CN101022440B - Compatiable DAB ground mobile multimedia broadcast receiving and transmitting method and system - Google Patents

Abstract

A method for receiving -transmitting ground mobile multimedia broadcast of compatible DAB includes receiving service data of multimedia broadcast, carrying out source and channel coding on service data, embedding coded data in main service channel MSC, identifying sub-channel information and carrying out channel coding on data in FIC channel, carrying out channel modulation and OFDM modulation as well as radio frequency modulation on data in FIC and MSC channels then sending modulated data out.

Description

The ground mobile multimedia broadcast receiving and transmitting method of Compatiable DAB and system

Technical field

The present invention relates to digital information transmission technical field, refer to ground mobile multimedia broadcast (T-MMB) receiving/transmission method and the system of a kind of compatible digital audio broadcasting (DAB, Digital Audio Broadcasting) especially.

Background technology

DMB is meant the multi-media broadcast broadcast mode that is used for handheld terminal, and paying close attention to many DMB standards in the industry at present is European standard DVB-H, the MediaFLO of the U.S. and Korea S standard T-DMB.

T-DMB, full name DMB (Digital Multimedia Broadcasting) grows up on the DAB basis.The DAB digital broadcasting is the association by 12 member compositions---famous EUREKA-147 develops, and the initial title of system is digital audio broadcasting (DAB), and is used as the standard of distinguishing real DAB broadcasting with other digital audio broadcasting always.1994, Eureka-147 was chosen to be the digital audio broadcasting international standard by International Organization for Standardization.Today, most of area, the world is not the digital broadcasting that has realized this standard, is exactly to test this standard.You Lika-147DAB the standard in Europe: in September, 1988, the European Community has carried out test You Lika-147DAB standard of You Lika-147DAB first in the nineteen ninety-five standardization on WARC, it is an a kind of typical DAB system, except Europe, also there is the development of certain degree some other countries and regions in the world, for example countries and regions such as Canada, Singapore, Australia.DAB (Digital Audio Broadcasting) compares with traditional AM/FM broadcasting system, DAB have save frequency spectrum resource, transmitting power low, contain much information, advantage such as tonequality is splendid, be to broadcast continue traditional amplitude modulation, third generation FM broadcasting after.Digital broadcasting has advantages such as antinoise, the decline of anti-interference, anti-radio wave propagation, suitable high-speed mobile reception, and it provides the stereo acoustic quality of CD level, and signal is zero distortion almost.

T-DMB is the ground digital multimedia broadcast system that Korea S releases, strictly speaking, and still European at last international standard.This standard is based upon on the basis of card 147 digital audio broadcastings (DAB) system in European manufacturer exploitation outstanding, has made some modifications, so that broadcast aerial digital television program to handheld devices such as mobile phone, PDA and mobile televisions.T-DMB steps into commercial stage in Korea S.Korea S is to the new licence of T-DMB broadcast operator granting.The same period, the mobile digital TV broadcast system DVB-H that Europe develops has just begun experiment work.

T-DMB has utilized the technical advantage (can at reliable reception signal under the high-speed mobile environment) of DAB fully, will transmit single audio-frequency information and expand to variety carrier such as data, literal, figure and video on function.T-DMB with digitlization audio frequency, vision signal and various data service signal, under digital state, compress, processing such as coding, modulation, transmission, can realize high-quality transmission,, have multimedia feature simultaneously concurrently, provide that capacity is big, efficient is high, the data message of good reliability transmits.From DAB to T-DMB, mean the leap from the digital audio broadcasting to the DMB, any digital information can be transmitted with a digitized plateform system, and this cover system can be enjoyed for the user provides the comprehensive audio-visual information service and the amusement that comprise audio frequency, video.

DVB-H standard full name is Digital Video Broadcasting Handheld, be that European DVB is organized in after the series standard of releasing digital television transfer, the transmission standard that provides multimedia service to formulate to the portable/handheld terminal by the received terrestrial digital broadcasting network is provided.

DVB-H is the standard that is based upon on DVB (data broadcasting) and two standards of DVB-T (transmission), is considered to the expanded application of DVB-T standard, though it is a transmission standard, in fact pays attention to agreement and realizes.System front end is made of DVB-H packaging machine and DVB-H modulator, and the DVB-H packaging machine is responsible for the IP data encapsulation is become the MPEG-2 system transport stream, and the DVB-H modulator is responsible for chnnel coding and modulation; System terminal is made of DVB-H demodulator and DVB-H terminal, and the DVB-H demodulator is responsible for channel demodulation, decoding, and the DVB-H terminal is responsible for related service and is shown, handles.

DVB-H possesses the part and the compatibility of DVB-T receiving circuit, simultaneously in order to satisfy the characteristic that handheld apparatus receives, requirement such as do not interrupt as low-power consumption, high mobility, common flat and network handed over service, can both normally watch in indoor, outdoor, walking or on the automobile in travelling guaranteeing, do many technological improvements.For improving the service time of battery, turn off to terminal periodic a part of receiving circuit to save power consumption; In order to satisfy portable demand, the antenna of DVB terminal is smaller and more exquisite, moves more flexible; Transmission system can guarantee to receive smoothly the DVB-H business under various rate travels; System has very strong antijamming capability, can provide enough flexibility to satisfy different transmission bandwidths and channel width application etc.

The MediaFLO technology is proposed by QAULCOMM, is a kind of novel air interface in essence.Receive design at mobile multicast fully: realize that fast channel switches receiver low energy consumption, abundant service content.Will be in a 6MHz channel, the modulating mode support is up to the robust data rate of 11Mbps.Gave prominence to fast channel average out to change-over time 1.5 seconds, and with it as one of trump that surmounts other competitive mobile TV standard.Adopt the TDM mode to send different programs, receiver extracts the destination service transmitting time from transmission frame head information, and begins constantly to accept at this.In the U.S., Qualcomm has bought 700MHz frequency (UHF TV Channel 55), can transmit the power up to 50kW.

And T-DMB, all there is the deficiency of different levels in three kinds of standards of DVB-H and MediaFLO: the T-DMB availability of frequency spectrum is low, T-DMB does not provide enough information throughput to satisfy the such high-quality service of mobile TV, and T-DMB does not provide enough power-saving measures for receiver; Because DVB-H inherits in DVB-T (fixedly receiving system), very limited at the space of mobile environment optimization on this basis, DVB-H fails to provide enough power-save mechanism for receiver, and some other performance index have been sacrificed, as increasing to 5 seconds switching time, in addition, available working frequency points is less; MediaFLO is an autonomous system, does not have a compatibility, is primarily aimed at the design of 700MHz frequency, does not have a generality.

Summary of the invention

In view of this, the invention provides a kind of ground mobile multimedia broadcast transmission method of Compatiable DAB, can be in mobile environment the efficient transmission of multimedia broadcast service data.

The present invention also provides a kind of ground mobile multimedia broadcast method of reseptance of Compatiable DAB, can be in mobile environment effective receiving multimedia broadcast business datum.

The present invention provides a kind of ground mobile multimedia broadcasting system of Compatiable DAB again, uses this system, can realize effectively transmitting and the receiving multimedia broadcast business datum in the mobile environment.

For achieving the above object, technical scheme of the present invention specifically is achieved in that

A kind of ground mobile multimedia broadcast transmission method of Compatiable DAB preestablishes the type of service of multimedia broadcasting, and described type of service comprises ground mobile multimedia broadcast T-MMB business, and this method comprises:

The receiving multimedia broadcast business datum according to its type of service, is carried out source encoding and chnnel coding successively to described business datum;

In the MSC MSC of data behind the coding with time-multiplexed mode embedded system, the multimedia broadcast business data of different service types, take the different subchannels among the described MSC, CU size in each subchannel is 32 * n, and wherein n is the Channel Modulation exponent number of the multimedia broadcast business data of subchannel corresponding service type;

Business datum corresponding service type, the subchannel information that takies, source encoding mode, channel coding method and channel modulation mode are carried out respective identification in the fast information channel in dab receiver FIC of system, and the data in the FIC channel are carried out chnnel coding; Wherein, for the T-MMB business datum, channel modulation mode adopts 8 differential phase-shift keying (DPSK) 8DPSK, 16 differential amplitudes and phase combining keying 16DAPSK or 64 differential amplitudes and phase combining keying 64DAPSK;

Transmission mode and described channel modulation mode according to determining carry out Channel Modulation to the data of FIC channel and MSC channel, and the data of the FIC channel after the Channel Modulation and MSC channel and synchronizing channel are carried out sending after OFDM modulation and the rf modulations.

Preferably, the business datum that receives is being carried out may further include between source encoding and the chnnel coding, the condition of carrying out successively of the data after the source encoding is being received scrambling and energy dissipation; And after chnnel coding, time division multiplexing takes a step forward and comprises, carries out time-interleaved to the data after the chnnel coding.

Preferably, when type of service is T-MMB when professional, described to business datum carry out chnnel coding can for, adopt cascaded code or low-density checksum LDPC sign indicating number that business datum is carried out chnnel coding.

Preferably, described with business datum corresponding service type, the subchannel information that takies, source encoding mode, channel coding method and channel modulation mode in the fast information channel in dab receiver FIC of system, carry out respective identification can for:

Set up the FIG of the FIC of T-MMB system channel based on the fast information group FIG of the FIC of DAB system channel, sign business datum corresponding service type, the subchannel information that takies, source encoding mode, channel coding method and channel modulation mode in the FIG of the FIC of T-MMB system channel.

Preferably, when type of service is T-MMB when professional, described in the FIG of the FIC of T-MMB system channel sign business datum corresponding service type can for: the DSCTy field in FIG type 0/ mode of extension 2 of the FIC of T-MMB system channel increases the type of service of T-MMB system and describes; User's application type User Application the type field in FIG type 0/ mode of extension 13 of the FIC of T-MMB system channel increases T-MMB user and uses description.

Preferably, when type of service is the T-MMB business, described in the FIG of the FIC of T-MMB system channel the subchannel information that takies of sign business datum can for: in the FIG of the FIC of T-MMB system channel, increase the subchannel identification field, be used for the subchannel of identification service data occupancy; In the FIG of the FIC of DAB system channel, increase the start address field, be used to identify the address of first CU of subchannel.

Preferably, when type of service is T-MMB when professional, described in the FIG of the FIC of T-MMB system channel the channel coding method of sign business datum and channel modulation mode can for:

In the FIG of the FIC of T-MMB system channel, increase type of coding CodingType field, be used to identify the channel coding method of T-MMB business;

In the FIG of the FIC of T-MMB system channel, increase sub-channel data region S ub-channelfield field, be used to identify the size of subchannel of T-MMB business and the protection level of the error correction coding that adopts;

In the FIG of the FIC of T-MMB system channel, increase modulation type ModuType field, be used to identify the channel modulation mode of T-MMB business.

Preferably, described definite transmission mode can for:

With reference to the corresponding relation of default channel modulation mode, transmission mode and working frequency points,, determine transmission mode according to the channel modulation mode that adopts and the working frequency points of system's appointment.

Preferably, when described channel modulation mode is m-DPSK or m-DAPSK,, then adopt transmission mode IV,, then adopt the transmission mode formula III if the working frequency points of T-MMB is L-Band if the working frequency points of T-MMB is BandIII; Described m is a kind of or combination in any in 16,32 or 64;

When described channel modulation mode is DQPSK, if the working frequency points of T-MMB is BandIII, then adopt transmission mode I, if the working frequency points of T-MMB is L-Band, then adopt transmission mode II.

A kind of ground mobile multimedia broadcast method of reseptance of Compatiable DAB, this method comprises:

Carry out radio demodulating, OFDM to the received signal and separate and be in harmonious proportion synchronously, obtain the data of FIC channel and MSC channel, and differentiate the transmission mode that adopts;

Data to described FIC channel are carried out channel demodulation and channel-decoding successively, according to the control information of FIC channel, and the business datum in the extraction MSC channel in the subchannel of corresponding service type; Wherein, the CU size in each subchannel is 32 * n, and n is the Channel Modulation exponent number of the multimedia broadcast business data of subchannel corresponding service type;

According to Channel Modulation, chnnel coding and the source encoding mode of all kinds of business datums that identify in transmission mode of differentiating and the FIC channel, the business datum after extracting is carried out channel demodulation, channel-decoding and source coding successively; Wherein, for the T-MMB business datum, channel modulation mode adopts 8 differential phase-shift keying (DPSK) 8DPSK, 16 differential amplitudes and phase combining keying 16DAPSK or 64 differential amplitudes and phase combining keying 64DAPSK.

Preferably, described discriminating transmission mode can for:

With reference to the default channel modulation mode and the corresponding relation of transmission mode and working frequency points, according to the channel modulation mode that adopts and the working frequency points of system's appointment, discriminating transmission mode.

A kind of ground mobile multimedia broadcasting system of Compatiable DAB, this system comprises: the network control center (NCC), transmitting station and receiver, wherein,

Described NCC is used for multimedia broadcast business data is sent to described transmitting station;

Described transmitting station, be used to receive multimedia broadcast business data from described NCC, according to its type of service, it is carried out source encoding and chnnel coding, in the MSC of data with time-multiplexed mode embedded system behind the coding, the multimedia broadcast business data of different service types takies the different subchannels among the described MSC, CU size in each subchannel is 32 * n, and wherein n is the Channel Modulation exponent number of the multimedia broadcast business data of subchannel corresponding service type; Business datum corresponding service type, the subchannel information that takies, source encoding mode, channel coding method and channel modulation mode are carried out respective identification in fast information channel in dab receiver FIC, and the data in the FIC channel are carried out chnnel coding; Wherein, for the T-MMB business datum, channel modulation mode adopts 8 differential phase-shift keying (DPSK) 8DPSK, 16 differential amplitudes and phase combining keying 16DAPSK or 64 differential amplitudes and phase combining keying 64DAPSK; Also be used for according to transmission mode and the described channel modulation mode determined, data to FIC channel and MSC channel are carried out Channel Modulation, and the data of the FIC channel after the Channel Modulation and MSC channel data and synchronizing channel are carried out being transmitted to intrasystem described receiver after OFDM modulation and the rf modulations;

Described receiver, be used for to the radiofrequency signal that the described transmitting station that receives sends carry out radio demodulating, OFDM separates and is in harmonious proportion synchronously; According to the control information of the FIC channel that obtains behind channel demodulation and the channel-decoding, the business datum in the subchannel of extraction corresponding service type is carried out channel demodulation, channel-decoding and source coding.

Preferably, described transmitting station comprises that receiver module, source encoding module, channel coding module, FIC data form module, channel multiplexing module and modulation and transmission module, wherein,

Described receiver module is used to receive the multimedia broadcast business data from described NCC, and business datum is transmitted to described source encoding module;

Described source encoding module is used for the type of service according to business datum, described receiver module is transmitted the signal that comes carry out source encoding, then the source encoding result is sent to described channel coding module;

Described channel coding module is used for the data that receive are carried out chnnel coding, and the result is sent to described channel multiplexing module;

Described FIC data form module, be used for business datum corresponding service type, the subchannel information that takies, source encoding mode, channel coding method and channel modulation mode are carried out respective identification at FIC, and the data in the FIC channel are carried out chnnel coding, coding result is sent to described channel multiplexing module;

Described channel multiplexing module, the business datum that receives is inserted in the MSC channel in time-multiplexed mode according to type of service, and MSC channel data and described FIC data are formed FIC coding result that module sends send to described modulation and transmission module after multiplexing;

Described modulation and transmission module, be used for according to transmission mode and the described channel modulation mode determined, the FIC channel that receives and the data of MSC channel are carried out Channel Modulation, and the data of the FIC channel after the Channel Modulation and MSC channel data and synchronizing channel are carried out sending to described receiver after OFDM modulation and the rf modulations.

Preferably, described transmitting station may further include condition and receives scrambler, energy dispnergy disperser and time-interleaved device, wherein,

Described source encoding module is used for that the source encoding result is sent to described condition and receives scrambler;

Described condition receives scrambler, is used for the data that receive are carried out sending to described energy dispnergy disperser after the condition reception scrambling;

Described energy dispnergy disperser is used for the data that receive are carried out sending to described channel coding module after the energy dissipation;

Described channel coding module is used for the result after the chnnel coding is sent to described time-interleaved device;

Described time-interleaved device is used for the data that receive are carried out sending to described channel multiplexing module after time-interleaved.

Preferably, described receiver can be a kind of or combination in any in DAB receiver, DAB-IP receiver, DMB T-DMB receiver and the T-MMB receiver.

Preferably, described T-MMB receiver can comprise receiving demodulation module, business datum extraction module, channel decoding module and source coding module, wherein,

Described receiving demodulation module, be used to receive the radiofrequency signal that described transmitting station sends, carry out radio demodulating, OFDM to the received signal and separate and be in harmonious proportion synchronously, obtain the data of FIC channel and MSC channel, send to described FIC data extraction module and described business datum extraction module respectively;

Described FIC data extraction module is used for the FIC channel data that receives is carried out channel demodulation and channel-decoding, and the control information of FIC is sent to described business datum extraction module, channel demodulation module, channel decoding module and source coding module;

The control information that provides according to FIC is provided described business datum extraction module, all kinds of business datums among the MSC is extracted, and send to described channel demodulation module;

Described channel demodulation module is used for the channel modulation mode of all kinds of business datums that identify according to the transmission mode of differentiating and FIC channel, the business datum that receives is carried out channel demodulation, and the data after the demodulation are sent to described channel decoding module;

Described channel decoding module is used for the channel coding method of the signal that identifies according to the FIC channel, the signal that receives is carried out corresponding channel-decoding, and the result is sent to described source coding module;

Described source coding module is used for carrying out source coding to the received signal according to type of service.

As seen from the above technical solution, the present invention is based on the DAB system, preestablish the type of service of the multimedia broadcasting that requires transmission, transmitting terminal in multimedia broadcast business data, after the original business datum of receiving multimedia broadcast, according to its type of service, this business datum is carried out information source and chnnel coding; Among the MSC of data after will encoding then, and the control informations such as subchannel of business datum correspondence are carried out respective identification in FIC, and the data in the FIC channel are carried out chnnel coding with time-multiplexed mode embedded system; Then the data after multiplexing carry out sending after Channel Modulation, OFDM modulation and the rf modulations to MSC and FIC.At receiving terminal, after the data that receive are carried out correspondingly radio demodulating, OFDM demodulation, obtain the FIC channel data, and it is carried out channel demodulation and channel-decoding, then according to the FIC channel control information of extracting, data on each Traffic Channel are carried out channel demodulation, channel and source coding, obtain original business datum.So by in FIC the employed subchannel of dissimilar business datums and its coded modulation scheme being identified, the system that makes can support the transmission of multiple multimedia broadcast business data.

Further,, can improve the band efficiency of system, and can provide stronger antijamming capability, be more suitable for the transmission of video frequency program for the data of transmission owing to can adopt chnnel coding modulation system efficiently.

In a word, this programme is based on the professional expansion of the DAB multimedia system of maturation, and the DAB system is exactly for hand-held mobile terminal designs, and proves reliable; This programme has overcome the low and professional single shortcoming of channel efficiency of existing DAB system, and is more suitable for the video frequency program transmission; Compare the mobile multimedia technology of other standard, the present invention has the frequency availability good; Simple synchronously, be easy to realize; Compatible good; The band efficiency height is supported portable and mobile reception; The receiver complexity is low, advantages such as easy realization.

Simultaneously, the present invention not only can be used for ground, and satellite and other transmission medium also can be used for data broadcasting, Internet and other wideband multimedia message transmission and integrated data business field.

Description of drawings

Fig. 1 is the overview flow chart of the T-MMB transmission method of Compatiable DAB of the present invention.

Fig. 2 is the overview flow chart of the T-MMB method of reseptance of Compatiable DAB of the present invention.

Fig. 3 is the overall construction drawing of the T-MMB system of Compatiable DAB of the present invention.

Fig. 4 is the theory diagram of T-MMB transmission method of the present invention.

Fig. 5 is the particular flow sheet of the T-MMB transmission method of Compatiable DAB in the embodiment of the invention.

RS external interleaver and the deinterleaver schematic diagram of Fig. 6 for adopting among the transmission method embodiment of the present invention.

Fig. 7 a is the frame structure of modulation system T-MMB system when being the LDPC sign indicating number for the 8DPSK channel coding method.

Fig. 7 b is the frame structure of modulation system T-MMB system when being RS+ convolution cascaded code for the 16DAPSK channel coding method.

Fig. 8 is the structure chart in the work organization district of the FIC information channel that adopts among the transmission method embodiment of the present invention.

The implication of each sign is as follows among Figure 10:

SId: task identifier.

Service Identifier description (task identifier description):

-Country Id: country identifier.

-Service reference: business reference.

-ECC: the country code of expansion.

Local flag: local flag.

CAId: condition inserts identifier.

Number of service components: professional one-tenth mark

Service component description (professional composition description):

-TMId: transmission mechanism identifier

-ASCTy: audio service component type

-SubChId: subchannel identifier

-P/S: main/secondary identity

-CA flag:CA mark

-DSCTy: DSCTy

-FIDCId: snap information data channel identifier

More than the particular content of each sign can be referring to DAB standard (ETSI EN300 401).

Fig. 9 is the structure chart of the new business subchannel of the FIC information channel that adopts among the transmission method embodiment of the present invention.

Figure 10 is the structure chart of user's application message of the FIC information channel that adopts among the transmission method embodiment of the present invention.

The 8PSK symbol constellation of Figure 11 for adopting among the transmission method embodiment of the present invention.

The 16APSK symbol constellation of Figure 12 for adopting among the transmission method embodiment of the present invention.

Figure 13 is the particular flow sheet of method of reseptance of the T-MMB of the Compatiable DAB in the embodiment of the invention.

Figure 14 is the concrete structure figure of the T-MMB system of Compatiable DAB in the embodiment of the invention.

Figure 15 is the concrete structure figure of the T-MMB transmission system transmitting station of Compatiable DAB in the embodiment of the invention.

Figure 16 is the concrete structure figure of the T-MMB receiver in the embodiment of the invention.

Embodiment

Core concept of the present invention is: the type of service that preestablishes the multimedia broadcasting that requires transmission, transmitting terminal in multimedia broadcast business data, after the original business datum of receiving multimedia broadcast,, this business datum is carried out information source and chnnel coding according to its type of service; Among the MSC of data after will encoding then, and the control informations such as subchannel of business datum correspondence are carried out respective identification in FIC, and the data in the FIC channel are carried out chnnel coding with time-multiplexed mode embedded system; Then the data after multiplexing carry out sending after Channel Modulation, OFDM modulation and the rf modulations to MSC and FIC.At receiving terminal, after the data that receive are carried out correspondingly radio demodulating, OFDM demodulation, obtain the FIC channel data, and it is carried out channel demodulation and channel-decoding, then according to the FIC channel control information of extracting, data on each Traffic Channel are carried out channel demodulation, channel and source coding, obtain original business datum.

The present invention is based on new multi-media transmission system and the method that original DAB system sets up, and in the present invention, channel constitutes identical with the DAB system, comprises FIC channel, MSC channel and synchronizing channel.Wherein, MSC channel bearing business datum, FIC channel bearing control data, synchronizing channel are used to realize signal Synchronization.

For making purpose of the present invention, technical scheme and advantage clearer, below with reference to the accompanying drawing preferred embodiment that develops simultaneously, the present invention is described in more detail.

Fig. 1 is the overview flow chart of the T-MMB transmission method of Compatiable DAB of the present invention.As shown in Figure 1, this method comprises:

Step 101 preestablishes the type of service of multimedia broadcasting, and described type of service comprises ground mobile multimedia broadcast T-MMB business.

Step 102, the receiving multimedia broadcast business datum according to its type of service, is carried out information source and chnnel coding successively to the business datum that receives.

Step 103, in the MSC MSC of data behind the coding with time-multiplexed mode embedded system, business datum corresponding service type, the subchannel information that takies and code modulation mode are carried out respective identification in fast information channel in dab receiver FIC, and the data in the FIC channel are carried out chnnel coding.

Step 104, according to transmission mode and the described channel modulation mode determined, data to FIC channel and MSC channel are carried out Channel Modulation, and the data of the FIC channel after the Channel Modulation and MSC channel data and synchronizing channel are carried out sending after OFDM modulation and the rf modulations.

Correspondingly, Fig. 2 is the overview flow chart of the T-MMB method of reseptance of Compatiable DAB of the present invention.As shown in Figure 2, this method comprises:

Step 201, the transmission data of receiving end/sending end are carried out radio demodulating, OFDM to it and are separated and be in harmonious proportion synchronously, obtain the data of FIC channel and MSC channel, and differentiate the transmission mode that adopts.

Step 202 is carried out channel demodulation and channel-decoding successively to the data of FIC channel, according to the control information of FIC channel, and the business datum in the extraction MSC channel in the subchannel of corresponding service type.

Step 203 according to Channel Modulation, chnnel coding and the source encoding mode of all kinds of business datums that identify in transmission mode of differentiating and the FIC channel, is carried out channel demodulation, channel-decoding and source coding successively to the business datum after extracting.

Fig. 3 is the overall construction drawing of the T-MMB system of Compatiable DAB of the present invention.As shown in Figure 3, this system comprises: the network control center (NCC) 310, transmitting station 320 and receiver 330.

In this system, NCC 310, are used for multimedia broadcast business data is sent to transmitting station 320.Multi-path digital multimedia broadcasting (program) signal that transmitting station 320 receives from NCC 320, according to its type of service, it is carried out source encoding and chnnel coding, in the MSC of data behind the coding with time-multiplexed mode embedded system, and this business datum corresponding service type, the subchannel information that takies, source encoding mode, channel coding method and channel modulation mode carried out respective identification in fast information channel in dab receiver FIC, and the data in the FIC channel are carried out chnnel coding; Also be used for according to transmission mode and the described channel modulation mode determined, data to FIC channel and MSC channel are carried out Channel Modulation, and the data of the FIC channel after the Channel Modulation and MSC channel data and synchronizing channel are carried out being transmitted to receiver 330 after OFDM modulation and the rf modulations.

Receiver 330 is used for that the radiofrequency signal that receives is carried out radio demodulating, OFDM and separates and be in harmonious proportion synchronously; According to the control information of the FIC channel that obtains behind channel demodulation and the channel-decoding, the business datum in the subchannel of extraction corresponding service type is carried out channel demodulation, channel-decoding and source coding.

The above-mentioned overview that is T-MMB transmission, method of reseptance and the system of Compatiable DAB of the present invention.Wherein, business datum is carried out before being multiplexed into the MSC channel is treated to source encoding and chnnel coding.In fact, in actual applications, also can as in the DAB system, between source encoding and chnnel coding, add the processing that optional condition receives scrambling and energy dissipation, after chnnel coding, increase time-interleaved processing, to adapt to the stronger channel circumstance of time variation better.

T-MMB is based on a kind of DMB mode of the professional expansion of digital audio broadcasting DAB multimedia system, it is melted into a whole state-of-the-art technology, take all factors into consideration the frequency resource, the receiver complexity, factor such as the availability of frequency spectrum and systematic function, overcome the existing problem of above-mentioned technology, to realize: good with the complete compatibility of DAB, low-cost design, low power dissipation design, frequency availability, support to move reception, single frequency network realization, spectral efficient, multi-service, high-quality service etc.It has following several characteristic:

(1) DAB-IP of complete compatible Eureka-147 (DAB), Britain and the T-DMB of Korea S.T-MMB has utilized the technical advantage (can at reliable reception signal under the high-speed mobile environment) of DAB fully, will transmit single audio-frequency information and expand to variety carrier such as data, literal, figure and video on function.

(2) overcome the lower shortcoming of DAB band system band efficient.

(3) the senior channel error correction coding LDPC sign indicating number and the DAPSK modulation scheme of high-efficient low-complexity have been adopted.

(4), have advantages such as complexity is low, power consumption is little, the frequency availability is good, compatibility is good than other standards such as DVB-H and MediaFLO.

The present invention utilizes the transmitter of existing DAB system, new multimedia service is embedded old DAB system with subchannel constitute new T-MMB system.Audio/video program or data, text, multimedia messagess such as picture process source encoding, transfer encoding, (old professional DAB signal is by traditional coded system for chnnel coding; New professional T-MMB signal is by new coded system) then launch by one or more transmitter, cover certain zone.The networking neatly of these transmitters both can have been formed multiple frequency network, MFN MFN (Multi-Frequency Network), also can form single frequency network SFN (Single Frequency Network).

Fig. 4 is the theory diagram of T-MMB transmission method of the present invention.As shown in Figure 4, T-MMB system signal structure is by compression layer, and transport layer and physical layer three parts are formed.Transmitting of T-MMB system can be synthetic by four road signals: the DAB signal, and the DAB-IP signal, T-DMB signal and T-MMB signal, wherein T-MMB, T-DMB and DAB-IP signal are with the professional DAB system that embeds independently.The main difference of four road signals is physical layer.

From the another one angle analysis, the transmitting terminal baseband signal of T-MMB system can be divided into the information source compressed encoding, code stream multiple connection, channel error correction coding, parts such as Channel Modulation.The code stream multiple connection belongs to transport layer, mainly according to MPEG-2 system layer standard the multichannel elementary stream is carried out multiple connection, audio code stream, video code flow, multiple a plurality of code streams such as data code flow are combined into a transmission code stream, and its transmission package length is fixed, so that the transmission of channel.DAB and T-DMB signal transport layer structure remain unchanged, T-MMB signal transport layer structure is different with traditional DAB system, adopted different error correction codings and modulation technique scheme, purpose is in order to improve spectrum efficiency and error-correcting performance, to make the T-MMB system be fit to the transmission of video program.In addition, FIC information channel transport layer structure remains unchanged equally.By above-mentioned transport layer structure, digital code stream is become data symbol insert synchronizing channel simultaneously, form the radio-frequency modulator that baseband signal is sent into the DAB transmitter through the ofdm signal generator, its radio frequency bandwidth is identical with the radio frequency bandwidth of DAB.

The transport layer that focuses on of the present invention.For the existing DAB of compatibility system, the present invention has kept the transmission structure of DAB system, the T-MMB system has only carried out modification and the frame structure of system transmissions to the transport layer structure of the newly-increased subservice channel of DAB system, multiplex mode, interleaving mode, FIC structure, synchronizing channel, the ofdm signal generator architecture, aspects such as transmitter all remain unchanged.More precisely, the T-MMB system extension support of DAB system to new chnnel coding and modulation technique, make that the T-MMB system can the transmission of video program.At the present invention is based on the part that the DAB system increases newly, introduce ins and outs involved among the present invention, and the part identical with DAB introduced no longer in the T-MMB system below.

The embodiment of the invention is an example with the business data transmission of carrying out four types of DAB, DAB-IP, T-DMB and T-MMB, illustrates among the present invention the receiving/transmission method of multimedia broadcast business data and the embodiment of system.

Embodiment:

Fig. 5 is the particular flow sheet of the T-MMB transmission method of Compatiable DAB in the embodiment of the invention.In the present embodiment, before business datum is multiplexed into the MSC main channel, carries out source encoding, condition successively and receive scrambling, energy dissipation, chnnel coding and time-interleaved, be consistent with the processing procedure of DAB system.As shown in Figure 5, this method specifically comprises:

Step 501 preestablishes the type of service of multimedia broadcasting, and described type of service comprises ground mobile multimedia broadcast T-MMB business.

In this step, the type of service that setting will be transmitted comprises the business datum of four types of DAB, DAB-IP, T-DMB and T-MMB.

Step 502, the receiving multimedia broadcast business datum according to its type of service, is carried out source encoding, condition reception scrambling and energy dissipation to the business datum that receives.

Source encoding is exactly aforesaid compression layer, comprises the compressed encoding of sound and image.In this step, at present mainly can be according to the MPEG1 of ISO/IEC, MPEG2, MPEG4, series standards such as AVS carry out the information source compression for the data of four kinds of types of service, along with the development of technology, can also adopt other new compression algorithm, wavelet coding for example, fractal image etc.After finishing the information source compression, form corresponding data flow or packet.The condition of carrying out then receives scrambling and energy dissipation, and its process promptly adopts the mode in the DAB system to carry out.Certainly, because condition reception scrambling is an optionally operation in the DAB system, therefore also can not carry out the processing that this condition receives scrambling here.

Step 503 is according to type of service, to carrying out chnnel coding and time-interleaved through the business datum after the energy dissipation.

In this step,, can adopt EN 300 401[1 of DAB system for DAB business datum and DAB-IP business datum] definition audio frequency (program) and the channel coding method of data service.But, though since in the MSC stream mode error protection method can guarantee the performance of audio service, the data service for adopting stream mode to transmit such as video traffic, but can not guarantee its performance.Therefore, in the present embodiment, regulation adopts stronger error correction coding scheme for the T-MMB signal, and concrete chnnel coding can be RS+ convolution cascaded code or LDPC sign indicating number.

A.RS+ convolution cascaded code

In order to make transmitting and receiving device that common characteristic as much as possible be arranged, outer coding directly uses the standard of DVB-T EN 300 744, and suitable error protection is provided.

In the present embodiment, provide a kind of extra outer coding (RS coding) and interweave (convolutional interleave) to handle outward.This handle in the MPEG-2 transmission multiplexing and DAB subchannel stream multiplexing between.

Definition is consistent among this process and the EN 300 744.

The error protection of DAB subchannel data streams and 188 byte transmission package:

1) rule

The transmission package length of each input is 188 bytes, and start byte is a sync byte, is worth to be 0x47.Transmission package can comprise arbitrary data.The details of more transport packet format can be with reference to ISO/IEC13818.

2) outer coding

Outer coding and the transmission package that is used to import of interweaving outward are as shown in table 1.

Sync byte 0x47

Mpeg

2 transport stream data (187 byte)

Table 1

(204,188, t=8) (255,239, t=8) coding is used for each transmission package (188 byte) to the brachymemma coding source to RS, produces the bag of an error protection from the RS of system.The protection range of RS coding comprises sync byte (0x47).In the present embodiment, setting the RS code length is 204 bytes, and message segment 188 bytes can be corrected in 204 bytes that receive any 8 bytes with interior mistake.

The sign indicating number generator polynomial is: g (x)=(x+ λ ⁰) (x+ λ ¹) (x+ λ ²) ... (x+ λ ¹⁵), λ=2 wherein.

The territory generator polynomial is: p (x)=x ⁸+ x ⁴+ x ³+ x ²+ 1.

Brachymemma RS coding can add 0 of 51 bytes at the front end of 188 information bytes, import then RS (255,239, t=8) encoder.Through abandoning 51 bytes 0 of interpolation behind the RS coding again, obtain the RS coding of N=204, as shown in table 2.

Sync byte 0x47

Mpeg

2 transport stream data (187 byte)

Check word (16 byte)

Table 2

3) outer interweaving

The outer of byte interweaves based on the method for Forney, interleave depth I=12, as shown in Figure 6.According to method shown in Figure 6, the convolutional deinterleaver of interleave depth I=12 is used for the bag of wrong protection.

The convolutional interleave process is based on the method for Forney, with the method compatibility of Ramsey type-iii, I=12.Interleaver has the branch of I=12, equals inlet flow by the input switch cycle and connects.Each branch j is the shift register of a first-in first-out (FIFO), and width is jM unit, M=17=N/I, N=204.Each cell fifo comprises a byte, and the input and output switch needs synchronously.For synchronously, sync byte (0x47) must pass through the branch " 0 " (corresponding not delay) of interleaver all the time.

Deinterleaver is similar with the principle of interleaver, but branch's pointer opposite (being the corresponding maximum time-delay of j=0).The sync byte that can make identification at first synchronously of deinterleaving is realized through branch " 0 ".

The b.LDPC coding

The similar forward error correction function that provides of LDPC sign indicating number and convolution code, but LDPC sign indicating number error-correcting performance is more powerful, the information that is more suitable for abominable channel is propagated, under the high s/n ratio several times iterative decoding just restrain.Therefore more power saving of receiver under the same terms.The LDPC sign indicating number of appropriate design has very low error floor, does not need the outer sign indicating number of cascade this moment.

The LDPC sign indicating number error protection, different business absolute coding such as provides to identical services in the embodiment of the invention.Forward error correction coding adopts the LDPC sign indicating number with accurate loop structure, and the available shift register of quasi-cyclic LDPC sign indicating number is encoded and is convenient to storage.

The check matrix H of quasi-cyclic LDPC code can be expressed as form:

A wherein _{I, j}Be that a row (row) weight is ω _{I, j}The circular matrix of t * t dimension, and ω _{I, j}＜＜t.The code word that is characterized by matrix H is called that (wherein N=c * t is a code length for N, K) LDPC sign indicating number, the length of K=(c-ρ) * t presentation code information bit.A _i=[A _{I, 1}, A _{I, 2}, A _{I, c}], i=1,2 ..., first row of ρ is called i the capable maker of H, then total ρ the capable maker of H.

The generator matrix G of check matrix H correspondence can be expressed as: G=[I|P], wherein I is a unit matrix, accurate circular matrix P can followingly represent:

P _j=[P _{1, j}, P _{2, j}... P _{C-ρ, j}] ^T, j=1,2 ..., first row of ρ are called j the column-generation device of generator matrix G, then total ρ the capable maker of G.

Cataloged procedure is as follows: at first fill b 0 after source bits, obtain the coded information bits that length is K, carry out the LDPC coding then.The LDPC sign indicating number of different code checks, 0 the number of filling is different.Table 3 has provided the coding parameter of two kinds of code rate LDPC codes.

N?	K?	b?	t?	ω i，j
					4608?	2304?	0?	72?	0 or 1
4608?	3096?	24?	72?	0 or 1

Table 3

Adopt above-mentioned suitable channel coding schemes that the T-MMB business datum is carried out chnnel coding as required, thereby obtain the better resisting interference performance.

For adapting to the stronger channel circumstance of time variation better, can be time-interleaved to carrying out through the business datum after the chnnel coding, this also is that the DAB system is suitable for moving an assurance greatly that receives.In the present embodiment, also adopt the time-interleaved mode identical, carry out time-interleaved the data after the chnnel coding with the DAB system.

Step 504 embeds the business datum after time-interleaved among the MSC MSC of DAB system in time-multiplexed mode.

In the present embodiment, the system transmissions frame adopts the form identical with the DAB transmission frame.Its MSC is made up of public interleaving frame (CIF).The lowest address unit of a CIF is capacity unit (CU).Each CIF is made up of 864 CU.The size of CU is a 32 * n bit.The value of n has three kinds, respectively corresponding three kinds of different differential modulation modes: n=2 (DQPSK), n=3 (8DPSK) and n=4 (16DAPSK).With transmission mode I, the T-MMB business is an example when transmitting with stream mode: when modulation system is 8DPSK, when channel coding method was the LDPC sign indicating number, the frame structure of T-MMB system was shown in Fig. 7 a; When modulation system is 16DAPSK, when channel coding method was RS+ convolution cascaded code, the frame structure of T-MMB system was shown in Fig. 7 b.

Certainly, in actual applications, can also adopt the more channel modulation mode of high-order, as 32DAPSK (n=5), 64DAPSK (n=6) etc.

As seen from Figure 7, the transmission method in the present embodiment has kept the frame structure of DAB system, and the CU size of DAB, DAB-IP and T-DMB signal correspondence is constant, and the CU size of T-MMB signal correspondence becomes with modulation system, but the CU number that CIF comprises is constant.System frame structure in the present embodiment can make Added Business support multiple modulation system.

Above-mentioned Fig. 7 is to be transmitted as the frame structure of example explanation with stream mode when the T-MMB business.In fact, method of the present invention can also support the T-MMB business to transmit with pack mode.When the T-MMB business is transmitted with pack mode, formation and Fig. 7 of frame structure are similar, just want earlier pack mode by DAB to break into subsequent treatment such as carrying out chnnel coding behind the packet of length-specific again, if encode again after also needing data pack buffer with length-specific to become the LDPC code length with the LDPC coding.

Step 505 is carried out respective identification with four kinds of business datum corresponding service types, the subchannel information that takies and code modulation modes, and the data of FIC channel is carried out chnnel coding in fast information channel in dab receiver FIC.

In the present embodiment, for can reaching the purpose of multiple business data multiplex transmission, with the type of service of miscellaneous service data, shared subchannel information and the code modulation mode of business datum carry out respective identification when embedding among the MSC in FIC.Be specially: set up the FIG of the FIC of T-MMB system channel based on the fast information group (FIG) of the FIC of DAB system Channel Transmission, sign business datum corresponding service type, the subchannel information that takies, source encoding mode, channel coding method and channel modulation mode in the FIG of the FIC of T-MMB system channel.

A. type of service is described

FIG type 0/ mode of extension 2 (0/2) that transmits in the FIC channel has defined among the DAB business information as shown in Figure 8.This definition can be specifically with reference to ETSI EN300401.In the present embodiment, the partial content of FIG0/2 is expanded, specific as follows:

-ASCTy (audio service component type): the type of the professional composition of this 6 bit regions indicative audio.Increased the sign of two kinds of audio coding modes in the present embodiment,

000011：MPEG-4HE?AAC?V2

000100：MPEG-4?ER-BSAC

-DSCTy (DSCTy): the type of the professional composition of this 6 bit designation data.This part specific explanations is seen TS 101 756[2], the definition of table 2.Increased a kind of new business type identification in the present embodiment,

011101：T-MMB?Service。

By indicate the subchannel information and the coded modulation scheme of all kinds of business at the FIG 0/15 that reserves (ETSI EN 300 401[1]).Specifically as shown in Figure 9.

SubChId (subchannel identifier): this 6 bit regions is encoded to signless binary number, is used to refer to certain subchannel.

Start Address (start address): this 10 bit regions is encoded to signless binary number (scope 0 to 863), the address of pointing out first capacity unit (CU) in the subchannel.

ModuType (modulation type): this 2 bit labeling is used to refer to and is the DQPSK/8DPSK/16DAPSK modulation, and is as follows:

00：DQPSK；

01：8DPSK；

10：16DAPSK；

11: keep.

CodingType (type of coding): this 1 bit is used to refer to channel coding method, and is as follows:

The 0:RS concatenated convolutional coding;

The 1:LDPC coding.

Rfu: this 1 bit is that interpolation in the future keeps.Before definition, be made as 0.

Sub-channel field (sub-channel data zone): this 12 bit has been indicated the size and the chnnel coding code check of subchannel.

-PL (protection class): this 2 bit has been indicated the chnnel coding code check, and is as follows:

00: protection level 1-C, expression chnnel coding code check is 1/2;

01: protection level 2-C, expression chnnel coding code check is 2/3;

Other be that in the future use keeps.

-Sub-channel Size (sub-channel size): this 10 bit regions is encoded to signless binary number (scope 1 to 864), has provided the capacity unit number that the subchannel that draws according to modulation system and protection level takies, and sees Table 4 and 5.Wherein, table 4 is the subchannel data size of 1-C, data rate different modulating mode when being 24n Kbit/s (n is the integer more than or equal to 1) for protection level; Table 7 is the subchannel data size of 2-C, data rate different modulating mode when being 32n Kbit/s (n is the integer more than or equal to 1) for protection level.

Modulation system	DQPSK?	8DPSK?	16DAPSK?
				Sub-channel size (CUs)	18n?	12n?	9n?

Table 4

Modulation system	DQPSK?	8DPSK?	16DAPSK?
				Sub-channel size (CUs)	18n?	12n?	9n?

Table 5

B. user profile is described

Defined user's application message among the FIG0/13 (ETSI EN 300 401[1]).On this pattern, expanded partial content in the present embodiment, specifically as shown in figure 10.

User Application Type (user's application type): this 11 bit has provided needs the user of decoding to use, and these application are identified by professional label (SId) and professional composition label (SCId), and it defines with reference to TS 101 756[2] table 16.In the present embodiment this option is expanded, specific as follows:

0x00b：T-MMB?service

User Application data (user's application data): this m * 8 Bit datas are used for transmission user application message data, are determined by user's application type during decoding.At the new business of T-MMB system, need to use the service attribute-VideoServiceObjectProfiled that byte is explained the T-MMB system.

T-MMB Video service framework 1, framework 2 can be identified by VideoServiceObjectProfileId=0x01, VideoServiceObjectProfileId=0x02 respectively.

Identical in process when the FIC channel data is carried out chnnel coding and the DAB system, just repeat no more here.

Step 506, according to transmission mode and the described channel modulation mode determined, data to FIC channel, MSC channel are carried out Channel Modulation, and the data of the FIC channel after the Channel Modulation and MSC channel data and synchronizing channel are carried out sending after OFDM modulation and the rf modulations.

In the present embodiment, stipulate a transmission frame by synchronizing channel (Sync), fast information channel in dab receiver (FIC) and MSC (MSC) constitute.Its essential structure is identical with the DAB system, just repeats no more here.

In the present embodiment, for the each several part technical description is clear, special modulation with the OFDM subcarrier is called Channel Modulation, and process OFDM is multiplexing and that symbol forms is called the OFDM modulation.Rf modulations after the OFDM modulation then is with the working frequency points of OFDM symbol-modulated to appointment.In fact, because the Channel Modulation that each channel data is carried out is actually the modulation that the OFDM subcarrier is carried out, therefore above-mentioned Channel Modulation and OFDM modulation dual mode can be referred to as the OFDM modulation.

Channel modulation mode in the original DAB system is 4 differential phase-shift keying (DPSK)s (DQPSK).Because digital of digital video data has higher code check, if the Channel Modulation scheme of the original DAB of employing system then can be brought the low defective of band efficiency.For overcoming this defective, in the present embodiment, on the DAB system-based, increased: 8 differential phase-shift keying (DPSK)s (8DPSK) and 16 differential amplitudes and phase combining keying (16DAPSK) two kinds of new modulation system supports.These several channel modulation modes all are at first to carry out sign map, carry out differential modulation then.

Two kinds of modulation schemes that following mask body introduction is newly-increased.At first introduce sign map:

1) 8 phase-shift keyings (8PSK)

The 8PSK constellation as shown in figure 11.To each OFDM symbol, the vector (p of 3K-bit _{L, n}) _N=0 ^3K-1(p wherein _{L, n}Referring to ETSI EN 300 401[1] the 14.4.2 joint) need be mapped to K 8PSK symbol in the following manner:

${\mathrm{<figure-callout\; id="1"\; label="q"\; filenames="H061G0929620061207E000051.png,H061G0929620061207E000061.png"\; state="\{\{state\}\}">q</figure-callout>}}_{1,m}=e^{{\mathrm{j\&Phi;}}_{l,m}},m=\mathrm{0,1,2},...,K-1$

Wherein K is a sub-carrier number, Φ _{L, m}As shown in table 6.

Φ l，m	p l，3m?p l，3m+1?p l，3m+2
		0?	0?0?1?
π/4?	0?0?0?
		π/2?	1?0?0?

3π/4?	1?1?0?
		π?	0?1?0?
5π/4?	0?1?1?
		3π/2?	1?1?1?
7π/4?	1?0?1?

Table 6

2) 16 amplitudes and phase combining keying (16APSK)

The 16APSK constellation as shown in figure 12.To each OFDM symbol, the vector (p of 4K-bit _{L, n}) _N=0 ^4K-1Be mapped to K 16APSK symbol in the following manner:

$q_{l,m}=A_{l,n}{e}^{j{\mathrm{\&Phi;}}_{l,m}},m=\mathrm{0,1,2},...,K-1$

Φ wherein _{L, m}It is as shown in table 3, $A_{l,m}={\mathrm{\&alpha;}}^{p_{l,4m}}$ 。

Φ l，m	p l，4m+1?p l，4m+2?p l，4m+3
		0?	0?0?1?
π/4?	0?0?0?
		π/2?	1?0?0?
3π/4?	1?1?0?
		π?	0?1?0?
5π/4?	0?1?1?
		3π/2?	1?1?1?
7π/4?	1?0?1?

Table 7

Next, introduce differential modulation:

1)8DPSK

Differential modulation is carried out (being the time domain difference) on the same subcarrier of two adjacent OFDM symbols, by as shown in the formula carrying out:

z _l，k＝z _l-1，k·y _l，k，l＝2，3，4，...，L，

-K/2≤k≤K/2

Z wherein _{L-1, k}The differential modulation signal of representing k subcarrier of l-1 OFDM symbol, y _{L, k}The mapping signal of k subcarrier of l OFDM symbol behind the expression frequency-domain-interleaving.

2)16DAPSK

DAPSK is the differential amplitude modulation scheme that combines with phase place.Its amplitude and phase place are independently carried out differential modulation respectively.The amplitude of 16DAPSK is modulated by 2DASK, and phase place is modulated by 8DPSK.

Differential modulation is carried out on the identical subcarrier of two adjacent OFDM symbols, and formula is as follows:

$z_{l-1,k}=R_L\&CenterDot;{\mathrm{\&alpha;}}^{p_{l-\mathrm{1,4}k}^{\&prime;}}\&CenterDot;e^{j{\mathrm{\&Phi;}}_{l-1,k}^{\&prime;}}$

$y_{l,k}={\mathrm{\&alpha;}}^{p_{l,4k}^{\&prime;}}\&CenterDot;e^{j{\mathrm{\&Phi;}}_{l,k}^{\&prime;}}$

$z_{l,k}=R_L\&CenterDot;{\mathrm{\&alpha;}}^{(p_{l-1.4k}^{\&prime;}+p_{l,4k}^{\&prime;})\mathrm{<figure-callout\; id="2"\; label="mod"\; filenames="H061G0929620061207E000061.png,H061G0929620061207E000072.png"\; state="\{\{state\}\}">mod</figure-callout>}2}\&CenterDot;e^{j({\mathrm{\&Phi;}}_{l-1,k}^{\&prime;}+{\mathrm{\&Phi;}}_{l,k}^{\&prime;})},l=\mathrm{2,3,4},...,L,$

$-K/2\&le;k\&le;K/2$

R wherein _LThe interior ring amplitude of expression 16DAPSK; p _L-1,4k', p _{L, 4k}Amplitude mapped bits behind the ' expression frequency-domain-interleaving in the corresponding symbol; Φ _{L-1, k}', Φ _{L, k}Phase information behind the ' expression frequency-domain-interleaving.

Above-mentionedly be two kinds of newly-increased channel modulation modes.According to the residing different channels of various data, can adopt different channel modulation modes.In the present embodiment, still adopt the mode of the DQPSK in the DAB system to carry out Channel Modulation to the data of FIC channel, the data of synchronizing channel also with the DAB system in identical, be used for carrying out differential modulation with FIC channel, MSC channel data.Also adopt the mode of original DQPSK in the DAB system to carry out Channel Modulation to the DAB in the MSC Traffic Channel and DAB-IP, T-MMB data.And the T-MMB signal in the MSC Traffic Channel can adopt suitable original or newly-increased Channel Modulation scheme as required.

Because Channel Modulation comes down to modulation that the OFDM subcarrier is carried out, therefore before Channel Modulation, at first to carry out deblocking, then according to different channel modulation modes, data to different channels are carried out sign map, after the result of sign map carries out frequency interlacing, insert the phase reference symbol of synchronizing channel again, the result carries out differential modulation with frequency interlacing, has promptly finished whole Channel Modulation process.

Data on the subcarrier are carried out piecemeal, need carry out according to different transmission modes.So-called transmission mode is meant, in original DAB system, when carrying out the OFDM modulation, to number of sub carrier wave, parameters such as protection gap length and wave band make up, and have formed four kinds of patterns and have selected for the user.Table 8 has provided four kinds of pattern corresponding parameters.

The parameter of table 8 DAB pattern

Parameter	Transmission mode I	Transmission mode II	The transmission mode formula III	Transmission mode IV
					S?	76?	76?	153?	76?
K?	1536?	384?	192?	768?
					N?	2048?	512?	256?	1024?
T s	～1246?	～312?	～156?	～623?
					T u	1000?	250?	125?	500?
T G	～246?	～62?	～31?	～123?
					T F	96?	24?	24?	48?

[0254]Annotate: the symbol description in the table 8

S: OFDM symbol numbers in each transmission frame (not comprising null symbol)

K: an OFDM symbol sub-carriers number

N:FFT size (point)

T _s: the duration (μ s) that the OFDM symbol is total

T _u: the duration (μ s) of useful signal in OFDM symbol

T _G: protection is (μ s) at interval

T _F: each transmission frame duration (ms)

DAB supports various wave bands in theory, and table 9 has provided the wave band that the various patterns permissions of DAB are used, and table 10 has provided the frequency range of various wave bands.

Table 9DAB pattern allows the wave band of use

Transmission mode	Allow the wave band of use in the DAB standard
		Transmission mode I	Band?I、Band?II、Band?III?
Transmission mode II	Band?I、Band?II、Band?III、Band?IV、Band?V、L-Band?
		The transmission mode formula III	＜3GHz?
Transmission mode IV	Band?I、Band?II、Band?III、Band?IV、Band?V、L-Band?

Table 10 wavelength band

Wave band	Frequency range (MHz)
		Band?I?	47-86?
Band?II?	87.5-108?
		Band?III?	174-230?
Band?IV/V?	470-790?
		L-Band?	1452-1492?

At present, DAB working frequency points Band III and L-Band, most of area has obtained distributing in the world, and especially in Europe, DAB infrastructure has accounted for 80%, and table 11 has provided various patterns of DAB and the actual operating position of wave band.What various modes was commonly used just has two kinds in fact, corresponding respectively Band-III and L-Band.What be worth emphasizing is that this correspondence is to be to be optimum under the DQPSK situation in modulation system, and when the T-MMB system had adopted the modulation scheme of high-order, as 16DAPSK, the present pattern and the corresponding relation of working frequency points were not optimum.Therefore, need reselect pattern.

The actual operating position of table 11

Wave band	The actual wave band that uses in the DAB system	Actual corresponding transmission mode in the DAB system	The transmission mode of recommending in the T-MMB system
				Band?I?	Not	Not	Not
Band?II?	Not	Not	Not
				Band?III?	Be	Transmission mode I	Transmission mode IV
Band?IV?	Not	Not	Not
				L-Band?	Be	Transmission mode II	The transmission mode formula III

Because the T-MMB system adopted more high-order modulating, the time influence of disturbing that becomes dry can not ignore.The factor of disturbing that becomes dry when influencing has: translational speed, carrier frequency point, the block length of OFDM symbol.To become dry in order resisting and to disturb, the T-MMB system is to carrier number, the protection gap length, and the parameters such as number of service band and modulation constellation reconfigure.By reducing the block length of OFDM symbol, become dry during opposing and disturb.For the Compatiable DAB system, T-MMB reduces the block length of OFDM symbol by adjusting the pairing pattern of wave band of the actual use of DAB.By revising, T-MMB systems support high effect low complex degree 16DAPSK modulation system supports high-speed mobile to receive simultaneously.Table 11 has provided the pattern and the corresponding wave band of T-MMB system recommendations, compares DAB, DAB-IP and T-DMB system, and the carrier number of OFDM symbol has reduced half.

In the present embodiment, can in advance the transmission mode of channel modulation mode, employing and the corresponding relation of working frequency points be set, as, when channel modulation mode adopts DQPSK, can adopt the corresponding relation of original transmission mode and working frequency points; Channel coding method when channel modulation mode employing more efficient during as 16QAPSK, can adopt the corresponding relation of transmission mode shown in the table 11 and working frequency points.

Before carrying out Channel Modulation, be about to the channel modulation mode of employing and the working frequency points of system according to each channel data, determine transmission mode with reference to default corresponding relation, and then the size of specified data piece, and in view of the above the data of different channels are carried out piecemeal.Then, the channel modulation mode according to the setting of parameters in the transmission mode and each channel needs adopt carries out Channel Modulation, OFDM modulation to each channel data, at last the OFDM symbol-modulated is launched on the working frequency points of appointment.

So far, the T-MMB transmission method flow process of the Compatiable DAB in the present embodiment finishes.By above-mentioned flow process as can be seen, transmission method of the present invention can transmit the multiple business data that comprise DAB, DAB-IP, T-DMB and T-MMB simultaneously, and on the basis of original DAB system, chnnel coding and modulation scheme have been expanded, make it can support coded modulation scheme more efficiently, increase the channel modulation mode of 8DPSK and 16DAPSK in the present embodiment, can certainly adopt modulation system such as 64DAPSK more efficiently.The application of multiple high efficient coding modulation scheme makes the system of present embodiment be more suitable for transmitting video data.Further, when adopting the efficient channel modulation system, present embodiment has carried out correspondingly revising to the frequency and the transmission mode of practical application, to adapt to the modulation system of high-efficient low-complexity better.

In above-mentioned transmission method, the process of source encoding and chnnel coding and embedding MSC channel that business datum is carried out is carried out before FIC channel logo coded modulation scheme and subchannel information, also is step 502～504th, carries out before step 505.In fact, after determining coded modulation scheme, the process of carrying out source encoding and chnnel coding and embedding the MSC channel can be carried out simultaneously with the operation of FIC channel logo coded modulation scheme and subchannel information, or be carried out with reverse order.

Corresponding with this transmission method, present embodiment also provides the method for reseptance of the T-MMB of Compatiable DAB.Be used to receive and use above-mentioned transmission method and send the data of handling, and carry out respective handling and be reduced to original multimedia service data.

Figure 13 is the particular flow sheet of method of reseptance of the T-MMB of the Compatiable DAB in the embodiment of the invention.As shown in figure 15, this method comprises:

Step 1301 is carried out the synchronous and OFDM demodulation of radio demodulating to the received signal, obtains the data of FIC channel and MSC channel.

In this step, the radio demodulating that carries out corresponding reception data according to the method for DAB system synchronously and the OFDM demodulation get final product, repeat no more here.

Step 1302 is carried out channel demodulation and channel-decoding to the data of FIC channel, according to the control information of FIC channel, and the business datum in the extraction MSC channel in the subchannel of corresponding service type.

In this step, the data of FIC channel are carried out channel demodulation and channel-decoding, thereby obtain all kinds of control informations in the FIC channel and the code modulation mode of all kinds of business datums according to the mode in the DAB system.

With transmitting terminal subchannel information is carried out label manner accordingly in the FIC channel, read each position of type of service data in the MSC channel according to the position of Fig. 8 sub-channels information in the FIC channel, and, four class business datums are extracted according to this position.

Step 1303 according to the channel modulation mode of all kinds of business datums that identify in transmission mode of differentiating and the FIC channel, is carried out channel demodulation to the data in the business datum MSC channel after extracting.

In this step, the mode of discriminating transmission mode is, with reference to the default channel modulation mode and the corresponding relation of transmission mode and working frequency points, according to the channel modulation mode that adopts and the working frequency points of system's appointment, discriminating transmission mode.

When business datum is carried out channel demodulation,, carry out channel demodulation according to the standard of original DAB for DAB and DAB-IP, T-DMB signal.For the T-MMB signal, because at transmitting terminal, the channel modulation mode that may adopt present embodiment to increase, therefore need according in advance to the control information setting of Channel Modulation scheme, be extracted in the control information of the respective channel modulation scheme in the FIC channel, carry out corresponding channel demodulation according to sign wherein.Particularly, in the present embodiment,, parse the Channel Modulation scheme, carry out channel demodulation because transmitting terminal according to the Channel Modulation scheme of Fig. 8 sign, takes out the content of corresponding field according to Fig. 8 too in this step.

Step 1304 according to the control information in the FIC channel, is carried out channel-decoding and source coding to all kinds of business datums.

In this step,, carry out according to the standard of original DAB for DAB and DAB-IP, T-DMB signal.For the T-MMB signal, because at transmitting terminal, the channel coding method that may adopt present embodiment to increase, therefore when this two classes signal is carried out channel and source coding, need according in advance to the control information setting of encoding scheme, be extracted in the control information of the corresponding encoded scheme in the FIC channel, according to wherein the information source and the channel coding schemes of sign carry out corresponding channel and source coding.Particularly, in the present embodiment,, according to Fig. 8 the content of corresponding field is taken out too, parse information source and channel coding schemes, carry out channel and source coding according to the information source and the channel coding schemes of transmitting terminal according to Fig. 8 sign.

When transmitting terminal comprises that condition receives scrambling, energy dissipation and time-interleaved process, then after receiving terminal is also correspondingly extracting business datum, the data on each subchannel are carried out successively time de-interweaving, channel-decoding, energy are separated diffusion, condition receives descrambling and source coding.

So far, corresponding with sending method in the embodiment of the invention, the method for reseptance flow process of the T-MMB of Compatiable DAB finishes.In fact, reception for DAB, DAB-IP in the transmission data of the present invention and T-DMB signal, because this three classes signal carries out according to original standard separately in carrying out code modulated process, therefore utilize DAB method of reseptance, DAB-IP method of reseptance and T-DMB method of reseptance promptly can receive separately signal smoothly, and carry out the normal play behind the demodulating and decoding.And can four kinds of signals that comprise DAB, DAB-IP, T-DMB and T-MMB be received and corresponding demodulating and decoding and broadcast normally according to recipient's rule among the present invention.

More than be the T-MMB transmission of Compatiable DAB in the embodiment of the invention and the embodiment of method of reseptance, can realize the purpose of high efficiency of transmission multiple business data, and be suitable for moving reception, the frequency availability is good.

Above-mentioned sending method can be implemented in concrete transmitter in the present embodiment, and the multimedia service signal that forms is launched by transmitter, cover certain zone, the corresponding receiver in this zone can adopt above-mentioned method of reseptance that multimedia service signal is received.The networking neatly of these transmitter and receivers both can have been formed multiple frequency network, MFN (MFN), also can form single frequency network (SFN), thereby formed the T-MMB transmission system of Compatiable DAB.Below be example just to form single frequency network, the embodiment of the T-MMB transmission system of Compatiable DAB among the present invention is described.

Figure 14 is the concrete structure figure of the T-MMB system of Compatiable DAB in the embodiment of the invention.As shown in figure 14, this system comprises: the broadcasting station or the network control center (NCC) 1410, and the more than one transmitting station 1420 that is positioned at different regions, they can be local broadcast platform or zonal transmitting base station, more than one receiver 1430.

The ground mobile multimedia broadcast net that so promptly can form a whole, the radio network in the present embodiment is a single frequency network.Multi-path digital multimedia broadcasting (program) signal that transmitting station 1420 receives from certain broadcasting station or the network control center 1410, these signals can comprise the DAB signal, the DAB-IP signal, T-DMB signal and T-MMB signal, it is carried out source encoding and chnnel coding, embed the data behind the coding among the MSC MSC of DAB system in time-multiplexed mode; Also business datum signal corresponding service type, the subchannel information that takies and code modulation mode are carried out respective identification in fast information channel in dab receiver FIC, and the data in the FIC channel are carried out chnnel coding; Transmission mode and channel modulation mode according to determining carry out Channel Modulation to the data of FIC channel and MSC channel, and the data of the FIC channel after the Channel Modulation and MSC channel data and synchronizing channel are carried out launching after OFDM modulation and the rf modulations.The signal of launching utilizes surface wave to be transferred to ground mobile receiver or portable receiver 1430, as mobile TV.Receiver 1430 is used for that the radiofrequency signal that receives is carried out radio demodulating, OFDM and separates and be in harmonious proportion synchronously; Then according to the control information of the FIC channel that obtains behind channel demodulation and the channel-decoding, business datum in the subchannel of extraction corresponding service type, and, the business datum after extracting is carried out channel demodulation, channel-decoding and source coding successively according to the coded system of corresponding service type in the FIC channel.

Receiver user 1430 in the area of coverage can be the DAB receiver, the DAB-IP receiver, T-DMB receiver and T-MMB receiver, and covering depends on many factors, for example, landform, the height of launching tower and power, receiver antenna and gain/directive property etc., the signal that the user is received not only has direct signal, signal of process one or many reflection, and multiple frequency network, MFN in addition or the signal of launching with distant place transmitter in netting frequently, therefore, with regard to the problem that exists a multipath to disturb, in addition, for mobile receiver, there is Doppler effect, therefore, transmission channel is modeled as time-variant multipath channel, because the present invention has adopted the DAB system configuration, the design of its transport layer itself is that this time-variant multipath channel is customized, and therefore T-MMB transmission system of the present invention support is moved and received and the SFN networking.

The most basic transmitting station comprises receiver module, source encoding module, channel coding module, channel multiplexing module and modulation and transmission module.In the present embodiment, further comprise condition and receive scrambler, energy dispnergy disperser and time-interleaved device.Particularly, the structure of transmitting station 1420 as shown in figure 15.Transmitting station 1420 comprises that receiver module 1421, source encoding module 1422, condition receive scrambler 1423, energy dispnergy disperser 1424, channel coding module 1425, time-interleaved device 1426, the formation of FIC data module 1427, channel multiplexing module 1428 and modulation and transmission module 1429.

In transmitting station 1420, receiver module 1421 is used to receive multi-path digital multimedia broadcasting (program) signal from certain broadcasting station or the network control center 1620, and gives source encoding module 1422 with signal forwarding; These signals can comprise the DAB signal, DAB-IP signal, T-DMB signal and T-MMB signal.

Source encoding module 1422 is used for the type of service according to signal, receiver module 1421 is transmitted the signal that comes carry out source encoding, and the condition that then coding result sent to receives scrambler 1423.Condition receives scrambler 1423, is used for the data that the receive condition of carrying out is received scrambling, and the result is sent to energy dispnergy disperser 1424.Energy dispnergy disperser 1424 is used for the data that receive are carried out energy dissipation, and the result is sent to channel coding module 1425.Channel coding module 1425 is used for the type of service according to signal, and the signal that receives is carried out chnnel coding, specifically can carry out according to the channel modulation mode in the step 503 shown in Figure 5, and the result is sent to time-interleaved device 1426.Time-interleaved device 1426 is used for the data that receive are carried out time-interleaved, and the result is sent to channel multiplexing module 1428.The FIC data form module 1427, be used for business datum corresponding service type, the subchannel information that takies, source encoding mode, channel coding method and channel modulation mode are carried out respective identification at FIC, and the data in the FIC channel are carried out chnnel coding, coding result is sent to channel multiplexing module 1428.Channel multiplexing module 1428 is inserted signal among the MSC in time-multiplexed mode according to type of service, and MSC channel data and FIC data are formed FIC coding result that module 1427 sends sends to modulation and transmission module 1429 after multiplexing.Modulation and transmission module 1429, be used for according to transmission mode and the channel modulation mode determined, FIC channel and the MSC channel data that receives carried out Channel Modulation, and the data of the FIC channel after the Channel Modulation and MSC channel data and synchronizing channel are carried out OFDM modulation, and the result is modulated on the predetermined working frequency points sends.

DAB receiver, DAB-IP receiver and T-DMB receiver can receive signal separately smoothly, and carry out the normal play behind the demodulating and decoding.Here, introduce the structure of T-MMB receiver in detail.Figure 16 is the concrete structure figure of the T-MMB receiver in the embodiment of the invention.Receiving terminal mainly comprises and the transmitting terminal reversed in order, four steps of process contrary, that is: radio demodulating, base band demodulating, channel decoding and source decoding.Particularly, T-MMB receiver 1430 comprises receiving demodulation module 1431, FIC data extraction module 1432, business datum extraction module 1433, channel demodulation module 1434, channel decoding module 1435 and source coding module 1436.In addition, owing to comprise in the transmitting station of present embodiment that condition receives scrambler, energy dispnergy disperser and time-interleaved device, comprise further also in receiver that therefore time de-interweaving device 1437, energy are separated diffuser 1438 and condition receives descrambler 1439.

In this receiver 1430, receiving demodulation module 1431 is used for by antenna receiving signal, carries out the synchronous and OFDM demodulation of radio demodulating to the received signal, obtain the data of FIC channel and MSC channel, and send to FIC data extraction module 1432 and business datum extraction module 1433 respectively.FIC data extraction module 1432, be used for the FIC channel data that receives is carried out channel demodulation and channel-decoding, and the control information of FIC is sent to business datum extraction module 1433, channel demodulation module 1434, channel decoding module 1435 and source coding module 1436.

The control information that provides according to FIC is provided business datum extraction module 1433, all kinds of business datums among the MSC is extracted, and send to channel demodulation module 1434.Channel demodulation module 1434 is used for the channel modulation mode of all kinds of business datums that identify according to the transmission mode of differentiating and FIC channel, the business datum that receives is carried out channel demodulation, and the data after the demodulation are sent to time de-interweaving device 1437.Time de-interweaving device 1437 is used for the data that receive are carried out transmitting channel decoder module 1435 behind the time de-interweaving.

Channel decoding module 1435 is used for the channel coding method of the signal that identifies according to the FIC channel, the signal that receives is decoded accordingly, and the result is sent to energy separate diffuser 1438.Energy is separated diffuser 1438, is used for the data that receive are carried out sending to condition reception descrambler 1439 after energy is separated diffusion.Condition receives descrambler 1439, is used for the data that receive are carried out sending to source coding module 1436 behind the condition reception descrambling.Source coding module 1436 is used for carrying out source coding to the received signal according to type of service.

Because DAB signal and T-DMB signal transmission structure remain unchanged, therefore, when the user was DAB, DAB-IP or T-DMB receiver, receiver can be handled the corresponding service signal, but can not handle the T-MMB service signal.And the T-MMB receiver can be handled DAB, DAB-IP, T-DMB and four kinds of service signals of T-MMB.So, the complete Compatiable DAB of T-MMB system, DAB-IP and T-DMB system.

Above-mentioned is based on the concrete structure of the T-MMB transmission system of single frequency network in the embodiment of the invention.Certainly,, a plurality of single frequency network can constitute multiple frequency network, MFN by being made up, and identical in the internal structure of concrete transmitting station and receiver and the transmission system of single frequency network in multiple frequency network, MFN, be the network construction form difference, the zone of covering is bigger.Here just repeat no more.

The above-mentioned the specific embodiment of the present invention that is.In an embodiment, suppose the transmission of carrying out DAB, DAB-IP, T-DMB and T-MMB signal in this system.In fact, the traffic data type of transmitting in the system can be adjusted according to actual needs, and the transmission method of signal of selecting for use is constant.

T-MMB receiving/transmission method of the present invention and system, DAB system based on maturation carries out the multimedia service expansion, on the one hand, and owing to the DAB system designs for hand-held mobile terminal exactly, therefore the present invention is suitable for too moving and receives, and has shown gratifying reception; On the other hand, because having expanded for the relevant information of each subservice channel, the control information in the FIC channel describes, make method and system of the present invention can transmit polytype multimedia service data simultaneously, overcome the single defective of DAB system business; Also have, because system of the present invention has carried out the expansion of chnnel coding modulation scheme to original DAB system, the efficient channel modulation scheme of introducing as 8DPSK and 16QAPSK, has overcome the low shortcoming of channel efficiency of existing DAB system, the stronger error correction coding scheme of introducing, as the LDPC sign indicating number, be multi-medium data, especially video data, stronger antijamming capability is provided, has made entire method and system be more suitable for the video frequency program transmission; At last, at the efficient channel modulation scheme that adopts, the time exsiccation that brings is thus disturbed the problem of enhancing, compensate by the symbol block length that shortens OFDM, and in the actual measurement process, obtained good effect, thereby ensured that the user is for the quality of signals requirement when band efficiency improves.

In a word, compare the mobile multimedia technology of other standard, it is good that the present invention has the frequency availability; Simple synchronously, be easy to realize; Compatible good; The band efficiency height is supported portable and mobile reception; The receiver complexity is low, advantages such as easy realization.

The above is preferred embodiment of the present invention only, is not to be used to limit protection scope of the present invention, all any modifications of being made within the spirit and principles in the present invention, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (16)

1. the ground mobile multimedia broadcast T-MMB transmission method of a compatible digital audio broadcasting DAB is characterized in that preestablish the type of service of multimedia broadcasting, described type of service comprises the T-MMB business, and this method comprises:

The receiving multimedia broadcast business datum according to its type of service, is carried out source encoding and chnnel coding successively to described business datum;

In the MSC MSC of data behind the coding with time-multiplexed mode embedded system, the multimedia broadcast business data of different service types, take the different subchannels among the described MSC, CU size in each subchannel is 32 * n, and wherein n is the Channel Modulation exponent number of the multimedia broadcast business data of subchannel corresponding service type;

Business datum corresponding service type, the subchannel information that takies, source encoding mode, channel coding method and channel modulation mode are carried out respective identification in the fast information channel in dab receiver FIC of system, and the data in the FIC channel are carried out chnnel coding; Wherein, for the T-MMB business datum among the MSC, channel modulation mode adopts 8 differential phase-shift keying (DPSK) 8DPSK, 16 differential amplitudes and phase combining keying 16DAPSK or 64 differential amplitudes and phase combining keying 64DAPSK;

Transmission mode and described channel modulation mode according to determining carry out Channel Modulation to the data of FIC channel and MSC channel, and the data of the FIC channel after the Channel Modulation and MSC channel and synchronizing channel are carried out sending after OFDM modulation and the rf modulations.

2. method according to claim 1 is characterized in that,

The business datum that receives is being carried out further comprising between source encoding and the chnnel coding, the condition of carrying out successively of the data after the source encoding is being received scrambling and energy dissipation; And after chnnel coding, time division multiplexing takes a step forward and comprises, carries out time-interleaved to the data after the chnnel coding.

3. method according to claim 1 and 2 is characterized in that, when type of service is T-MMB when professional, described business datum is carried out chnnel coding is to adopt cascaded code or low-density checksum LDPC sign indicating number that business datum is carried out chnnel coding.

4. method according to claim 1, it is characterized in that, describedly business datum corresponding service type, the subchannel information that takies, source encoding mode, channel coding method and channel modulation mode are carried out respective identification be in the fast information channel in dab receiver FIC of system:

Set up the FIG of the FIC of T-MMB system channel based on the fast information group FIG of the FIC of DAB system channel, sign business datum corresponding service type, the subchannel information that takies, source encoding mode, channel coding method and channel modulation mode in the FIG of the FIC of T-MMB system channel.

5. method according to claim 4, it is characterized in that, when type of service was the T-MMB business, the described business datum corresponding service type that identifies in the FIG of the FIC of T-MMB system channel is: the DSCTy field in FIG type 0/ mode of extension 2 of the FIC of T-MMB system channel increased the type of service of T-MMB system and describes; User's application type User Application the type field in FIG type 0/ mode of extension 13 of the FIC of T-MMB system channel increases T-MMB user and uses description.

6. method according to claim 4, it is characterized in that, when type of service is the T-MMB business, the described subchannel information that the sign business datum takies in the FIG of the FIC of T-MMB system channel is: increase the subchannel identification field in the FIG of the FIC of T-MMB system channel, be used for the subchannel of identification service data occupancy; In the FIG of the FIC of T-MMB system channel, increase the start address field, be used to identify the address of first CU of subchannel.

7. method according to claim 4 is characterized in that, when type of service was the T-MMB business, described channel coding method and the channel modulation mode that identifies business datum in the FIG of the FIC of T-MMB system channel was:

In the FIG of the FIC of T-MMB system channel, increase type of coding CodingType field, be used to identify the channel coding method of T-MMB business;

In the FIG of the FIC of T-MMB system channel, increase sub-channel data region S ub-channel field field, be used to identify the size of subchannel of T-MMB business and the protection level of the error correction coding that adopts;

In the FIG of the FIC of T-MMB system channel, increase modulation type ModuType field, be used to identify the channel modulation mode of T-MMB business.

8. method according to claim 1 is characterized in that, described definite transmission mode is:

With reference to the corresponding relation of default channel modulation mode, transmission mode and working frequency points,, determine transmission mode according to the channel modulation mode that adopts and the working frequency points of system's appointment.

9. method according to claim 8 is characterized in that,

When described channel modulation mode is m-DPSK or m-DAPSK, if the working frequency points of T-MMB is BandIII, then adopt transmission mode IV, if the working frequency points of T-MMB is L-Band, then adopt the transmission mode formula III; Described m is a kind of in 16,32 or 64;

When described channel modulation mode is DQPSK, if the working frequency points of T-MMB is BandIII, then adopt transmission mode I, if the working frequency points of T-MMB is L-Band, then adopt transmission mode II.

10. the ground mobile multimedia broadcast T-MMB method of reseptance of a compatible digital audio broadcasting DAB is characterized in that preestablish the type of service of multimedia broadcasting, described type of service comprises the T-MMB business, and this method comprises:

Carry out radio demodulating, OFDM to the received signal and separate and be in harmonious proportion synchronously, obtain the data of FIC channel and MSC channel, and differentiate the transmission mode that adopts;

Data to described FIC channel are carried out channel demodulation and channel-decoding successively, according to the control information of FIC channel, and the business datum in the extraction MSC channel in the subchannel of corresponding service type; Wherein, the CU size in each subchannel is 32 * n, and n is the Channel Modulation exponent number of the multimedia broadcast business data of subchannel corresponding service type;

According to Channel Modulation, chnnel coding and the source encoding mode of all kinds of business datums that identify in transmission mode of differentiating and the FIC channel, the business datum after extracting is carried out channel demodulation, channel-decoding and source coding successively; Wherein, for the T-MMB business datum, channel modulation mode adopts 8 differential phase-shift keying (DPSK) 8DPSK, 16 differential amplitudes and phase combining keying 16DAPSK or 64 differential amplitudes and phase combining keying 64DAPSK.

11. method according to claim 10 is characterized in that, described discriminating transmission mode is:

With reference to the default channel modulation mode and the corresponding relation of transmission mode and working frequency points, according to the channel modulation mode that adopts and the working frequency points of system's appointment, discriminating transmission mode.

12. the ground mobile multimedia broadcast T-MMB system of a compatible digital audio broadcasting DAB is characterized in that, preestablishes the type of service of multimedia broadcasting, described type of service comprises the T-MMB business, this system comprises: the NCC of the network control center, transmitting station and receiver, wherein

Described NCC is used for multimedia broadcast business data is sent to described transmitting station;

Described transmitting station, be used to receive multimedia broadcast business data from described NCC, according to its type of service, it is carried out source encoding and chnnel coding, in the MSC of data with time-multiplexed mode embedded system behind the coding, the multimedia broadcast business data of different service types takies the different subchannels among the described MSC, CU size in each subchannel is 32 * n, and wherein n is the Channel Modulation exponent number of the multimedia broadcast business data of subchannel corresponding service type; Business datum corresponding service type, the subchannel information that takies, source encoding mode, channel coding method and channel modulation mode are carried out respective identification in fast information channel in dab receiver FIC, and the data in the FIC channel are carried out chnnel coding; Wherein, for the T-MMB business datum, channel modulation mode adopts 8 differential phase-shift keying (DPSK) 8DPSK, 16 differential amplitudes and phase combining keying 16DAPSK or 64 differential amplitudes and phase combining keying 64DAPSK; Also be used for according to transmission mode and the described channel modulation mode determined, data to FIC channel and MSC channel are carried out Channel Modulation, and the data of the FIC channel after the Channel Modulation and MSC channel data and synchronizing channel are carried out being transmitted to intrasystem described receiver after OFDM modulation and the rf modulations;

Described receiver, be used for to the radiofrequency signal that the described transmitting station that receives sends carry out radio demodulating, OFDM separates and is in harmonious proportion synchronously; According to the control information of the FIC channel that obtains behind channel demodulation and the channel-decoding, the business datum in the subchannel of extraction corresponding service type is carried out channel demodulation, channel-decoding and source coding.

13. system according to claim 12 is characterized in that, described transmitting station comprises that receiver module, source encoding module, channel coding module, FIC data form module, channel multiplexing module and modulation and transmission module, wherein,

Described receiver module is used to receive the multimedia broadcast business data from described NCC, and business datum is transmitted to described source encoding module;

Described source encoding module is used for the type of service according to business datum, described receiver module is transmitted the signal that comes carry out source encoding, then the source encoding result is sent to described channel coding module;

Described channel coding module is used for the data that receive are carried out chnnel coding, and the result is sent to described channel multiplexing module;

Described FIC data form module, be used for business datum corresponding service type, the subchannel information that takies, source encoding mode, channel coding method and channel modulation mode are carried out respective identification at FIC, and the data in the FIC channel are carried out chnnel coding, coding result is sent to described channel multiplexing module;

Described channel multiplexing module, the business datum that receives is inserted in the MSC channel in time-multiplexed mode according to type of service, and MSC channel data and described FIC data are formed FIC coding result that module sends send to described modulation and transmission module after multiplexing;

Described modulation and transmission module, be used for according to transmission mode and the described channel modulation mode determined, the FIC channel that receives and the data of MSC channel are carried out Channel Modulation, and the data of the FIC channel after the Channel Modulation and MSC channel data and synchronizing channel are carried out sending to described receiver after OFDM modulation and the rf modulations.

14. system according to claim 13 is characterized in that, described transmitting station comprises that further condition receives scrambler, energy dispnergy disperser and time-interleaved device, wherein,

Described source encoding module is used for that the source encoding result is sent to described condition and receives scrambler;

Described condition receives scrambler, is used for the data that receive are carried out sending to described energy dispnergy disperser after the condition reception scrambling;

Described energy dispnergy disperser is used for the data that receive are carried out sending to described channel coding module after the energy dissipation;

Described channel coding module is used for the result after the chnnel coding is sent to described time-interleaved device;

Described time-interleaved device is used for the data that receive are carried out sending to described channel multiplexing module after time-interleaved.

15., it is characterized in that described receiver is: a kind of or combination in any in DAB receiver, DAB-IP receiver, DMB T-DMB receiver and the T-MMB receiver according to any described system in the claim 12 to 14.

16. system according to claim 15 is characterized in that, described T-MMB receiver comprises receiving demodulation module, FIC data extraction module, business datum extraction module, channel demodulation module, channel decoding module and source coding module, wherein,

Described receiving demodulation module, be used to receive the radiofrequency signal that described transmitting station sends, carry out radio demodulating, OFDM to the received signal and separate and be in harmonious proportion synchronously, obtain the data of FIC channel and MSC channel, send to described FIC data extraction module and described business datum extraction module respectively;

Described FIC data extraction module is used for the FIC channel data that receives is carried out channel demodulation and channel-decoding, and the control information of FIC is sent to described business datum extraction module, channel demodulation module, channel decoding module and source coding module;

The control information that provides according to FIC is provided described business datum extraction module, all kinds of business datums among the MSC is extracted, and send to described channel demodulation module;

Described channel demodulation module is used for the channel modulation mode of all kinds of business datums that identify according to the transmission mode of differentiating and FIC channel, the business datum that receives is carried out channel demodulation, and the data after the demodulation are sent to described channel decoding module;

Described channel decoding module is used for the channel coding method of the signal that identifies according to the FIC channel, the signal that receives is carried out corresponding channel-decoding, and the result is sent to described source coding module;

Described source coding module is used for carrying out source coding to the received signal according to type of service.

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