CN1984325A - System and method for realizing wireless digital TV-set broadcast - Google Patents
System and method for realizing wireless digital TV-set broadcast Download PDFInfo
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- CN1984325A CN1984325A CN 200610066675 CN200610066675A CN1984325A CN 1984325 A CN1984325 A CN 1984325A CN 200610066675 CN200610066675 CN 200610066675 CN 200610066675 A CN200610066675 A CN 200610066675A CN 1984325 A CN1984325 A CN 1984325A
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Abstract
The key ideal of invention is: the central radio digital TV broadcast transmitter uses spatial transmission diversity technique to divide video transmission stream into two-way signals that are transmitted by two antennas; the broadcast station subsystem firstly processes the video data into video transmission stream; the central radio digital broadcast transmitter makes process for the video transmission stream, which including the transmission process for signals having spatial transmission diversity modulation function, to generate two-way signals; the first way signals are transmitted by using its own antenna, and the second way signals are transmitted by the transmitting module of a remote end. When the user end receives two way signals, it makes receiving process and baseband backward process for the signals having spatial transmission diversity demodulation function to get video data.
Description
Technical field
The present invention relates to the wireless digital broadcasting technology, particularly relate to a kind of system and method for realizing wireless digital TV-set broadcast.
Background technology
Along with the development of digital technology, the wireless digital broadcasting system can provide abundant digital broadcast television program to user terminal.
Fig. 1 is a typical wireless digital TV-set broadcast system.As shown in Figure 1, the wireless digital TV-set broadcast system generally comprises: broadcast station subsystem, wireless digital TV-set transmitter, user terminal.
Wherein, the program data that broadcast station subsystem is used for that content supplier is provided obtains video transmission stream (TS), and TS stream is exported to the wireless digital TV-set transmitter after carrying out scrambling, multiplexing etc. the processing; The wireless digital TV-set transmitter carries out Base-Band Processing earlier with TS stream, obtain digital baseband signal, again digital baseband signal is obtained analog baseband signal through digital-to-analogue conversion, then analog baseband signal is carried out analog processes such as frequency conversion, amplification, filtering successively, obtain radiofrequency signal, launch by antenna at last; User terminal then with the radiofrequency signal that receives earlier through the contrary processing procedure of analog signals such as filtering, amplification, frequency conversion, obtain analog baseband signal, again with analog baseband signal through the contrary processing procedure of base band, obtain video data, TV programme is presented to the user.
Terrestrial wireless digital television broadcasting candidate technologies comprises at present: ground digital television broadcast transmission system (DMB-T), adopt time-division synchronous OFDM (TDS-OFDM); Ground advanced digital television broadcasting system (ADTB-T) adopts the offset orthogonal amplitude modulation(PAM).But, generally all be that video data finally is modulated to one road signal, and launch from the antenna of wireless digital TV-set transmitter no matter be to adopt which kind of modulator approach.Because the radio wave propagation of launching is very complicated, through influence of various factors such as effect, Doppler effect, various declines can take place in signal, cause the decline of terminal receptivity more than generally can existing.
This shows in existing wireless digital broadcasting system, in the technology, also do not have a kind of system and method that can improve the terminal receptivity.
Summary of the invention
In view of this, main purpose of the present invention is to provide a kind of system of wireless digital TV-set broadcast, can improve the receptivity of user terminal.In addition, at the system that the present invention proposes, the invention allows for a kind of method of realization wireless digital TV-set broadcast of the receptivity that can improve user terminal.
In order to achieve the above object, the technical scheme of the present invention's proposition is:
A kind of system that realizes wireless digital TV-set broadcast, this system comprises at least: the broadcast station subsystem, central radio digital broadcast transmitter and the user terminal that video data are carried out scrambling and multiplexing back acquisition video transmission stream, it is characterized in that this system further comprises: one or more far-end transmitter modules;
Described central radio digital broadcast transmitter, the signal emission that be used for carrying out Base-Band Processing by the video transmission stream of broadcast station subsystem input, comprises the spatial emission diversity modulation function is handled, generate two paths of signals, first via signal is launched from self antenna, the second road signal is sent to one or more far-end transmitter modules;
Described each far-end transmitter module is used to receive the second road signal by the input of central radio digital broadcast transmitter, carries out further signal emission and handles, and obtains radiofrequency signal, launches from self antenna again;
Described user terminal is used to receive the two paths of signals by central radio digital broadcast transmitter and the emission of far-end transmitter module, and the signal that comprises the spatial emission diversity demodulation function receives and handles, base band is contrary handles, and obtains video data.
Preferably, this system further comprises:
Conversion and control equipment is used to receive the second road signal by the input of central radio digital broadcast transmitter, is light signal with the second tunnel conversion of signals, and sends to the far-end transmitter module by optical fiber;
The light signal that the far-end transmitter module is further used for being inputed to self by conversion and control equipment is converted to the signal of telecommunication.
Preferably, the described central radio digital broadcast transmitter two paths of signals that is further used for generating carries out delay process.
Preferably, described central radio digital broadcast transmitter is further used for first via signal is carried out delay process;
Described conversion and control equipment is further used for the second road signal is carried out delay process.
Another goal of the invention that the present invention proposes is achieved like this: a kind of method that realizes wireless digital TV-set broadcast, and this method may further comprise the steps:
A, video data is carried out scrambling and multiplexing, obtain video transmission stream;
B, with video transmission stream carry out Base-Band Processing, the signal emission that comprises the spatial emission diversity modulation function handles, obtain first via signal, and in Base-Band Processing with comprise in the signal emission processing procedure of spatial emission diversity modulation function and obtain the second road signal, the second road signal zoomed out and carry out further signal emission and handle, then the first via signal and the second road signal are launched simultaneously;
The signal that C, user terminal comprise the spatial emission diversity demodulation function with the first via signal that receives and the second road signal receives and handles, base band is contrary handles, and obtains video data.
Preferably, the described Base-Band Processing of step B is: video flowing is encoded and carrier modulation;
The described signal emission that comprises the spatial emission diversity modulation function is treated to: baseband signal is carried out spatial emission diversity modulation, analog-to-digital conversion and analog.
Preferably, described the second road signal of step B is: unmodulated baseband signal, modulated baseband signal or analog signal.
Preferably, if the second road signal is a unmodulated baseband signal, the acquisition methods of described the second road signal of step B is: between coding and carrier modulation, generate the two-way unmodulated baseband signal, and will be wherein one the tunnel as the second road signal;
The method that the described further signal emission of step B is handled is: the second road signal is carried out carrier modulation, spatial emission diversity modulation, analog-to-digital conversion and analog process, generate radiofrequency signal.
Preferably, if the second road signal is the modulated baseband signal, the acquisition methods of described the second road signal of step B is: between the modulation of carrier modulation and spatial emission diversity, generate two-way modulated baseband signal, and will be wherein one the tunnel as the second road signal;
The method that the described further signal emission of step B is handled is: the second road signal is carried out spatial emission diversity modulation, analog-to-digital conversion and analog process.
Preferably, if the second road signal is the modulated baseband signal, the acquisition methods of described the second road signal of step B is: between spatial emission diversity modulation and digital-to-analogue conversion, generate two-way modulated baseband signal, and will be wherein one the tunnel as the second road signal;
The method that the described further signal emission of step B is handled is: the second road signal is carried out analog-to-digital conversion and analog process.
Preferably, if the second road signal is an analog signal, the acquisition methods of described the second road signal of step B is: after digital-to-analogue conversion, generate the two-way analog signal, and will be wherein one the tunnel as the second road signal;
The method that the described further signal emission of step B is handled is: the second road signal is carried out further analog.
Preferably, described acquisition the second road signal of step B and the second road signal zoomed out between further comprise:
Respectively the first via signal and the second road signal are carried out delay process.
Preferably, the method for described delay process is: the method or the way to play for time that change path-length.
Preferably, step B is described to carry out delay process with the first via signal and the second road signal respectively, and further comprises between the second road signal zoomed out: with signal form is that the second tunnel conversion of signals of the signal of telecommunication is a light signal;
Step B is described to zoom out the second road signal and carry out further signal emission and further comprise between handling: with signal form is that the second tunnel conversion of signals of light signal is the signal of telecommunication.
In sum, the advantage of a kind of wireless digital TV-set broadcast system and method that the present invention proposes is: the central radio digital broadcast transmitter utilizes transmit diversity techniques, signal is carried out the spatial emission diversity modulation, generate the two independent signal, will be wherein one road signal launch from self antenna, other one road signal is launched by the far-end transmitter module.Because the possibility of decline is smaller simultaneously in the process of transmission for the two independent signal, user terminal carries out diversity with the signal that receives and merges, and can improve receptivity, guarantees video quality.
Description of drawings
Fig. 1 is a typical wireless digital TV-set broadcast system basic structure schematic diagram in the prior art;
Fig. 2 is system's basic structure schematic diagram of using first preferred embodiment of the present invention program;
Fig. 3 is system's basic structure schematic diagram of using second preferred embodiment of the present invention program;
Fig. 4 is a flow chart of realizing the present invention program;
Fig. 5 is a method embodiment flow chart of using the present invention program.
Embodiment
For making the purpose, technical solutions and advantages of the present invention clearer, the present invention is described in further detail below in conjunction with the accompanying drawings and the specific embodiments.
The system of wireless digital TV-set broadcast comprises at least among the present invention: broadcast station subsystem, central radio digital broadcast transmitter, one or more far-end transmitter modules, user terminal.
Wherein, broadcast station subsystem is used for video data is carried out scrambling and multiplexing, obtains video transmission stream.
The central radio digital broadcast transmitter, the signal emission that be used for carrying out Base-Band Processing by the video transmission stream of broadcast station subsystem input, comprises the spatial emission diversity modulation function is handled, generate two paths of signals, first via signal is launched from self antenna, the second road signal is sent to the far-end transmitter module.
One or more far-end transmitter modules, each far-end transmitter module is used to receive the second road signal by the input of central radio digital broadcast transmitter, carry out further signal emission and handle, will handle the radiofrequency signal of back acquisition again and launch from each far-end transmitter module self antenna.
User terminal is used to receive the signal by central radio digital broadcast transmitter and the emission of one or more far-end transmitter modules, and the signal that comprises the spatial emission diversity demodulation function receives and handles, base band is contrary handles, and obtains video data.
Among the present invention, the central radio digital broadcast transmitter need carry out Base-Band Processing with video transmission stream, comprise the signal emission processing of spatial emission diversity modulation function, obtains first via signal, and first via signal is launched from the antenna of self.Wherein, baseband processing method is generally: earlier video transmission stream is encoded, carry out carrier modulation again, obtain baseband signal; The process that comprises the signal emission processing of spatial emission diversity modulation function is generally: baseband signal is carried out the spatial emission diversity modulation, carry out digital-to-analogue conversion again, obtain analog baseband signal, then analog baseband signal is carried out analog, obtain radiofrequency signal.
Among the present invention, the central radio digital broadcast transmitter is in the process of video transmission stream being carried out Base-Band Processing and the signal emission processing that comprises the spatial emission diversity modulation function, can generate the second road signal, and send to one or more far-end transmitter module.That is to say, the central radio digital broadcast transmitter can in the unmodulated baseband signal of video transmission stream being encoded and carrying out generating between the carrier modulation as the second road signal, by transmission mediums such as cables the second road signal is drawn again, send to one or more far-end transmitter module; Can by transmission mediums such as cables the second road signal be drawn again the modulated baseband signal that between carrier modulation and analog-to-digital conversion, generates as the second road signal, send to one or more far-end transmitter module.Modulated baseband signal described here can be the modulated baseband signal that generates between carrier modulation and spatial emission diversity modulation, also can be the modulated baseband signal that generates between spatial emission diversity modulation and digital-to-analogue conversion.The central radio digital broadcast transmitter can also be the analog signal that generates after digital-to-analogue conversion and analog process as the second road signal, by transmission mediums such as cables the second road signal is drawn again, send to one or more far-end transmitter module.Described analog signal may be intermediate-freuqncy signal or radiofrequency signal, and this is relevant with actual central radio digital broadcast transmitter design, repeats no more herein.
In a word, the central radio digital broadcast transmitter can outwards send two paths of signals: first via signal is an analog signal, launches from self antenna; The second road signal is digital signal or analog signal, and digital signal is above-mentioned unmodulated baseband signal or modulated baseband signal, and the second road signal is sent to one or more far-end transmitter module.
Among the present invention, each far-end transmitter module need carry out the second road signal further signal emission to be handled.Further signal emission described here is handled relevant with the signal form of the second road signal itself.If the second road signal is a unmodulated baseband signal, then the far-end transmitter module carries out the emission of further signal and is treated to: the second road signal is carried out carrier modulation, spatial emission diversity modulation, analog-to-digital conversion and analog process successively; If it is the modulated baseband signal that the central radio digital broadcast transmitter obtains the second road signal, then each far-end transmitter module carries out the emission of further signal and is treated to: the second road signal is carried out spatial emission diversity modulation, analog-to-digital conversion and analog process successively, perhaps the second road signal is carried out analog-to-digital conversion and analog process successively; And the rest may be inferred.In a word, the first via signal and the second tunnel Signal Processing process are roughly the same, but because the second road signal may be from the generation midway of processing procedure, other processing procedure is then realized by the far-end transmitter module so.
If the second road signal is the same with first via signal, it all is the radiofrequency signal that produces through after Base-Band Processing, spatial emission diversity modulation, digital-to-analogue conversion, the analog, then each far-end transmitter module can no longer carry out other processing, and directly the second road signal is launched from self antenna; Processing such as the far-end transmitter module also can amplify again, filtering are launched the second road signal then.In order to narrate conveniently, no matter how the far-end transmitter module is handled the second road signal that receives, the present invention unifies to be called further signal emission and handles.
System embodiment
Fig. 2 has shown the basic structure schematic diagram of using the present invention program's system embodiment.As shown in Figure 2, present embodiment comprises: broadcast station subsystem 201, central radio digital broadcast transmitter 202, conversion and control equipment 203, far-end transmitter module 204 and user terminal 205.
Wherein, broadcast station subsystem 201 is used for video data is carried out scrambling and multiplexing, obtains video transmission stream, and is transferred to central radio digital broadcast transmitter 202.
Central radio digital broadcast transmitter 202, be used for and carry out Base-Band Processing, spatial emission diversity modulation, analog-to-digital conversion, analog by the video transmission stream of broadcast station subsystem 201 inputs, generate the two-way radiofrequency signal, respectively the two-way radiofrequency signal is carried out delay process, and first via signal launched from self antenna, the second road signal is sent to conversion and control equipment 203.
Conversion and control equipment 203 is used to receive the second road signal by 202 inputs of central radio digital broadcast transmitter, is light signal with the second tunnel conversion of signals, and sends to far-end transmitter module 204 by optical fiber.
Far-end transmitter module 204 is used to receive the second road signal by 203 inputs of conversion and control equipment, is the signal of telecommunication with the second tunnel conversion of signals earlier, amplifies and Filtering Processing again, and the second road signal after will handling is then launched from self antenna.
In the present embodiment, broadcast station subsystem 201 is carried out scrambling and multiplexing with video data, obtains video transmission stream, and video transmission stream is transferred to central radio digital broadcast transmitter 202; Central radio digital broadcast transmitter 202 carries out Base-Band Processing, spatial emission diversity modulation, analog-to-digital conversion, analog with video transmission stream, generating the two paths of signals form is the radiofrequency signal of analog signal, will be wherein one the tunnel as first via signal, with other one the tunnel as the second road signal; Central radio digital broadcast transmitter 202 carries out delay process with two paths of signals respectively again, will send to conversion and control equipment 203 through the second road signal after the delay process; Conversion and control equipment 203 is that the second tunnel conversion of signals of the signal of telecommunication is a light signal with signal form, sends to far-end transmitter module 204 by optical fiber again; Far-end transmitter module 204 is the signal of telecommunication with the second tunnel conversion of signals again, and amplifies once more and Filtering Processing; Central radio digital broadcast transmitter 202 and far-end transmitter module 204 are launched the first via signal and the second road signal respectively simultaneously; User terminal 205 receives after central radio digital broadcast transmitter 202 and far-end emission mould certainly launches 204 the first via signal and the second road signal, the signal that comprises the spatial emission diversity demodulation function receives and handles, base band is contrary handles, and obtains video data.
In the present embodiment, broadcast station subsystem 201, central radio digital broadcast transmitter 202, far-end transmitter module 204 and user terminal 205 are essential, and conversion and control equipment 203 then can be selected arbitrarily.That is to say, when center wireless digital TV-set broadcast transmitter 202 directly sends to far-end transmitter module 204 by transmission mediums such as copper cables with the second road signal, just can need not to utilize conversion and control equipment 203 to carry out opto-electronic conversion.
In addition, when if central radio digital broadcast transmitter 202 does not carry out delay process with the second road signal, can in conversion and control equipment 203 the second road signal be carried out delay process, promptly conversion and control equipment 203 can further increase the function of delay process.Certainly, in actual applications, if the space length of central radio digital broadcast transmitter 202 and far-end transmitter module 204 is smaller, the first via signal and the second road signal need not to carry out delay process and just can guarantee to launch from central radio digital broadcast transmitter 202 and far-end transmitter module 204 simultaneously, then also can not comprise the function of delay process in central radio digital broadcast transmitter 202 or the far-end transmitter module 204.
Use the present invention program, if user terminal is covered by central radio digital broadcast transmitter 202 and far-end transmitter module 204, promptly receive two paths of signals simultaneously, can pass through the spatial emission diversity demodulation function, it is road signal after the diversity folding obtains to merge, weaken the decline effect in the transmission of wireless signals, improve the receptivity of user terminal, guarantee video quality.
In actual applications, the system of wireless digital TV-set broadcast can be provided with an above far-end transmitter module, and user terminal can be covered by central radio digital broadcast transmitter and an above far-end transmitter module simultaneously.Fig. 3 has shown that terminal is simultaneously by central radio digital broadcast transmitter and two situations that the far-end transmitter module covers.As shown in Figure 3, the system of wireless digital TV-set broadcast comprises: broadcast station subsystem 301, central radio digital broadcast transmitter 302, conversion and control equipment 303, the first far-end transmitter module 304, the second far-end transmitter module 305, user terminal 306.Wherein, broadcast station subsystem 301, central radio digital broadcast transmitter 302, conversion and control equipment 303, user terminal 306 are identical with the function of broadcast station subsystem 201, central radio digital broadcast transmitter 202, conversion and control equipment 203, user terminal 205 among Fig. 2 respectively; The first far-end transmitter module 304 is all identical with the function of far-end transmitter module 204 among Fig. 2 with the second far-end transmitter module 305, repeats no more herein.Its difference is: conversion and control equipment 303 sends to the first far-end transmitter module 304 and the second far-end transmitter module 305 by two different interfaces respectively with secondary signal.Certainly, in actual applications, conversion and control equipment 303 also can pass through same interface, and the second road signal is sent to the first far-end transmitter module 304 and the second far-end transmitter module 305 respectively.In addition, receive when user terminal 306 after three road signals of central radio digital broadcast transmitter 302, the first far-end transmitter module 304,305 emissions of the second far-end transmitter module, still can three road signals be merged into one road signal by the method that diversity merges, can improve receptivity better.
In actual applications,, also still can obtain vision signal, satisfy basic receptivity according to one road signal if user terminal is only covered by central radio digital broadcast transmitter or some far-end transmitter modules.
System at the present invention's proposition, the invention allows for a kind of method that realizes wireless digital TV-set broadcast, its basic thought is: utilize the spatial emission diversity technology, video transmission stream is modulated to two paths of signals, and respectively from central radio digital broadcast transmitter and the emission of far-end transmitter module, receive described two paths of signals by the user again, merge processing again, obtain video data.
Fig. 4 has shown the flow chart of realizing the present invention program.As shown in Figure 4, the present invention program realizes that the method for wireless digital TV-set broadcast may further comprise the steps:
Step 401: video data is carried out scrambling and multiplexing, obtain video transmission stream.
Step 402: with video transmission stream carry out Base-Band Processing, the signal emission that comprises the spatial emission diversity modulation function handles, obtain first via signal, and in Base-Band Processing with comprise in the signal emission processing procedure of spatial emission diversity modulation function and obtain the second road signal, the second road signal zoomed out and carry out further signal emission and handle, then the first via signal and the second road signal are launched simultaneously.
In actual applications, described Base-Band Processing is generally: earlier video transmission stream is encoded, carry out carrier modulation again, obtain digital baseband signal; The described signal emission that comprises the spatial emission diversity modulation function is handled and is comprised: earlier digital baseband signal is carried out the spatial emission diversity modulation, carry out digital-to-analogue conversion again, obtain analog baseband signal, carry out analog then, obtain radiofrequency signal.
Among the present invention, the central radio digital broadcast transmitter generates two paths of signals, first via signal is the radiofrequency signal through obtaining after the signal emission processing procedure that comprises the spatial emission diversity modulation function, the second road signal can be unmodulated baseband signal, modulated baseband signal or analog signal for launching the signal that obtains in the processing procedure at Base-Band Processing and the signal that comprises the spatial emission diversity modulation function.Wherein, be unmodulated baseband signal at the second road signal of video transmission stream being encoded and carry out generating between the carrier modulation; The second road signal that generates between carrier modulation and analog-to-digital conversion is the modulated baseband signal, can be the signal that generates between the modulation of carrier modulation and spatial emission diversity, also can be the signal that generates between spatial emission diversity modulation and the digital-to-analogue conversion; The signal that generates after digital-to-analogue conversion is an analog signal, can be intermediate-freuqncy signal, also can be radiofrequency signal.
Among the present invention, the method and the second tunnel signal correction that the further signal emission that the far-end transmitter module carries out is handled.If the second road signal that the far-end transmitter module receives is a unmodulated baseband signal, then further the signal emission is treated to: earlier the second road signal is carried out carrier modulation, carry out the spatial emission diversity modulation again, carry out analog-to-digital conversion and analog then; If the second road signal that the far-end transmitter module receives is the modulated baseband signal, then further the signal emission is treated to: earlier the second road signal is carried out the spatial emission diversity modulation, carry out analog-to-digital conversion again, carry out analog then, perhaps be: earlier the second road signal is carried out analog-to-digital conversion, carry out analog again; If the second road signal that the far-end transmitter module receives is an analog signal, then the far-end transmitter module can directly be launched the second road signal, also can further amplify, analog such as filtering, the second road signal is launched again.
In a word, the first via signal and the second tunnel Signal Processing process are roughly the same, and just the second road signal may produce from processing procedure, and carries out other processing procedure by the far-end transmitter module.
Step 403: user terminal will receive signal reception processing, the contrary processing of base band that signal comprises the spatial emission diversity demodulation function, obtain video data.
Among the present invention, described spatial emission diversity demodulation is merged into one road signal with the two paths of signals that receives in fact exactly, and contrary processing of described base band then is processing procedures such as demodulation, decoding.
Among the present invention, described spatial emission diversity modulation and demodulation method is actually has utilized transmit diversity techniques to realize.The characteristics of transmit diversity techniques are to utilize in the nature wireless propagation environment independently multipath signal to realize diversity.Because it is smaller that the possibility that declines appears in multipath signal simultaneously, so, can earlier signal be modulated to two paths of signals and launch again, terminal then merges the two paths of signals that receives, can improve instantaneous signal-to-noise ratio and average signal-to-noise ratio, promptly can improve the receptivity of user terminal.
In actual applications, the method for spatial emission diversity modulation can be methods such as sky sign indicating number modulation frequently, empty time-code (STC) modulation or space-time block code (STBC) modulation.Following STBC is modulated to the basic principle of example prescribed space transmit diversity modulator approach.
At first, transmitter is paired symbol by the space-time block coding scheme with signal encoding, and sends pair of symbols simultaneously by two antennas.Through the symbol that obtains behind the space-time block coding as shown in Table 1:
| The symbol of antenna a emission | The symbol of antenna b emission | |
| T constantly | s 0 | s 1 |
| T+ Δ t constantly | -s 1 * | s 0 * |
Table one
Wherein, s
0And s
1Be pair of symbols, constantly launch by antenna a and antenna b respectively at T;-s
1 *And s
0 *Be pair of symbols, represent s respectively
0And s
1Conjugation, constantly launch by antenna a and antenna b respectively at T+ Δ t.Like this, when terminal at t
0Constantly receive s by antenna a and antenna b emission
0And s
1The time, can picked up signal r
0When terminal at t
0+ Δ t receive constantly by antenna a and antenna b emission-s
1 *And s
0 *The time, can picked up signal r
1
r
0Can be by formula r
0=r (t
0)=h
0s
0+ h
1s
1+ n
0Expression, r
1Can be by formula r
1=r (t
0+ Δ t)=-h
0s
1 *+ h
1s
0 *+ n
1Expression.Wherein, h
0Be illustrated in symbol s
0Channel response in duration, h
1Be illustrated in symbol s
1Channel response in duration, n
0Be illustrated in symbol s
0Noise in duration, n
1Be illustrated in symbol s
1Noise in duration.Terminal merges signal after the processing, just can improve receptivity.
In the present invention, according to above-mentioned diversity technique principle, the antenna of the antenna of central radio digital broadcast transmitter and far-end transmitter module is equivalent to antenna a and antenna b respectively, needs outwards emission two independent signal.Because the spatial emission diversity modulation will produce the two independent signal, as produce a road signal and b road signal, the a road signal that then can directly the central radio digital broadcast transmitter be carried out obtaining after the spatial emission diversity modulation is as first via signal, as the second road signal, vice versa with the b road signal that obtains.
If the second road signal obtained before the spatial emission diversity modulation, then this moment, the first via signal and the second road signal were duplicate, as: can be unmodulated baseband signal.So, after center wireless digital TV-set broadcast transmitter carried out the first via signal spatial emission diversity modulation, can get a road signal was first via signal, and gives up b road signal; Correspondingly, after the far-end transmitter module carried out the second road signal spatial emission diversity modulation, can get b road signal was the second road signal, and gives up a road signal.Certainly, in actual applications, it is first via signal that the central radio digital broadcast transmitter also can be got b road signal, and it is the second road signal that the far-end transmitter module can be got a road signal.
In a word, among the present invention, outwards the two paths of signals of emission is the different independently signal after handling through diversity.
Method embodiment
Fig. 5 has shown the method embodiment flow chart of using the present invention program.As shown in Figure 5, present embodiment realizes that the method for wireless digital TV-set broadcast may further comprise the steps:
Step 501: broadcast station subsystem is carried out scrambling and multiplexing with video data, obtains video transmission stream, sends to the central radio digital broadcast transmitter.
Step 502: the central radio digital broadcast transmitter obtains the two-way radiofrequency signal after the video transmission stream that obtains is carried out Base-Band Processing, spatial emission diversity modulation, digital-to-analogue conversion and analog process.
In this step, described Base-Band Processing comprises coding, carrier modulation, and carrier modulation can adopt orthogonal frequency division modulated modulator approaches such as (OFDM).The spatial emission diversity modulation is the modulation of carrying out in order to realize transmit diversity, can be modulator approaches such as sky sign indicating number modulation frequently, STC modulation or STBC modulation.Described analog process can comprise processing such as frequency conversion, amplification, filtering.
Step 503: the central radio digital broadcast transmitter carries out delay process with the first via signal and the second road signal respectively, will send to conversion and control equipment through the second road signal of delay process.
In the present embodiment, the second road signal that sends to conversion and control equipment is an analog signal.For first via signal and the second road signal can be launched from central radio digital broadcast transmitter and far-end transmitter module respectively simultaneously, the central radio digital broadcast transmitter can adopt the method that changes path-length to carry out delay process.The method of change path-length described here is a kind of delay process method at analog signal, is a kind of known technology, no longer is described in detail herein.
In actual applications, the second road signal can also then can adopt the mode of buffering to carry out delay process for digital signals such as unmodulated baseband signal, modulated baseband signals.
No matter be that analog signal is delayed time, still digital signal to be delayed time, first via signal is relevant with actual system design with the concrete time of the second road signal demand time-delay, no longer is described in detail herein.For example:, then the transmission delay of the first via signal and the second road signal should be controlled in Cyclic Prefix (CP) the duration length, i.e. 10 microsecond magnitudes when base band adopts orthogonal frequency division modulated.
In actual applications, time-delay to the second road signal can be by the central radio digital broadcast transmitter processes, also can earlier the second road signal of delaying time be sent to conversion and control equipment, come the second road signal is carried out delay process by conversion and control equipment again.
In actual applications, if the space length of central radio digital broadcast transmitter and far-end transmitter module is closer, can guarantee that the first via signal and the second road signal launch simultaneously, then can the first via signal and the second road signal not carried out delay process.
Step 504: conversion and control equipment is light signal with the second tunnel conversion of signals, and sends to the far-end transmitter module by optical fiber.
In actual applications, can be not light signal also, and directly utilize transmission mediums such as copper cable that the second road signal is sent to the far-end transmitter module the second tunnel conversion of signals.
In addition, this step is described sends to the far-end transmitter module with the second road signal and also is commonly referred to signal is zoomed out.
Step 505: the second tunnel conversion of signals that the far-end transmitter module will receive earlier is the signal of telecommunication, amplify again, filtering etc. further the signal emission handle.
In actual applications, the far-end transmitter module can be not yet to being that the second road signal of radiofrequency signal carries out further signal emission and handles, and directly the second road signal is launched from antenna.
Step 506: central radio digital broadcast transmitter and far-end transmitter module send the first via signal and the second road signal respectively simultaneously.
Be not absolute synchronization in the time of described in this step, but as long as with the ERROR CONTROL of launch time of the first via signal and the second road signal in certain limit, do not influence user terminal and obtain video data and get final product according to receiving two paths of signals.
Step 507: user terminal receives two paths of signals, and the signal that comprises the spatial emission diversity demodulation function receives and handles, base band is contrary handles, and obtains video data.
After user terminal receives two paths of signals, carry out the spatial emission diversity demodulation, the demodulation of promptly empty sign indicating number frequently, STC demodulation or STBC demodulation etc. are merged into one road signal with two paths of signals, reach high specific and merge the identical diversity gain of receive diversity, improve receptivity.
In sum, more than be preferred embodiment of the present invention only, be not to be used to limit protection scope of the present invention.Within the spirit and principles in the present invention all, any modification of being done, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (14)
1, a kind of system that realizes wireless digital TV-set broadcast, this system comprises at least: the broadcast station subsystem, central radio digital broadcast transmitter and the user terminal that video data are carried out scrambling and multiplexing back acquisition video transmission stream, it is characterized in that this system further comprises: one or more far-end transmitter modules;
Described central radio digital broadcast transmitter, the signal emission that be used for carrying out Base-Band Processing by the video transmission stream of broadcast station subsystem input, comprises the spatial emission diversity modulation function is handled, generate two paths of signals, first via signal is launched from self antenna, the second road signal is sent to one or more far-end transmitter modules;
Described each far-end transmitter module is used to receive the second road signal by the input of central radio digital broadcast transmitter, carries out further signal emission and handles, and obtains radiofrequency signal, launches from self antenna again;
Described user terminal is used to receive the two paths of signals by central radio digital broadcast transmitter and the emission of far-end transmitter module, and the signal that comprises the spatial emission diversity demodulation function receives and handles, base band is contrary handles, and obtains video data.
2, system according to claim 1 is characterized in that, this system further comprises:
Conversion and control equipment is used to receive the second road signal by the input of central radio digital broadcast transmitter, is light signal with the second tunnel conversion of signals, and sends to the far-end transmitter module by optical fiber;
The light signal that the far-end transmitter module is further used for being inputed to self by conversion and control equipment is converted to the signal of telecommunication.
3, system according to claim 1 and 2 is characterized in that, the two paths of signals that described central radio digital broadcast transmitter is further used for generating carries out delay process.
4, system according to claim 2 is characterized in that, described central radio digital broadcast transmitter is further used for first via signal is carried out delay process;
Described conversion and control equipment is further used for the second road signal is carried out delay process.
5, a kind of method that realizes wireless digital TV-set broadcast is characterized in that, this method may further comprise the steps:
A, video data is carried out scrambling and multiplexing, obtain video transmission stream;
B, with video transmission stream carry out Base-Band Processing, the signal emission that comprises the spatial emission diversity modulation function handles, obtain first via signal, and in Base-Band Processing with comprise in the signal emission processing procedure of spatial emission diversity modulation function and obtain the second road signal, the second road signal zoomed out and carry out further signal emission and handle, then the first via signal and the second road signal are launched simultaneously;
The signal that C, user terminal comprise the spatial emission diversity demodulation function with the first via signal that receives and the second road signal receives and handles, base band is contrary handles, and obtains video data.
6, method according to claim 5 is characterized in that, the described Base-Band Processing of step B is: video flowing is encoded and carrier modulation;
The described signal emission that comprises the spatial emission diversity modulation function is treated to: baseband signal is carried out spatial emission diversity modulation, analog-to-digital conversion and analog.
7, method according to claim 6 is characterized in that, described the second road signal of step B is: unmodulated baseband signal, modulated baseband signal or analog signal.
8, method according to claim 7, it is characterized in that, if the second road signal is a unmodulated baseband signal, the acquisition methods of described the second road signal of step B is: between coding and carrier modulation, generate the two-way unmodulated baseband signal, and will be wherein one the tunnel as the second road signal;
The method that the described further signal emission of step B is handled is: the second road signal is carried out carrier modulation, spatial emission diversity modulation, analog-to-digital conversion and analog process, generate radiofrequency signal.
9, method according to claim 7, it is characterized in that, if the second road signal is the modulated baseband signal, the acquisition methods of described the second road signal of step B is: between the modulation of carrier modulation and spatial emission diversity, generate two-way modulated baseband signal, and will be wherein one the tunnel as the second road signal;
The method that the described further signal emission of step B is handled is: the second road signal is carried out spatial emission diversity modulation, analog-to-digital conversion and analog process.
10, method according to claim 7, it is characterized in that, if the second road signal is the modulated baseband signal, the acquisition methods of described the second road signal of step B is: between spatial emission diversity modulation and digital-to-analogue conversion, generate two-way modulated baseband signal, and will be wherein one the tunnel as the second road signal;
The method that the described further signal emission of step B is handled is: the second road signal is carried out analog-to-digital conversion and analog process.
11, method according to claim 7 is characterized in that, if the second road signal is an analog signal, the acquisition methods of described the second road signal of step B is: after digital-to-analogue conversion, generate the two-way analog signal, and will be wherein one the tunnel as the second road signal;
The method that the described further signal emission of step B is handled is: the second road signal is carried out further analog.
12, according to Claim 8 to 11 each described methods, it is characterized in that, described acquisition the second road signal of step B and the second road signal zoomed out between further comprise:
Respectively the first via signal and the second road signal are carried out delay process.
13, method according to claim 12 is characterized in that, the method for described delay process is: the method or the way to play for time that change path-length.
14, method according to claim 13, it is characterized in that, step B is described to carry out delay process with the first via signal and the second road signal respectively, and further comprises between the second road signal zoomed out: with signal form is that the second tunnel conversion of signals of the signal of telecommunication is a light signal;
Step B is described to zoom out the second road signal and carry out further signal emission and further comprise between handling: with signal form is that the second tunnel conversion of signals of light signal is the signal of telecommunication.
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| CN 200610066675 CN1984325A (en) | 2006-04-19 | 2006-04-19 | System and method for realizing wireless digital TV-set broadcast |
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| CN 200610066675 CN1984325A (en) | 2006-04-19 | 2006-04-19 | System and method for realizing wireless digital TV-set broadcast |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110022494A (en) * | 2018-01-03 | 2019-07-16 | 鸿海精密工业股份有限公司 | Display device structure |
| CN107197390B (en) * | 2017-05-27 | 2019-11-12 | 上海东方明珠广播电视研究发展有限公司 | Wireless signal emission system, method, method for receiving and processing signal and terminal |
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2006
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107197390B (en) * | 2017-05-27 | 2019-11-12 | 上海东方明珠广播电视研究发展有限公司 | Wireless signal emission system, method, method for receiving and processing signal and terminal |
| CN110022494A (en) * | 2018-01-03 | 2019-07-16 | 鸿海精密工业股份有限公司 | Display device structure |
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