A kind of transmission method of broadcast television signal, system and device
Technical field
The present invention relates to communication technical field, relate in particular to a kind of transmission method, system and device of broadcast television signal.
Background technology
In order to realize the emission of broadcast television signal multiple frequency synchronous, often need make each transmitting base station send the high-frequency carrier signal of identical frequency spectrum, and can carry out accurate time delay control, to reduce the co-channel interference between the adjacent base station to carrier signal.
As shown in Figure 1, broadcast television signal transmission center of the prior art (for example certain TV station) is sent the signal of each cover broadcast TV program into the corresponding digital coding unit, and the radio and television digital code stream after encoded is transferred to each base station through transmitting element.In each base station, the receiving element reduction obtains radio and television digital code stream signal, and send into modulating unit, modulating unit is modulated into radio and television digital code stream signal the high-frequency carrier signal of broadcast television signal, and, adopt global positioning system (GPS, global positioning system) clock signal is carried out the time delay adjustment to this high-frequency carrier signal, so that the time delay of the high frequency carrier that contains broadcast television signal that each base station goes out is synchronous, the adjusted high-frequency carrier signal that contains broadcast television signal of time delay is launched after power amplification.
This shows, in the multiple frequency synchronous emission system of existing broadcast television signal, the radio and television high-frequency carrier signal of each channel is by independently modulator generation of base station, promptly for the broadcast television signal of each channel, all need an independent modulators modulate to produce the radio and television high-frequency carrier signal of this channel, yet when the broadcast television signal multiple frequency synchronous was launched, the high frequency carrier frequency spectrum that produces in each modulator of each base station was not in full accord.
For example, in two transmitting base stations of A, B, when same digital broadcasting-television signal is modulated into the high-frequency carrier signal of same frequency, experienced a nonlinear process, the high frequency carrier frequency spectrum that two base stations of A, B produce not is in full accord, when the high-frequency carrier signal of A, B base station drops on a receiving terminal simultaneously, will form homogenous frequency signal and disturb.Therefore, two transmitting base stations of A, B are in order to ensure the carrier frequency unanimity of sending, adopted the high precision reference clock signal of GPS to carry out synchronously, the GPS reference clock signal locks local oscillation signal by phase-locked loop, the centre frequency of the high-frequency carrier signal that transmitting base station sends is constantly revised and reached stable, but, above process can not guarantee that the instantaneous frequency of the high-frequency carrier signal that two transmitting base stations of A, B are launched is identical, and small frequency error must cause quite serious co-channel interference.And, because prior art at same set of broadcast TV program, needs to be modulated at each inside of base station respectively the high-frequency carrier signal of same frequency, and carries out synchronous debugging by the GPS standard time clock, thereby cause the system equipment cost very high, the debugging complexity is also very high.
In sum, prior art is when synchronous transmission multichannel broadcast television signal, and co-channel interference is bigger, and system cost is higher, and debugging is complicated.
Summary of the invention
The embodiment of the invention provides a kind of transmission method, system and a kind of base station of broadcast television signal, in order to solve prior art when the synchronous transmission multichannel broadcast television signal, have that co-channel interference is big, system cost is higher, and the debugging complicated problems.
The launching technique of a kind of broadcast television signal that the embodiment of the invention provides comprises:
The base station receives the transmission signals from the broadcast emission, and therefrom restore the radio and television high-frequency carrier signal that contains a plurality of different channels, wherein, after described transmission signals comprises that described broadcast is modulated each group broadcast television signal respectively, the radio and television high-frequency carrier signal of each channel that obtains, wherein, one group of corresponding channel of broadcast television signal;
The time delay adjustment is carried out to the described radio and television high-frequency carrier signal that receives in described base station, and will carry out the filtering frequency-selecting through the adjusted radio and television high-frequency carrier signal of described time delay and handle, and restores the radio and television high-frequency carrier signal of each channel;
User terminal is given with the radio and television high-frequency carrier signal synchronized transmissions of described each channel that restores in described base station.
The launching technique of a kind of broadcast television signal that the embodiment of the invention provides comprises:
Broadcast is modulated each group broadcast television signal respectively, obtains the radio and television high-frequency carrier signal of each channel, wherein, and one group of corresponding channel of broadcast television signal;
Described broadcast is given the base station with the radio and television high-frequency carrier signal of described each channel by the transmission medium synchronized transmissions, make the base station from the transmission signals that receives, restore the radio and television high-frequency carrier signal that contains a plurality of different channels, and described radio and television high-frequency carrier signal carried out the time delay adjustment, to carry out the filtering frequency-selecting through the adjusted radio and television high-frequency carrier signal of described time delay and handle, isolate the radio and television high-frequency carrier signal of each channel.
The transmission method of a kind of broadcast television signal that the embodiment of the invention provides comprises:
Broadcast is modulated each group broadcast television signal respectively, obtain the radio and television high-frequency carrier signal of each channel, and give the base station by the transmission medium synchronized transmissions with the radio and television high-frequency carrier signal of described each channel, wherein, one group of corresponding channel of broadcast television signal;
The time delay adjustment is carried out to described radio and television high-frequency carrier signal in described base station, and will carry out the filtering frequency-selecting through the adjusted radio and television high-frequency carrier signal of described time delay and handle, restore the radio and television high-frequency carrier signal of each channel, and give user terminal the radio and television high-frequency carrier signal synchronized transmissions of described each channel that restores.
The transmission system of a kind of broadcast television signal that the embodiment of the invention provides comprises:
Broadcast, be used for respectively each group broadcast television signal being modulated, obtain the radio and television high-frequency carrier signal of each channel, and give the base station by the transmission medium synchronized transmissions with the radio and television high-frequency carrier signal of described each channel, wherein, one group of corresponding channel of broadcast television signal;
The base station, be used for described radio and television high-frequency carrier signal is carried out the time delay adjustment, and will carry out the filtering frequency-selecting through the adjusted radio and television high-frequency carrier signal of described time delay and handle, restore the radio and television high-frequency carrier signal of each channel, and give user terminal the radio and television high-frequency carrier signal synchronized transmissions of described each channel that restores.
The emitter of a kind of broadcast television signal that the embodiment of the invention provides comprises:
Modulating unit is used for each group broadcast television signal is modulated, and must cut open the radio and television high-frequency carrier signal of each channel, wherein, and one group of corresponding channel of broadcast television signal;
Transmission unit, be used for giving the base station by the transmission medium synchronized transmissions with the radio and television high-frequency carrier signal of described each channel, make the base station from the transmission signals that receives, restore the radio and television high-frequency carrier signal that contains a plurality of different channels, and described radio and television high-frequency carrier signal carried out the time delay adjustment, to carry out the filtering frequency-selecting through the adjusted radio and television high-frequency carrier signal of described time delay and handle, isolate the radio and television high-frequency carrier signal of each channel.
A kind of base station that the embodiment of the invention provides comprises:
Transmission unit, be used to receive transmission signals from the broadcast emission, and therefrom restore the radio and television high-frequency carrier signal that contains a plurality of different channels, wherein, after described transmission signals comprises that described broadcast is modulated each group broadcast television signal respectively, the radio and television high-frequency carrier signal of each channel that obtains, wherein, one group of corresponding channel of broadcast television signal;
The time delay adjustment unit is used for the radio and television high-frequency carrier signal that contains a plurality of different channels that described transmission unit reduction obtains is carried out the time delay adjustment;
Filtering frequency-selecting unit is used for that described radio and television high-frequency carrier signal is carried out the filtering frequency-selecting and handles, and restores the radio and television high-frequency carrier signal of each channel;
Transmitter unit is used for giving user terminal with the radio and television high-frequency carrier signal synchronized transmissions of described each channel that restores.
Description of drawings
The embodiment of the invention by the transmission signals of base station reception from broadcast, and therefrom restores the radio and television high-frequency carrier signal that contains a plurality of different channels; Filtering frequency-selecting processing is carried out to described radio and television high-frequency carrier signal in described base station, isolates the radio and television high-frequency carrier signal of each channel; User terminal is given with the radio and television high-frequency carrier signal synchronized transmissions of described isolated each channel in described base station.Because the spectrum component of the radio and television high-frequency carrier signal of the same channel that each base station reduction obtains is identical, particularly the transient behavior relative difference on frequency is zero, thereby avoided the problem that the frequency spectrum of the radio and television high-frequency carrier signal of the same channel of each base station there are differences in the prior art, the radio and television high-frequency carrier signal of the same channel of each base station of the present invention drops on same user terminal simultaneously, reduces to minimum thereby the homogenous frequency signal that produces disturbs; And, because the broadcast singal that comprises in the transmission signals that each base station receives is the radio and television high-frequency carrier signal that has modulated, therefore, saved each base station and the broadcast television signal of each channel has been modulated into the process of the radio and television high-frequency carrier signal of this channel, thereby system cost obviously reduces, and it is very simple that system debug becomes.
Fig. 1 is the structural representation of the multiple frequency synchronous emission system of broadcast television signal in the prior art;
The structural representation of the transmission system of a kind of broadcast television signal that Fig. 2 provides for the embodiment of the invention;
Embodiment
The schematic flow sheet of the transmission method of a kind of broadcast television signal that Fig. 3 provides for example of the present invention.
The embodiment of the invention provides a kind of frequency division multiplexing synchronization transfer method, system and device of broadcast television signal, in order to reduce the co-channel interference of radio and television high-frequency carrier signal, reduces system cost, makes system debug simpler.
The described radio and television high-frequency carrier signal of the embodiment of the invention is the high-frequency carrier signal that comprises broadcast television signal.
Below in conjunction with accompanying drawing, the embodiment of the invention is specifically described.
Referring to Fig. 2, the transmission system of a kind of broadcast television signal that the embodiment of the invention provides comprises:
Broadcast 21, be used for each group broadcast television signal (promptly respectively organizing vision signal) is modulated, obtain the radio and television high-frequency carrier signal of each channel, and give base station 22 by the transmission medium synchronized transmissions the radio and television high-frequency carrier signal of each channel.
The described broadcast television signal of respectively organizing is each group vision signal, one group of vision signal correspondence a channel, for example, if there are 10 groups of vision signals to need to send, then need these 10 groups of vision signals are modulated into the radio and television high-frequency carrier signal of 10 channels, promptly respectively organize vision signal and adopt the high-frequency carrier signal of different frequency to send.
Described transmission medium can be a microwave, also can be optical fiber, therefore, broadcast 21 need be converted to microwave signal or light signal with the radio and television high-frequency carrier signal of first channel and second channel, is transmitted to each base station by microwave or optical fiber then.
The present invention is transmitted to each signal of base station (for example microwave signal or light signal) with broadcast and is called transmission signals, comprising the radio and television high-frequency carrier signal of a plurality of channels.
Base station 22, be used to receive transmission signals from broadcast 21, and therefrom reduction obtains containing the radio and television high-frequency carrier signal of each channel, and this radio and television high-frequency carrier signal is carried out the filtering frequency-selecting handle, isolate the radio and television high-frequency carrier signal of each channel, and give user terminal the radio and television high-frequency carrier signal synchronized transmissions of isolated each channel.
The embodiment of the invention is that example describes with the broadcast television signal that transmits two channels.
Preferably, described broadcast 21 comprises:
Coding unit 210 is used for first group of broadcast television signal carried out encoding process, obtains first group digital broadcasting-television signal.
Modulating unit 211 is used for first group of digital broadcasting-television signal modulated, and obtains the radio and television high-frequency carrier signal of first channel.
Coding unit 212 is used for second group of broadcast television signal carried out encoding process, obtains second group digital broadcasting-television signal.
Modulating unit 213 is used for second group of digital broadcasting-television signal modulated, and obtains the radio and television high-frequency carrier signal of second channel.
Transmission unit 214, the radio and television high-frequency carrier signal that is used to contain first channel and second channel is given base station 22 by the transmission medium synchronized transmissions.
Need to prove that coding unit exists in order to generate digital broadcasting-television signal,, only need the transportation simulator broadcast television signal, then do not need coding unit if do not need to generate the array broadcast television signal.
Preferably, described base station comprises:
Transmission unit 220 is used to receive the transmission signals from broadcast 21.If broadcast 21 adopts microwave emission broadcast television signal, then the transmission signals that receives of transmission unit 220 is a microwave signal, and transmission unit 220 need be reduced into the microwave signal that receives the radio and television high-frequency carrier signal that contains first channel and second channel; If broadcast 21 adopts optical fiber emission broadcast television signal, then the transmission signals that receives of transmission unit 220 is a light signal, and transmission unit 220 need be reduced into the light signal that receives the radio and television high-frequency carrier signal that contains first channel and second channel.
Time delay adjustment unit 221 is used for the radio and television high-frequency carrier signal that contains first channel and second channel that described transmission unit 220 reduction obtain is carried out time delay adjustment uniformly.
Filtering frequency-selecting unit 222 is used for the radio and television high-frequency carrier signal of described time delay adjustment unit 221 adjusted first channels and second channel is carried out filtering frequency-selecting processing, isolates the radio and television high-frequency carrier signal of first channel.
Amplifying unit 223 is used for the radio and television high-frequency carrier signal of described filtering frequency-selecting unit 222 isolated first channels is carried out the power amplification processing.
Filtering frequency-selecting unit 224 is used for that the described time delay adjustment unit 221 adjusted radio and television high-frequency carrier signals that contain first channel and second channel are carried out the filtering frequency-selecting and handles, and isolates the radio and television high-frequency carrier signal of second channel.
Amplifying unit 225 is used for the radio and television high-frequency carrier signal of described filtering frequency-selecting unit 224 isolated second channels is carried out the power amplification processing.
Transmitter unit 226 is used for giving user terminal with first channel after handling through power amplification and the radio and television high-frequency carrier signal synchronized transmissions of second channel.
This shows, in the system that the embodiment of the invention provides, by the broadcast unification each group broadcast television signal is modulated into the radio and television high-frequency carrier signal of each channel, has avoided each base station each group broadcast television signal to be modulated into radio and television high-frequency carrier signal loaded down with trivial details of each channel; And, in each base station, radio and television high-frequency carrier signal to each channel carries out unified time delay adjustment, thereby avoid each base station in the prior art to the radio and television high-frequency carrier signal of each channel need carry out separately that time delay adjusts loaded down with trivial details and, also avoided the radio and television high-frequency carrier signal of each channel to carry out the error that the time delay adjustment is brought through different time delay adjustment units.Therefore, the system that the embodiment of the invention provides not only can reduce the co-channel interference of radio and television high-frequency carrier signal, but also can reduce system cost largely, makes system debug more quick.
Introduce the method that the embodiment of the invention provides below.
Referring to Fig. 3, the transmission method of a kind of broadcast television signal that the embodiment of the invention provides comprises:
S301, broadcast are carried out encoding process with each group broadcast television signal, are respectively organized digital broadcasting-television signal.
S302, broadcast are modulated each group digital broadcasting-television signal, obtain the radio and television high-frequency carrier signal of each channel.
S303, broadcast are given the base station with the radio and television high-frequency carrier signal of each channel by the transmission medium synchronized transmissions.
S304, base station receive the transmission signals from broadcast, and therefrom restore the radio and television high-frequency carrier signal that contains described each channel, and the described radio and television high-frequency carrier signal that contains each channel carried out the time delay adjustment, so that the time delay unanimity of the radio and television high-frequency carrier signal of the same channel of each base station in the system is avoided co-channel interference.
Filtering frequency-selecting processing will be carried out through the adjusted radio and television high-frequency carrier signal that contains each channel of time delay in S305, base station, isolate the radio and television high-frequency carrier signal of each channel.
S306, base station carry out the radio and television high-frequency carrier signal of isolated each channel to be transmitted to user terminal after power amplification is handled.
In sum, the embodiment of the invention obtains the radio and television high-frequency carrier signal of a plurality of channels that the broadcast unification modulates by the base station, filtering frequency-selecting processing is carried out to the radio and television high-frequency carrier signal of each channel in the base station, isolates the radio and television high-frequency carrier signal of each channel; User terminal is given with the radio and television high-frequency carrier signal synchronized transmissions of isolated each channel in the base station.Because the spectrum component of the radio and television high-frequency carrier signal of each channel that each base station obtains is identical, particularly the transient behavior relative difference on frequency is zero, thereby avoided the problem that the frequency spectrum of the radio and television high-frequency carrier signal of the same channel of each base station there are differences in the prior art, the radio and television high-frequency carrier signal of the same channel of each base station of the present invention drops on same user terminal simultaneously, reduces to minimum thereby the homogenous frequency signal that produces disturbs; And, because what each base station reduction obtained is the radio and television high-frequency carrier signal that has modulated, therefore, saved each base station and the broadcast television signal of each channel has been modulated into the process of radio and television high-frequency carrier signal, thereby system cost obviously reduces, and it is very simple that system debug becomes.
Obviously, those skilled in the art can carry out various changes and modification to the present invention and not break away from the spirit and scope of the present invention.Like this, if of the present invention these are revised and modification belongs within the scope of claim of the present invention and equivalent technologies thereof, then the present invention also is intended to comprise these changes and modification interior.