Anti-fading mobile signal transmission method for digital broadcast single-frequency network
Technical field
The invention belongs to wireless communication field, relate more specifically to a kind of anti-fading mobile signal transmission method for digital broadcast single-frequency network.
Background technology
Digital Television digital broadcast single-frequency network wireless transmitting system, as the important component part of Digital Television wireless digital broadcasting, the development of its correlation technique, closely bound up with people's quality of life, and be therefore subject to people's extensive concern especially.Digital Television wireless digital broadcasting correlation technique and related industry thereof are that in Communications And Computer field, development is very fast, the industry of good market prospect.In Digital Television wireless digital broadcasting correlation technique, the emphasis that various countries pay close attention to is at present that the Digital Television wireless digital broadcasting how to pass under environment for complex wave provides the implementation of reliable high-speed mobile cheaply.The anti-fading movable signal transmitter of digital broadcast single-frequency network framing modulation technique is the key technology of Digital Television wireless digital broadcasting system, for whole system performance, plays conclusive effect, 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 and becomes more and more easier.Because OFDM Multicarrier Transmission Technology has simple in structure, the availability of frequency spectrum is high, the plurality of advantages such as in the time of can resisting frequency selectivity and channel, becomes and extremely everybody concern obtain deep research and the extensive use in the numerous areas such as Xdsl, wide-band mobile communication, wideband wireless local area network, Digital Television wireless digital 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 system linearity scope can not meet the variation of signal, can cause signal distortion, signal spectrum is changed, thereby cause the orthogonality between subchannel to be destroyed, produce 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 nonlinear distortion impact.
The networking model of employing single frequency network (that is, the same time of several transmitting stations is launched same signal to realize the reliable covering to certain coverage in same frequency) can improve the availability of frequency spectrum of Digital Television digital broadcast single-frequency network wireless transmitting system greatly.In actual single frequency network communication environment, Digital Television digital broadcast single-frequency network performance in wireless communication systems is subject to the impact of the factors such as lock in time, clock jitter, channel fading, channel disturbance.The anti-fading movable signal transmitter of each digital broadcasting transmission method in single frequency network is the key technology that realizes reliable digit Television Digital broadcast single frequency network wireless transmission.
Utilizing Digital Television digital broadcast single-frequency network wireless transmitting 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 Television Digital broadcast single frequency network wireless transmitting system satisfies social needs.
Based on above background, the present invention is directed to practical communication environment and propose a kind of anti-fading mobile signal transmission method for digital broadcast single-frequency network just, can meet the needs that High Data Rate can be controlled multi-service Digital Television digital broadcast single-frequency network wireless transmission.
Wish is done more deep understanding to 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?Issue?on?Global?Digital?Television:Technology?and?Emerging?Services,pp.37-43,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?Servicespp.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.
Summary of the invention
The present invention is directed to High Data Rate and can control multi-service Digital Television digital broadcast single-frequency network wireless issue, proposed a kind of anti-fading mobile signal transmission method for digital broadcast single-frequency network.
A kind of anti-fading mobile signal transmission method for digital broadcast single-frequency network that the present invention proposes, is characterized in that it comprises the following steps:
1) the centre data manager of single frequency network converts the multi-medium data media data processor of flowing through to bit stream, and the scrambler sequence of utilizing feedback shift register to produce is carried out scrambling processing to form input data bit flow;
2) the network data management device of single frequency network by input data bit flow through RS coding, convolutional interleave, LDPC coding,
Code element modulation forms the cascade interweaved coding modulation data piece of FFT with code element rotation, symbol interleave on frequency domain, RS represents Reed-Solomon, LDPC represents Low Density Parity Check, and the length of the cascade interweaved coding modulation data piece of FFT is K, and the numerical value of K is got even number;
3) the network data management device of single frequency network adopts the space-frequency coding device that code check is 1 that the cascade interweaved coding modulation data piece of the FFT forming on frequency domain is modulated in the anti-fading movable signal transmitter branches of each digital broadcasting in single frequency network and forms the cascade interweaved coding modulation data piece of empty frequency modulation FFT processed, and the time synchronized of adjusting the anti-fading movable signal transmitter branches of each digital broadcast single-frequency network is all processed the cascade interweaved coding modulation data piece of empty frequency modulation FFT processed at one time with all transmitters in assurance network;
4) the anti-fading movable signal transmitter of each digital broadcasting in single frequency network adopts IFFT that the cascade interweaved coding modulation data piece of empty frequency modulation FFT processed is transformed to the cascade interweaved coding modulation data sample value of sky frequency modulation time domain discrete processed piece D
total=[d
0, d
1..., d
k-2, d
k-1];
5) the anti-fading movable signal transmitter of each digital broadcasting in single frequency network is by empty frequency modulation time domain discrete processed cascade interweaved coding modulation data sample value piece demultiplexing and according to the sequencing odd even of the cascade interweaved coding modulation data sample value of each the empty frequency modulation time domain discrete processed successively separated strange sub-block D of the cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed that generates
very=[d
0, d
2..., d
k-4, d
k-2] and the even sub-block D of the cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed
even=[d
1, d
3..., d
k-3, d
k-1];
6) the anti-fading movable signal transmitter of each digital broadcasting in single frequency network passes through peak-to-average power ratio adjustment unit to the strange sub-block D of the cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed
very, the even sub-block D of the cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed
evencarry out signal power adjustment and corresponding signal and process also the synthetic new cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed piece D again
new, the new cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed piece D
newadopt following generate pattern to obtain, generate pattern 1 is D
new=[D
very, D
even], generate pattern 2 is
generate pattern 3 is
generate pattern 4 is
generate pattern 5 is
generate pattern 6 is
generate pattern 7 is D
new=[D
* very, D
even], generate pattern 8 is
generate pattern 9 is
generate pattern 10 is
generate pattern 11 is
generate pattern 12 is
generate pattern 13 is D
new=[D
very, D
* even], generate pattern 14 is
generate pattern 15 is
generate pattern 16 is
generate pattern 17 is
generate pattern 18 is
compare the synthetic cascade interweaved coding modulation data sample value of the empty frequency modulation time domain discrete processed piece D of 18 kinds of generate patterns
new, choose wherein there is minimum peak-to-average power ratio the cascade interweaved coding modulation data sample value of the empty frequency modulation time domain discrete processed of peak-to-average power ratio piece falls
and the cascade interweaved coding modulation data sample value of the empty frequency modulation time domain discrete processed of peak-to-average power ratio piece will fall
the corresponding generate pattern information adopting send to operational indicator sequence setting unit, wherein, D
* veryexpression is to the strange sub-block D of the cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed
verythe cascade interweaved coding modulation data sample value of each sky frequency modulation time domain discrete processed carry out conjugate operation processing and the cascade interweaved coding modulation data sample value of the empty frequency modulation time domain discrete processed sub-block that obtains; D
* evenexpression is to the even sub-block D of the cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed
eventhe cascade interweaved coding modulation data sample value of each sky frequency modulation time domain discrete processed carry out conjugate operation processing and the cascade interweaved coding modulation data sample value of the empty frequency modulation time domain discrete processed sub-block that obtains;
7) the anti-fading movable signal transmitter of each digital broadcasting in single frequency network Insert service index series after training sequence forms time-domain training sequence discrete sample block in time domain, and operational indicator sequence is comprising and unique each system parameters and business model information of expressing the anti-fading movable signal transmitter of each digital broadcasting in single frequency network;
8) the anti-fading movable signal transmitter of each digital broadcasting in single frequency network inserts using Cyclic Prefix as protection interval and falls the cascade interweaved coding modulation data sample value of the empty frequency modulation time domain discrete processed of peak-to-average power ratio piece, the discrete cascade interweaving encoding of the empty frequency modulation time domain cyclic prefix processed of peak-to-average power ratio modulating data sample value piece falls in formation, as frame, the length of Cyclic Prefix is C;
9) the anti-fading movable signal transmitter of each digital broadcasting in single frequency network is that frame head is inserted into that to fall the discrete cascade interweaving encoding of the empty frequency modulation time domain cyclic prefix processed of peak-to-average power ratio modulating data sample value piece be frame by time-domain training sequence discrete sample block, to form signal frame;
10) the anti-fading movable signal transmitter of each digital broadcasting in single frequency network adopts square root raised cosine filter to be shaped to the signal pulse of signal frame;
11) the anti-fading movable signal transmitter of each digital broadcasting in single frequency network forms emission of radio frequency signals to on-air radio channel by baseband signal up-conversion to carrier wave;
12) radiofrequency signal that the anti-fading movable signal transmitter of each digital broadcasting in the anti-fading movable signal receiver detection of the digital broadcasting in single frequency network reception single frequency network sends also forms baseband signal by its down-conversion, utilizes the architectural characteristic of training sequence characteristic and signal frame to carry out baseband signal reception & disposal.
According to above-mentioned anti-fading mobile signal transmission method for digital broadcast single-frequency network, it is characterized in that: the anti-fading movable signal transmitter of each digital broadcasting in single frequency network the cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed of peak-to-average power ratio piece falls by empty frequency modulation time domain discrete processed cascade interweaved coding modulation data sample value piece demultiplexing and carry out signal power adjustment and corresponding signal according to the empty frequency modulation time domain discrete processed strange sub-block of cascade interweaved coding modulation data sample value of the sequencing odd even of the cascade interweaved coding modulation data sample value of each empty frequency modulation time domain discrete processed successively separated generation and the cascade interweaved coding modulation data sample value idol of empty frequency modulation time domain discrete processed sub-block and process and pass through 18 kinds of generate patterns of particular design and again synthesize, the training sequence of the anti-fading movable signal transmitter of each digital broadcasting in single frequency network is comprised of the first training sequence and the second training sequence, the first training sequence alternately inserts the new sequence of generation by each symbol of permanent envelope zero auto-correlation CAZAC sequence B and pseudorandom PN sequence A and Cyclic Prefix that length is G forms, the second training sequence is by permanent envelope zero auto-correlation CAZAC sequence-B
*with pseudorandom PN sequence A
*each symbol alternately insert the Cyclic Prefix that the new sequence that produces and length thereof are G and form, B
*expression is carried out conjugate operation processing, A to each symbol of B
*expression is carried out conjugate operation processing to each symbol of A, and B has identical symbol lengths L with A, the circulating prefix-length G of the first training sequence and the second training sequence be the first training sequence and the second training sequence symbol lengths L 1/8, the circulating prefix-length C of the anti-fading movable signal transmitter signal of each digital broadcasting frame in single frequency network is 1/16 of the cascade interweaved coding modulation data block length of FFT K, the operational indicator sequence of the anti-fading movable signal transmitter of each digital broadcasting in single frequency network has pseudo-random characteristics, by one group of Phase shift m sequence, is realized, each different operational indicator sequence of the anti-fading movable signal transmitter of each digital broadcasting in single frequency network is comprising and unique each system parameters and business model information of expressing the anti-fading movable signal transmitter of each digital broadcasting in single frequency network, the cascade interweaved coding modulation data piece of FFT of the anti-fading movable signal transmitter of each digital broadcasting in single frequency network is comprised of subcarrier, and the frequency interval of subcarrier is got a kind of in 2KHz, 4KHz, 1KHz, the encoding rate of LDPC coding is in 1/4,1/2,5/8,3/4 and 7/8, code element is modulated to a kind of in QPSK, 16QAM, 64QAM and 256QAM, and symbol constellations figure mapping mode adopts Gray code mapping, code element rotation is by rotating to an angle and realize symbol constellations figure, 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 random interleaving mode, the code check of space-frequency coding device is 1.The anti-fading movable signal receiver of digital broadcasting in single frequency network can make full use of the architectural characteristic of training sequence characteristic and signal frame and carry out baseband signal reception & disposal, comprising the time domain and frequency domain combined alternate analysis to signal frame head and signal frame body, processes.
Feature of the present invention:
The present invention is the framing modulation scheme that a kind of spatial domain time-domain and frequency-domain mixes.Empty frequency modulation of the present invention time domain discrete processed cascade interweaved coding modulation data sample value piece demultiplexing also generates the empty frequency modulation time domain discrete processed strange sub-block of cascade interweaved coding modulation data sample value and the even sub-block of the cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed and the corresponding signal power adjustment of carrying out and signal processing according to the sequencing odd even of the cascade interweaved coding modulation data sample value of each empty frequency modulation time domain discrete processed successively separation, what by particular design 18 kinds fell the generate pattern of the cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed of peak-to-average power ratio piece and had a minimum peak-to-average power ratio falls the cascade interweaved coding modulation data sample value of peak-to-average power ratio sky frequency modulation time domain discrete processed piece choosing method, but the very high large peak power signal probability of the maximum peak power that not only can make full use of ofdm signal is very low, the power regularity of distribution that the characteristic that the real part of the ofdm signal when number of sub carrier wave is larger (or imaginary part) is multiple Gaussian random process and whose amplitude obeys Rayleigh distribution and then low complex degree ground effectively change over frame signal reaches the object that reduces peak-to-average power ratio, the amount of information of the required extra transmission of generate pattern 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.Training sequence in the signal frame of the anti-fading movable signal transmitter of each digital broadcasting in single frequency network is obtained through certain optimisation design by permanent envelope zero auto-correlation CAZAC sequence and pseudorandom PN sequence, the signal frame of the anti-fading movable signal transmitter of each digital broadcasting in single frequency network is that frame head is inserted into that to fall the discrete cascade interweaving encoding of the empty frequency modulation time domain cyclic prefix processed of peak-to-average power ratio modulating data sample value piece be frame and forming by time-domain training sequence discrete sample block, these have guaranteed that the anti-fading movable signal receiver of digital broadcast single-frequency network 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.Using Cyclic Prefix as protection interval, insert and fall the cascade interweaved coding modulation data sample value of the empty frequency modulation time domain discrete processed of peak-to-average power ratio piece to form signal frame body, can reduce the interference effect between signal frame head and frame data.Input data are carried out to cascade interweaved coded modulation and improved diversity order, the bit error performance that communication system has been had under multidiameter fading channel.Code element modulation rotates with code element the diversity that mobile digital broadcast signal is provided.Each different operational indicator sequence of the anti-fading movable signal transmitter of each digital broadcasting in single frequency network is comprising and unique each system parameters and business model information of expressing the anti-fading movable signal transmitter of each digital broadcasting in single frequency network, can, so that Digital Television digital broadcast single-frequency network wireless transmitting system can provide free television broadcasting, paid television broadcasting, Secret Information Transmission, multimedia value-added service etc. can control multi-service, satisfy social needs.Transmission method of the present invention has low peak-to-average power ratio, 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 Television digital broadcast single-frequency network wireless transmission.
Accompanying drawing explanation
Fig. 1 is according to the embodiment schematic diagram of signal transmission between the transmitter and receiver of anti-fading mobile signal transmission method for digital broadcast single-frequency network of the present invention.
Fig. 2 is the embodiment schematic diagram forming according to signal frame in signals transmission between the transmitter and receiver of anti-fading mobile signal transmission method for digital broadcast single-frequency network of the present invention.
Embodiment
Below in conjunction with accompanying drawing, specific embodiments of the invention are described in detail.
The embodiment schematic diagram of signal transmission between the transmitter and receiver of the anti-fading mobile signal transmission method for digital broadcast single-frequency network proposing according to the present invention, as shown in Figure 1, follows these steps to carry out:
1) the centre data manager of single frequency network converts the multi-medium data media data processor of flowing through to bit stream, and the scrambler sequence of utilizing feedback shift register to produce is carried out scrambling processing to form input data bit flow;
2) the network data management device of single frequency network forms the cascade interweaved coding modulation data piece of FFT by flow through RS coding, convolutional interleave, LDPC coding, the code element modulation of input data bit with code element rotation, symbol interleave on frequency domain, RS represents Reed-Solomon, LDPC represents Low Density Parity Check, the length of the cascade interweaved coding modulation data piece of FFT is K, and the numerical value of K is got even number; The encoding rate of LDPC coding is in 1/4,1/2,5/8,3/4 and 7/8; Code element is modulated to a kind of in QPSK, 16QAM, 64QAM and 256QAM, and symbol constellations figure mapping mode adopts Gray code mapping; Code element rotation is by rotating to an angle and realize symbol constellations figure, 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 random interleaving mode;
3) the network data management device of single frequency network adopts the space-frequency coding device that code check is 1 that the cascade interweaved coding modulation data piece of the FFT forming on frequency domain is modulated in the anti-fading movable signal transmitter branches of each digital broadcasting in single frequency network and forms the cascade interweaved coding modulation data piece of empty frequency modulation FFT processed, and the time synchronized of adjusting the anti-fading movable signal transmitter branches of each digital broadcast single-frequency network is all processed the cascade interweaved coding modulation data piece of empty frequency modulation FFT processed at one time with all transmitters in assurance network;
4) the anti-fading movable signal transmitter of each digital broadcasting in single frequency network adopts IFFT that the cascade interweaved coding modulation data piece of empty frequency modulation FFT processed is transformed to the cascade interweaved coding modulation data sample value of sky frequency modulation time domain discrete processed piece D
total=[d
o, d
1..., d
k-2, d
k-1];
5) the anti-fading movable signal transmitter of each digital broadcasting in single frequency network is by empty frequency modulation time domain discrete processed cascade interweaved coding modulation data sample value piece demultiplexing and according to the sequencing odd even of the cascade interweaved coding modulation data sample value of each the empty frequency modulation time domain discrete processed successively separated strange sub-block D of the cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed that generates
very=[d
0, d
2..., d
k-4, d
k-2] and the even sub-block D of the cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed
even=[d
1, d
3..., d
k-3, d
k-1];
6) the anti-fading movable signal transmitter of each digital broadcasting in single frequency network passes through peak-to-average power ratio adjustment unit to the strange sub-block D of the cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed
very, the even sub-block D of the cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed
evencarry out signal power adjustment and corresponding signal and process also the synthetic new cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed piece D again
new, the new cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed piece D
newadopt following generate pattern to obtain, generate pattern 1 is D
new=[D
very, D
even], generate pattern 2 is
generate pattern 3 is
generate pattern 4 is
generate pattern 5 is
generate pattern 6 is
generate pattern 7 is D
new=[D
* very, D
even], generate pattern 8 is
generate pattern 9 is
generate pattern 10 is
generate pattern 11 is
generate pattern 12 is
generate pattern 13 is D
new=[D
very, D
* even], generate pattern 14 is
generate pattern 15 is
generate pattern 16 is
generate pattern 17 is
generate pattern 18 is
compare the synthetic cascade interweaved coding modulation data sample value of the empty frequency modulation time domain discrete processed piece D of 18 kinds of generate patterns
new, choose wherein there is minimum peak-to-average power ratio the cascade interweaved coding modulation data sample value of the empty frequency modulation time domain discrete processed of peak-to-average power ratio piece falls
and the cascade interweaved coding modulation data sample value of the empty frequency modulation time domain discrete processed of peak-to-average power ratio piece will fall
the corresponding generate pattern information adopting send to operational indicator sequence setting unit, wherein, D
*very represent the strange sub-block D of the cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed
verythe cascade interweaved coding modulation data sample value of each sky frequency modulation time domain discrete processed carry out conjugate operation processing and the cascade interweaved coding modulation data sample value of the empty frequency modulation time domain discrete processed sub-block that obtains; D
* evenexpression is to the even sub-block D of the cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed
eventhe cascade interweaved coding modulation data sample value of each sky frequency modulation time domain discrete processed carry out conjugate operation processing and the cascade interweaved coding modulation data sample value of the empty frequency modulation time domain discrete processed sub-block that obtains;
7) the anti-fading movable signal transmitter of each digital broadcasting in single frequency network Insert service index series after training sequence forms time-domain training sequence discrete sample block in time domain, and operational indicator sequence is comprising and unique each system parameters and business model information of expressing the anti-fading movable signal transmitter of each digital broadcasting in single frequency network;
8) the anti-fading movable signal transmitter of each digital broadcasting in single frequency network inserts using Cyclic Prefix as protection interval and falls the cascade interweaved coding modulation data sample value of the empty frequency modulation time domain discrete processed of peak-to-average power ratio piece, the discrete cascade interweaving encoding of the empty frequency modulation time domain cyclic prefix processed of peak-to-average power ratio modulating data sample value piece falls in formation, as frame, the length of Cyclic Prefix is C;
9) the anti-fading movable signal transmitter of each digital broadcasting in single frequency network is that frame head is inserted into that to fall the discrete cascade interweaving encoding of the empty frequency modulation time domain cyclic prefix processed of peak-to-average power ratio modulating data sample value piece be frame by time-domain training sequence discrete sample block, to form signal frame;
10) the anti-fading movable signal transmitter of each digital broadcasting in single frequency network adopts square root raised cosine filter to be shaped to the signal pulse of signal frame;
11) the anti-fading movable signal transmitter of each digital broadcasting in single frequency network forms emission of radio frequency signals to on-air radio channel by baseband signal up-conversion to carrier wave;
12) radiofrequency signal that the anti-fading movable signal transmitter of each digital broadcasting in the anti-fading movable signal receiver detection of the digital broadcasting in single frequency network reception single frequency network sends also forms baseband signal by its down-conversion, utilizes the architectural characteristic of training sequence characteristic and signal frame to carry out baseband signal reception & disposal.
The embodiment that forms (suppose in single frequency network have N transmitter) according to signal frame in signals transmission between the transmitter and receiver of anti-fading mobile signal transmission method for digital broadcast single-frequency network of the present invention, as shown in Figure 2, is specifically implemented as follows:
The centre data manager of single frequency network converts the multi-medium data media data processor of flowing through to bit stream, and the scrambler sequence of utilizing feedback shift register to produce is carried out scrambling processing to form input data bit flow.
The network data management device of single frequency network forms the cascade interweaved coding modulation data piece of FFT by flow through RS coding, convolutional interleave, LDPC coding, the code element modulation of input data bit with code element rotation, symbol interleave on frequency domain, RS represents Reed-Solomon, and LDPC represents Low Density Parity Check; Adopt the space-frequency coding device that code check is 1 that the cascade interweaved coding modulation data piece of the FFT forming on frequency domain is modulated in the anti-fading movable signal transmitter branches of each digital broadcasting in single frequency network and forms the cascade interweaved coding modulation data piece of empty frequency modulation FFT processed, and the time synchronized of adjusting the anti-fading movable signal transmitter branches of each digital broadcast single-frequency network is all processed at one time to the cascade interweaved coding modulation data piece of empty frequency modulation FFT processed with all transmitters in assurance network; Through IFFT, be transformed to the cascade interweaved coding modulation data sample value of sky frequency modulation time domain discrete processed piece again, by peak-to-average power ratio adjustment unit, generate and choose the cascade interweaved coding modulation data sample value of empty frequency modulation time domain discrete processed of the peak-to-average power ratio piece that falls wherein with minimum peak-to-average power ratio and the generate pattern information of institute's correspondence employing is sent to operational indicator sequence setting unit simultaneously.
The cascade interweaved coding modulation data piece of FFT of the anti-fading movable signal transmitter of each digital broadcasting in single frequency network is comprised of subcarrier, and the frequency interval of subcarrier is got a kind of in 2KHz, 4KHz, 1KHz; The encoding rate of LDPC coding is in 1/4,1/2,5/8,3/4 and 7/8; Code element is modulated to a kind of in QPSK, 16QAM, 64QAM and 256QAM, and symbol constellations figure mapping mode adopts Gray code mapping; Code element rotation is by rotating to an angle and realize symbol constellations figure, 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 random interleaving mode.
The training sequence of the anti-fading movable signal transmitter of each digital broadcasting in single frequency network is comprised of the first training sequence and the second training sequence; The first training sequence alternately inserts the new sequence of generation by each symbol of permanent envelope zero auto-correlation CAZAC sequence B and pseudorandom PN sequence A and Cyclic Prefix that length is G forms; The second training sequence is by permanent envelope zero auto-correlation CAZAC sequence-B
*with pseudorandom PN sequence A
*each symbol alternately insert the Cyclic Prefix that the new sequence that produces and length thereof are G and form; B
*expression is carried out conjugate operation processing, A to each symbol of B
*expression is carried out conjugate operation processing to each symbol of A, and B has identical symbol lengths L with A; The circulating prefix-length G of the first training sequence and the second training sequence be the first training sequence and the second training sequence symbol lengths L 1/8.
The anti-fading movable signal transmitter of each digital broadcasting Insert service index series after training sequence in single frequency network forms time-domain training sequence discrete sample block in time domain.
The operational indicator sequence of the anti-fading movable signal transmitter of each digital broadcasting in single frequency network has pseudo-random characteristics, by one group of Phase shift m sequence, is realized; Each different operational indicator sequence of the anti-fading movable signal transmitter of each digital broadcasting in single frequency network is comprising and unique each system parameters and business model information of expressing the anti-fading movable signal transmitter of each digital broadcasting in single frequency network.
The anti-fading movable signal transmitter of each digital broadcasting in single frequency network inserts using Cyclic Prefix as protection interval and falls the cascade interweaved coding modulation data sample value of the empty frequency modulation time domain discrete processed of peak-to-average power ratio piece, the discrete cascade interweaving encoding of the empty frequency modulation time domain cyclic prefix processed of peak-to-average power ratio modulating data sample value piece falls in formation, as frame, the length of Cyclic Prefix is C; The anti-fading movable signal transmitter of each digital broadcasting in single frequency network is that frame head is inserted into that to fall the discrete cascade interweaving encoding of the empty frequency modulation time domain cyclic prefix processed of peak-to-average power ratio modulating data sample value piece be frame by time-domain training sequence discrete sample block, to form signal frame; The circulating prefix-length C of the anti-fading movable signal transmitter signal of each digital broadcasting frame in single frequency network is 1/16 of the cascade interweaved coding modulation data block length of FFT K.
The anti-fading movable signal transmitter of each digital broadcasting in single frequency network adopts square root raised cosine filter to carry out pulse shaping to the signal of signal frame.
The anti-fading movable signal transmitter of each digital broadcasting in single frequency network forms emission of radio frequency signals to on-air radio channel by baseband signal up-conversion to carrier wave.
The radiofrequency signal that the anti-fading movable signal transmitter of each digital broadcasting in the anti-fading movable signal receiver detection of digital broadcasting reception single frequency network in single frequency network sends also forms baseband signal by its down-conversion, utilize the architectural characteristic of training sequence characteristic and signal frame to carry out baseband signal reception & disposal, comprising the time domain and frequency domain combined alternate analysis to signal frame head and signal frame body, process.
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, in the spirit and scope situation of claim that does not depart from the application, those skilled in the art can make various modifications or remodeling.