CN102299887B - Multimedia broadcasting wireless signal robust framing modulation method - Google Patents

Abstract

The invention discloses a multimedia broadcasting wireless signal robust framing modulation method which is a time domain and frequency domain mixed framing modulation scheme. The multimedia broadcasting wireless signal robust framing modulation method provided by the invention has the advantages of low peak average power ratio, short synchronizing time, robustness, capability of controlling multiple services, and the like.

Description

A kind of multimedia broadcast wireless signal robust framing modulator approach

Technical field

The invention belongs to wireless communication field, relate more specifically to a kind of multimedia broadcast wireless signal robust framing modulator approach.

Background technology

Digital TV multimedia broadcast radio correlation technique and related industry thereof are that development is very fast in the Communications And Computer field, the industry of good market prospect.Multimedia broadcast wireless signal robust transmitter framing modulation technique is the key technology of digital TV multimedia broadcast wireless 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 OFDM multi-carrier transmission technology has simple in structure, the availability of frequency spectrum high plurality of advantages such as becomes and extremely everybody concern and obtain deep research and the extensive use in numerous areas such as Xdsl, wide-band mobile communication, wideband wireless local area network, digital TV multimedia broadcast wireless transmissions system in the time of can resisting frequency selectivity and channel.

The higher peak-to-average power ratio (PAPR) of ofdm signal has very high requirement to the range of linearity of amplifier and digital to analog converter, 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, in order in equaling or exceeding the symbol sebolic addressing of minimum free distance, obtain independent decline.The different coding form of cascade can take full advantage 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 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 broadcast wireless signal robust transmitter framing modulator approach is to realize the key technology of reliable digit television multimedia broadcast wireless transmissions.

Utilizing digital TV multimedia broadcast wireless transmissions system to provide free television broadcasting, paid television broadcasting, security information transmission, multimedia value-added service etc. can control multi-service is the embodiment 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 broadcast wireless signal robust framing modulator approach, can satisfy the needs that High Data Rate can be controlled multi-service digital TV multimedia broadcast wireless transmissions.

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 and can control multi-service digital TV multimedia broadcast wireless transmissions problem, proposed a kind of multimedia broadcast wireless signal robust framing modulator approach.

A kind of multimedia broadcast wireless signal robust framing modulator approach that the present invention proposes is characterized in that it comprises the following steps:

1) multimedia broadcast wireless signal robust transmitter is with the input data bit of oneself Bose-Chaudhuri-Hocquenghem Code (the Bose Chaudhuri Hocquenghem that flows through, BCH), Bit Interleave, LDPC (the Low Density Parity Check that encodes, LDPC), form the cascade interweaved coding modulation data piece of FFT at frequency domain after code element modulation, the symbol interleave, FFT represents the fast discrete Fourier conversion, and the length of the cascade interweaved coding modulation data piece of FFT is K;

2) multimedia broadcast wireless signal robust transmitter 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;

3) multimedia broadcast wireless signal robust transmitter 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];

4) multimedia broadcast wireless signal robust transmitter 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 new cascade interweaved coding modulation data sample value of time domain discrete piece D again _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 $D_{\mathrm{new}}=[D_1,\sqrt{1/2}(D_1+D_2)],$ 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 $D_{\mathrm{new}}=\left[\sqrt{1/2}({D^{*}}_1+D_2){,D}_2\right],$ Generate pattern 11 is $D_{\mathrm{new}}=[\sqrt{1/2}({D^{*}}_1-D_2),D_2],$ Generate pattern 12 is $D_{\mathrm{new}}=[\sqrt{1/2}({D^{*}}_1+D_2),\sqrt{1/2}({D^{*}}_1-D_2)],$ Compare the synthetic 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;

5) multimedia broadcast wireless signal robust transmitter 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, and the length of falling the discrete cascade interweaving encoding modulating data sample value piece of peak-to-average power ratio time domain cyclic prefix is C+K;

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

7) discrete sample block of the multimedia broadcast wireless signal robust transmitter sequence of plural training that will constitute in time domain repeats 2 times continuously and forms time domain repetition training series of discrete sample value piece on time domain, as frame head;

8) multimedia broadcast wireless signal robust transmitter 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;

9) multimedia broadcast wireless signal robust transmitter adopts square root raised cosine filter that the signal pulse of signal frame is shaped;

10) multimedia broadcast wireless signal robust transmitter with the baseband signal up-conversion to carrier wave.

Multimedia broadcast wireless signal robust framing modulator approach according to above-mentioned is characterized in that: multimedia broadcast wireless signal robust transmitter 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; Has periodic time domain repetition training series of discrete sample value piece in the signal frame of multimedia broadcast wireless signal robust transmitter; The length X of the training sequence of multimedia broadcast wireless signal robust transmitter 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; The training sequence of multimedia broadcast wireless signal robust transmitter, operational indicator sequence are formed by a series of 1 or-1, have pseudo-random characteristics; Training sequence, the operational indicator sequence of multimedia broadcast wireless signal robust transmitter have orthogonality each other; Each different operational indicator sequence of multimedia broadcast wireless signal robust transmitter is comprising and unique each system parameters and business model information of expressing multimedia broadcast wireless signal robust transmitter; 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 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 take full advantage 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 adopting 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 multimedia broadcast wireless signal robust transmitter, the training sequence of multimedia broadcast wireless signal robust transmitter, the operational indicator sequence has pseudo-random characteristics, the training sequence of multimedia broadcast wireless signal robust transmitter, the operational indicator sequence has orthogonality each other, the signal frame of multimedia broadcast wireless signal robust transmitter 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 and forming by time domain repetition training series of discrete sample value piece, and these have guaranteed that multimedia broadcast wireless signal robust 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 cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece 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 multimedia broadcast wireless signal robust transmitter is comprising and unique each system parameters and business model information of expressing multimedia broadcast wireless signal robust transmitter, digital TV multimedia broadcast wireless transmissions system can satisfy social needs so that can provide free television broadcasting, paid television broadcasting, security information transmission, multimedia value-added service etc. can control multi-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 high cascade interweaving encoding modulation data rate can control plurality of advantages such as multi-service digital TV multimedia broadcast wireless transmissions.

Description of drawings

Fig. 1 is the embodiment schematic diagram according to certain transmitter of multimedia broadcast wireless signal robust framing modulator approach of the present invention.

Fig. 2 is the embodiment schematic diagram according to certain transmitter signal framing modulation of multimedia broadcast wireless signal robust 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 certain transmitter of the multimedia broadcast wireless signal robust framing modulator approach that proposes according to the present invention as shown in Figure 1, follows these steps to carry out:

1) this certain multimedia broadcast wireless signal robust transmitter is with the input data bit of oneself Bose-Chaudhuri-Hocquenghem Code (the Bose Chaudhuri Hocquenghem that flows through, BCH), Bit Interleave, LDPC (the Low Density Parity Check that encodes, LDPC), form the cascade interweaved coding modulation data piece of FFT at frequency domain after code element modulation, the symbol interleave, 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) this certain multimedia broadcast wireless signal robust transmitter 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;

3) this certain multimedia broadcast wireless signal robust transmitter 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];

4) this certain multimedia broadcast wireless signal robust transmitter 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 new cascade interweaved coding modulation data sample value of time domain discrete piece D again _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 $D_{\mathrm{new}}=[D_1,\sqrt{1/2}(D_1+D_2)],$ 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 $D_{\mathrm{new}}=[\sqrt{1/2}({D^{*}}_1+D_2),\sqrt{1/2}({D^{*}}_1-D_2)],$ 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;

5) multimedia broadcast wireless signal robust transmitter 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, and the length of falling the discrete cascade interweaving encoding modulating data sample value piece of peak-to-average power ratio time domain cyclic prefix is C+K;

6) multimedia broadcast wireless signal robust transmitter is with the real part sequence of training sequence as sequence of plural training, the operational indicator sequence is arranged the set operational indicator sequence in unit as the imaginary part sequence of sequence of plural training, constitute the discrete sample block of sequence of plural training in time domain, 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 multimedia broadcast wireless signal robust transmitter, and X gets 512,1024, in 2048 one; When X got 512, K got 2048, C and gets 1/4 of K size, and the frequency interval of the cascade interweaved coding modulation data piece of FFT subcarrier is got 4KHz; When X got 1024, K got 4096, C and gets 1/8 of K size, and the frequency interval of the cascade interweaved coding modulation data piece of FFT subcarrier is got 2KHz; When X got 2048, K got 8192, C and gets 1/16 of K size, and the frequency interval of the cascade interweaved coding modulation data piece of FFT subcarrier is got 1KHz;

7) discrete sample block of the multimedia broadcast wireless signal robust transmitter sequence of plural training that will constitute in time domain repeats 2 times continuously and forms time domain repetition training series of discrete sample value piece on time domain, as frame head;

8) multimedia broadcast wireless signal robust transmitter 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;

9) this certain multimedia broadcast wireless signal robust transmitter adopts square root raised cosine filter that the signal pulse of signal frame is shaped;

10) this certain multimedia broadcast wireless signal robust transmitter with the baseband signal up-conversion to carrier wave.

Embodiment according to certain transmitter signal framing of multimedia broadcast wireless signal robust framing modulator approach of the present invention is modulated, as shown in Figure 2, specifically implement as follows:

This certain multimedia broadcast wireless signal robust transmitter is with the input data bit of oneself Bose-Chaudhuri-Hocquenghem Code of flowing through, Bit Interleave, the LDPC coding, the code element modulation, form the cascade interweaved coding modulation data piece of FFT at frequency domain after the symbol interleave, the length of the cascade interweaved coding modulation data piece of FFT is K, the cascade interweaved coding modulation data piece of FFT is made up of subcarrier, 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 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.

This certain multimedia broadcast wireless signal robust transmitter 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.

This certain multimedia broadcast wireless signal robust transmitter with training sequence as the real part sequence of sequence of plural training, the operational indicator sequence is arranged the set operational indicator sequence in unit as the imaginary part sequence of sequence of plural training, constitute the discrete sample block of sequence of plural training in time domain, the length of the discrete sample block of training sequence, operational indicator sequence, sequence of plural training all is X, and the operational indicator sequence is comprising and unique each system parameters and business model information of expressing multimedia broadcast wireless signal robust transmitter.

The discrete sample block of the sequence of plural training that this certain multimedia broadcast wireless signal robust transmitter will constitute in time domain repeats 2 times continuously and forms time domain repetition training series of discrete sample value piece on time domain, as frame head.

This certain multimedia broadcast wireless signal robust transmitter 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.

This certain multimedia broadcast wireless signal robust transmitter adopts square root raised cosine filter that the signal pulse of signal frame is shaped.

This certain multimedia broadcast wireless signal robust transmitter with the baseband signal up-conversion to carrier wave.

The X of this certain multimedia broadcast wireless signal robust transmitter gets in 512,1024,2048; When X got 512, K got 2048, C and gets 1/4 of K size, and the frequency interval of the cascade interweaved coding modulation data piece of FFT subcarrier is got 4KHz; When X got 1024, K got 4096, C and gets 1/8 of K size, and the frequency interval of the cascade interweaved coding modulation data piece of FFT subcarrier is got 2KHz; When X got 2048, K got 8192, C and gets 1/16 of K size, and the frequency interval of the cascade interweaved coding modulation data piece of FFT subcarrier is got 1KHz; Training sequence, operational indicator sequence as multimedia broadcast wireless signal robust transmitter are formed by a series of 1 or-1, have pseudo-random characteristics, and training sequence, operational indicator sequence have orthogonality each other.The training sequence that satisfies above-mentioned feature can be by realizing as one group of displacement m sequence of a kind of specific type of pseudo-random number sequence with as the walsh sequence of orthogonal sequence, Hadamard sequences or by the orthogonal sequence that other modes produce.Each different operational indicator sequence is comprising and unique each system parameters and business model information of expressing multimedia broadcast wireless signal robust transmitter.When X got 512, the corresponding signal to signal frame carried out the rolloff-factor of the square root raised cosine filter of pulse shaping and gets 0.1; When X got 1024, the corresponding signal to signal frame carried out the rolloff-factor of the square root raised cosine filter of pulse shaping and gets 0.05; When X got 2048, the corresponding signal to signal frame carried out the rolloff-factor of the square root raised cosine filter of pulse shaping and gets 0.025.

By reference to the accompanying drawings specific embodiments of the invention are had been described in detail above, but the present invention is not limited to above-described embodiment, 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 multimedia broadcast wireless signal robust framing modulator approach is characterized in that it comprises the following steps:

1) multimedia broadcast wireless signal robust transmitter is flowed through the input data bit of oneself and is formed the cascade interweaved coding modulation data piece of FFT at frequency domain after Bose-Chaudhuri-Hocquenghem Code, Bit Interleave, LDPC coding, code element modulation, the symbol interleave, BCH represents Bose Chaudhuri Hocquenghem, LDPC represents Low Density Parity Check, and the length of the cascade interweaved coding modulation data piece of FFT is K;

2) multimedia broadcast wireless signal robust transmitter 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

3) multimedia broadcast wireless signal robust transmitter 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];

4) multimedia broadcast wireless signal robust transmitter 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 new cascade interweaved coding modulation data sample value of time domain discrete piece D again _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 $D_{\mathrm{new}}=[D_1,\sqrt{1/2}(D_1-D_2)],$ Generate pattern 4 is $D_{\mathrm{new}}=[\sqrt{1/2}(D_1+D_2),D_2],$ Generate pattern 5 is

Generate pattern 6 is $D_{\mathrm{new}}=[\sqrt{1/2}(D_1+D_2),\sqrt{1/2}(D_1-D_2)],$ Generate pattern 7 is D _New=[D ^* ₁, D ₂], generate pattern 8 is $D_{\mathrm{new}}=[{D^{*}}_1,\sqrt{1/2}({D^{*}}_1+D_2)],$ Generate pattern 9 is $D_{\mathrm{new}}=[{D^{*}}_1,\sqrt{1/2}({D^{*}}_1-D_2)],$ Generate pattern 10 is Generate pattern 11 is

Generate pattern 12 is $D_{\mathrm{new}}=[\sqrt{1/2}({D^{*}}_1+D_2),\sqrt{1/2}({D^{*}}_1-D_2)],$ 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;

5) multimedia broadcast wireless signal robust transmitter 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, and the length of falling the discrete cascade interweaving encoding modulating data sample value piece of peak-to-average power ratio time domain cyclic prefix is C+K;

6) multimedia broadcast wireless signal robust transmitter with training sequence as the real part sequence of sequence of plural training, the operational indicator sequence is arranged the set operational indicator sequence in unit as the imaginary part sequence of sequence of plural training, constitute the discrete sample block of sequence of plural training in time domain, the length of the discrete sample block of training sequence, operational indicator sequence, sequence of plural training all is X, and the operational indicator sequence is comprising and unique each system parameters and business model information of expressing multimedia broadcast wireless signal robust transmitter; X gets in 512,1024,2048; When X got 512, K got 2048, C and gets 1/4 of K size; When X got 1024, K got 4096, C and gets 1/8 of K size; When X got 2048, K got 8192, C and gets 1/16 of K size;

7) discrete sample block of the multimedia broadcast wireless signal robust transmitter sequence of plural training that will constitute in time domain repeats 2 times continuously and forms time domain repetition training series of discrete sample value piece on time domain, as frame head;

8) multimedia broadcast wireless signal robust transmitter 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;

9) multimedia broadcast wireless signal robust transmitter adopts square root raised cosine filter that the signal pulse of signal frame is shaped;

10) multimedia broadcast wireless signal robust transmitter with the baseband signal up-conversion to carrier wave.

2. by the multimedia broadcast wireless signal robust framing modulator approach of claim 1, it is characterized in that: described training sequence, operational indicator sequence are formed by a series of 1 or-1, have pseudo-random characteristics.

3. by the multimedia broadcast wireless signal robust framing modulator approach of claim 1, it is characterized in that: described training sequence, operational indicator sequence have orthogonality each other.

4. by the multimedia broadcast wireless signal robust framing modulator approach of claim 1, it is characterized in that: the encoding rate of described 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.

5. by the multimedia broadcast wireless signal robust framing modulator approach of claim 1, it is characterized in that: the cascade interweaved coding modulation data piece of described FFT is made up of subcarrier; When X got 512, the frequency interval of subcarrier was got 4KHz; When X got 1024, the frequency interval of subcarrier was got 2KHz; When X got 2048, the frequency interval of subcarrier was got 1KHz.

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