CN102291358B - Robust multi-media mobile broadcast signal framing modulation method - Google Patents

Abstract

The invention discloses a robust multimedia mobile broadcast signal framing modulation method, which is a framing modulation scheme mixed in time domain and frequency domain. The robust multimedia mobile broadcasting signal framing modulation method of the present invention is aimed at the technical problems that need to be solved for the signal peak-to-average power ratio, channel time variation, Doppler frequency shift and noise faced by the broadband multi-carrier multimedia mobile broadcasting system. The low-complexity peak-to-average power ratio reduction technology and joint coding and modulation technology make the broadband multi-carrier multimedia mobile broadcasting system have the advantages of low peak-to-average power ratio, short synchronization time, robustness, and controllable multi-service.

Description

A robust multimedia mobile broadcast signal framing modulation method

technical field

The invention belongs to the field of mobile communication, and more specifically relates to a robust multimedia mobile broadcast signal framing modulation method.

Background technique

At present, television broadcasting has gradually developed from analog to digital. Digital TV broadcasting transmission system, as an important part of digital TV broadcasting, the development of its related technologies is closely related to people's quality of life, and therefore has received extensive attention from people. The technology related to digital TV broadcasting and related industries are industries with rapid development and good market prospects in the field of communication and computer. In terms of technologies related to digital TV broadcasting, countries are currently focusing on how to provide low-cost, reliable and high-speed mobile solutions for digital TV broadcasting in a complex wave propagation environment. The framing modulation technology is the key technology of the digital TV broadcasting system, plays a decisive role in the performance of the whole system, and is the object of everyone's key research.

Due to the rapid development of digital signal processing technology and integrated circuit technology, the system realization of Orthogonal Frequency Division Multiplexing (OFDM) technology becomes easier and easier. Because OFDM multi-carrier transmission technology has many advantages such as simple structure, high spectrum utilization rate, and resistance to frequency selectivity and channel time variation, it has attracted much attention and has been deeply researched and applied in Xdsl, broadband mobile communication, broadband mobile local area network, It is widely used in many fields such as digital TV broadcasting.

The high peak-to-average power ratio (PAPR) of OFDM signals has high requirements on the linear range of amplifiers and digital-to-analog converters. If the linear range of the system cannot meet the signal changes, it will cause signal distortion and signal spectrum changes. , resulting in the destruction of the orthogonality between sub-channels, resulting in mutual interference and deteriorating system performance. Therefore, it is necessary to consider how to reduce the occurrence probability of high peak power signals in OFDM signals and reduce the impact of nonlinear distortion.

Under multipath fading channels, the cascade optimization design of coding, interleaving and modulation schemes can achieve the largest possible signal diversity order, so as to obtain independent fading in symbol sequences equal to or exceeding the minimum free distance. Cascading different coding forms can make full use of the advantages of different coding techniques; inserting a bit interleaver between coding and symbol modulation can make the coding and modulation processes relatively independent and expand the diversity order from different multi-ary symbols To a different number of binary bits, so that the order of diversity is significantly improved and has good error characteristics in multipath fading channels.

In the actual communication environment, the performance of the digital TV multimedia mobile broadcasting communication system is affected by factors such as synchronization time, clock jitter, channel fading, and channel interference. The framing modulation method of the multimedia mobile broadcasting signal transmitter is the key technology to realize the robust multimedia mobile broadcasting of reliable digital TV.

Using the digital TV multimedia mobile broadcast transmission system to provide controllable multi-services such as free TV broadcast, paid TV broadcast, confidential information transmission, and multimedia value-added services is the embodiment of the new generation of digital TV robust multimedia mobile broadcast transmission system to meet social needs.

Based on the above background, the present invention proposes a robust multimedia mobile broadcast signal framing modulation method for the actual communication environment, which can meet the needs of high data rate controllable multi-service digital television robust multimedia mobile broadcast transmission.

For a more in-depth understanding of the patent background, please refer to the following literature:

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, Soecial 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, J 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.

Contents of the invention

Aiming at the problem of high data rate controllable multi-service digital television robust multimedia mobile broadcasting, the invention proposes a robust multimedia mobile broadcasting signal framing modulation method.

A kind of robust multimedia mobile broadcast signal framing modulation method that the present invention proposes is characterized in that it comprises the following steps:

1) The robust multimedia mobile broadcast signal transmitter passes its input data bit stream through BCH encoding (BoseChaudhuri Hocquenghem, BCH), bit interleaving, multi-bit rate punctured convolutional coding, symbol modulation and symbol rotation, and symbol interleaving Form the FFT cascaded interleaved coding modulation data block in the frequency domain afterward, FFT represents fast discrete Fourier transform, and the length of the FFT cascade interleaving coding modulation data block is K;

2) The robust multimedia mobile broadcast signal transmitter uses IFFT to transform the FFT concatenated interleaved coded modulation data block into a time-domain discrete concatenated interleaved coded modulated data sample block D _total , and IFFT means inverse fast discrete Fourier transform;

3) The robust multimedia mobile broadcast signal transmitter divides the time-domain discrete concatenated interleaving coded modulation data sample block into two equally in sequence, the time domain discrete concatenated interleaved coded modulated data sample sub-block D ₁ and the time domain discrete level Interleaved coded modulation data sample sub-block D ₂ , D _total = [D ₁ , D ₂ ];

所对应采用的生成模式信息发送给业务指标序列设置单元，其中，D^* ₁表示对时域离散级联交织编码调制数据样值子块D₁的各时域离散级联交织编码调制数据样值进行共轭运算处理而得到的时域离散级联交织编码调制数据样值子块；4) The robust multimedia mobile broadcast signal transmitter uses the peak-to-average power ratio adjustment unit to perform the time-domain discrete concatenated interleaving coded modulation data sample sub-block D ₁ and the time-domain discrete concatenated interleaved coded modulated data sample sub-block D ₂ Signal addition, subtraction, and conjugate operation processing and re-synthesis of a new time-domain discrete concatenated interleaved coded modulation data sample block _Dnew , the new time-domain discrete concatenated interleaved coded modulated data sample block _Dnew is obtained by the following generation mode , generation mode 1 is D _new = [D ₁ , D ₂ ], 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 ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({{\mathrm{D.}}^{*}}_1+{\mathrm{D.}}_2),\sqrt{1/2}({{\mathrm{D.}}^{*}}_1-{\mathrm{D.}}_2)],$ Compare the time-domain discrete concatenated interleaved coded modulation data sample block _Dnew synthesized by 12 generation modes, and select the time-domain discrete concatenated interleaved coded modulated data sample block with the lowest peak-to-average power ratio among them And reduce the peak-to-average power ratio time-domain discrete concatenated interleaved coding modulation data sample block

The corresponding generated mode information is sent to the service index sequence setting unit, wherein D ^* ₁ represents each time-domain discrete concatenated interleaved coded modulation data sample value for the time domain discrete concatenated interleaved coded modulated data sample sub-block D ₁ Time-domain discrete concatenated interleaved coded modulation data sample sub-block obtained by performing conjugate operation processing;

5) The robust multimedia mobile 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 a complex training sequence in the time domain The discrete sample value block of the sequence, the length of the discrete sample value block of the training sequence, the service index sequence, and the complex training sequence are all X, and the service index sequence contains and uniquely expresses the system parameters of the robust multimedia mobile broadcast signal transmitter and business model information;

6) The robust multimedia mobile broadcasting signal transmitter repeats the discrete sample blocks of the complex training sequence formed in the time domain for 4 consecutive times in the time domain to form a time domain embedded training sequence discrete sample block, and the time domain embedded training sequence is discrete The length of the sample value block and the length of the peak-to-average power ratio time-domain discrete concatenated interleaved coded modulation data sample block are equal in value, that is, K=4×X;

7) The robust multimedia mobile broadcasting signal transmitter directly superimposes the reduced peak-to-average power ratio time-domain discrete cascaded interleaved coded modulation data sample blocks and the time-domain embedded training sequence discrete sample blocks to form a time-domain embedded training sequence to reduce the peak-to-average power Than the time-domain discrete cascaded interleaved coding modulated data sample block, as a frame body;

8) The robust multimedia mobile 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 time domain discrete cascade interleaving coding modulates the data sample block, that is, the frame body, to form a signal frame , the length of the cyclic prefix is C;

9) The robust multimedia mobile broadcast signal transmitter uses a square root raised cosine roll-off filter to shape the signal pulse of the signal frame;

10) The robust multimedia mobile broadcast signal transmitter up-converts the baseband signal to the carrier.

According to the above-mentioned robust multimedia mobile broadcast signal framing modulation method, it is characterized in that: the peak-to-average power ratio of the robust multimedia mobile broadcast signal transmitter is reduced by time-domain discrete concatenated interleaved coded modulation data sample block by time-domain discrete concatenated Interleaved coded modulation data sample sub-blocks are re-synthesized through signal addition, subtraction, and conjugate operation processing for 12 specific generation modes; the signal frame of the robust multimedia mobile broadcast signal transmitter has periodic time-domain embedding training Sequence discrete sample value block; the length X of the training sequence of the robust multimedia mobile broadcast signal transmitter is one of 512, 1024, 2048, and the length K of the corresponding FFT concatenated interleaving coded modulation data block is 2048, 4096, 8192, the frequency intervals of the corresponding subcarriers are 4KHz, 2KHz, and 1KHz, and the corresponding cyclic prefix lengths C are 1/4, 1/8, and 1/16 of the length K of the FFT concatenated interleaved coded modulation data block. The training sequence and the service index sequence of the robust multimedia mobile broadcast signal transmitter are composed of a series of 1 or -1, which have pseudo-random characteristics; the training sequence and the service index sequence of the robust multimedia mobile broadcast signal transmitter have mutual Orthogonality; each different service index sequence of the robust multimedia mobile broadcast signal transmitter contains and uniquely expresses the system parameters and business mode information of the robust multimedia mobile broadcast signal transmitter; multi-rate punctured convolutional coding The encoding rate is one of 1/4, 1/2, 5/8, 3/4 and 7/8; the bit interleaving adopts random interleaving; the symbol modulation is one of QPSK, 16QAM, 64QAM and 256QAM, The symbol constellation map mapping method of symbol modulation adopts Gray code mapping; the symbol rotation is realized by rotating the symbol constellation map at a certain angle, the symbol constellation map rotation angle of QPSK is 22.5 degrees, and the symbol constellation map rotation angle of 16QAM is 11.25 degrees, the rotation angle of the symbol constellation diagram of 64QAM is 5.626 degrees, and the rotation angle of the symbol constellation diagram of 256QAM is 2.8125 degrees; the code element interleaving adopts the random interleaving method.

Features of the present invention:

The invention is a framing modulation scheme of mixing time domain and frequency domain. The generation mode of the peak-to-average power ratio time-domain discrete concatenated interleaved coded modulation data sample block and the method for selecting the peak-to-average power ratio time-domain discrete cascaded interleaved coded modulated data sample block with the lowest peak-to-average power ratio of the present invention , not only can make full use of the maximum peak power of OFDM signal is very high but the probability of high peak power signal is very low, when the number of subcarriers is large, the real part (or imaginary part) of OFDM signal is a complex Gaussian random process and the amplitude obeys Rayleigh distribution The characteristics of the used generation mode require a small amount of additional information to be sent, and it is easy to process and restore the original signal of the OFDM signal at the receiver without destroying the orthogonality of the subcarrier signal and generating additional nonlinearity distortion. The signal frame of the robust multimedia mobile broadcast signal transmitter has periodic time-domain embedded training sequence discrete sample blocks, the training sequence and service index sequence of the robust multimedia mobile broadcast signal transmitter have pseudo-random characteristics, and the robust multimedia mobile broadcast signal transmitter has pseudo-random characteristics. The training sequence and service index sequence of the broadcast signal transmitter are orthogonal to each other, and the time-domain embedding training sequence of the robust multimedia mobile broadcast signal transmitter reduces the peak-to-average power ratio to the time-domain discrete cascade interleaving coded modulation data sample block It is formed by the direct superposition of time-domain discrete concatenated interleaved coded modulation data sample blocks and time-domain embedded training sequence discrete sample blocks, which ensure that the robust multimedia mobile broadcast signal receiver can achieve fast and accurate frame synchronization, frequency synchronization, time synchronization, estimation of channel transmission characteristics, and reliable tracking of phase noise and channel transmission characteristics. Inserting the cyclic prefix as a guard interval into the time-domain embedding training sequence to reduce the peak-to-average power ratio time-domain discrete concatenated interleaving coding modulated data sample blocks to form a signal frame, which can reduce the interference between adjacent signal frames. The cascaded interleaving coding and modulation of the input data increases the diversity order, which makes the communication system have good bit error characteristics in the multipath fading channel. Symbol modulation and symbol rotation provide diversity effects for mobile multimedia broadcasting signals. Each different service index sequence of the robust multimedia mobile broadcast signal transmitter contains and uniquely expresses the system parameters and service mode information of the robust multimedia mobile broadcast signal transmitter, which can make the digital TV robust multimedia mobile broadcast transmission system capable of Provide controllable multi-services such as free TV broadcasting, paid TV broadcasting, confidential information transmission, and multimedia value-added services to meet social needs. The framing modulation method of the present invention has low peak-to-average power ratio, short synchronization time, small clock jitter, anti-channel fading, anti-channel interference, and can provide high-level interleaved coding modulation data rate controllable multi-service digital TV robust multimedia mobile broadcasting transmission and many other advantages.

Description of drawings

Fig. 1 is a schematic diagram of an embodiment of a transmitter of a robust multimedia mobile broadcasting signal framing modulation method according to the present invention.

Fig. 2 is a schematic diagram of an embodiment of signal framing modulation of a transmitter according to the robust multimedia mobile broadcasting signal framing modulation method of the present invention.

Detailed ways

Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

According to the embodiment of a certain transmitter of the robust multimedia mobile broadcasting signal framing modulation method proposed by the present invention, as shown in Figure 1, proceed according to the following steps:

1) The certain robust multimedia mobile broadcasting signal transmitter passes its input data bit stream through BCH coding, bit interleaving, multi-code rate punctured convolutional coding, symbol modulation and symbol rotation, and symbol interleaving, and then transmits the data in frequency Form FFT cascaded interleaving coded modulation data blocks on the domain, FFT means fast discrete Fourier transform, the length of FFT concatenated interleaved coded modulated data blocks is K; the coding rate of multi-code rate punctured convolutional codes is 1/4, 1/ One of 2, 5/8, 3/4 and 7/8; bit interleaving adopts random interleaving; symbol modulation is one of QPSK, 16QAM, 64QAM and 256QAM, symbol constellation mapping method of symbol modulation Gray code mapping is used; symbol rotation is realized by rotating the symbol constellation diagram at a certain angle. The rotation angle of the symbol constellation diagram of QPSK is 22.5 degrees, the rotation angle of the symbol constellation diagram of 16QAM is 11.25 degrees, and the symbol constellation diagram of 64QAM The rotation angle is 5.626 degrees, and the rotation angle of the symbol constellation diagram of 256QAM is 2.8125 degrees; the code element interleaving adopts the random interleaving method.

2) The certain robust multimedia mobile broadcast signal transmitter uses IFFT to transform the FFT concatenated interleaved coded modulation data block into a time-domain discrete concatenated interleaved coded modulated data sample block D _total , and IFFT stands for Inverse Fast Discrete Fourier Transform;

3) The certain robust multimedia mobile broadcasting signal transmitter divides the time-domain discrete concatenated interleaved coded modulation data sample block into two equally in sequence, the time domain discrete concatenated interleaved coded modulated data sample sub-block _D1 and the time domain Domain discrete concatenated interleaving coding modulated data sample sub-block D ₂ , D _total = [D ₁ , D ₂ ];

并将降峰均功率比时域离散级联交织编码调制数据样值块

所对应采用的生成模式信息发送给业务指标序列设置单元，其中，D^* ₁表示对时域离散级联交织编码调制数据样值子块D₁的各时域离散级联交织编码调制数据样值进行共轭运算处理而得到的时域离散级联交织编码调制数据样值子块；4) The certain robust multimedia mobile broadcast signal transmitter adjusts the time-domain discrete concatenated interleaving coded modulation data sample sub-block D ₁ , the time domain discrete concatenated interleaved coded modulated data sample sub-block through the peak-to-average power ratio adjustment unit D ₂ performs signal addition, subtraction, and conjugate operation processing and re-synthesizes a new time-domain discrete concatenated interleaved coded modulation data sample block _Dnew , and the new time-domain discrete concatenated interleaved coded modulated data sample block _Dnew is as follows The generation mode is obtained, 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 ${\mathrm{D.}}_{\mathrm{new}}=[\sqrt{1/2}({{\mathrm{D.}}^{*}}_1+{\mathrm{D.}}_2),\sqrt{1/2}({{\mathrm{D.}}^{*}}_1-{\mathrm{D.}}_2)],$ Compare the time-domain discrete concatenated interleaved coded modulation data sample block _Dnew synthesized by 12 generation modes, and select the time-domain discrete concatenated interleaved coded modulated data sample block with the lowest peak-to-average power ratio among them

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

The corresponding generated mode information is sent to the service index sequence setting unit, wherein D ^* ₁ represents each time-domain discrete concatenated interleaved coded modulation data sample value for the time domain discrete concatenated interleaved coded modulated data sample sub-block D ₁ Time-domain discrete concatenated interleaved coded modulation data sample sub-block obtained by performing conjugate operation processing;

5) The certain robust multimedia mobile 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, in the time domain The discrete sample value blocks that constitute the complex training sequence, the length of the discrete sample value blocks of the training sequence, service index sequence, and complex training sequence are all X, and the service index sequence contains and uniquely expresses each of the robust multimedia mobile broadcast signal transmitters. System parameters and business mode information, X takes one of 512, 1024, and 2048;

6) The certain robust multimedia mobile broadcasting signal transmitter repeats the discrete sample blocks of the complex training sequence formed in the time domain continuously 4 times in the time domain to form a time domain embedded training sequence discrete sample block, and the time domain embedding The length of the training sequence discrete sample block is equal to the length of the peak-to-average power ratio time-domain discrete concatenated interleaved coded modulation data sample block, that is, K=4×X; when X is 512, K is 2048, The frequency interval of the corresponding subcarrier is 4KHz; when X is 1024, K is 4096, and the frequency interval of the corresponding subcarrier is 2KHz; when X is 2048, K is 8192, and the frequency interval of the corresponding subcarrier Take 1KHz;

7) The certain robust multimedia mobile broadcasting signal transmitter directly superimposes the peak-to-average power ratio time-domain discrete concatenated interleaving coded modulation data sample block and the time-domain embedded training sequence discrete sample block to form a time-domain embedded training sequence drop Peak-to-average power ratio time-domain discrete cascaded interleaved coded modulation data sample block, as a frame body;

8) The certain robust multimedia mobile broadcast signal transmitter uses the cyclic prefix as a guard interval, that is, inserts the frame header into the time-domain embedding training sequence, and reduces the peak-to-average power ratio of the time-domain discrete cascade interleaving coded modulation data sample block, that is, the frame body, to Form a signal frame, the length of the cyclic prefix is C; when X is 512, C is 1/4 of the size of K; when X is 1024, C is 1/8 of the size of K; when X is 2048, C is K 1/16 of the size;

9) The certain robust multimedia mobile broadcast signal transmitter uses a square root raised cosine roll-off filter to shape the signal pulse of the signal frame;

10) The certain robust multimedia mobile broadcast signal transmitter up-converts the baseband signal to the carrier.

According to an embodiment of a certain transmitter signal framing modulation of the robust multimedia mobile broadcast signal framing modulation method of the present invention, as shown in Figure 2, the specific implementation is as follows:

The certain robust multimedia mobile broadcasting signal transmitter processes its input data bit stream in the frequency domain after BCH encoding, bit interleaving, multi-rate punctured convolutional coding, symbol modulation and symbol rotation, and symbol interleaving Form the FFT concatenated interleaved coded modulation data block, and then transform it into a time-domain discrete concatenated interleaved coded modulated data sample block by IFFT, and select the peak-reduced one with the lowest peak-to-average power ratio through the peak-to-average power ratio adjustment unit The average power ratio time-domain discrete concatenated interleaving code modulation data sample block simultaneously sends the corresponding generation mode information to the service index sequence setting unit. The coding rate of multi-code rate punctured convolutional coding is one of 1/4, 1/2, 5/8, 3/4 and 7/8; the bit interleaving adopts random interleaving; the symbol modulation is QPSK, 16QAM, One of 64QAM and 256QAM, the symbol constellation mapping method of symbol modulation adopts Gray code mapping; the symbol rotation is realized by rotating the symbol constellation at a certain angle, and the QPSK symbol constellation rotation angle is 22.5 degrees, The rotation angle of the symbol constellation diagram of 16QAM is 11.25 degrees, the rotation angle of the symbol constellation diagram of 64QAM is 5.626 degrees, and the rotation angle of the symbol constellation diagram of 256QAM is 2.8125 degrees; the code element interleaving adopts the random interleaving method.

The FFT cascaded interleaved coded modulation data block consists of subcarriers. The length of the FFT concatenated interleaving coded modulation data block is K; when X is 512, the corresponding K is 2048, and the frequency interval of the corresponding subcarrier is 4KHz; when X is 1024, the corresponding K is 4096, The frequency interval of the corresponding subcarriers is 2KHz; when X is 2048, the corresponding K is 8192, and the frequency interval of the corresponding subcarriers is 1KHz.

The certain robust multimedia mobile broadcast signal transmitter uses the training sequence as the real part sequence of the complex training sequence, and uses the service index sequence as the imaginary part sequence of the complex training sequence to form discrete sample value blocks of the complex training sequence in the time domain, Repeat it four times continuously in the time domain to form discrete sample blocks of time domain embedding training sequence. The length of the discrete sample block of the training sequence, the service index sequence, and the complex training sequence is X, where X is one of 512, 1024, and 2048, and the length of the discrete sample block of the time domain embedded training sequence is K, K=4× X.

As a robust multimedia mobile broadcast signal transmitter, the training sequence and service index sequence are composed of a series of 1 or 1, which have pseudo-random characteristics, and the training sequence and service index sequence are orthogonal to each other. The training sequence satisfying the above characteristics can be realized by a special type of shifted m-sequence as a pseudo-random number sequence and Walsh sequence, Hadamard sequence or orthogonal sequence generated by other methods as an orthogonal sequence. Each different service index sequence contains and uniquely expresses various system parameters and service mode information of the robust multimedia mobile broadcast signal transmitter.

This certain robust multimedia mobile broadcasting signal transmitter directly superimposes the peak-to-average power ratio time-domain discrete concatenated interleaving coded modulation data sample block and the time-domain embedded training sequence discrete sample block to form a time-domain embedded training sequence with a peak-to-average reduction Power ratio time-domain discrete concatenated interleaved coded modulation data sample block, as a frame body; in the time domain embedding training sequence peak-to-average power ratio time domain discrete concatenated interleaved coded modulated data sample block, insert a cyclic prefix as a guard interval, Form a signal frame. The length of the cyclic prefix used as the guard interval is C; when X takes 512, the corresponding C takes 1/4 of the size of K; when X takes 1024, the corresponding C takes 1/8 of the size of K; when X takes When 2048, the corresponding C takes 1/16 of the size of K.

The certain robust multimedia mobile broadcast signal transmitter employs a square root raised cosine roll-off filter to pulse shape the signal of the signal frame. When X is 512, the roll-off coefficient of the square root raised cosine roll-off filter corresponding to the pulse shaping of the signal frame is 0.1; when X is 1024, the corresponding pulse shaping of the signal frame is The roll-off coefficient of the square root raised cosine roll-off filter is 0.05; when X is 2048, the corresponding roll-off coefficient of the square root raised cosine roll-off filter for pulse shaping the signal frame is 0.025.

The specific embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and those skilled in the art can make various modifications without departing from the spirit and scope of the claims of the application modify or remodel.

Claims (7)

1. a robust Multimedia Mobile broadcast singal framing modulator approach is characterized in that it comprises the following steps:

1) robust Multimedia Mobile broadcast signal transmission machine is flowed through the input data bit of oneself and is formed the cascade interweaved coding modulation data piece of FFT at frequency domain after Bose-Chaudhuri-Hocquenghem Code, Bit Interleave, multi code Rate of Chinese character are deleted surplus convolutional encoding, code element modulation and code element rotation, symbol interleave, BCH represents Bose Chaudhuri Hocquenghem, LDPC represents LowDensity Parity Check, and the length of the cascade interweaved coding modulation data piece of FFT is K;

2) robust Multimedia Mobile broadcast signal transmission machine adopts IFFT that the cascade interweaved coding modulation data piece of FFT is transformed to the cascade interweaved coding modulation data sample value of time domain discrete piece D _Total

3) robust Multimedia Mobile broadcast signal transmission machine is divided equally into two with the cascade interweaved coding modulation data sample value of time domain discrete piece in order, the sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete ₁With the sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete ₂, D _Total=[D ₁, D ₂];

4) robust Multimedia Mobile broadcast signal transmission machine passes through the peak-to-average power ratio adjustment unit to the sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete ₁, the sub-piece D of the cascade interweaved coding modulation data sample value of time domain discrete ₂Carry out that signal adds, subtracts, conjugate operation is handled and the synthetic 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 $D_{\mathrm{new}}=[\sqrt{1/2}(D_1-D_2),D_2]$ , 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 $D_{\mathrm{new}}=[\sqrt{1/2}({D^{*}}_1+D_2),\sqrt{1/2}({D^{*}}_1-D_2\left)\right],$ 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) robust Multimedia Mobile broadcast signal transmission machine 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 robust Multimedia Mobile broadcast signal transmission machine;

6) discrete sample block of the robust Multimedia Mobile broadcast signal transmission machine sequence of plural training that will constitute in time domain repeats to form time domains 4 times continuously and embeds training sequence discrete sample block on time domain, time domain embeds the length and the length numerically equal of falling the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece, i.e. K=4 * X of training sequence discrete sample block;

7) robust Multimedia Mobile broadcast signal transmission machine will fall the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece, time domain and embed training sequence discrete sample block and directly superpose and form time domain and embed training sequence and fall the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece, as frame;

8) robust Multimedia Mobile broadcast signal transmission machine at interval is that frame head inserts time domain and embeds training sequence to fall the cascade interweaved coding modulation data sample value of peak-to-average power ratio time domain discrete piece be frame with Cyclic Prefix as protection, to form signal frame, the length of Cyclic Prefix is C;

9) robust Multimedia Mobile broadcast signal transmission machine adopts square root raised cosine filter that the signal pulse of signal frame is shaped;

10) robust Multimedia Mobile broadcast signal transmission machine with the baseband signal up-conversion to carrier wave.

2. by the robust Multimedia Mobile broadcast singal framing modulator approach of claim 1, it is characterized in that: the length X of the discrete sample block of the training sequence of described robust Multimedia Mobile broadcast signal transmission machine, operational indicator sequence, sequence of plural training is got in 512,1024,2048.

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

4. by the robust Multimedia Mobile broadcast singal framing modulator approach of claim 2, it is characterized in that: described training sequence, operational indicator sequence have orthogonality each other.

5. by the robust Multimedia Mobile broadcast singal 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, sub-carrier number got 2048, and the frequency interval of subcarrier is got 4KHz; When X got 1024, sub-carrier number got 4096, and the frequency interval of subcarrier is got 2KHz; When X got 2048, sub-carrier number got 8192, and the frequency interval of subcarrier is got 1KHz.

6. by the robust Multimedia Mobile broadcast singal framing modulator approach of claim 1, it is characterized in that: the length C value of described Cyclic Prefix is relevant with the X value; 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.

7. by the robust Multimedia Mobile broadcast singal framing modulator approach of claim 1, it is characterized in that: the encoding rate that described multi code Rate of Chinese character is deleted surplus convolutional encoding is in 1/4,1/2,5/8,3/4 and 7/8; Bit Interleave adopts the random interleaving mode; Code element is modulated to a kind of among QPSK, 16QAM, 64QAM and the 256QAM, and the symbol constellations figure mapping mode of code element modulation adopts the Gray code mapping; The code element rotation realizes by symbol constellations figure is rotated to an angle, the symbol constellations figure anglec of rotation of QPSK is 22.5 degree, the symbol constellations figure anglec of rotation of 16QAM is 11.25 degree, the symbol constellations figure anglec of rotation of 64QAM is 5.626 degree, and the symbol constellations figure anglec of rotation of 256QAM is 2.8125 degree; Symbol interleave adopts the random interleaving mode.

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