CN102263761B - Method for modulating framing of multimedia wireless broadcast signals - Google Patents

Abstract

The invention discloses a method for modulating framing of multimedia wireless broadcast signals, and relates to a time domain/frequency domain mixed framing modulating method. The method for modulating framing of multimedia wireless broadcast signals has the advantages of low peak-to-average power ratio, short synchronization time, resistance to fading and noise, controllable multiple services and the like.

Description

A kind of method for modulating framing of multimedia wireless broadcast signals

Technical field

The invention belongs to wireless communication field, relate more specifically to a kind of method for modulating framing of multimedia wireless broadcast signals.

Background technology

At present, television broadcasting is from simulating gradually to the digitlization future development.Digital Television radio multimedium broadcast transmission system, as the important component part of Digital Television radio multimedium broadcasting, the development of its correlation technique, closely bound up with people's quality of life, and therefore be subject to people's extensive concern especially.Digital Television radio multimedium broadcasting correlation technique and related industry thereof be in the Communications And Computer field development comparatively fast, the industry of good market prospect.On digital TV multimedia radio broadcasting correlation technique, various countries' outline is at present, and the digital TV multimedia radio broadcasting how to pass under environment for complex wave provides the implementation of reliable high-speed mobile cheaply.Multi-media radio broadcast signal transmission machine framing modulation technique is the key technology of digital TV multimedia wireless broadcast system, plays conclusive effect for the whole system performance, is the object of everybody primary study.

Due to the develop rapidly of Digital Signal Processing and integrated circuit technique, the system of OFDM (OFDM) technology realizes becoming more and more easier.Because the OFDM Multicarrier Transmission Technology has simple in structure, the availability of frequency spectrum is high, the plurality of advantages such as becomes in the time of can resisting frequency selectivity and channel and extremely everybody concern and obtain deep research and the extensive use in the numerous areas such as Xdsl, wide-band mobile communication, wideband wireless local area network, digital TV multimedia radio broadcasting.

The peak-to-average power ratio that ofdm signal is higher (PAPR) 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, can cause signal distortion, signal spectrum is changed, thereby cause the orthogonality between 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 large peak power signal in ofdm signal and reduce the nonlinear distortion impact.

Chnnel coding is the important component part of digital communication system.Along with the develop rapidly of modern information technologies, channel coding technology has become the indispensable technology in modern communications field.Embed redundancy symbol in information sequence, the effect of channel coding technology by redundancy symbol reduces signal and makes a mistake in transmitting procedure, thereby improves reliability of Communication System.Serially concatenated coding be a kind of message transmission rate that can make near theoretical maximum, i.e. the encoding scheme of shannon limit.

In the practical communication environment, Digital Television radio multimedium broadcast communication system performance is subject to the impact of the factors such as lock in time, clock jitter, channel fading, channel disturbance.Multi-media radio broadcast signal transmission machine framing modulator approach is to realize the key technology of reliable digit television multimedia radio broadcasting.

Utilizing Digital Television radio multimedium broadcast transmission system to provide free television broadcasting, paid television broadcasting, Secret Information Transmission, multimedia value-added service etc. can control multi-service is the embodiment that new-generation digital tv wireless multimedia broadcast transmission 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 method for modulating framing of multimedia wireless broadcast signals, can satisfy the needs that High Data Rate can be controlled multi-service digital TV multimedia radio transmission.

Wish is done more deep understanding to the patent background can be with reference to following documents and materials:

R.V.Nee，R.Prasad.“OFDM?for?wireless?multimedia?communications””.Boston：Artech?House，2000.

Y.Wu，S.Hirakawa，U.H.Reimers，and?J.Whitaker.“Overview?of?digital?television?development，”Proceedings?of?the?IEEE，Special?Issue?on?Global?Digital?Television：Technology?and?Emerging?Services，pp.8-21，Jan.2006.

M.S.Richer，G.Reitmeier，T.Gurley，G.A.Jones，J.Whitaker，and?R.Rast.“The?ATSC?digital?television?system，”Proceedings?of?the?IEEE，Special?Issueon?Global?Digital?Television：Technology?and?Emerging?Services，pp.37-43，Jan.2006.

U.Ladebusch?and?C.A.Li?ss.“Terrestrial?DVB(DVB-T)：A?broadcast?technology?for?stationary?portable?and?mobile?use，”Proceedings?of?the?IEEE，Special?Issueon?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?and?G.Montorsi.“Iterative?decoding?of?serially?concatenated?convolutional?codes，”Electronics?Letters，pp.1186-1188，1996.

Summary of the invention

The present invention is directed to High Data Rate and can control multi-service digital TV multimedia radio broadcasting problem, proposed a kind of method for modulating framing of multimedia wireless broadcast signals.

A kind of method for modulating framing of multimedia wireless broadcast signals that the present invention proposes is characterized in that it comprises the following steps:

1) multi-media radio broadcast signal transmission machine is deleted the input data bit of oneself the serially concatenated multi code Rate of Chinese character of flowing through remaining convolutional encoding form the FFT coded data block on frequency domain, and FFT represents the fast discrete Fourier conversion, and the length of FFT coded data block is K;

2) multi-media radio broadcast signal transmission machine adopts IFFT that the FFT coded data block is transformed to time domain discrete coded data sample value piece D _Total, IFFT represents the fast discrete Fourier inverse transformation;

3) multi-media radio broadcast signal transmission machine is divided equally into two with time domain discrete coded data sample value piece in order, time domain discrete coded data sample value sub-block D ₁With time domain discrete coded data sample value sub-block D ₂, D _Total=[D ₁, D ₂];

4) multi-media radio broadcast signal transmission machine passes through the peak-to-average power ratio adjustment unit to time domain discrete coded data sample value sub-block D ₁, time domain discrete coded data sample value sub-block D ₂Carry out that signal adds, subtracts, conjugate operation is processed and synthetic new time domain discrete coded data sample value piece D again _new, new time domain discrete coded data sample value 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 time domain discrete coded data sample value piece D of 12 kinds of generate patterns _new, choose wherein have a minimum peak-to-average power ratio peak-to-average power ratio time domain discrete coded data sample value piece falls

And peak-to-average power ratio time domain discrete coded data sample value piece will fall The corresponding generate pattern information that adopts send to operational indicator sequence setting unit, wherein, D ^* ₁Expression is to time domain discrete coded data sample value sub-block D ₁Each time domain discrete coded data sample value carry out that conjugate operation is processed and the time domain discrete coded data sample value sub-block that obtains;

5) multi-media radio broadcast signal transmission machine with training sequence as the real part sequence of sequence of plural training, operational indicator sequence that operational indicator sequence setting unit is the set imaginary part sequence as sequence of plural training, consist of the discrete sample block of sequence of plural training on time domain, the length of the discrete sample block of training sequence, operational indicator sequence, sequence of plural training is all X, and the operational indicator sequence is comprising and unique each system parameters and business model information of expressing multi-media radio broadcast signal transmission machine;

6) multi-media radio broadcast signal transmission machine will repeat continuously 4 times 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 consists of on time domain, time domain embeds the length and the length numerically equal of falling peak-to-average power ratio time domain discrete coded data sample value piece, i.e. K=4 * X of training sequence discrete sample block;

7) multi-media radio broadcast signal transmission machine will fall peak-to-average power ratio time domain discrete coded data sample value piece, time domain and embed training sequence discrete sample block and directly superpose and form time domain and embed training sequence and fall peak-to-average power ratio time domain discrete coded data sample value piece, as frame;

8) multi-media radio broadcast signal transmission machine is that frame head inserts time domain and embeds training sequence to fall peak-to-average power ratio time domain discrete coded data sample value piece be frame with Cyclic Prefix as the protection interval, and to form signal frame, the length of Cyclic Prefix is C;

9) multi-media radio broadcast signal transmission machine adopts square root raised cosine filter that the signal pulse of signal frame is shaped;

10) multi-media radio broadcast signal transmission machine with the baseband signal up-conversion to carrier wave.

Method for modulating framing of multimedia wireless broadcast signals according to above-mentioned is characterized in that: the falling that the signal that peak-to-average power ratio time domain discrete coded data sample value piece undertakies by specific 12 kinds of generate patterns by time domain discrete coded data sample value sub-block adds, subtracts, conjugate operation is processed of multi-media radio broadcast signal transmission machine and again synthetic; Have periodic time domain in the signal frame of multi-media radio broadcast signal transmission machine and embed training sequence discrete sample block; The length X of the training sequence of multi-media radio broadcast signal transmission machine is in 512,1024,2048, the length K of corresponding FFT data block 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 FFT data block length K size; The training sequence of multi-media radio broadcast signal transmission machine, operational indicator sequence form by a series of 1 or-1, have pseudo-random characteristics; Training sequence, the operational indicator sequence of multi-media radio broadcast signal transmission machine have orthogonality each other; Each different operational indicator sequence of multi-media radio broadcast signal transmission machine is comprising and unique each system parameters and business model information of expressing multi-media radio broadcast signal transmission machine; The serially concatenated multi code Rate of Chinese character is deleted remaining convolutional encoding and is formed more than being deleted by the random interleaving serially concatenated by two convolutional encodings, and the encoding rate that the serially concatenated multi code Rate of Chinese character is deleted remaining convolutional encoding is in 1/4,4/9,3/8,7/16 and 5/9.

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 peak-to-average power ratio time domain discrete coded data sample value piece of the present invention and have a minimum peak-to-average power ratio peak-to-average power ratio time domain discrete coded data sample value piece choosing method falls, but the very high large 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 of the ofdm signal when number of sub carrier wave is larger (or imaginary part) is the characteristic of multiple Gaussian random process and whose amplitude obeys Rayleigh distribution, the amount of information of the required extra transmission of generate pattern of adopting is little, be easy to process at receiver end the primary signal of recovering to obtain ofdm signal, 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 multi-media radio broadcast signal transmission machine and embed training sequence discrete sample block, the training sequence of multi-media radio broadcast signal transmission machine, the operational indicator sequence has pseudo-random characteristics, the training sequence of multi-media radio broadcast signal transmission machine, the operational indicator sequence has orthogonality each other, it is by falling peak-to-average power ratio time domain discrete coded data sample value piece that peak-to-average power ratio time domain discrete coded data sample value piece falls in the time domain embedding training sequence of multi-media radio broadcast signal transmission machine, time domain embeds training sequence discrete sample block and directly superposes and form, these have guaranteed that the multi-media radio 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 are reliably followed the tracks of.Cyclic Prefix is embedded training sequence as protection interval insertion time domain fall peak-to-average power ratio time domain discrete coded data sample value piece to form signal frame, can reduce the interference effect between the adjacent signals frame.Adopting the serial multi code Rate of Chinese character to delete remaining convolutional encoding carries out chnnel coding to the input data error-correcting performance near shannon limit is provided.Each different operational indicator sequence of multi-media radio broadcast signal transmission machine is comprising and unique each system parameters and business model information of expressing multi-media radio broadcast signal transmission machine, can so that digital TV multimedia radio transmission system can provide free television broadcasting, paid television broadcasting, Secret Information Transmission, multimedia value-added service etc. can control multi-service, satisfy social needs.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 Data Rate can control the plurality of advantages such as multi-service digital TV multimedia radio transmission.

Description of drawings

Fig. 1 is the embodiment schematic diagram according to certain transmitter of method for modulating framing of multimedia wireless broadcast signals of the present invention.

Fig. 2 forms the embodiment schematic diagram of signal frame according to certain transmitter of method for modulating framing of multimedia wireless broadcast signals 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 method for modulating framing of multimedia wireless broadcast signals that proposes according to the present invention as shown in Figure 1, follows these steps to carry out:

1) this certain multi-media radio broadcast signal transmission machine is deleted the input data bit of oneself the serially concatenated multi code Rate of Chinese character of flowing through remaining convolutional encoding form the FFT coded data block on frequency domain, FFT represents the fast discrete Fourier conversion, and the length of FFT coded data block is K; The serially concatenated multi code Rate of Chinese character is deleted remaining convolutional encoding and is formed more than being deleted by the random interleaving serially concatenated by two convolutional encodings, and the encoding rate that the serially concatenated multi code Rate of Chinese character is deleted remaining convolutional encoding is in 1/4,4/9,3/8,7/16 and 5/9;

2) this certain multi-media radio broadcast signal transmission machine adopts IFFT that the FFT coded data block is transformed to time domain discrete coded data sample value piece D _Total, IFFT represents the fast discrete Fourier inverse transformation;

3) this certain multi-media radio broadcast signal transmission machine is divided equally into two with time domain discrete coded data sample value piece in order, time domain discrete coded data sample value sub-block D ₁With time domain discrete coded data sample value sub-block D ₂, D _Total=[D ₁, D ₂];

4) this certain multi-media radio broadcast signal transmission machine passes through the peak-to-average power ratio adjustment unit to time domain discrete coded data sample value sub-block D ₁, time domain discrete coded data sample value sub-block D ₂Carry out that signal adds, subtracts, conjugate operation is processed and synthetic new time domain discrete coded data sample value piece D again _new, new time domain discrete coded data sample value 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 time domain discrete coded data sample value piece D of 12 kinds of generate patterns _new, choose wherein have a minimum peak-to-average power ratio peak-to-average power ratio time domain discrete coded data sample value piece falls

And peak-to-average power ratio time domain discrete coded data sample value piece will fall

The corresponding generate pattern information that adopts send to operational indicator sequence setting unit, wherein, D ^* ₁Expression is to time domain discrete coded data sample value sub-block D ₁Each time domain discrete coded data sample value carry out that conjugate operation is processed and the time domain discrete coded data sample value sub-block that obtains;

5) this certain multi-media radio broadcast signal transmission machine is with the real part sequence of training sequence as sequence of plural training, the operational indicator sequence that operational indicator sequence setting unit is set is as the imaginary part sequence of sequence of plural training, consist of the discrete sample block of sequence of plural training on time domain, training sequence, the operational indicator sequence, the length of the discrete sample block of sequence of plural training is all X, the operational indicator sequence is comprising and unique each system parameters and business model information of expressing multi-media radio broadcast signal transmission machine, X gets 512, 1024, in 2048 one,

6) this certain multi-media radio broadcast signal transmission machine will repeat continuously 4 times 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 consists of on time domain, time domain embeds the length and the length numerically equal of falling peak-to-average power ratio time domain discrete coded data sample value 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;

7) this certain multi-media radio broadcast signal transmission machine will fall peak-to-average power ratio time domain discrete coded data sample value piece, time domain and embed training sequence discrete sample block and directly superpose and form time domain and embed training sequence and fall peak-to-average power ratio time domain discrete coded data sample value piece, as frame;

8) this certain multi-media radio broadcast signal transmission machine is that frame head inserts time domain and embeds training sequence to fall peak-to-average power ratio time domain discrete coded data sample value piece be frame with Cyclic Prefix as the protection interval, and 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;

9) this certain multi-media radio broadcast signal transmission machine adopts square root raised cosine filter that the signal pulse of signal frame is shaped;

10) this certain multi-media radio broadcast signal transmission machine with the baseband signal up-conversion to carrier wave.

Form the embodiment of signal frame according to certain transmitter of method for modulating framing of multimedia wireless broadcast signals of the present invention, as shown in Figure 2, specifically be implemented as follows:

This certain multi-media radio broadcast signal transmission machine is deleted the input data bit of oneself the serially concatenated multi code Rate of Chinese character of flowing through remaining convolutional encoding form the FFT coded data block on frequency domain, through IFFT, it is transformed to the discrete coded data sample value piece of time domain again, generates by the peak-to-average power ratio adjustment unit and choose the peak-to-average power ratio time domain discrete coded data sample value 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 operational indicator sequence setting unit; The serially concatenated multi code Rate of Chinese character is deleted remaining convolutional encoding and is formed more than being deleted by the random interleaving serially concatenated by two convolutional encodings, and the encoding rate that the serially concatenated multi code Rate of Chinese character is deleted remaining convolutional encoding is in 1/4,4/9,3/8,7/16 and 5/9.

The FFT data block is comprised of subcarrier.The length of FFT data block 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 multi-media radio 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, consist of the discrete sample block of sequence of plural training on time domain, then it is repeated continuously formation time domains embedding training sequence discrete sample block on time domain 4 times.The length of the discrete sample block of training sequence, operational indicator sequence, sequence of plural training is all 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 multi-media radio broadcast signal transmission machine form 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 as one group of Phase shift m sequence of a kind of specific type of pseudo-random number sequence with as walsh sequence, the Hadamard sequences of orthogonal sequence or realized 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 multi-media radio broadcast signal transmission machine.

This certain multi-media radio broadcast signal transmission machine will fall peak-to-average power ratio time domain discrete coded data sample value piece, time domain and embed training sequence discrete sample block and directly superpose and form time domain and embed training sequence and fall peak-to-average power ratio time domain discrete coded data sample value piece, as frame; Insert Cyclic Prefix as the protection interval in peak-to-average power ratio time domain discrete coded data sample value piece falls in time domain embedding training sequence, form signal frame.Length as the Cyclic Prefix of protecting the 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 multi-media radio broadcast signal transmission machine adopts square root raised cosine filter to carry out pulse shaping to the signal of signal frame.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.

The above has been described in detail specific embodiments of the invention by reference to the accompanying drawings, but the present invention is not limited to above-described embodiment, and in 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 (4)

1. A method for framing modulation of multimedia wireless broadcast signals, characterized in that it comprises the following steps: 1) The multimedia wireless broadcast signal transmitter forms an FFT coded data block in the frequency domain by serially cascading multi-code rate punctured convolution coding of its own input data bit stream. The length of the FFT coded data block is K, and the serial level Concatenated multi-rate punctured convolutional coding is formed by two convolutional codes through random interleaving and serial concatenation puncturing, and the coding rates of serial concatenated multi-rate punctured convolutional coding are 1/4, 4/9 , 3/8, 7/16 and 5/9; 2) The multimedia wireless broadcast signal transmitter adopts IFFT to transform the FFT coded data block into a time-domain discrete coded data sample block D _total ; 3) The multimedia wireless broadcast signal transmitter divides the time-domain discretely coded data sample block into two blocks in sequence, the time-domain discretely coded data sample sub-block D ₁ and the time-domain discretely coded data sample sub-block D ₂ , D _total = [D ₁ , D ₂ ]; 4) The multimedia wireless broadcast signal transmitter performs signal addition, subtraction, and conjugate operation processing on the time-domain discretely encoded data sample sub-block D ₁ and the time-domain discretely encoded data sample sub-block D ₂ through the peak-to-average power ratio adjustment unit. Re-synthesize a new time-domain discretely coded data sample block _Dnew , and the new time-domain discretely coded data sample block _Dnew is obtained by the following generation mode, generation mode 1 is _Dnew = [D ₁ , D ₂ ], generation mode 2 for ${\mathrm{D.}}_{\mathrm{new}}=[{\mathrm{D.}}_1,\sqrt{1/2}({\mathrm{D.}}_1+{\mathrm{D.}}_2)],$ 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 ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({{\mathrm{D.}}^{*}}_1+{\mathrm{D.}}_2),\sqrt{1/2}({{\mathrm{D.}}^{*}}_1-{\mathrm{D.}}_2)],$ Compare the time-domain discrete-coded data sample block D _new synthesized by 12 generation modes, and select the time-domain discrete-coded data sample block with the lowest peak-to-average power ratio

and reduce the peak-to-average power ratio time-domain discretely coded data sample block The generated mode information correspondingly adopted is sent to the service index sequence setting unit, wherein, D ^* ₁ means that the time domain discrete coded data samples of the time domain discrete coded data sample sub-block _D1 are conjugated and processed Time-domain discretely coded data sample sub-blocks; 5) The multimedia wireless broadcast signal transmitter 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 to form the complex training sequence in the time domain Discrete sample value block, the length of the discrete sample value block of the training sequence, service index sequence, and complex training sequence is X, and the service index sequence contains and uniquely expresses the system parameters and service mode information of the multimedia wireless broadcast signal transmitter; X takes one of 512, 1024, 2048; 6) The multimedia wireless broadcast signal transmitter repeats the discrete sample blocks of the complex training sequence formed in the time domain four times continuously in the time domain to form a time domain embedded training sequence discrete sample block, and the time domain embedded training sequence discrete sample value The block length is numerically equal to the length of the peak-to-average power ratio time-domain discretely encoded data sample block, that is, K=4×X; 7) The multimedia wireless broadcast signal transmitter directly superimposes the time-domain discrete coded data sample block with reduced peak-to-average power ratio and the discrete sample value block of time-domain embedded training sequence to form time-domain embedded training sequence reduced peak-to-average power ratio time-domain discrete coded data Sample block, as a frame body; 8) The multimedia wireless broadcast signal transmitter uses the cyclic prefix as a guard interval, that is, inserts the frame header into the time domain, embeds the training sequence, reduces the peak-to-average power ratio, and the discretely encoded data sample block in the time domain, that is, the frame body, to form a signal frame. The length of the cyclic prefix is C; when X is 512, K is 2048, and C is 1/4 of the size of K; when X is 1024, K is 4096, and C is 1/8 of the size of K; when X is 2048, K is 8192, C takes 1/16 of the size of K; 9) The multimedia wireless broadcast signal transmitter uses a square root raised cosine roll-off filter to shape the signal pulse of the signal frame; 10) The multimedia wireless broadcast signal transmitter up-converts the baseband signal to the carrier. 2. The method for framing modulation of multimedia wireless broadcast signals according to claim 1, characterized in that: said training sequence and service index sequence are composed of a series of 1 or -1, and have pseudo-random characteristics. 3. The method for framing and modulating multimedia wireless broadcast signals according to claim 1, characterized in that: the training sequence and the service index sequence are orthogonal to each other. 4. by the multimedia wireless broadcasting signal framing modulation method of claim 1, it is characterized in that: described FFT data block is made up of subcarrier; When X gets 512, subcarrier number gets 2048, and the frequency interval of subcarrier gets 4KHz; When X is 1024, the number of subcarriers is 4096, and the frequency interval of subcarriers is 2KHz; when X is 2048, the number of subcarriers is 8192, and the frequency interval of subcarriers is 1KHz.

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