CN102394853B - Multimedia broadcasting single-frequency network robust wireless signal framing modulation method - Google Patents

Abstract

The invention discloses a framing modulation method of a robust wireless signal of a multimedia broadcasting single frequency network, which is a framing modulation scheme of mixing time domain, frequency domain and space domain. The robust wireless signal framing modulation method of the multimedia broadcast single frequency network of the present invention has the advantages of low peak-to-average power ratio, short synchronization time, robustness, controllable multi-service, and the like.

Description

A kind of multimedia broadcasting single-frequency network robust wireless signal framing modulator approach

Technical field

The invention belongs to wireless communication field, relate more specifically to a kind of multimedia broadcasting single-frequency network robust wireless signal framing modulator approach.

Background technology

Peak-to-average power ratio (PAPR) pair amplifier that OFDM (OFDM) signal is higher and the range of linearity of digital to analog converter have very high requirement, 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.Cascade different coding form can make full use of the different coding technological merit; 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.The networking model of employing single frequency network can improve the availability of frequency spectrum of digital TV multimedia broadcast wireless transmissions system greatly.In actual single frequency network communication environment, digital TV multimedia broadcast radio communication system performance is subjected to the influence of factors such as lock in time, clock jitter, channel fading, channel disturbance.Multimedia broadcasting single-frequency network robust wireless signal transmitter framing modulator approach is to realize the key technology of reliable digit television multimedia broadcast single frequency network wireless transmission.

Utilizing digital TV multimedia broadcast single frequency network wireless transmitting 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 TV multimedia broadcast wireless transmissions of new generation system satisfies social needs.

Just be based on above background, the present invention is directed to the practical communication environment and propose a kind of multimedia broadcasting single-frequency network robust wireless signal framing modulator approach, can satisfy the needs of High Data Rate may command multi-service digital TV multimedia broadcast single frequency network wireless 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.

U.Ladebusch?and?C.A.Liss.“Terrestrial?DVB(DVB-T)：A?broadcast?technology?for?stat?ionary?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.

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 TV multimedia broadcast single frequency network wireless transmission problem, proposed a kind of multimedia broadcasting single-frequency network robust wireless signal framing modulator approach.

A kind of multimedia broadcasting single-frequency network robust wireless 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 data bit Bose-Chaudhuri-Hocquenghem Code (the Bose Chaudhuri Hocquenghem that flows through, BCH), Bit Interleave, LDPC (the Low Density Parity Check that encodes, LDPC), code element modulation, symbol interleave form the cascade interweaved coding modulation data piece of FFT 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;

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 multimedia broadcasting robust wireless signal 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 multimedia broadcasting robust wireless signal 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 multimedia broadcasting robust wireless signal transmitter in the single frequency network adopts IFFT 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 D that frequently modulates _Total, IFFT represents the fast discrete Fourier inverse transformation;

4) each multimedia broadcasting robust wireless signal transmitter in the single frequency network is modulated sky frequently the cascade interweaved coding modulation data sample value of time domain discrete piece in order and is divided equally into two, the empty sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete that frequently modulates ₁Frequently modulate the sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete with sky ₂, D _Total=[D ₁, D ₂];

5) each multimedia broadcasting robust wireless signal transmitter in the single frequency network is modulated the sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete by the peak-to-average power ratio adjustment unit frequently to sky ₁, the empty sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete that frequently modulates ₂Carry out that signal adds, subtracts, conjugate operation is handled and the synthetic new again empty cascade interweaved coding modulation data sample value of the time domain discrete piece D that frequently modulates _New, the new empty cascade interweaved coding modulation data sample value of the time domain discrete 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 $D_{\mathrm{new}}=[D_1,\sqrt{1/2}(D_1+D_2)],$ Generate pattern 3 is $D_{\mathrm{new}}=[D_1,\sqrt{1/2}(D_1-D_2)],$ Generate pattern 4 is $D_{\mathrm{new}}=[\sqrt{1/2}(D_1+D_2),D_2],$ Generate pattern 5 is $D_{\mathrm{new}}=[\sqrt{1/2}(D_1-D_2),D_2],$ Generate pattern 6 is $D_{\mathrm{new}}=[\sqrt{1/2}(D_1+D_2),\sqrt{1/2}(D_1-D_2)],$ Generate pattern 7 is D _New=[D ^* ₁, D ₂], generate pattern 8 is $D_{\mathrm{new}}=[{D^{*}}_1,\sqrt{1/2}({D^{*}}_1+D_2)],$ Generate pattern 9 is $D_{\mathrm{new}}=[{D^{*}}_1,\sqrt{1/2}({D^{*}}_1-D_2)],$ Generate pattern 10 is $D_{\mathrm{new}}=[\sqrt{1/2}({D^{*}}_1+D_2),D_2],$ Generate pattern 11 is $D_{\mathrm{new}}=[\sqrt{1/2}({D^{*}}_1-D_2),D_2],$ Generate pattern 12 is $D_{\mathrm{new}}=[\sqrt{1/2}({D^{*}}_1+D_2),\sqrt{1/2}({D^{*}}_1-D_2)],$ Relatively 12 kinds of synthetic empty frequencies of generate pattern are modulated the cascade interweaved coding modulation data sample value of time domain discrete 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 the cascade interweaved coding modulation data sample value of time domain discrete piece

And the empty cascade interweaved coding modulation data sample value of the time domain discrete 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 the cascade interweaved coding modulation data sample value of time domain discrete frequently to sky ₁Each empty modulate that the cascade interweaved coding modulation data sample value of time domain discrete carries out that conjugate operation is handled frequently and the empty sub-piece of the cascade interweaved coding modulation data sample value of time domain discrete of frequently modulating that obtains;

6) each multimedia broadcasting robust wireless signal transmitter in the single frequency network inserts Cyclic Prefix at interval as protection and falls the empty cascade interweaved coding modulation data sample value of the time domain discrete piece of frequently modulating of peak-to-average power ratio, the empty discrete cascade interweaving encoding modulating data sample value piece of time domain cyclic prefix of frequently modulating of peak-to-average power ratio falls in formation, as frame, the length of Cyclic Prefix is C, and falling the empty length of modulating the discrete cascade interweaving encoding modulating data sample value piece of time domain cyclic prefix frequently of peak-to-average power ratio is C+K;

7) each multimedia broadcasting robust wireless signal transmitter in the single frequency network 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 multimedia broadcasting robust wireless signal transmitter;

8) each multimedia broadcasting robust wireless signal transmitter in the single frequency network will repeat 2 times continuously in the sequence of plural training discrete sample block that constitutes on the time domain and form time domain repetition training series of discrete sample value piece on time domain, as frame head;

9) each multimedia broadcasting robust wireless signal transmitter in the single frequency network is that frame head is inserted into and falls peak-to-average power ratio empty to modulate the discrete cascade interweaving encoding modulating data sample value piece of time domain cyclic prefix frequently be frame with time domain repetition training series of discrete sample value piece, to form signal frame;

10) each multimedia broadcasting robust wireless signal transmitter in the single frequency network adopts square root raised cosine filter that the signal pulse of signal frame is shaped;

11) in the single frequency network each multimedia broadcasting robust wireless signal transmitter with the baseband signal up-conversion to carrier wave.

Multimedia broadcasting single-frequency network robust wireless signal framing modulator approach according to above-mentioned is characterized in that: each multimedia broadcasting robust wireless signal transmitter in the single frequency network fall that peak-to-average power ratio is empty modulates that the cascade interweaved coding modulation data sample value of time domain discrete piece modulates frequently by sky that the signal that the sub-piece of the cascade interweaved coding modulation data sample value of time domain discrete undertakies by specific 12 kinds of generate patterns adds, subtracts, conjugate operation is handled frequently and synthetic again; Has periodic time domain repetition training series of discrete sample value piece in the signal frame of each multimedia broadcasting robust wireless signal transmitter in the single frequency network; The length X of the training sequence of each multimedia broadcasting robust wireless signal transmitter in the single frequency network is in 512,1024,2048, corresponding empty length K of modulating the cascade interweaved coding modulation data piece of FFT 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 cascade interweaved coding modulation data block length of the FFT K size of frequently modulating; The training sequence of each multimedia broadcasting robust wireless 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 multimedia broadcasting robust wireless signal transmitter in the single frequency network have orthogonality each other; Each different operational indicator sequence of each multimedia broadcasting robust wireless signal transmitter in the single frequency network is comprising and unique each system parameters and business model information of expressing each multimedia broadcasting robust wireless signal transmitter in the single frequency network; The code check of space-frequency coding device is 1; The encoding rate of LDPC coding 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, 16QAM, 32QAM and the 64QAM, and symbol constellations figure mapping mode adopts the Gray code mapping; Symbol interleave adopts the random interleaving mode.

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 the cascade interweaved coding modulation data sample value of time domain discrete piece frequently of peak-to-average power ratio of falling of the present invention is modulated the cascade interweaved coding modulation data sample value of time domain discrete 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.Has periodic time domain repetition training series of discrete sample value piece in the signal frame of each multimedia broadcasting robust wireless signal transmitter in the single frequency network, the training sequence of each multimedia broadcasting robust wireless signal transmitter in the single frequency network, the operational indicator sequence has pseudo-random characteristics, the training sequence of each multimedia broadcasting robust wireless signal transmitter in the single frequency network, the operational indicator sequence has orthogonality each other, the signal frame of each multimedia broadcasting robust wireless signal transmitter in the single frequency network is that frame head is inserted into that to fall the empty discrete cascade interweaving encoding modulating data sample value piece of time domain cyclic prefix of frequently modulating of peak-to-average power ratio be frame and forming by time domain repetition training series of discrete sample value piece, and these have guaranteed that multimedia broadcasting robust wireless 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 fallen the empty cascade interweaved coding modulation data sample value of the time domain discrete piece of frequently modulating of peak-to-average power ratio to form signal frame body as the insertion of protection interval, can reduce the interference effect between the cascade interweaved coding modulation data of signal frame head and 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.Each different operational indicator sequence of each multimedia broadcasting robust wireless signal transmitter in the single frequency network is comprising and unique each system parameters and business model information of expressing each multimedia broadcasting robust wireless signal transmitter in the single frequency network, digital TV multimedia broadcast single frequency network wireless transmitting 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 TV multimedia broadcast single frequency network wireless transmission.

Description of drawings

Fig. 1 is the embodiment schematic diagram according to the single frequency network transmitter of multimedia broadcasting single-frequency network robust wireless 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 multimedia broadcasting single-frequency network robust wireless 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 multimedia broadcasting single-frequency network robust wireless 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 Bose-Chaudhuri-Hocquenghem Code, Bit Interleave, LDPC coding, code element modulation, symbol interleave of data bit and form the cascade interweaved coding modulation data piece of FFT 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 of LDPC coding 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, 16QAM, 32QAM and the 64QAM, and symbol constellations figure mapping mode adopts the Gray code mapping; Symbol interleave adopts the random interleaving mode;

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 multimedia broadcasting robust wireless signal 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 multimedia broadcasting robust wireless signal 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 multimedia broadcasting robust wireless signal transmitter in the single frequency network adopts IFFT 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 D that frequently modulates _Total, IFFT represents the fast discrete Fourier inverse transformation;

4) each multimedia broadcasting robust wireless signal transmitter in the single frequency network is modulated sky frequently the cascade interweaved coding modulation data sample value of time domain discrete piece in order and is divided equally into two, the empty sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete that frequently modulates ₁Frequently modulate the sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete with sky ₂, D _Total=[D ₁, D ₂];

5) each multimedia broadcasting robust wireless signal transmitter in the single frequency network is modulated the sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete by the peak-to-average power ratio adjustment unit frequently to sky ₁, the empty sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete that frequently modulates ₂Carry out that signal adds, subtracts, conjugate operation is handled and the synthetic new again empty cascade interweaved coding modulation data sample value of the time domain discrete piece D that frequently modulates _New, the new empty cascade interweaved coding modulation data sample value of the time domain discrete 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 $D_{\mathrm{new}}=[D_1,\sqrt{1/2}(D_1+D_2)],$ Generate pattern 3 is $D_{\mathrm{new}}=[D_1,\sqrt{1/2}(D_1-D_2)],$ Generate pattern 4 is $D_{\mathrm{new}}=[\sqrt{1/2}(D_1+D_2),D_2],$ Generate pattern 5 is $D_{\mathrm{new}}=[\sqrt{1/2}(D_1-D_2),D_2],$ Generate pattern 6 is $D_{\mathrm{new}}=[\sqrt{1/2}(D_1+D_2),\sqrt{1/2}(D_1-D_2)],$ Generate pattern 7 is D _New=[D ^* ₁, D ₂], generate pattern 8 is $D_{\mathrm{new}}=[{D^{*}}_1,\sqrt{1/2}({D^{*}}_1+D_2)],$ Generate pattern 9 is $D_{\mathrm{new}}=[{D^{*}}_1,\sqrt{1/2}({D^{*}}_1-D_2)],$ Generate pattern 10 is $D_{\mathrm{new}}=[\sqrt{1/2}({D^{*}}_1+D_2),D_2],$ Generate pattern 11 is $D_{\mathrm{new}}=[\sqrt{1/2}({D^{*}}_1-D_2),D_2],$ Generate pattern 12 is $D_{\mathrm{new}}=[\sqrt{1/2}({D^{*}}_1+D_2),\sqrt{1/2}({D^{*}}_1-D_2)],$ Relatively 12 kinds of synthetic empty frequencies of generate pattern are modulated the cascade interweaved coding modulation data sample value of time domain discrete 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 the cascade interweaved coding modulation data sample value of time domain discrete piece

And the empty cascade interweaved coding modulation data sample value of the time domain discrete 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 the cascade interweaved coding modulation data sample value of time domain discrete frequently to sky ₁Each empty modulate that the cascade interweaved coding modulation data sample value of time domain discrete carries out that conjugate operation is handled frequently and the empty sub-piece of the cascade interweaved coding modulation data sample value of time domain discrete of frequently modulating that obtains;

6) each multimedia broadcasting robust wireless signal transmitter in the single frequency network inserts Cyclic Prefix at interval as protection and falls the empty cascade interweaved coding modulation data sample value of the time domain discrete piece of frequently modulating of peak-to-average power ratio, the empty discrete cascade interweaving encoding modulating data sample value piece of time domain cyclic prefix of frequently modulating of peak-to-average power ratio falls in formation, as frame, the length of Cyclic Prefix is C, and falling the empty length of modulating the discrete cascade interweaving encoding modulating data sample value piece of time domain cyclic prefix frequently of peak-to-average power ratio is C+K;

7) each multimedia broadcasting robust wireless signal transmitter in the single frequency network 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 multimedia broadcasting robust wireless signal transmitter; X gets in 512,1024,2048; When X got 512, K got 2048, and C gets 1/4 of K size, and the empty frequency interval of modulating the cascade interweaved coding modulation data piece of FFT subcarrier is frequently got 4KHz; When X got 1024, K got 4096, and C gets 1/8 of K size, and the empty frequency interval of modulating the cascade interweaved coding modulation data piece of FFT subcarrier is frequently got 2KHz; When X got 2048, K got 8192, and C gets 1/16 of K size, and the empty frequency interval of modulating the cascade interweaved coding modulation data piece of FFT subcarrier is frequently got 1KHz;

8) each multimedia broadcasting robust wireless signal transmitter in the single frequency network will repeat 2 times continuously in the sequence of plural training discrete sample block that constitutes on the time domain and form time domain repetition training series of discrete sample value piece on time domain, as frame head;

9) each multimedia broadcasting robust wireless signal transmitter in the single frequency network is that frame head is inserted into and falls peak-to-average power ratio empty to modulate the discrete cascade interweaving encoding modulating data sample value piece of time domain cyclic prefix frequently be frame with time domain repetition training series of discrete sample value piece, to form signal frame;

10) each multimedia broadcasting robust wireless signal transmitter in the single frequency network adopts square root raised cosine filter that the signal pulse of signal frame is shaped;

11) in the single frequency network each multimedia broadcasting robust wireless signal transmitter with the baseband signal up-conversion to carrier wave.

Embodiment according to the single frequency network transmitter signal framing of multimedia broadcasting single-frequency network robust wireless 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 Bose-Chaudhuri-Hocquenghem Code, Bit Interleave, LDPC coding, code element modulation, symbol interleave of data bit and form the cascade interweaved coding modulation data piece of FFT on frequency domain; The encoding rate of LDPC coding 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, 16QAM, 32QAM and the 64QAM, and symbol constellations figure mapping mode adopts the Gray code mapping; Symbol interleave adopts the random interleaving mode; Adopting code check 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 multimedia broadcasting robust wireless signal transmitter branch road in the single frequency network and emptyly frequently modulates the cascade interweaved coding modulation data piece of FFT, and the time synchronized of adjusting each multimedia broadcasting robust wireless signal 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; Through IFFT it is transformed to the empty cascade interweaved coding modulation data sample value of the time domain discrete piece of frequently modulating again, generates and choose the empty cascade interweaved coding modulation data sample value of the time domain discrete 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.

Each multimedia broadcasting robust wireless signal transmitter in the single frequency network inserts Cyclic Prefix at interval as protection and falls the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece; the discrete cascade interweaving encoding modulating data sample value piece of peak-to-average power ratio time domain cyclic prefix falls in formation; as frame, the length of Cyclic Prefix is C.Each multimedia broadcasting robust wireless signal transmitter in the single frequency network 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 multimedia broadcasting robust wireless signal transmitter.Each multimedia broadcasting robust wireless signal transmitter in the single frequency network will repeat 2 times continuously and form time domain repetition training series of discrete sample value piece on time domain in the discrete sample block of the sequence of plural training that constitutes on the time domain, as frame head.Each multimedia broadcasting robust wireless signal transmitter in the single frequency network is that frame head is inserted into that to fall the discrete cascade interweaving encoding modulating data sample value piece of peak-to-average power ratio time domain cyclic prefix be frame with time domain repetition training series of discrete sample value piece, to form signal frame.Each multimedia broadcasting robust wireless signal transmitter in the single frequency network adopts square root raised cosine filter that the signal pulse of signal frame is shaped.Each multimedia broadcasting robust wireless signal transmitter in the single frequency network with the baseband signal up-conversion to carrier wave.

The X of each multimedia broadcasting robust wireless signal transmitter in the single frequency network gets in 512,1024,2048; When X got 512, K got 2048, and C gets 1/4 of K size, and the empty frequency interval of modulating the cascade interweaved coding modulation data piece of FFT subcarrier is frequently got 4KHz; When X got 1024, K got 4096, and C gets 1/8 of K size, and the empty frequency interval of modulating the cascade interweaved coding modulation data piece of FFT subcarrier is frequently got 2KHz; When X got 2048, K got 8192, and C gets 1/16 of K size, and the empty frequency interval of modulating the cascade interweaved coding modulation data piece of FFT subcarrier is frequently got 1KHz; Training sequence, operational indicator sequence as each multimedia broadcasting robust wireless 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 multimedia broadcasting robust wireless signal transmitter in the single frequency network.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 (5)

1. a kind of multimedia broadcast single frequency network robust wireless signal framing modulation method, it is characterized in that it comprises the following steps: 1) The network data manager of the single frequency network forms an FFT concatenated interleaving coded modulation data block in the frequency domain through BCH coding, bit interleaving, LDPC coding, symbol modulation, and symbol interleaving of the input data bit stream, BCH means BoseChaudhuri Hocquenghem , LDPC means Low Density Parity Check, and the length of the FFT concatenated interleaved coding modulation data block is K; 2) The network data manager of the single frequency network uses a space-frequency encoder with a code rate of 1 to modulate the FFT concatenated interleaved coded modulation data block formed in the frequency domain to each multimedia broadcasting robust wireless signal in the single frequency network for transmission Form space-frequency modulation FFT concatenated interleaving coding modulation data blocks on the machine branch, and adjust the time synchronization of each multimedia broadcasting robust wireless signal transmitter branch to ensure that all transmitters in the network perform space-frequency modulation FFT stages at the same time Co-interleave coded modulation data blocks for processing; 3) Each multimedia broadcasting robust wireless signal transmitter in the single frequency network adopts IFFT to transform the space-frequency modulation FFT concatenated interleaved coded modulation data block into a space-frequency modulated time-domain discrete concatenated interleaved coded modulated data sample block D _total ; 4) Each multimedia broadcast robust wireless signal transmitter in the single frequency network divides the space-frequency modulation time-domain discrete concatenated interleaving coded modulation data sample block into two equally in sequence, and the space-frequency modulated time-domain discrete concatenated interleaved coded modulation The data sample sub-block D ₁ and the space-frequency modulation time-domain discrete concatenated interleaving coding modulation data sample sub-block D ₂ , D _total = [D ₁ , D ₂ ]; 5) Each multimedia broadcasting robust wireless signal transmitter in the single frequency network uses the peak-to-average power ratio adjustment unit to discretely concatenate and interleave coded and modulated data sample sub-block D ₁ in the space-frequency modulation time domain, and the time-domain discrete level of the space-frequency modulation The interleaved coded modulation data sample sub-block D ₂ performs signal addition, subtraction, and conjugate operation processing and recombines a new space-frequency modulation time-domain discrete concatenated interleaved coded modulation data sample block D _new , the new space-frequency modulation The domain discrete concatenated interleaved coded modulation data sample block D _new is obtained by the following generation mode, the generation mode 1 is D _new = [D ₁ , D ₂ ], and the generation mode 2 is ${\mathrm{D.}}_{\mathrm{new}}=[{\mathrm{D.}}_1,\sqrt{1/2}({\mathrm{D.}}_1+{\mathrm{D.}}_2)],$ Generate schema 3 as ${\mathrm{D.}}_{\mathrm{new}}=[{\mathrm{D.}}_1,\sqrt{1/2}({\mathrm{D.}}_1-{\mathrm{D.}}_2)],$ Generate schema 4 as ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({\mathrm{D.}}_1+{\mathrm{D.}}_2),{\mathrm{D.}}_2],$ Generate schema 5 as ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({\mathrm{D.}}_1-{\mathrm{D.}}_2),{\mathrm{D.}}_2],$ Generate schema 6 as ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({\mathrm{D.}}_1+{\mathrm{D.}}_2),\sqrt{1/2}({\mathrm{D.}}_1-{\mathrm{D.}}_2)],$ Generation mode 7 is D _new = [D ^* ₁ , D ₂ ], generation mode 8 is ${\mathrm{D.}}_{\mathrm{new}}=[{{\mathrm{D.}}^{*}}_1,\sqrt{1/2}({{\mathrm{D.}}^{*}}_1+{\mathrm{D.}}_2)],$ Generate schema 9 as ${\mathrm{D.}}_{\mathrm{new}}=[{{\mathrm{D.}}^{*}}_1,\sqrt{1/2}({{\mathrm{D.}}^{*}}_1-{\mathrm{D.}}_2)],$ Generate schema 10 as ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({{\mathrm{D.}}^{*}}_1+{\mathrm{D.}}_2),{\mathrm{D.}}_2],$ Generate schema 11 as ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({{\mathrm{D.}}^{*}}_1-{\mathrm{D.}}_2),{\mathrm{D.}}_2],$ Generate schema 12 as ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({{\mathrm{D.}}^{*}}_1+{\mathrm{D.}}_2),\sqrt{1/2}({{\mathrm{D.}}^{*}}_1-{\mathrm{D.}}_2)],$ Comparing the space-frequency modulation time-domain discrete concatenated interleaving coded modulation data block D _new synthesized by 12 kinds of generation modes, and selecting the one with the lowest peak-to-average power ratio with reduced peak-to-average power ratio data sample block

And reduce the peak-to-average power ratio space-frequency modulation time-domain discrete concatenated interleaved coded modulation data sample block

The generation mode information adopted correspondingly is sent to the service index sequence setting unit, wherein, D ^* ₁ represents each space-frequency modulation time-domain discrete concatenation of the space-frequency modulation time-domain interleaved coded modulation data sample sub-block D ₁ Space-frequency modulated time-domain discrete concatenated interleaved coded modulation data sample sub-block obtained by performing conjugate operation on the interleaved coded modulated data samples; 6) Each multimedia broadcasting robust wireless signal transmitter in the single frequency network inserts the cyclic prefix as a guard interval into the reduced peak-to-average power ratio space-frequency modulation time-domain discrete concatenated interleaved coded modulation data sample block to form a reduced peak-to-average power ratio Space-frequency modulation time-domain cyclic prefix discrete concatenated interleaved coding modulated data sample block, as a frame body, the length of the cyclic prefix is C, and the peak-to-average power ratio is reduced The length of the block is C+K; 7) Each multimedia broadcasting robust wireless signal transmitter in the single frequency network uses the training sequence as the real part sequence of the complex training sequence, and uses the service index sequence set by the service index sequence setting unit as the imaginary part sequence of the complex training sequence. In the time domain, the discrete sample blocks that constitute the complex training sequence, the length of the training sequence, the service index sequence, and the discrete sample block of the complex training sequence are all X, and the service index sequence contains and uniquely expresses the robust wireless signal transmission of multimedia broadcasting Each system parameter and business mode information of the computer; X takes one of 512, 1024, and 2048; when X takes 512, K takes 2048, and C takes 1/4 of the size of K; when X takes 1024, K takes 4096, C takes 1/8 of the size of K; when X takes 2048, K takes 8192, and C takes 1/16 of the size of K; 8) Each multimedia broadcasting robust wireless signal transmitter in the single frequency network repeats the discrete sample value blocks of the complex training sequence formed in the time domain continuously for 2 times in the time domain to form the discrete sample value blocks of the repeated training sequence in the time domain, as frame header; 9) Each multimedia broadcasting robust wireless signal transmitter in the single frequency network inserts the discrete sample block of the time-domain repeated training sequence, that is, the frame header, into the reduced peak-to-average power ratio space-frequency modulation time-domain cyclic prefix discrete concatenated interleaved coded modulation data The sample block is the frame body to form a signal frame; 10) Each multimedia broadcasting robust wireless signal transmitter in the single frequency network adopts a square root raised cosine roll-off filter to shape the signal pulse of the signal frame; 11) Each multimedia broadcasting robust wireless signal transmitter in the single frequency network up-converts the baseband signal to the carrier. 2. by the multimedia broadcast single frequency network robust wireless signal framing modulation method of claim 1, it is characterized in that: described training sequence, service index sequence are made up of a series of 1 or-1, have pseudo-random characteristic. 3. The method for framing and modulating the robust wireless signal of the multimedia broadcasting single frequency network according to claim 1, characterized in that: the training sequence and the service index sequence are mutually orthogonal. 4. by the multimedia broadcast single frequency network robust wireless signal framing modulation method of claim 1, it is characterized in that: the encoding rate of described LDPC encoding is 1/4, 1/2, 5/8, 3/4 and 7 One of /8; bit interleaving adopts random interleaving; symbol modulation is one of QPSK, 16QAM, 32QAM and 64QAM, symbol constellation mapping adopts Gray code mapping; symbol interleaving adopts random interleaving. 5. by the multimedia broadcasting single frequency network robust wireless signal framing modulation method of claim 1, it is characterized in that: said space-frequency modulation FFT cascading interleaving coding modulation data block is made up of subcarrier; When X gets 512, subcarrier The frequency interval is 4KHz; when X is 1024, the frequency interval of subcarriers is 2KHz; when X is 2048, the frequency interval of subcarriers is 1KHz.

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