multimedia broadcast signal transmitter in the single frequency network at interval is that frame head inserts time domain and embeds training sequence and fall peak-to-average power ratio empty frequently to modulate time domain discrete coded data sample value piece be frame with Cyclic Prefix as protection, to form signal frame, the length of Cyclic Prefix is C;
10) each antinoise mobile multimedia broadcast signal transmitter in the single frequency network adopts square root raised cosine filter that the signal pulse of signal frame is shaped;
11) each antinoise mobile multimedia broadcast signal transmitter in the single frequency network with the baseband signal up-conversion to carrier wave.
Single-frequency network anti-noise mobile multimedia broadcast signal framing modulator approach according to above-mentioned is characterized in that: each antinoise mobile multimedia broadcast signal transmitter in the single frequency network fall that peak-to-average power ratio is empty modulates that time domain discrete coded data sample value piece modulates frequently by sky that the signal that the sub-piece of time domain discrete coded data sample value undertakies by specific 12 kinds of generate patterns adds, subtracts, conjugate operation is handled frequently and synthetic again; Have periodic time domain in the signal frame of each antinoise mobile multimedia broadcast signal transmitter in the single frequency network and embed training sequence discrete sample block; The length X of the training sequence of each antinoise mobile multimedia broadcast signal transmitter in the single frequency network is in 512,1024,2048, corresponding empty length K of modulating the FFT coded data block frequently is respectively 2048,4096,8192, the frequency interval of corresponding subcarrier is respectively 4KHz, 2KHz, 1KHz, and corresponding circulating prefix-length C is respectively empty 1/4,1/8,1/16 of the FFT coded data block length K size of frequently modulating; The training sequence of each antinoise mobile multimedia broadcast signal transmitter in the single frequency network, operational indicator sequence are formed by a series of 1 or-1, have pseudo-random characteristics; Training sequence, the operational indicator sequence of each antinoise mobile multimedia broadcast signal transmitter in the single frequency network have orthogonality each other; Each different operational indicator sequence of each antinoise mobile multimedia broadcast signal transmitter in the single frequency network is comprising and unique each system parameters and business model information of expressing each antinoise mobile multimedia broadcast signal transmitter in the single frequency network; The code check of space-frequency coding device is 1.
Characteristics of the present invention:
The present invention is the framing modulation scheme that mix in a kind of time-domain and frequency-domain spatial domain.The empty generate pattern of modulating time domain discrete coded data sample value piece frequently of peak-to-average power ratio of falling of the present invention is modulated time domain discrete coded data sample value piece choosing method with the empty frequency of peak-to-average power ratio that falls with minimum peak-to-average power ratio, but the very high big peak power signal probability of the maximum peak power that not only can make full use of ofdm signal is very low, the real part (or imaginary part) of the ofdm signal when number of sub carrier wave is big is the characteristic of multiple Gaussian random process and whose amplitude obeys Rayleigh distribution, the amount of information of the required extra transmission of being adopted of generate pattern is little, be easy to handle the primary signal of recovering to obtain ofdm signal at receiver end, the orthogonal property that can not destroy sub-carrier signal simultaneously can not produce extra nonlinear distortion yet.Have periodic time domain in the signal frame of each antinoise mobile multimedia broadcast signal transmitter in the single frequency network and embed training sequence discrete sample block, the training sequence of each antinoise mobile multimedia broadcast signal transmitter in the single frequency network, the operational indicator sequence has pseudo-random characteristics, the training sequence of each antinoise mobile multimedia broadcast signal transmitter in the single frequency network, the operational indicator sequence has orthogonality each other, it is by falling the empty time domain discrete coded data sample value piece of frequently modulating of peak-to-average power ratio that the empty time domain discrete coded data sample value piece of frequently modulating of peak-to-average power ratio falls in the time domain embedding training sequence of each antinoise mobile multimedia broadcast signal transmitter in the single frequency network, time domain embeds training sequence discrete sample block and directly superposes and form, and these have guaranteed that each mobile multimedia broadcast signal receiver in the single frequency network 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 embedding training sequence at interval as protection fall the empty time domain discrete coded data sample value piece of frequently modulating of peak-to-average power ratio, can reduce the interference effect between the adjacent signals frame to form signal frame.Adopt the LDPC coding that the input data are carried out chnnel coding error-correcting performance near shannon limit is provided.Code element modulation and constellation rotation provide the diversity of mobile multimedia broadcast signal.Each different operational indicator sequence of each antinoise mobile multimedia broadcast signal transmitter in the single frequency network is comprising and unique each system parameters and business model information of expressing each antinoise mobile multimedia broadcast signal transmitter in the single frequency network, digital television single-frequency network antinoise Mobile Multimedia Broadcasting 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.Framing modulator approach of the present invention has the equal power ratio of ebb, lock in time is short, clock jitter is little, anti-channel fading, anti-channel disturbance, can provide plurality of advantages such as High Data Rate may command multi-service digital television single-frequency network antinoise Mobile Multimedia Broadcasting transmission.
Description of drawings
Fig. 1 is the embodiment schematic diagram according to the single frequency network transmitter of single-frequency network anti-noise mobile multimedia broadcast signal framing modulator approach of the present invention.
Fig. 2 is the embodiment schematic diagram according to the single frequency network transmitter signal framing modulation of single-frequency network anti-noise mobile multimedia broadcast signal framing modulator approach of the present invention.
Embodiment
Below in conjunction with accompanying drawing specific embodiments of the invention are described in detail.
The embodiment of the single frequency network transmitter of the single-frequency network anti-noise mobile multimedia broadcast signal framing modulator approach that proposes according to the present invention as shown in Figure 1, follows these steps to carry out:
1) the network data management device of single frequency network will be imported flow through LDPC coding, code element modulation of data bit and form the FFT coded data block with code element rotation back on frequency domain, LDPC represents low-density checksum, FFT represents the fast discrete Fourier conversion, and the length of FFT coded data block is K; Code element is modulated to a kind of among QPSK, 16QAM, 64QAM and the 256QAM, and the symbol constellations figure mapping mode of code element modulation adopts the Gray code mapping; The code element rotation realizes by symbol constellations figure is rotated to an angle, 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;
2) to adopt code check be that FFT coded data block that 1 space-frequency coding device will form on frequency domain is modulated to form on each antinoise mobile multimedia broadcast signal transmitter branches in the single frequency network and emptyly frequently modulates the FFT coded data block to the network data management device of single frequency network, and the time synchronized of adjusting each antinoise mobile multimedia broadcast signal transmitter branches is all modulated the FFT coded data block frequently to sky at one time and handled to guarantee all transmitters in the network;
3) each antinoise mobile multimedia broadcast signal transmitter in the single frequency network adopts IFFT that sky is modulated the FFT coded data block frequently and is transformed to the empty time domain discrete coded data sample value piece D that frequently modulates
Total, IFFT represents the fast discrete Fourier inverse transformation;
4) each antinoise mobile multimedia broadcast signal transmitter in the single frequency network is modulated sky frequently time domain discrete coded data sample value piece in order and is divided equally into two, the empty sub-piece D of time domain discrete coded data sample value that frequently modulates
1Frequently modulate the sub-piece D of time domain discrete coded data sample value with sky
2, D
Total=[D
1, D
2];
5) each antinoise mobile multimedia broadcast signal transmitter in the single frequency network is modulated the sub-piece D of time domain discrete coded data sample value by the peak-to-average power ratio adjustment unit frequently to sky
1, the empty sub-piece D of time domain discrete coded data sample value that frequently modulates
2Carry out that signal adds, subtracts, conjugate operation is handled and the synthetic new again empty time domain discrete coded data sample value piece D that frequently modulates
New, the new empty time domain discrete coded data sample value piece D that frequently modulates
NewAdopt following generate pattern to obtain, generate pattern 1 is D
New=[D
1, D
2], 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
* 1, D
2], generate pattern 8 is
Generate pattern 9 is
Generate pattern 10 is
Generate pattern 11 is
Generate pattern 12 is
Relatively 12 kinds of synthetic empty frequencies of generate pattern are modulated time domain discrete coded data sample value piece D
New, choose the empty frequency of peak-to-average power ratio that falls that wherein has minimum peak-to-average power ratio and modulate time domain discrete coded data sample value piece
And the empty time domain discrete coded data sample value piece of frequently modulating of peak-to-average power ratio will fall
The corresponding generate pattern information that adopts send to the operational indicator sequence unit be set, wherein, D
* 1Expression is modulated the sub-piece D of time domain discrete coded data sample value frequently to sky
1Each empty modulate that time domain discrete coded data sample value carries out that conjugate operation is handled frequently and the empty sub-piece of time domain discrete coded data sample value of frequently modulating that obtains;
6) each antinoise mobile multimedia broadcast signal transmitter in the single frequency network is with the real part sequence of training sequence as sequence of plural training, the operational indicator sequence is provided with the imaginary part sequence of the set operational indicator sequence in unit as sequence of plural training, on time domain, constitute the discrete sample block of sequence of plural training, training sequence, the operational indicator sequence, the length of the discrete sample block of sequence of plural training all is X, the operational indicator sequence is comprising and unique each system parameters and business model information of expressing each antinoise mobile multimedia broadcast signal transmitter in the single frequency network, and X gets 512,1024, in 2048 one;
7) each antinoise mobile multimedia broadcast signal transmitter in the single frequency network will repeat 4 times continuously and form time domain embedding training sequence discrete sample block on time domain in the discrete sample block of the sequence of plural training that constitutes on the time domain, time domain embeds the length of training sequence discrete sample block and falls the empty length numerically equal of frequently modulating time domain discrete coded data sample value piece of peak-to-average power ratio, i.e. K=4 * X; When X got 512, K got 2048, and the frequency interval of corresponding subcarrier is got 4KHz; When X got 1024, K got 4096, and the frequency interval of corresponding subcarrier is got 2KHz; When X got 2048, K got 8192, and the frequency interval of corresponding subcarrier is got 1KHz;
8) each antinoise mobile multimedia broadcast signal transmitter in the single frequency network will fall the empty time domain discrete coded data sample value piece, time domain frequently modulated of peak-to-average power ratio and embed training sequence discrete sample block and directly superpose and form time domain and embed training sequence and fall that peak-to-average power ratio is empty frequently modulates time domain discrete coded data sample value piece, as frame;
9) each antinoise mobile multimedia broadcast signal transmitter in the single frequency network at interval is that frame head inserts time domain and embeds training sequence and fall peak-to-average power ratio empty frequently to modulate time domain discrete coded data sample value piece be frame with Cyclic Prefix as protection, to form signal frame, the length of 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;
10) each antinoise mobile multimedia broadcast signal transmitter in the single frequency network adopts square root raised cosine filter that the signal pulse of signal frame is shaped;
11) each antinoise mobile multimedia broadcast signal transmitter in the single frequency network with the baseband signal up-conversion to carrier wave.
Embodiment according to the single frequency network transmitter signal framing of single-frequency network anti-noise mobile multimedia broadcast signal framing modulator approach of the present invention is modulated, as shown in Figure 2, specifically implement as follows:
The network data management device of single frequency network will be imported flow through LDPC coding, code element modulation of data bit and form the FFT coded data block with code element rotation back on frequency domain; Adopting code check is that FFT coded data block that 1 space-frequency coding device will form on frequency domain is modulated to form on each antinoise mobile multimedia broadcast signal transmitter branches in the single frequency network and emptyly frequently modulates the FFT coded data block, and the time synchronized of adjusting each antinoise mobile multimedia broadcast signal transmitter branches is all modulated the FFT coded data block frequently to sky at one time and handled to guarantee all transmitters in the network; Through IFFT it is transformed to the empty time domain discrete coded data sample value piece of frequently modulating again, generates and choose the empty time domain discrete coded data sample value piece of frequently modulating of peak-to-average power ratio that falls that wherein has minimum peak-to-average power ratio by the peak-to-average power ratio adjustment unit and simultaneously the generate pattern information of the corresponding employing of institute is sent to the operational indicator sequence unit is set.Code element is modulated to a kind of among QPSK, 16QAM, 64QAM and the 256QAM, and the symbol constellations figure mapping mode of code element modulation adopts the Gray code mapping; The code element rotation realizes by symbol constellations figure is rotated to an angle, 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.Empty frequency is modulated the FFT coded data block and is made up of subcarrier.Empty length of modulating the FFT coded data block frequently is K; When X got 512, corresponding K got 2048, and the frequency interval of corresponding subcarrier is got 4KHz; When X got 1024, corresponding K got 4096, and the frequency interval of corresponding subcarrier is got 2KHz; When X got 2048, corresponding K got 8192, and the frequency interval of corresponding subcarrier is got 1KHz.Each antinoise mobile multimedia broadcast signal 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 each antinoise mobile multimedia broadcast signal transmitter in the single frequency network 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 each antinoise mobile multimedia broadcast signal transmitter in the single frequency network.Each antinoise mobile multimedia broadcast signal transmitter in the single frequency network will fall the empty time domain discrete coded data sample value piece, time domain frequently modulated of peak-to-average power ratio and embed training sequence discrete sample block and directly superpose and form time domain and embed training sequence and fall that peak-to-average power ratio is empty frequently modulates time domain discrete coded data sample value piece, as frame; Fall empty frequently modulation of peak-to-average power ratio at time domain embedding training sequence and insert Cyclic Prefix in the time domain discrete coded data sample value piece, form signal frame as the protection interval.Length as protection Cyclic Prefix at interval is C; When X got 512, corresponding C got 1/4 of K size; When X got 1024, corresponding C got 1/8 of K size; When X got 2048, corresponding C got 1/16 of K size.Each antinoise mobile multimedia broadcast signal 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.