CN104394390A - Diversity reception method for satellite digital television - Google Patents

Abstract

The invention relates to a diversity reception method for a satellite digital television, and the diversity reception method is used to receive broadcast signals of the satellite digital television on a mobile carrier. If the traditional satellite receiving system is installed on the mobile carrier, and signals are interrupted when there is a barrier between a receiving antenna and a satellite. Through the spatial diversity method, multiple receiving antennas are configured to receive digital television signals of the satellite from different positions, signals of the multiple antennas are demodulated, and the demodulation outputs are marked, aligned and combined to eliminate the wrong output data caused due to barrier interference. Under the existing satellite receiving frame, outputs of multiple channel demodulating modules are marked, aligned, combined and selected by the method, thereby improving the receiving performance of the receiving system and achieving the purpose of steadily receiving the digital television broadcast signals.

Description

A kind of diversity receiving method of satellite digital TV

Technical field

The invention belongs to satellite digital TV reception technique field, relate to a kind of diversity receiving method of satellite digital TV.

Background technology

Digital video broadcast-satellite system utilizes the transponder of the communication satellite be positioned on geostationary orbit to forward the upstream digital TV signal from the earth usually, and satellite digital tv receiver utilizes satellite earth antenna to receive the digital television signal of satellite forwarding.If traditional satellite receiving system is arranged on mobile vehicle, between reception antenna and satellite, there is shelter appearance to cause signal interruption, such as, when satellite receiver is installed ON TRAINS, satellite earth antenna is in mobile status, although can ensure that antenna points to the communication satellite on geostationary orbit all the time by technological means, but due to the operation of train, the satellite-signal between reception antenna and satellite is inevitably blocked by tunnel, tree crown etc. and causes the short interruption of Digital TV Receiving.

Summary of the invention

The invention provides a kind of diversity receiving method of satellite digital TV, on the carrier of movement, can arrange multiple reception antenna by the method for space diversity receives from the digital television signal of satellite from diverse location, and respectively demodulation is carried out to the signal from multiple antenna, demodulation is exported and carries out marking, align, merge, eliminate the output error in data blocking and disturb and cause, reach the object of stable receiving digital television broadcast.

Present invention employs multiple channel demodulation module for carrying out demodulation respectively to the signal from the different multiple antennas in position, demodulation module adopts existing channel demodulation module.Because satellite-signal may be different through the processing delay that each demodulation module brings, also certain staggering can be there is in time in the TS packet sequence that therefore demodulation module exports, in order to solve TS packet sequence staggering in time, first the present invention needs to mark TS bag.

The present invention is applicable to have employed the digital television system of TS stream as data transmission format of mpeg standard, TS stream is wrapped by the TS of a series of regular lengths continuous in time and forms, demodulation module receiving satellite signal also completes the Defect Indication information TS_ERR providing each packet while TS stream is sent in demodulation, this information represents when being 0 that corresponding TS bag does not exist reception mistake, this information represents when being 1 that corresponding TS bag exists and receives mistake, TS_ERR by by TS inclusion of the present invention and module utilize to reject the packet that there is mistake.In addition according to the requirement of mpeg standard, transmitting terminal can periodically select some TS to wrap in wherein lift-launch program clock reference information (PCR) in TS stream, and the positional information that PCR occurs is wrapped being used for marking each TS by the present invention so that the TS stream alignment exported by each channel demodulation.

The each TS bag comprised during the TS that each receiver exports for the output of each channel demodulation module by the present invention first respectively flows marks, then labeled TS is wrapped and carry out the alignment of TS bag according to mark, again the TS bag after alignment is carried out choice according to the error indication signal of TS stream itself afterwards to merge, finally the TS stream that the TS bag after merging is formed is sent to follow-up source coding module and carries out decoding process, wherein coding/decoding method conventionally.

Implementation step of the present invention is as follows:

Step 1, on mobile vehicle dispersion install n satellite earth antenna Ant (1), Ant (2), Ant (n), n channel demodulation module Dem (1), Dem (2) ... Dem (n), satellite earth antenna is identical with channel demodulation module number; Wherein channel demodulation module adopts existing module;

Step 2, by the output TS of each channel demodulation module flow together with mistake instruction TS_err mark, labeling method is:

Step (1), corresponding each channel demodulation module installation blip counting device: C (1), C (2) ..., C (n);

Step (2), by C (1), C (2) ..., C (n) is initialized as 0;

Step (3), flow according to the output TS of each channel demodulation module in each TS bag update mark counter C (i), i=1,2, n, the method upgrading C (i) is: if current TS handbag is containing PCR, the C (i) clear 0 of this bag correspondence; As current TS comprises PCR, the C (i) of this bag correspondence adds 1;

The end that step 3, the TS that the value of blip counting device C (i) after renewal is appended to correspondence wrap;

Step 4, wrap the count value that adds of end according to each TS the input traffic from each channel demodulation module is alignd in time, alignment consistent according to wrapping the count value that end adds for the TS of each input traffic after alignment;

Step 5, check alignment after each TS flow in mark value identical TS bag error indication signal TS_err: if mark value identical TS bag in there is the situation that error indication signal TS_err is 0, then direct using TS_err be 0 TS bag as this mark value TS bag send, and ignore the TS bag of the same tag that other individual channels are sent into, this this mark value of the data flow finally exported error indication signal TS_err_out is set to 0 simultaneously; If all error indication signal TS_err are 1 in the TS bag that mark value is identical, represent that all bags are all wrong, the TS bag that any one TS selecting this mark value corresponding wraps as this mark value is sent, and ignore the TS bag of same tag on other each data paths, this mark value of the data flow finally exported error indication signal TS_err_out is put 1 simultaneously;

Step 6, the TS bag identical to each mark value in each TS stream operate according to step 5, will be inserted into the count value deletion that each TS wraps end, and form final TS and flow TS_out after merging;

Step 7, TS flowed TS_out and be sent to source coding module and carry out decoding to obtain audio/video information, described source coding module adopts existing module.

The invention has the advantages that, under existing satellite reception framework, by marking the output of multiple channel demodulation module, align, merge choice, improve the receptivity of receiving system.Used channel demodulation module, source coding module all can adopt existing software, hardware.

Accompanying drawing explanation

Fig. 1 is block diagram of the present invention;

Fig. 2 is the block diagram of the embodiment of the present invention;

Fig. 3 is that in embodiment, TS packet making Qian Ge road TS flows and mistake instruction schematic diagram;

Fig. 4 is that in embodiment, TS packet making Hou Ge road TS flows and mistake instruction schematic diagram;

Fig. 5 flows and error indication signal, TS stream after merging and error indication signal schematic diagram through each road TS of alignment in embodiment.

Embodiment

Step of the present invention as shown in Figure 1, choose a representational satellite digital television receiving system below in conjunction with accompanying drawing to be described the specific embodiment of the present invention, the present embodiment is for have employed European second generation satellite reception standard DVBS2 satellite television receiving system of the present invention, arrange 3 channel demodulation modules in this system, concrete implementation step is as follows:

Step 1, on mobile vehicle, disperse installation 3 satellite earth antenna Ant (1) as shown in Figure 2, Ant (2), Ant (3), 3 channel demodulation module Dem (1), Dem (2), Dem (3), satellite earth antenna is identical with channel demodulation module number; Wherein channel demodulation module adopts existing module;

Step 2, by the output TS of each channel demodulation module flow together with mistake instruction TS_err mark, labeling method is:

Step (1), corresponding each channel demodulation module installation blip counting device: C (1), C (2), C (3);

Step (2), by C (1), C (2), C (3) are initialized as 0;

Step (3), flow according to the output TS of each channel demodulation module in each TS bag update mark counter C (i), i=1,2,3, the method upgrading C (i) is: if current TS handbag is containing PCR, the C (i) clear 0 of this bag correspondence; As current TS comprises PCR, the C (i) of this bag correspondence adds 1;

In the present embodiment, TS packet making Qian Ge road TS stream and error indication signal are as shown in Figure 3, in figure:

TS_err1 represents when being high that handbag corresponding in TS1 contains mistake;

TS_err2 represents when being high that handbag corresponding in TS2 contains mistake;

TS_err3 represents when being high that handbag corresponding in TS3 contains mistake;

Each TS plays the handbag of shade containing PCR in flowing;

The end that step 3, the TS that the value of blip counting device C (i) after renewal is appended to correspondence wrap;

In the present embodiment, TS packet making Hou Ge road TS stream and error indication signal are as shown in Figure 4, in figure: each TS wraps end and added the value of labelling technique device C (i), and the value of the blip counting device that the bag end wherein comprising PCR adds is 0;

Step 4, wrap the count value that adds of end according to each TS the input traffic from each channel demodulation module is alignd in time, alignment consistent according to wrapping the count value that end adds for the TS of each input traffic after alignment; 3 road TS in the present embodiment after alignment flow as shown in Figure 5, wherein:

TS1', TS2', TS3' are respectively each TS after alignment and flow;

TS_err1', TS_err2', TS_err3' are respectively and error indication signal corresponding to TS1', TS2', TS3';

Step 5, check alignment after each TS flow in mark value identical TS bag error indication signal TS_err: if mark value identical TS bag in there is the situation that error indication signal TS_err is 0, then direct using TS_err be 0 TS bag as this mark value TS bag send, and ignore the TS bag of the same tag that other individual channels are sent into, this this mark value of the data flow finally exported error indication signal TS_err_out is set to 0 simultaneously; If all error indication signal TS_err are 1 in the TS bag that mark value is identical, represent that all bags are all wrong, the TS bag that any one TS selecting this mark value corresponding wraps as this mark value is sent, and ignore the TS bag of same tag on other each data paths, this mark value of the data flow finally exported error indication signal TS_err_out is put 1 simultaneously;

In the present embodiment shown in Fig. 5, the merging process that each TS flows is:

Mark value be 854 3 TS bag be respectively TS1 (2), TS2 (0), TS3 (3) is according to the mistake instruction TS_err1' of correspondence, TS_err2', the known TS1 of TS_err3' (2), TS2 (0) does not all comprise mistake, chooses TS1 (2) and is sent to TS_out, and the TS_err_out that this bag is corresponding simultaneously sets to 0;

Mark value be 03 TS bag be respectively TS1 (3), TS2 (1), TS3 (4), according to the mistake instruction TS_err1' of correspondence, the known TS2 of TS_err2', TS_err3' (1), TS3 (4) all do not comprise mistake, choose TS2 (1) and be sent to TS_out, the TS_err_out that this bag is corresponding simultaneously sets to 0;

Mark value be 13 TS bag be respectively TS1 (4), TS2 (2), TS3 (5), according to the mistake instruction TS_err1' of correspondence, TS_err2', TS_err3' these three Bao Jun known comprise mistake, and random selecting TS1 (4) is sent to TS_out, and the TS_err_out that this bag is corresponding simultaneously puts 1;

Mark value be 23 TS bag be respectively TS1 (5), TS2 (3), TS3 (6), according to the mistake instruction TS_err1' of correspondence, TS_err2', the known TS3 of TS_err3' (6) does not comprise mistake, chooses TS3 (6) and is sent to TS_out, and the TS_err_out that this bag is corresponding simultaneously sets to 0;

Mark value be 33 TS bag be respectively TS1 (6), TS2 (4), TS3 (7), according to the mistake instruction TS_err1' of correspondence, TS_err2', TS_err3' these three Bao Jun known do not comprise mistake, and random selecting TS1 (6) is sent to TS_out, and the TS_err_out that this bag is corresponding simultaneously sets to 0;

Step 6, the TS bag identical to each mark value in each TS stream operate according to step 5, will be inserted into the count value deletion that each TS wraps end, and form final TS and flow TS_out as shown in Figure 5 after merging;

Step 7, TS flowed TS_out and be sent to source coding module and carry out decoding to obtain audio/video information, described source coding module adopts existing module.

It should be understood that above-mentioned example is just to explanation of the present invention, instead of limitation of the present invention, any innovation and creation do not exceeded in spirit of the present invention, all fall within protection scope of the present invention.

Claims (1)

1. a diversity receiving method for satellite digital TV, is characterized in that the method concrete steps are:

Step 1, on mobile vehicle dispersion install n satellite earth antenna Ant (1), Ant (2), Ant (n), n channel demodulation module Dem (1), Dem (2) ... Dem (n), satellite earth antenna is identical with channel demodulation module number;

Step 2, by the output TS of each channel demodulation module flow together with mistake instruction TS_err mark, labeling method is:

Step (1), corresponding each channel demodulation module installation blip counting device: C (1), C (2) ..., C (n);

Step (2), by C (1), C (2) ..., C (n) is initialized as 0;

Step (3), flow according to the output TS of each channel demodulation module in each TS bag update mark counter C (i), i=1,2, n, the method upgrading C (i) is: if current TS handbag is containing PCR, the C (i) clear 0 of this bag correspondence; As current TS comprises PCR, the C (i) of this bag correspondence adds 1;

The end that step 3, the TS that the value of blip counting device C (i) after renewal is appended to correspondence wrap;

Step 4, wrap the count value that adds of end according to each TS the input traffic from each channel demodulation module is alignd in time, alignment consistent according to wrapping the count value that end adds for the TS of each input traffic after alignment;

Step 5, check alignment after each TS flow in mark value identical TS bag error indication signal TS_err: if mark value identical TS bag in there is the situation that error indication signal TS_err is 0, then direct using TS_err be 0 TS bag as this mark value TS bag send, and ignore the TS bag of the same tag that other individual channels are sent into, this this mark value of the data flow finally exported error indication signal TS_err_out is set to 0 simultaneously; If all error indication signal TS_err are 1 in the TS bag that mark value is identical, represent that all bags are all wrong, the TS bag that any one TS selecting this mark value corresponding wraps as this mark value is sent, and ignore the TS bag of same tag on other each data paths, this mark value of the data flow finally exported error indication signal TS_err_out is put 1 simultaneously;

Step 6, the TS bag identical to each mark value in each TS stream operate according to step 5, will be inserted into the count value deletion that each TS wraps end, and form final TS and flow TS_out after merging;

Step 7, TS flowed TS_out and be sent to source coding module and carry out decoding to obtain audio/video information.