CN1348302A - Frame sync generating method in ground digital multimedia TV broad cast system - Google Patents
Frame sync generating method in ground digital multimedia TV broad cast system Download PDFInfo
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Abstract
A method for producing frame synchronization in ground digital multimedia television broadcast system, of which the frame synchronization signal is composed of a front synchronization, a PN series and a back synchronization, includes steps as: (1) to create a eight steps m series by Fibonacci type linear feed-back shift register, (2) to select a sixteen steps Wolsch code word by DMB-T network supervisor as a base station (emission station), (3) to expand the sixteen bit Wolsh code to a vector of 256/304/384 position by duplicating each, "1" and each "0" 16/19/24 times according to the big or small or front synchronization/back synchronization in PN series, (4) to carry out one position by one position exclusive OR (XOR) to the vector produce by step (2) and the frame synchronization series to be coded to establish the frame synchronization series of Wolsh spread spectrum coding.
Description
The application is that on August 25th, 2000 application, application number are dividing an application of 00123597.4 " ground digital multimedia TV broad cast system ".
Technical field
The invention belongs to the digital information transmission field, relate more specifically to the frame-synchronization generation method in a kind of ground digital multimedia TV broad cast system.
Background technology
For television transmission system, on the basis of simulated television, through insistent research and development of more than ten years, Digital Television Terrestrial Broadcasting (Digital Television Terrestrial Broadcasting, DTTB) obtained a lot of achievements, having reached can implementation phase.From in November, 1998 North America and the Europe DTTB program that started broadcasting, many countries have announced that their DTTB standard selects and realize a plan.At present, mainly contain three kinds of DTTB transmission standards in the world:
1) ATSC of the U.S. (Advanced Television Systems Committee) digital television standard.
2) Ou Zhou DVB-T (Digital Video Terrestrial Broadcasting-Terrestrial) digital video broadcast-terrestrial standard.
3) Ri Ben ISDB-T (Integrated Service Digital Broadcasting-Terrestrial) floor synthetic service digital broadcast standard.
Along with the development of technology and deepening continuously of research, people recognize at signal peak one average power ratio, C/N thresholding, move receive, indoor/outer reception, spectrum efficiency, HDTV transmittability, with frequency/adjacent channel disturb, aspect the flexibility of interference, single frequency network and co-channel forwarding, impulse disturbances and continuous wave interference to having simulated television now, phase noise, static state/dynamically multipath distortion, system or the like, respectively there are its pluses and minuses in above-mentioned three systems.
At above-mentioned present three problems that terrestrial digital television system exists in the world, applicant of the present invention has proposed ground digital multimedia TV broad cast system a kind of novelty, that be fit to China's actual conditions and (has abbreviated as: the DMB-T system).
In this system, time-domain synchronization OFDM (Time Domain Synchronous-OrthogonalFrequency Division Multiplexing, TDS-OFDM) modulation technique have been adopted.It is different with the COFDM in Europe, and it is the scheme that a kind of time-domain and frequency-domain mixes.In this scheme, do not insert the COFDM pilot signal, but utilized spread spectrum, promptly utilize the PN pseudo noise code of spread spectrum to carry out frame synchronization, Frequency Synchronization, time synchronized, channel transfer characteristic estimation and follow the tracks of phase noise etc.So just avoided the shortcoming of DVB-T COFDM.
Ground digital multimedia TV broad cast (DMB-T) agreement is based on the TDS-OFDM technology, and its physical channel frame structure as shown in Figure 1.Frame structure is classification, and a basic frame structure is called a signal frame.The frame group is defined as 255 signal frames, and its first frame definition is a frame group head.Signal frame among the frame group has unique frame number, label from 0 to 254, and signal frame number (FN) is encoded in the frame synchronization PN sequence of current demand signal frame.
Superframe is defined as a framing group, and the top layer of frame structure is called the superframe group.Superframe is numbered, from 0 to largest frames group number.Hyper Frame Number (SFN) is encoded in first frame group head of superframe with superframe group number (SFGN).
Superframe group number (SFGN) is defined as the calendar date of superframe pocket transmission, and the superframe group is to carry out periodicity the cycle to repeat with a consecutive days, and it is encoded as preceding two bytes in first frame group head of a superframe among the downgoing line superframe group.At Pacific standard time (PST) or Beijing time 0:0:0 AM, physical channel frame structure is reset and begins a new superframe group.
Therefore, the physical channel of DMB-T agreement is the cycle, and and Absolute Time Synchronization, the reception function is just started shooting in needs, this means that receiver can be designed to have only when receiving needed information, just enters accepting state, to reach purpose of power saving.
A signal frame is made up of two parts: frame synchronization and frame.The baseband signalling rate of frame synchronization and frame is identical, is defined as 7.56MSps.
Frame synchronizing signal adopts the random sequence of walsh codes, to realize many identification of base stations.Frame synchronization comprises preamble, PN sequence and back synchronously.Unlike signal frame among the signal frame group has different frame synchronizing signals.So frame synchronization can be made the frame synchronization feature of a distinctive signal frame and be used for identification.Frame synchronization adopt the BPSK modulation with obtain stable synchronously.
The baseband signal of frame is an OFDM (OFDM) piece.An OFDM piece can further be divided into protection interval and a DFT piece, and the DFT piece has 3780 samplings in its time domain, and they are contrary discrete fourier transforms of 3780 subcarriers in the frequency domain.
5 kinds of optionally protection gap size are arranged, promptly 1/6 of the DFT block size, 1/9,1/12,1/20,1/30.Protection signal at interval is same as the final stage of DPT piece time-domain signal.The synchronization scenario of U.S. ATSC system has adopted the time domain mode, and is relatively simple.One of the implication of " coding " among the DVB-T standard code OFDM COFDM of Europe is meant has inserted some " pilot tone " signals at random in the OFDM frequency spectrum, here so-called " pilot tone " is meant the carrier wave of some OFDM like this, they are by the known data-modulated of receiver, what they transmitted is not modulating data itself, because it is known that these data receivers are systems, to be system transmit the characteristic of the parameter of some transmitter or test channel or be used for system synchronization by the data on the pilot tone purpose that pilot tone is set.
The effect of pilot tone in COFDM is very important, and its use comprises: frame synchronization, Frequency Synchronization, time synchronized, channel transfer characteristic are estimated, transmission mode is discerned and follow the tracks of phase noise etc.The data of modulated pilots are the pseudo random sequences that generates from a pseudo-random sequence generator of stipulating in advance.Distribution pilot tone and continuous pilot have been stipulated among the DVB-T.The position of continuous pilot in each COFDM symbol all fixed, and inserted 177 continuous pilot in the 8k pattern, inserted 45 continuous pilot in the 2k pattern.The position of scattering pilot tone is different in different COFDM symbols, but with four COFDM symbols is loop cycle, that is to say the 1st, 2,3, the position of the distribution pilot tone in 4 COFDM symbols has nothing in common with each other, but the 5th COFDM symbol is identical with pilot frequency locations in the 1st the OFDM symbol, the 6th COFDM symbol is identical with pilot frequency locations in the 2nd the COFDM symbol, the 7th COFDM symbol is identical with pilot frequency locations in the 3rd the COFDM symbol, the 8th COFDM symbol is identical with pilot frequency locations in the 4th the COFDM symbol,, the rest may be inferred for all the other COFDM symbols.
No matter how the position of pilot tone changes, the number that is used to transmit the carrier wave of effective programme information in each COFDM symbol all is constant, is 1512 in the 2k pattern, is 6048 in the k pattern.Because the effect of pilot tone in system is important, for guaranteeing the reliability of data on the pilot tone, prevent noise jamming, the average power of pilot signal is bigger 16/9 times than the average power of other carrier signal, and promptly pilot signal is launched on " lifting " power level.
From European DVB-T standard as can be known, data are to be modulated on K the subcarrier in theory, it is realized by inverse discrete fourier transform IDFT (or its fast algorithm IFFT), so, need a discrete Fourier transform (DFT) DFT (perhaps its fast algorithm FFT) to recover initial data equally in receiving end.Receiving end will be carried out the FFT computing, just need recovery system at first synchronously, comprise frame synchronization, carrier frequency, time synchronized and channel estimating etc., we know from top narration, the foundation of synchro system need rely on the pilot frequency information that is inserted in the FFT coefficient.Like this, the foundation of FFT computing and synchro system (channel estimating) has just formed a feedback cycle process, because FFT and pilot tone are mutual demands in COFDM, pilot tone is inserted after IFFT, and FFT calculating needs (pilot tone) at first synchronously, could calculate FFT then.Therefore, COFDM adopts the iterative approach algorithm, so just has a convergence error and convergence time problem.
In view of this, though in the DMB-T system, also adopted multi-carrier modulation technology---orthogonal frequency division multiplex OFDM, but it is different with the COFDM in Europe, this system has adopted the modulation technique that is called time-domain synchronization OFDM TDS-OFDM, it had both had the advantage of OFDM, had avoided the shortcoming of above-mentioned European COFDM again.In TDS-OFDM, do not insert the COFDM pilot signal, but utilized spread spectrum in the spread spectrum communication, inserted the PN spread-spectrum signal, be used for frame synchronization, Frequency Synchronization, time synchronized, channel transfer characteristic estimation and follow the tracks of phase noise etc. as Domain Synchronous.
So, compare with the pilot signal of European DVB-T, obtain what benefit with PN spread spectrum Domain Synchronous?
In decades, the communication technology is development and differentiation constantly, basically is the variation of medium and channel from wired (cable, optical fiber) to wireless (shortwave, VHF/UHF, microwave, satellite), and breakthrough progress and few, the appearance of spread spectrum communication (SpreadSpectrum Communication) technology, be the communication technology, particularly wireless communication technology important breakthrough.The essential characteristic of spread spectrum communication is to use than the pseudo noise code of much higher times of the information data rate that sends expands the frequency spectrum of the baseband signal of carrying information data, and the signal that forms the low power spectral density in broadband is launched.
What is its rationale so? Shannon (Shannon) has just drawn the formula of channel capacity in information-theoretical research:
R＝W?log
2(1+S/N)
This formula indicates: if rate of information throughput R is constant, then bandwidth W and signal to noise ratio S/N can exchange, increase bandwidth in other words and just can under the situation of lower signal to noise ratio, come reliable transmission information with identical information rate, even under the situation that signal is flooded by noise, as long as the corresponding signal bandwidth that increases, still keep communication reliably, just can exchange benefit on the signal to noise ratio for transmission inromation bandwidth with spectrum spreading method.The basic thought of spread spectrum communication that Here it is and theoretical foundation.
Information data D is through conventional data-modulated, having become bandwidth is base band (arrowband) signal of B1, use pseudorandomcode (the PN sign indicating number: Pseudo Noise Code) of spread spectrum coding generator generation again, baseband signal is made band spectrum modulation, formation bandwidth B 2 (B2 is much larger than B1), the spread-spectrum signal that power spectral density is extremely low, this is equivalent to the rule of the signal of arrowband B1 with PN sign indicating number defined is distributed on the B2 of broadband, launches again.Receiving terminal uses pseudorandomcode identical when launching to do spread spectrum demodulation, WBSR wideband signal recovery is become conventional baseband signal, promptly extracting the composition integration corresponding with emission according to the rule of PN sign indicating number from the broadband gets up, form common baseband signal, then, can demodulate information data transmitted D with conventional communication process again.
Summary of the invention
The purpose of this invention is to provide the frame-synchronization generation method in a kind of ground digital multimedia TV broad cast system.Stablize realizing.Frame synchronization is recovered reliably.
According to the frame-synchronization generation method in the ground digital multimedia TV broad cast system of the present invention, wherein: frame synchronizing signal constitutes synchronously by behind a preamble, PN sequence and one; It is characterized in that described frame-synchronization generation method comprises the following steps:
(1) use Fibonacci molded lines feedback shift register (LFSR) to produce the m sequence on one 8 rank;
(2) be that one 16 rank Walsh code word is selected in base station (transmitting station) by the DMB-T network manager;
(3), repeat each " 1 " in the code word and each according to the preamble/back of PN sequence size synchronously
" 0 " 16/19/24 time expands to the walsh code of 16 bits on one 256/304/384 arrow
Amount;
(4) vector of frame synchronization sequence that will be encoded and the generation of (2) step carries out XOR (XOR) by turn,
To set up the frame synchronization sequence of walsh code spread spectrum coding.
According to the frame-synchronization generation method in the ground digital multimedia TV broad cast system of the present invention, it is further characterized in that: preamble may be defined as 0,24 and 25 symbol, after may be defined as 1,25 and 104 symbol synchronously, the PN sequence has 255 symbols.Preamble and after may be defined as the cyclic extensions of PN sequence synchronously.The proper polynomial of described Fibonacci molded lines feedback shift register may be defined as x
8+ x
6+ x
5+ x+1.The phase place of m sequence can be determined by the initial condition module, and promptly initial condition is determined the m sequence of one 255 bit.Described N rank walsh code Ke Yong Ha Dema matrix generates.But described N rank Ha Dema matrix recursion produces.
The above-mentioned frame synchornization method of the present invention has adopted straight expansion mode, but also can adopt other spread spectrum mode to realize TDS-OFDM.The fundamental mode that realizes spread spectrum has 4 kinds: 1. direct sequence spread spectrum (Direct Sequence SpreadSpectrum) working method (be called for short the DS mode, directly expand formula); 2. jump frequency (Freguency Hopping) working method (be called for short FH mode); 3. bound-time (Time Hopping) working method (be called for short TH mode); 4. linear frequency modulation (Chirp Modulation) working method (Chirp mode).
Straight expansion mode is at the direct frequency spectrum of using the spread spectrum coding with high code check to remove spread signal of making a start, and makes spread-spectrum signal be reduced to primary signal and carry out despreading in receiving end with identical spread spectrum coding.At transmitting terminal, the information D that just send is at the frequency expansion sequence of exclusive-OR device modulation pseudo-noise code generator generation, again through the carrier modulator modulated carrier signal.The modulation back obtains the spread-spectrum signal in broadband, launches after wide-band amplifier amplifies.At receiving terminal, the demodulation spreading code that the PN code generator produces and the spreading code of transmission carry out relevant treatment, can acquired information data D.
Frame synchornization method of the present invention how to solve multiple access communication and signal detects? this is two basic characteristics of spread spectrum communication: i.e. pseudorandomcode modulation and signal correction are handled.The core of pseudorandomcode modulation is to produce the pseudorandomcode (PN sign indicating number) that meets the spread spectrum communication needs, with this as being spread spectrum coding (Spreading Code).When straight expansion mode, the linear feedback shift register sequence of spread spectrum coding maximum length commonly used, i.e. m sequence, it can be produced by linear feedback shift register, and the length of m sequence is determining the ability of spread spectrum.Because of can being provided with, its initial state that produces pseudorandom code sequence produces different PN sign indicating numbers, so available different initial state decides the PN sign indicating number.And different PN sign indicating numbers carries out relevant treatment to spread-spectrum signal, can solve the baseband signal in the spread-spectrum signal of identical with it PN sign indicating number modulation, and elimination remaining part.So just can realize multiple access communication, and fabulous anti-interference is arranged.
Frame synchornization method of the present invention has adopted above-mentioned spread spectrum technic, carry out band spectrum modulation with spread spectrum coding making a start, collect mail with the correlation demodulation technology in receiving end, this process make frame synchornization method of the present invention had many other Digital Terrestrial Television Broadcast systems do not possess good characteristic:
(1) noise resisting ability extremely strong (the thresholding signal to noise ratio is very low)
An important parameter of expression spread spectrum communication characteristic is spreading gain G (Spreading Gain), and it is defined as the ratio of the signal bandwidth B2 behind signal bandwidth B1 and the spread spectrum before the spread spectrum.In the G=B2/B1 spread spectrum communication, receiving terminal is done spread spectrum demodulation to the received signal, only extract that bandwidth is the signal composition of B1 after the spread spectrum coding relevant treatment, and got rid of the influence of the interference, noise and other telex networks that expand among the B2 of broadband, be equivalent to received signal to noise ratio has been improved G doubly.Consider the signal to noise ratio and the receiving system loss of output, can think being improved as of signal to noise ratio that actual spreading gain brings:
M=G-output signal to noise ratio
---the M in the system loss formula is called AJ margin.
Therefore, through behind the spread spectrum, can obtain huge signal to noise ratio and improve.This means that simultaneously signal level can be submerged among the noise level fully, system still can operate as normal, therefore we can say to have only spread spectrum system just can work in negative signal to noise ratio.
Therefore, compare with European DVB-T, U.S. ATSC, even signal has been covered under noise, DBM-T also can provide reliably synchronously.
(2) antijamming capability is extremely strong
To the pseudo-code spread spectrum system, separate because of pseudo-code being correlated with to expand in receiving end, very high peak value output is just arranged after having only pseudo-code signal relevant, and other any unwanted signal, comprise aiming (with frequently) interference, industrial interference, broad-band interference and many artificial disturbances, because of uncorrelated with pseudo-code, output is very low after the despreading.Therefore, spread spectrum system has extremely strong antijamming capability.
(3) anti-fading ability is strong
The frequency band that spread-spectrum signal occupies is very wide, but causes for a certain reason when declining, and only can make the decline of sub-fraction frequency spectrum, can not make whole signal produce distortion.Therefore, the DMB-T of Tsing-Hua University synchro system has the ability of anti-frequency selective fading.
(4) the anti-multipath interference performance is strong
Because the pseudo-code that adopts in the spread spectrum system has good autocorrelation performance usually, the signal that the transmission of different paths comes is easy to separated opening, and can align again in time and phase place, forms the stack of several roads, can improve the performance of system significantly.Thereby make DMB-T system of Tsing-Hua University disturb and can turn bane into boon multipath, this is that any other system is not facile.
(5) can adopt code division multiple access (CDMA) and orthogonal frequency division multiplex OFDM technology to realize the single-frequency Cellular Networks
The pseudo-code spread spectrum system is easy to be loaded with the code division multiple access mode and realizes multi-address communication.Code division multiple access can more effectively utilize frequency resource than frequency division multiple access and time-division multiple access.CDMA networking does not simultaneously need strict net synchronous, and broadcast base station can network at random, increases and decreases the broadcast base station address whenever and wherever possible.Make full use of the correlation properties between the spread spectrum coding of different sign indicating number types, distribute to the different spread spectrum coding of different broadcast base stations, just can distinguish the signal of different broadcast base stations.Simultaneously, the key property of OFDM is exactly the anti-multipath interference performance, and the signal of different broadcast base stations can be regarded as a multipath signal of far-end.
Therefore, numerous broadcast base stations as long as use the spread spectrum coding of oneself, just can use same frequency for communication without interfering with each other simultaneously, thereby realize channeling, and crowded frequency spectrum is fully used, and DMB-T can constitute a single-frequency cellular network thus.
Description of drawings
Fig. 1 is the structure chart of ground digital multimedia TV broad cast system channel data bag.
Fig. 2 is that a Fibonacci molded lines feedback shift register (LFSR) is realized block diagram.
Fig. 3 is one 16 rank walsh code, and the left side one row illustrate the label of Walsh code word.
Fig. 4 is that the LFSR of a character used in proper names and in rendering some foreign names Luo Hua form realizes block diagram.
Embodiment
Below in conjunction with accompanying drawing specific embodiments of the invention are described in detail.
The base band frame synchronizing signal constitutes synchronously by behind a preamble, PN sequence and one.Preamble may be defined as 0,24 and 25 symbol, after may be defined as 1,25 and 104 symbol synchronously, the PN sequence has 255 symbols.Unlike signal frame among the signal frame group has different frame synchronizing signals.So frame synchronization can be made the frame synchronization feature of a distinctive signal frame and be used for identification.Preamble and after be defined as the cyclic extensions of PN sequence synchronously.
The PN sequence definition is one 8 rank m sequence, is realized by a Fibonacci molded lines feedback shift register (LFSR).Its proper polynomial is defined as x
8+ x
6+ x
5+ x+1.The LFSR block diagram is shown among Fig. 2.The initial condition module is determined the phase place of the m sequence produced, and promptly initial condition is determined the m sequence of one 255 bit.
It is the binary signal of non-return-to-zero to the mapping transformation of-1 value that the PN sequence reaches " 1 " through " 0 " to+1 value.
A N rank walsh code can generate with the Ha Dema matrix.A N rank Ha Dema matrix is that recursion produces.
2 rank Ha Dema matrix H (2) are defined as
0 0
0 1
4 rank Ha Dema matrix H (4) are defined as
H(4)＝H(2)×H(2)＝
0 0 0 0
0 1 0 1
0 0 1 1
0 1 1 0
For N=2
k, N rank Ha Dema matrix H (N) are defined as
H(N)＝H(2)×H(N/2)
N rank walsh code is defined by the row of N rank Ha Demate matrix, i.e. the delegation that the Walsh code word is the Ha Demate matrix.The label of Walsh code word is defined as in the code word by 0 to 1 with by 1 to 0 number of times of changing.
Fig. 3 illustrates one 16 rank walsh code, and the left side one row illustrate the label of Walsh code word.
A frame synchronization sequence is by one 16 rank walsh code word code, to realize many base stations (transmitting station) identification.The walsh code coding step of the PN sequence of carrying out for identification of base stations is as follows:
(1) use Fibonacci molded lines feedback shift register (LFSR) to produce the m sequence on one 8 rank;
(2) be that one 16 rank Walsh code word is selected in base station (transmitting station) by the DMB-T network manager;
(3) according to the preamble/back of PN sequence size synchronously, repeat each " 1 " and each " 0 " 16/19/24 time in the code word, the walsh code of 16 bits is expanded to one 256/304/384 vector;
(4) vector of frame synchronization sequence that will be encoded and the generation of (2) step carries out XOR (XOR) by turn, to set up the frame synchronization sequence of walsh code spread spectrum coding.
The frame address structure is based on the m sequence of one group of displacement, and it is a kind of specific type of pseudo random number (PN) sequence.One 8 rank m sequence is that one-period is 255 periodic sequence.Based on the initial condition of the LFSR among Fig. 2, can produce the m sequence of 255 outs of phase.The m sequence is by the initial condition numbering of its LFSR in Fig. 2.
With the proper polynomial among Fig. 2, initial condition is by x
16nCoding.
For example, the initial condition of the m sequence of sequence number 0 is 000000001, and it is x
16 * 0=1.The initial condition of the m sequence of sequence number 1 is 11110011, and it is x
16 * 1=x
16The initial condition of the m sequence of sequence number 2 is 11110100, and it is x
16 * 2=x
32The initial condition of the m sequence of sequence number 254 is 00010110, and it is x
16 * 254=x
239Here x is a Boolean variable.
Time power arbitrarily of x can transform to a state with proper polynomial, and the LFSR of a character used in proper names and in rendering some foreign names Luo Hua form shown in Figure 4 produces each time power of x with continuous order.
Arbitrary signal frame among frame group can be assert by its frame synchronization.Have 255 different m sequences synchronous as signal frame, they are to being applied to 255 signal frames among the frame group.Arbitrary frame group of a superframe is by label, and from 0 to 511, and can be by the parameter identification in the DFT piece in the frame group head.
Arbitrary superframe of a superframe group is since 0 label, and it can be by the data identification of PST (Pacific standard time) time or frame.
It is synchronous that frame synchronization m sequence is used to signal frame.Frame synchronization m sequence in the frame group head is used to the signal frame group synchronization.The frame group energy of a superframe is assert by its frame group head.Frame synchronizing signal can be used for symbol timing recovery.Frame synchronization sequence is predictable behind the initial capture-process of process.
Method of the present invention not only can be used for ground, satellite, wired, microwave and other transmission medium, also can be used for data broadcasting, Internet and other wideband multimedia message transmission and integrated data business field.
Claims (7)
1, the frame-synchronization generation method in a kind of ground digital multimedia TV broad cast system, wherein: frame synchronizing signal
Constitute synchronously by behind a preamble, PN sequence and one;
It is characterized in that, comprise the following steps:
(1) produces the m sequence on one 8 rank with Fibonacci molded lines feedback shift register;
(2) be that base station/transmitting station is selected one 16 rank Walsh code word by the DMB-T network manager;
(3) according to the preamble/back of PN sequence size synchronously, repeat each " 1 " and each " 0 " 16/19/24 time in the code word, the walsh code of 16 bits is expanded to one 256/304/384 vector;
(4) vector of frame synchronization sequence that will be encoded and the generation of (2) step carries out XOR by turn, to set up the frame synchronization sequence of walsh code spread spectrum coding.
2, according to the frame-synchronization generation method in the ground digital multimedia TV broad cast system of claim 1, it is characterized in that: preamble is defined as 0,24 and 25 symbol, after may be defined as 1,25 and 104 symbol synchronously, the PN sequence has 255 symbols.
3, according to the frame-synchronization generation method in the ground digital multimedia TV broad cast system of claim 1, it is characterized in that: preamble and after be defined as the cyclic extensions of PN sequence synchronously.
4, according to the frame-synchronization generation method in the ground digital multimedia TV broad cast system of claim 1, it is characterized in that: the proper polynomial of described Fibonacci molded lines feedback shift register is defined as x
8+ x
6+ x
5+ x+1.
5, according to the frame-synchronization generation method in the ground digital multimedia TV broad cast system of claim 1, it is characterized in that: the phase place of m sequence determined by the initial condition module, and promptly initial condition is determined the m sequence of one 255 bit.
6, according to the frame-synchronization generation method in the ground digital multimedia TV broad cast system of claim 1, it is characterized in that: described N rank walsh code generates with the Ha Dema matrix.
7, according to the frame-synchronization generation method in the ground digital multimedia TV broad cast system of claim 1, it is characterized in that: described N rank Ha Dema matrix is that recursion produces.
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| CN 01130659 CN1131626C (en) | 2001-08-17 | 2001-08-17 | Frame sync generating method in ground digital multimedia TV broad cast system |
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|---|---|---|---|
| CN 01130659 CN1131626C (en) | 2001-08-17 | 2001-08-17 | Frame sync generating method in ground digital multimedia TV broad cast system |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN00123597A Division CN1118195C (en) | 2000-08-25 | 2000-08-25 | Ground digital multimedia TV broadcasting system |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1306808C (en) * | 2003-02-14 | 2007-03-21 | 上海交通大学 | Spread spectrum transmission method of system information in digital terrestrial broadcasting transmission |
| CN100356783C (en) * | 2003-02-14 | 2007-12-19 | 上海交通大学 | Frame field synchronizing system in digital terrestrial broadcasting transmission |
| CN100413314C (en) * | 2005-06-20 | 2008-08-20 | 乐金电子(中国)研究开发中心有限公司 | Terminal with slide showing function for digital broadcast and slide showing method |
| CN105391961A (en) * | 2006-03-02 | 2016-03-09 | Lg电子株式会社 | Method for processing and receiving broadcast signal and broadcast signal transmitter and receiver |
-
2001
- 2001-08-17 CN CN 01130659 patent/CN1131626C/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1306808C (en) * | 2003-02-14 | 2007-03-21 | 上海交通大学 | Spread spectrum transmission method of system information in digital terrestrial broadcasting transmission |
| CN100356783C (en) * | 2003-02-14 | 2007-12-19 | 上海交通大学 | Frame field synchronizing system in digital terrestrial broadcasting transmission |
| CN100413314C (en) * | 2005-06-20 | 2008-08-20 | 乐金电子(中国)研究开发中心有限公司 | Terminal with slide showing function for digital broadcast and slide showing method |
| CN105391961A (en) * | 2006-03-02 | 2016-03-09 | Lg电子株式会社 | Method for processing and receiving broadcast signal and broadcast signal transmitter and receiver |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1131626C (en) | 2003-12-17 |
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