CN102651724A - Signaling demodulation method and signaling demodulation device in China mobile multimedia broadcasting (CMMB) system - Google Patents
Signaling demodulation method and signaling demodulation device in China mobile multimedia broadcasting (CMMB) system Download PDFInfo
- Publication number
- CN102651724A CN102651724A CN2011100454655A CN201110045465A CN102651724A CN 102651724 A CN102651724 A CN 102651724A CN 2011100454655 A CN2011100454655 A CN 2011100454655A CN 201110045465 A CN201110045465 A CN 201110045465A CN 102651724 A CN102651724 A CN 102651724A
- Authority
- CN
- China
- Prior art keywords
- data
- signaling
- signaling information
- bit
- module
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Abstract
The invention discloses a signaling demodulation method in a China mobile multimedia broadcasting (CMMB) system. Channel response estimation results obtained by a receiving machine are utilized for carrying out weakened data pre-correction on received data, and the multiplicative interference overlapped on the data by the channel response is eliminated; positions of signaling information in received data are extracted, and in addition, a hard judgment mode is adopted for calculating signaling transmission data bits; the data bits are subjected to statistics judgment to obtain estimation values of signaling information of the current data frame; and the estimation values of the signaling information are filtered to obtain system signaling information. The invention also discloses a signaling demodulation device of the CMMB system used for the method. The method and the device have the advantage that the signaling information can be simply and accurately demodulated.
Description
Technical field
The present invention relates to the digital information transmission field, particularly relate to the signal demodulation method in a kind of CMMB (China MobileMultimedia Broadcasting, China Mobile's DMB TV) system.The invention still further relates to a kind of signal demodulation device that is used for the CMMB receiving system of said method.
Background technology
CMMB is the China Mobile multimedia broadcasting industry standard of China national General Bureau of Radio, Film and Television in October, 2006 promulgation, and this standard was in formal enforcement on November 1 in 2006.It is a kind of wireless broadcast system based on multi-carrier OFDM (OFDM) technology, adopts advanced channel error correction coding and multi-carrier OFDM modulation technique, has improved antijamming capability and to ambulant support; Adopt the time slot radiation pattern to reduce the power consumption at terminal.According to the imagination of the CMMB network coverage, the CMMB signal realizes that by S-band satellite overlay network and U wave band ground overlay network signal covers.S-band satellite overlay network broadcast channel is used for direct reception, and the Ku wave band is up, and S-band is descending; Distribution channels is used for ground supplement and transmits reception, and the Ku wave band is up, and the Ku wave band is descending, transfers S-band to by ground supplement forwarded device and sends to the CMMB terminal.For realizing effective covering of crowded city mobile multimedia broadcast television signal, adopt the emission of U wave band terrestrial wireless to make up U wave band ground, city overlay network.
In order to recover to received signal at receiving terminal, according to the CMMB standard, the CMMB system has inserted several redundant datas according to the distribution pattern of standard code in the frequency-region signal frame, and these redundant datas all are known for the transmitting-receiving two-end of CMMB system; Part redundant data is used for carrying out the processing such as signal Synchronization, channel response estimation of receiving terminal, and some comprises the transmission indication information, and these redundant datas are referred to as system signaling information, totally 16 bits, and transmission is 4 times in every frame data; Adopt BPSK (binary phase shift keying) modulation.These signaling informations can be used when receiving terminal carries out data demodulates, and receiving terminal need carry out demodulation to said signaling information.
How not only simple the but also signaling information that obtains high accuracy be the major issue that the CMMB system receiving terminal need solve.
Summary of the invention
The technical problem that the present invention will solve provides the signal demodulation method in a kind of CMMB system, can be simply and high accuracy demodulate signaling information; For this reason, the present invention also will provide a kind of signal demodulation device that is used for the CMMB receiving system of said method.
For solving the problems of the technologies described above, the signal demodulation method in the CMMB of the present invention system comprises the steps:
Step 1 uses receiving terminal estimated channel response results to carry out data precorrection to receiving data, eliminates channel response and is superimposed upon the property the taken advantage of interference that receives on the data;
Step 2 is extracted the signaling position that receives in the data, and adopts the hard decision mode to calculate the data bit that transmits signaling;
Step 3 is carried out statistical decision to the data bit of said transmission signaling, obtains the estimated value of the signaling information of current data frame;
Step 4 is carried out filtering to the estimated value of said signaling information, obtains system signaling information.
The signal demodulation device that is used for the CMMB receiving system of said method of the present invention comprises:
Data precorrection module is carried out precorrection to receiving data, eliminates channel response and is superimposed upon the property the taken advantage of interference that receives on the data, the sign bit bit that obtains after the output precorrection;
The signaling extraction module, the position output enable signal of signaling data in Frame;
The hard decision module is connected with the signaling extraction module with data precorrection module, under said enable signal control, the data of said data precorrection module output is carried out hard decision process;
The statistical decision module is connected with the hard decision module, and 4 hard decision results are added up, and obtains the estimated value of the signaling information of current data frame;
The finite state machine filter of four condition is connected with the statistical decision module, filters the burr in the estimated value of signaling information of said current data frame, and exports final system signaling information.
In the CMMB system, comprise some signaling informations in the transferring data frames, be used for the transmission of system transmissions indication information, receiving terminal need demodulate these information, is used for the demodulation of load data.The data preliminary treatment and the data statistics that the present invention is based on channel response are theoretical, have proposed a kind of the realization simply and the high signaling information demodulation method of demodulation accuracy, and the signal demodulation device that is used for the CMMB receiving system of said method.Adopt method and apparatus of the present invention can resist the interference in the transmission channel, the demodulation fault-tolerance is strong, and the complexity that realizes is low.
Description of drawings
Below in conjunction with accompanying drawing and embodiment the present invention is done further detailed explanation:
Fig. 1 is the CMMB receiving system structural representation that contains the signal demodulation device;
Fig. 2 is the structural representation of signal demodulation device.
Embodiment
Because signaling information inserts in the signal frame at frequency domain, the signal demodulation device is in after the FFT module in the CMMB receiving system.Fig. 1 is a CMMB receiving system theory diagram that meets the CMMB standard, and the radio frequency analog signal that receives at first gets into a demodulation module 100, produces a baseband complex signal after the data demodulates, comprises a real part and an imaginary part; Baseband complex signal gets into a FFT module 200 then, and will receive data is frequency domain from spatial transform; Frequency domain data after the conversion gets into descrambling module 300 and carries out the data de-scrambling computing; Data after the descrambling get into channel estimation module 400; The channel response of estimated signal in the Channel Transmission process; Meanwhile; Frequency domain data time-delay keep with channel response estimation result synchronously, frequency domain data and channel response estimation result get into signal demodulation device 500 afterwards, demodulate the use of command transmitting information confession CMMB system.
In conjunction with shown in Figure 2, said in one embodiment signal demodulation device 500 comprises: data precorrection module 510, signaling extraction module 520, hard decision module 530, statistical decision module 540, and the finite state machine filter 550 of four condition.
At first get into data precorrection module 510 from the data and the channel response estimation result of channel estimation module 400 outputs.It is to utilize channel response estimation result to eliminate the influence of the channel property taken advantage of interference in the data that traditional data is proofreaied and correct; Conjugation data with data and channel response estimation result during concrete the realization multiply each other; Again divided by the mould of channel response estimation result square, can obtain the data after channel estimating is proofreaied and correct.Because the signaling information in the CMMB system adopts the BPSK modulation, can carry out the BPSK demodulation if obtain the sign bit of the data after channel response is proofreaied and correct.Based on this analysis, in the present embodiment, data precorrection module 510 is utilized the sign bit of data and channel response estimation result, carries out XOR and handles, and just can obtain the sign bit of both multiplied result, and this sign bit bit output is got final product.Data precorrection module 510 in the present embodiment has been avoided the use of multiplier in the traditional data bearing calibration, the data precorrection that can be referred to as to weaken.
Carry out precorrection and can overcome that channel disturbance is for the interference of data in the transmission receiving data with channel response estimation result among the present invention, the said data hard decision process of the crippled mode of precorrection and back can be simplified the circuit implementation complexity.
Signaling extraction module 520, the position with all signaling informations is pre-stored in the ROM table in advance, provides enable signal through counter in corresponding position and is used to identify the signaling information position.The sign bit bit of this enable signal and 510 outputs of data precorrection module is sent into hard decision module 530 together.
Hard decision module 530 in the effective position of enable signal, is carried out hard decision process to the sign bit bit, accomplishes the BPSK demodulation, and with after 4 groups of hard decision result storages that obtain in each sign bit bit, sends into statistical decision module 540.
Statistical decision module 540; 4 groups of hard decision results to each sign bit bit add up; And with the bit result more than 50% in 4 groups of hard decision statisticses of each sign bit bit as the statistics of this signaling bit; Can obtain the signaling information estimated result of a string current data frame, this signaling information estimated result is sent into the finite state machine filter 550 of four condition.
The finite state machine filter 550 of four condition; When running into continuous two identical signaling information estimated results; Promptly get into lock-out state, and outgoing signaling information estimated result is as the signaling information of system, when running into continuous two different signaling information estimated results; Get into out-of-lock condition, from new search signaling information estimated result.The middle burr that produces can be filtered in the finite state machine filter 550 of four condition.Can obtain higher signal demodulation accuracy through data statistics and Filtering Processing.
Following table 1 is a signaling information location assignment table in the Frame.In signaling extraction module 520, can the position of signaling information in Frame be placed among the ROM, control circuit extracts the signaling information in the Frame in these positions.
Following table 2 is signalling information content resolution table, the signaling information of promptly said signal demodulation device 500 final outputs.
| Bit | B f＝8MHz | B f＝2MHz |
| 0 | 22、650、1860、2466 | 20 |
| 1 | 78、688、1916、2510 | 32 |
| 2 | 92、712、1948、2574 | 72 |
| 3 | 168、740、2008、2578 | 88 |
| 4 | 174、772、2062、2648 | 128 |
| 5 | 244、846、2094、2650 | 146 |
| 6 | 274、848、2124、2692 | 154 |
| 7 | 278、932、2132、2730 | 156 |
| 8 | 344、942、2142、2796 | 470 |
| 9 | 382、950、2226、2800 | 472 |
| 10 | 424、980、2228、2830 | 480 |
| 11 | 426、1012、2302、2900 | 498 |
| 12 | 496、1066、2334、2906 | 538 |
| 13 | 500、1126、2362、2982 | 554 |
| 14 | 564、1158、2386、2996 | 594 |
| 15 | 608、1214、2424、3052 | 606 |
Table 1
| Bit | Information |
| 0-5 | Timeslot number |
| 6 | The byte interleaver device sync id |
| 7 | The configuration change indication |
| 8～15 | Keep |
Table 2
More than through embodiment the present invention has been carried out detailed explanation, but these are not to be construed as limiting the invention.Under the situation that does not break away from the principle of the invention, those skilled in the art also can make many distortion and improvement, and these also should be regarded as protection scope of the present invention.
Claims (10)
1. the signal demodulation method in the CMMB system is characterized in that, comprises the steps:
Step 1 uses receiving terminal estimated channel response results to carry out data precorrection to receiving data, eliminates channel response and is superimposed upon the property the taken advantage of interference that receives on the data;
Step 2 is extracted the signaling position that receives in the data, and adopts the hard decision mode to calculate the data bit that transmits signaling;
Step 3 is carried out statistical decision to the data bit of said transmission signaling, obtains the estimated value of the signaling information of current data frame;
Step 4 is carried out filtering to the estimated value of said signaling information, obtains system signaling information.
2. the method for claim 1 is characterized in that: the described data precorrection of step 1 is that the sign bit that receives data and channel response result is carried out XOR.
3. the method for claim 1 is characterized in that: the signal frame body use multi-carrier modulation of said reception data.
4. method as claimed in claim 3 is characterized in that: described signal frame body is the multi-carrier signal frame symbol that meets the CMMB standard.
5. a signal demodulation device that is used for the CMMB receiving system of each said method of claim 1-4 is characterized in that, comprising:
Data precorrection module is carried out precorrection to receiving data, eliminates channel response and is superimposed upon the property the taken advantage of interference that receives on the data, the sign bit bit that obtains after the output precorrection;
The signaling extraction module, the position output enable signal of signaling data in Frame;
The hard decision module is connected with the signaling extraction module with data precorrection module, and under said enable signal control, the sign bit bit that said data precorrection module is exported carries out hard decision process;
The statistical decision module is connected with the hard decision module, and 4 hard decision results are added up, and obtains the estimated value of the signaling information of current data frame;
The finite state machine filter of four condition is connected with the statistical decision module, filters the burr in the estimated value of signaling information of said current data frame, and exports final system signaling information.
6. device as claimed in claim 5 is characterized in that: when said data precorrection module is carried out precorrection to receiving data, be that the sign bit that receives data and the sign bit of channel response estimation result are carried out XOR, and then obtain the sign bit bit.
7. device as claimed in claim 5 is characterized in that: said signaling extraction module is pre-stored in the position of all signaling informations among the ROM in advance, provides enable signal through counter in corresponding position and is used to identify the signaling information position.
8. device as claimed in claim 5; It is characterized in that: said hard decision module; In the effective position of enable signal, said sign bit bit is carried out hard decision process, accomplish binary phase shift keying BPSK demodulation; And, 4 groups of hard decision results are sent into the statistical decision module with after 4 groups of hard decision result storages that obtain in each sign bit bit.
9. device as claimed in claim 5; It is characterized in that: said statistical decision module; 4 groups of hard decision results to each sign bit bit add up; And with the bit result more than 50% in 4 groups of hard decision statisticses of each sign bit bit as the statistics of this signaling bit, can obtain the signaling information estimated result of a string current data frame.
10. device as claimed in claim 5; It is characterized in that: the finite state machine filter of said four condition when running into continuous two identical signaling information estimated results, promptly gets into lock-out state; And outgoing signaling information estimated result is as the signaling information of system; When running into continuous two different signaling information estimated results, get into out-of-lock condition, from new search signaling information estimated result.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011100454655A CN102651724A (en) | 2011-02-25 | 2011-02-25 | Signaling demodulation method and signaling demodulation device in China mobile multimedia broadcasting (CMMB) system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011100454655A CN102651724A (en) | 2011-02-25 | 2011-02-25 | Signaling demodulation method and signaling demodulation device in China mobile multimedia broadcasting (CMMB) system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN102651724A true CN102651724A (en) | 2012-08-29 |
Family
ID=46693619
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011100454655A Pending CN102651724A (en) | 2011-02-25 | 2011-02-25 | Signaling demodulation method and signaling demodulation device in China mobile multimedia broadcasting (CMMB) system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102651724A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103631161A (en) * | 2013-09-17 | 2014-03-12 | 北京理工大学 | Filtering method based on state machine |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101018269A (en) * | 2006-12-19 | 2007-08-15 | 北京创毅视讯科技有限公司 | Transmission and receiving method and end of the mobile digital multi-media broadcast physical layer signaling information |
| CN101562502A (en) * | 2009-06-04 | 2009-10-21 | 清华大学 | Physical-layer sub-channel allocation method, emission system and receiving system |
| CN101924721A (en) * | 2009-06-10 | 2010-12-22 | 清华大学 | Method for determining downlink multi-access system transmission mode, transmitting end device and receiving end device |
-
2011
- 2011-02-25 CN CN2011100454655A patent/CN102651724A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101018269A (en) * | 2006-12-19 | 2007-08-15 | 北京创毅视讯科技有限公司 | Transmission and receiving method and end of the mobile digital multi-media broadcast physical layer signaling information |
| CN101562502A (en) * | 2009-06-04 | 2009-10-21 | 清华大学 | Physical-layer sub-channel allocation method, emission system and receiving system |
| CN101924721A (en) * | 2009-06-10 | 2010-12-22 | 清华大学 | Method for determining downlink multi-access system transmission mode, transmitting end device and receiving end device |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103631161A (en) * | 2013-09-17 | 2014-03-12 | 北京理工大学 | Filtering method based on state machine |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110086742B (en) | Receiver and method for recovering payload data in a received signal | |
| Sun et al. | Overlay cognitive radio OFDM system for 4G cellular networks | |
| CA2927130C (en) | Wakeup message for a digital television system | |
| TWI535250B (en) | Transmitter and method of transmitting | |
| CA2914243C (en) | Transmitter and transmission method for transmitting payload data and emergency information | |
| EP3036847B1 (en) | System physical layer pipe for a digital television system | |
| CN101849365A (en) | Robust sensing for detecting signals using correlation | |
| JP2003514435A (en) | FM in-band on-channel digital audio broadcasting transmission / reception method and apparatus | |
| CN102142852B (en) | Method and equipment for transmitting digital-analog audio broadcasting | |
| CN102394714A (en) | Method and system for receiving digital broadcasting signals in frequency modulation (FM) broadcast bands | |
| CN105940626A (en) | Method and apparatus for receiving broadcast signal, and method and apparatus for transmitting broadcast signal | |
| US20200059895A1 (en) | Communications device, infrastructure equipment and methods | |
| TWI502900B (en) | Receiver and method of receiving | |
| CN102651724A (en) | Signaling demodulation method and signaling demodulation device in China mobile multimedia broadcasting (CMMB) system | |
| CN103095620B (en) | Sending, receiving method and the device of frequency modulation frequency band digital broadcast singal | |
| US11202113B2 (en) | Low adjacent channel interference mode for a digital television system | |
| CN202309690U (en) | Frequency modulation broadcast frequency range digital broadcast signal receiving system | |
| JP4459260B2 (en) | RELAY DEVICE, RECEPTION DEVICE, AND RADIO TRANSMISSION SYSTEM | |
| CN101360083B (en) | Transmission parameter signaling decoding system for digital terrestrial multimedia broadcast | |
| CN102761501A (en) | Method and device for evaluating signal-noise power in CMMB system | |
| CN101399974B (en) | Front end high definition audio and video interface device for interactive digital television and access method | |
| TWI680650B (en) | Transmitters, receivers and methods of transmitting and receiving | |
| WO2015026547A1 (en) | Low adjacent channel interference mode for a digital television system | |
| WO2013023595A1 (en) | Method and apparatus for frequency synchronization and receiving of digital audio broadcast signal | |
| KR20170037405A (en) | Transmitting apparatus and receiving apparatus and control method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20120829 |
|
| RJ01 | Rejection of invention patent application after publication |