A kind of robust digital mobile broadcast signal transmission method
Technical field
The invention belongs to moving communicating field, relate more specifically to a kind of robust digital mobile broadcast signal transmission method.
Background technology
At present, television broadcasting develops to the digitlization direction gradually from simulation.Digital television and broadcasting transinission system, as the important component part of digital television 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 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 broadcasting correlation technique, the emphasis of various countries' concern at present is that the digital television broadcasting how to pass under the environment for complex wave provides the implementation of reliable high-speed mobile cheaply.Transmission technology is the key technology of digital television broadcasting system, 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, broadband mobile LAN, digital television 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.
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.
In the practical communication environment, Digital Television digital mobile broadcast communication system performance is subjected to the influence of factors such as lock in time, clock jitter, channel fading, channel disturbance.Digital mobile broadcast signal transmission machine transmission method is the key technology that realizes reliable digit TV robust digital mobile broadcasting.
Utilizing Digital Television digital mobile 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 robust digital mobile broadcast 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 robust digital mobile broadcast signal transmission method, can satisfy the needs of High Data Rate may command multi-service Digital Television robust digital mobile broadcast transmitted.
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.
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?Issue?on?Global?Digital?Television:Technology?and?Emerging?Services,pp.251-256,Jan.2006.
G.Caire,G.Taricco,E.Biglieri,“Bit-interleaved?coded?modulation,”IEEE?Trans.Information?Theory,vol.44,no.3,pp.927-946,May?1998.
S.Benedetto,D.Divsalar,G.Montorsi,and?F.Pollara,“Serial?concatenation?of?interleaved?codes:performance?analysis,design,and?iterative?decoding,”IEEE?Trans.Inform.Theory,vol.44,no.3,pp.909-925,May?1998.
Summary of the invention
The present invention is directed to High Data Rate may command multi-service Digital Television robust digital mobile broadcast issue, proposed a kind of robust digital mobile broadcast signal transmission method.
A kind of robust digital mobile broadcast signal transmission method that the present invention proposes is characterized in that it comprises the following steps:
1) robust digital mobile broadcast signal transmission machine 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) robust digital mobile broadcast signal transmission machine is with the input data bit of oneself Bose-Chaudhuri-Hocquenghem Code (the Bose Chaudhuri Hocquenghem that flows through, BCH), Bit Interleave, multi code Rate of Chinese character form the cascade interweaved coding modulation data piece of FFT after deleting surplus convolutional encoding, code element modulation and code element rotation, symbol interleave on frequency domain, FFT represents the fast discrete Fourier conversion, and the length of the cascade interweaved coding modulation data piece of FFT is K;
3) robust digital mobile broadcast signal transmission machine adopts IFFT that the cascade interweaved coding modulation data piece of FFT is transformed to the cascade interweaved coding modulation data sample value of time domain discrete piece D
Total, IFFT represents the fast discrete Fourier inverse transformation;
4) robust digital mobile broadcast signal transmission machine is divided equally into two with the cascade interweaved coding modulation data sample value of time domain discrete piece in order, the sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete
1With the sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete
2, D
Total=[D
1, D
2];
5) robust digital mobile broadcast signal transmission machine passes through the peak-to-average power ratio adjustment unit to the sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete
1, the sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete
2Carry out that signal adds, subtracts, conjugate operation is handled and the synthetic again new cascade interweaved coding modulation data sample value of time domain discrete piece D
New, the cascade interweaved coding modulation data sample value of new time domain discrete 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
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
Compare the synthetic cascade interweaved coding modulation data sample value of the time domain discrete piece D of 12 kinds of generate patterns
New, choose wherein have a minimum peak-to-average power ratio the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece falls
And the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete 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 the cascade interweaved coding modulation data sample value of time domain discrete
1The cascade interweaved coding modulation data sample value of each time domain discrete carry out that conjugate operation is handled and the sub-piece of the cascade interweaved coding modulation data sample value of time domain discrete that obtains;
6) robust digital mobile broadcast signal transmission machine with training sequence as the real part sequence of 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, 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 robust digital mobile broadcast signal transmission machine;
7) robust digital mobile broadcast signal transmission machine 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 and the length numerically equal of falling the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece, i.e. K=4 * X of training sequence discrete sample block;
8) robust digital mobile broadcast signal transmission machine will fall the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece, time domain and embed training sequence discrete sample block and directly superpose and form time domain and embed training sequence and fall the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece, as frame;
9) robust digital mobile broadcast signal transmission machine at interval is that frame head inserts time domain and embeds training sequence to fall the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece be frame with Cyclic Prefix as protection, to form signal frame, the length of Cyclic Prefix is C;
10) robust digital mobile broadcast signal transmission machine adopts square root raised cosine filter that the signal pulse of signal frame is shaped;
11) robust digital mobile broadcast signal transmission machine forms emission of radio frequency signals to the on-air radio channel with the baseband signal up-conversion to carrier wave;
12) robust digital mobile broadcast signal receiver detect to receive radiofrequency signal that robust digital mobile broadcast signal transmission machine sent 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.
Robust digital mobile broadcast signal transmission method according to above-mentioned is characterized in that: robust digital mobile broadcast signal transmission machine fall the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece by the signal that the sub-piece of the cascade interweaved coding modulation data sample value of time domain discrete is undertaken by specific 12 kinds of generate patterns add, subtract, conjugate operation is handled and synthetic again; Have periodic time domain in the signal frame of robust digital mobile broadcast signal transmission machine and embed training sequence discrete sample block; The length X of the training sequence of robust digital mobile broadcast signal transmission machine is in 512,1024,2048, the length K 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; Training sequence, the operational indicator sequence of robust digital mobile broadcast signal transmission machine are formed by a series of 1 or 1, have pseudo-random characteristics; Training sequence, the operational indicator sequence of robust digital mobile broadcast signal transmission machine have orthogonality each other; Each different operational indicator sequence of robust digital mobile broadcast signal transmission machine is comprising and unique each system parameters and business model information of expressing robust digital mobile broadcast signal transmission machine; The encoding rate that multi code Rate of Chinese character is deleted surplus convolutional encoding 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, 64 QAM and 256 QAM, 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 16 QAM is 11.25 degree, the symbol constellations figure anglec of rotation of 64 QAM is 5.626 degree, and the symbol constellations figure anglec of rotation of 256 QAM is 2.8125 degree; Symbol interleave adopts the random interleaving mode.Robust digital mobile broadcast signal receiver can make full use of the Cyclic Prefix characteristic of signal frame and the architectural characteristic of signal frame is carried out baseband signal reception processing, handles comprising the time domain and frequency domain combined alternate analysis to signal frame head and signal frame body.
Characteristics of the present invention:
The present invention is the transmission plan that a kind of time-domain and frequency-domain mixes.Generate pattern of falling the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece of the present invention and have a minimum peak-to-average power ratio the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece choosing method falls, 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 robust digital mobile broadcast signal transmission machine and embed training sequence discrete sample block, the training sequence of robust digital mobile broadcast signal transmission machine, the operational indicator sequence has pseudo-random characteristics, the training sequence of robust digital mobile broadcast signal transmission machine, the operational indicator sequence has orthogonality each other, it is by falling the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece that the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece falls in the time domain embedding training sequence of robust digital mobile broadcast signal transmission machine, time domain embeds training sequence discrete sample block and directly superposes and form, and these have guaranteed that robust digital mobile broadcast signal receiver 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 cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece, can reduce the interference effect between the adjacent signals frame to form signal frame.The input data are carried out cascade interweaved coded modulation improved diversity order, make communication system under multidiameter fading channel, have good bit error performance.The code element modulation is rotated the diversity that mobile multimedia broadcast signal is provided with code element.Each different operational indicator sequence of robust digital mobile broadcast signal transmission machine is comprising and unique each system parameters and business model information of expressing robust digital mobile broadcast signal transmission machine, Digital Television robust digital mobile 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.Transmission method 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 cascade interweaving encoding modulation data rate may command multi-service Digital Television robust digital mobile broadcast transmitted.
Description of drawings
Fig. 1 is the embodiment schematic diagram according to signal transmission between certain transmitter and receiver of robust digital mobile broadcast signal transmission method of the present invention.
Fig. 2 is the embodiment schematic diagram that forms according to signal frame in the signals transmission between certain transmitter and receiver of robust digital mobile broadcast signal transmission method of the present invention.
Embodiment
Below in conjunction with accompanying drawing specific embodiments of the invention are described in detail.
The embodiment schematic diagram of signal transmission between certain transmitter and receiver of the robust digital mobile broadcast signal transmission method that proposes according to the present invention as shown in Figure 1, follows these steps to carry out:
1) this certain robust digital mobile broadcast signal transmission machine 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) this certain robust digital mobile broadcast signal transmission machine is flowed through the input data bit of oneself and is formed the cascade interweaved coding modulation data piece of FFT after Bose-Chaudhuri-Hocquenghem Code, Bit Interleave, multi code Rate of Chinese character are deleted surplus convolutional encoding, code element modulation and code element rotation, symbol interleave on frequency domain, FFT represents the fast discrete Fourier conversion, and the length of the cascade interweaved coding modulation data piece of FFT is K; The encoding rate that multi code Rate of Chinese character is deleted surplus convolutional encoding 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, 64 QAM 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 16 QAM is 11.25 degree, the symbol constellations figure anglec of rotation of 64 QAM is 5.626 degree, and the symbol constellations figure anglec of rotation of 256QAM is 2.8125 degree; Symbol interleave adopts the random interleaving mode.
3) this certain robust digital mobile broadcast signal transmission machine adopts IFFT that the cascade interweaved coding modulation data piece of FFT is transformed to the cascade interweaved coding modulation data sample value of time domain discrete piece D
Total, IFFT represents the fast discrete Fourier inverse transformation;
4) this certain robust digital mobile broadcast signal transmission machine is divided equally into two with the cascade interweaved coding modulation data sample value of time domain discrete piece in order, the sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete
1With the sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete
2, D
Total=[D
1, D
2];
5) this certain robust digital mobile broadcast signal transmission machine passes through the peak-to-average power ratio adjustment unit to the sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete
1, the sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete
2Carry out that signal adds, subtracts, conjugate operation is handled and the synthetic again new cascade interweaved coding modulation data sample value of time domain discrete piece D
New, the cascade interweaved coding modulation data sample value of new time domain discrete 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
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
Compare the synthetic cascade interweaved coding modulation data sample value of the time domain discrete piece D of 12 kinds of generate patterns
New, choose wherein have a minimum peak-to-average power ratio the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece falls
And the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete 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 the cascade interweaved coding modulation data sample value of time domain discrete
1The cascade interweaved coding modulation data sample value of each time domain discrete carry out that conjugate operation is handled and the sub-piece of the cascade interweaved coding modulation data sample value of time domain discrete that obtains;
6) this certain robust digital mobile broadcast signal transmission machine 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 robust digital mobile broadcast signal transmission machine, and X gets 512,1024, in 2048 one;
7) this certain robust digital mobile broadcast signal transmission machine 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 and the length numerically equal of falling the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece, i.e. K=4 * X of training sequence discrete sample block; 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) this certain robust digital mobile broadcast signal transmission machine will fall the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece, time domain and embed training sequence discrete sample block and directly superpose and form time domain and embed training sequence and fall the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece, as frame;
9) this certain robust digital mobile broadcast signal transmission machine at interval is that frame head inserts time domain and embeds training sequence to fall the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete 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) this certain robust digital mobile broadcast signal transmission machine adopts square root raised cosine filter that the signal pulse of signal frame is shaped;
11) this certain robust digital mobile broadcast signal transmission machine forms emission of radio frequency signals to the on-air radio channel with the baseband signal up-conversion to carrier wave;
12) this certain robust digital mobile broadcast signal receiver detects and receives radiofrequency signal that robust digital mobile broadcast signal transmission machine sent and its down-conversion is formed baseband signal, utilize the Cyclic Prefix characteristic of signal frame and the architectural characteristic of signal frame to carry out baseband signal reception processing, handle comprising time domain and frequency domain combined alternate analysis to signal frame head and signal frame body.
According to the embodiment schematic diagram that signal frame in the signals transmission between certain transmitter and receiver of robust digital mobile broadcast signal transmission method of the present invention forms, as shown in Figure 2, specifically implement as follows:
This certain robust digital mobile broadcast signal transmission machine 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.
This certain robust digital mobile broadcast signal transmission machine is with the input data bit of oneself Bose-Chaudhuri-Hocquenghem Code of flowing through, Bit Interleave, multi code Rate of Chinese character is deleted surplus convolutional encoding, code element modulation and code element rotation, on frequency domain, form the cascade interweaved coding modulation data piece of FFT after the symbol interleave, through IFFT it is transformed to the discrete cascade interweaving encoding modulating data sample value piece of time domain again, generates by the peak-to-average power ratio adjustment unit and choose the cascade interweaved coding modulation data sample value of the peak-to-average power ratio time domain discrete piece that falls that wherein has minimum peak-to-average power ratio and simultaneously the generate pattern information of the corresponding employing of institute is sent to the operational indicator sequence unit is set.The encoding rate that multi code Rate of Chinese character is deleted surplus convolutional encoding 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, 64 QAM and 256 QAM, 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 16 QAM is 11.25 degree, the symbol constellations figure anglec of rotation of 64 QAM is 5.626 degree, and the symbol constellations figure anglec of rotation of 256 QAM is 2.8125 degree; Symbol interleave adopts the random interleaving mode.
The cascade interweaved coding modulation data piece of FFT is made up of subcarrier.The length of the cascade interweaved coding modulation data piece of FFT 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.
This certain robust digital mobile broadcast signal transmission machine 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 robust digital mobile broadcast signal transmission machine 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 robust digital mobile broadcast signal transmission machine.
This certain robust digital mobile broadcast signal transmission machine will fall the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece, time domain and embed training sequence discrete sample block and directly superpose and form time domain and embed training sequence and fall the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece, as frame; Embed training sequence in time domain and fall and insert Cyclic Prefix in the cascade interweaved coding modulation data sample value of the peak-to-average power ratio time domain discrete piece 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 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.
This certain robust digital mobile broadcast signal transmission machine 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.
This certain robust digital mobile broadcast signal transmission machine forms emission of radio frequency signals to the on-air radio channel with the baseband signal up-conversion to carrier wave.
This certain robust digital mobile broadcast signal receiver detects and receives radiofrequency signal that robust digital mobile broadcast signal transmission machine sent and its down-conversion is formed baseband signal, utilize the Cyclic Prefix characteristic of signal frame and the architectural characteristic of signal frame to carry out baseband signal reception processing, handle comprising time domain and frequency domain combined alternate analysis to signal frame head and signal frame body.
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.