Summary of the invention
The objective of the invention is to overcome the shortcoming of prior art; Provide a kind of rational in infrastructure; Integrated level is high, and can cover the multi-modulation scheme analog optical fiber broadband access system based on shift frequency of a plurality of frequency band signals (like GSM, DCS, CDMA, WCDMA, TD-SCDMA etc.) simultaneously.
In order to realize this purpose, the present invention adopts following technical scheme:
A kind of multi-modulation scheme analog optical fiber broadband access system based on shift frequency, its difference is: it comprises common formation down link, up link, and down link, up link include near-end unit and far-end unit; The near-end unit is connected with the mobile communication base station of different frequency range through coupler simultaneously, and the near-end unit is connected through optical fiber with far-end unit; The near-end unit comprises that the multiplex (MUX) divides mixer, analog down module, simulation up-conversion module, light integrated module; Far-end unit comprises that the multiplex (MUX) divides mixer, analog down module, simulation up-conversion module, light integrated module, power amplifier module, low noise amplifier module, duplexer module.
By above scheme, the down link that makes progress at side signal transmission comprises successively:
Near-end analog down module is used for the radiofrequency signal of affiliated link is carried out down-conversion, makes it become analog if signal;
Near-end the multiplex (MUX) divide mixer, is used for synthetic each frequency range analog if signal, output analog intermediate frequency composite signal;
Near-end light integrated module is used for the electric light conversion, divides the analog intermediate frequency composite signal modulated optical carrier of mixer output with the multiplex (MUX), the output modulated optical signal;
Far-end light integrated module is used for opto-electronic conversion, from the light signal that receives, recovers the analog intermediate frequency composite signal through photodetector;
Far-end the multiplex (MUX) divide mixer, is used for the filtering of analog intermediate frequency composite signal is isolated the analog if signal of different frequency range;
Far-end simulation up-conversion module is used for the analog if signal of affiliated link is carried out up-conversion, makes it become radiofrequency signal;
Power amplifier module, the radiofrequency signal of link under being used to amplify;
Duplexer module is used for the interference signal of the radiofrequency signal of filtering power amplifier module output, sends to portable terminal through antenna element then.
By above scheme, make progress at side signal transmission, its up link comprises successively:
Duplexer module is used for the interference signal of the radiofrequency signal that the filtering antenna receives, and is transferred to low noise amplifier module then;
Low noise amplifier module is used for the radiofrequency signal that low noise amplifies duplexer module output;
Far-end analog down module is used for the radiofrequency signal of low noise amplifier module output is carried out down-conversion, makes it become analog if signal;
Far-end the multiplex (MUX) divide mixer, is used to close the analog if signal of each frequency range of road, output analog intermediate frequency composite signal;
Far-end light integrated module is used for the electric light conversion, divides the analog intermediate frequency composite signal modulated optical carrier of mixer output with the multiplex (MUX), the output modulated optical signal;
Near-end light integrated module is used for opto-electronic conversion, from the light signal that receives, recovers the analog intermediate frequency composite signal through photodetector;
Near-end simulation up-conversion module is used for the analog if signal of affiliated link is carried out up-conversion, makes it become radiofrequency signal.
Based on the method for transmitting signals of the multi-modulation scheme analog optical fiber broadband access system of shift frequency, its difference is: its method comprises transmitting step and the transmitting step in up link of signal in down link; When signal transmits in down link; At first through the radiofrequency signal of coupler coupling from a plurality of frequency ranges of different base station; Through the corresponding simulating down conversion module radiofrequency signal of different frequency range is down-converted to different intermediate frequency frequency ranges respectively then; And divide the multiplex (MUX) and to close the road in the mixer and become the analog intermediate frequency composite signal, then the analog intermediate frequency composite signal is modulated into light signal through the light integrated module and through Optical Fiber Transmission to far-end unit; The light integrated module of far-end unit reverts to the analog intermediate frequency composite signal with light signal, and the multiplex (MUX) who is transferred to far-end unit divides mixer; The multiplex (MUX) divides mixer the analog intermediate frequency composite signal to be separated into the analog if signal of different frequency range; The analog if signal of each frequency range becomes radiofrequency signal through the module recovery of simulation up-conversion respectively; The radiofrequency signal of each frequency range is amplified through power amplifier, and covers to accomplish signal through exporting antenna behind the duplexer filtering interference signals to;
When signal transmits in up link; From the radiofrequency signal of the different frequency range of remote unit antenna earlier through the duplexer filtering interference signals; Radiofrequency signal with each frequency range is down-converted to different intermediate frequency frequency ranges through the low noise amplifier amplification and through the analog down module respectively then; Divide the multiplex (MUX) and to close the road in the mixer and become the analog intermediate frequency composite signal; Then the analog intermediate frequency composite signal is modulated into light signal and arrives the near-end unit through Optical Fiber Transmission through the light integrated module, the light integrated module of near-end unit recovers to become the analog intermediate frequency composite signal with light signal; The multiplex (MUX) of near-end unit divides mixer the analog intermediate frequency composite signal to be separated into the analog if signal of different frequency range; Each frequency range analog if signal becomes radiofrequency signal through the module recovery of simulation up-conversion respectively, through coupler the radiofrequency signal of different frequency range is exported to the base station of correspondence at last.
The relative prior art of the present invention has following advantage and effect:
1, multiband transmission: present device can be unified transmission with the mobile communication signal of a plurality of different frequency ranges between base station and far-end unit, is transferred to far-end unit to the signal of a plurality of frequency ranges such as GSM, DCS, CDMA, WCDMA, TD-SCDMA etc. simultaneously and covers.
2, networking cost is low: when carrying out the covering of a plurality of frequency band signals, only with satisfying the multi-band signal transmission requirements once this equipment of cover.
3, it is few to take fiber resource: when carrying out the covering of a plurality of frequency band signals, want an optical fiber with this device just.
4, native system closes the road after the radiofrequency signal of different frequency range is down-converted to intermediate frequency; Directly closing the road with radiofrequency signal compares; Native system has reduced the centre frequency and the bandwidth of closing the road signal; Thereby reduced the distortion of signal in transmission course, reduced system and realized difficulty and cost, improved systematic function.
5, volume is little, and is easy for installation.The present invention can replace the fiber broadband connecting systems of many cover one-segment, thereby characteristics such as it is little to have floor space, and line is simple.
Embodiment
Below in conjunction with embodiment and accompanying drawing the present invention is described in further detail.
Fig. 1 shows concrete structure of the present invention; This is made up of near-end unit and far-end unit based on the multi-modulation scheme analog optical fiber broadband access system of shift frequency jointly; Be connected through an optical fiber between said near-end unit and the far-end unit, form the up link and the down link of signal transmission.Said near-end unit comprises that the multiplex (MUX) divides mixer, analog down module, simulation up-conversion module, light integrated module.Said far-end unit comprises that the multiplex (MUX) divides mixer, analog down module, simulation up-conversion module, light integrated module, power amplifier module, low noise amplifier module, duplexer module.
As shown in Figure 1, base station 11 is the GSM base station, and base station 12 is the DCS base station, and base station 13 is the TD-SCDMA base station.Because GSM, DCS, the shared frequency range of TD-SCDMA have nothing in common with each other; Thereby in the near-end unit; Base station 11 is connected with analog down module 31 through coupler 21; Base station 12 is connected with analog down module 32 through coupler 22, and base station 13 is connected with analog down module 33 through coupler 23, and the other end and the multiplex (MUX) of analog down module 31, analog down module 32, analog down module 33 divides mixer 51 to be connected.Analog down module 31, analog down module 32, analog down module 33 are down-converted to GSM, DCS, TD-SCDMA radiofrequency signal respectively and are sent to the multiplex (MUX) after the different intermediate frequency frequency ranges and divide mixer 51; The multiplex (MUX) divides 51 pairs of three analog if signals of mixer to close the road, thereby synthesizes the analog intermediate frequency composite signal and be separated in the down link.
In down link: this analog intermediate frequency composite signal at first is transferred in the light integrated module 61 of near-end unit and handles, and the light integrated module 61 usefulness analog intermediate frequency composite signals of near-end unit are come modulated optical carrier, forms modulated optical signal.Modulated optical signal is transmitted through the fiber to the light integrated module 71 of far-end unit; The light integrated module 71 of far-end unit recovers the analog intermediate frequency composite signal from modulated optical signal; The multiplex (MUX) who then this analog intermediate frequency composite signal is transferred to far-end unit divides mixer 81; The multiplex (MUX) divides mixer 81 the analog intermediate frequency composite signal to be separated into the analog if signal of different frequency range; And the analog if signal of different frequency range transferred to simulation up-conversion module 91, simulation up-conversion module 92, simulation up-conversion module 93 respectively; Simulation up-conversion module 91, simulation up-conversion module 92, simulation up-conversion module 93 are distinguished up-conversion to radio frequency with the analog if signal of different frequency range, obtain GSM, DCS, TD-SCDMA radiofrequency signal.After the GSM radiofrequency signal is amplified respectively through power amplifier 113 through power amplifier 112, TD-SCDMA radiofrequency signal through power amplifier 111, DCS radiofrequency signal; Again respectively by duplexer 131, duplexer 132, duplexer 133 filtering interference signals; Transfer to antenna 141, antenna 142, antenna 143 at last and cover, can accomplish downstream signal from the base station 11, the transmission of base station 12, base station 13 to antenna 141, antenna 142, antenna 143.
The transmission direction and the down link of up link are opposite, and principle is close.In up link: to antenna 141 feed-in GSM radiofrequency signals, the GSM radiofrequency signal at first is transferred to low noise amplifier module 121 and carries out the low noise amplification behind duplexer 131 filtering interference signals by portable terminal; To antenna 142 feed-in DCS radiofrequency signals, the DCS radiofrequency signal at first is transferred to low noise amplifier module 122 and carries out the low noise amplification behind duplexer 132 filtering interference signals by portable terminal; To antenna 143 feed-in TD-SCDMA radiofrequency signals, the TD-SCDMA radiofrequency signal at first is transferred to low noise amplifier module 123 and carries out the low noise amplification behind duplexer 133 filtering interference signals by portable terminal; GSM radio signal transmission to analog down module 101 after then low noise being amplified; With DCS radio signal transmission to the analog down module 102 after the low noise amplification; With TD-SCDMA radio signal transmission to the analog down module 103 after the low noise amplification; Analog down module 101, analog down module 102, analog down module 103 are down-converted to the radiofrequency signal that receives and are sent to the multiplex (MUX) after the different intermediate frequency frequency ranges and divide mixer 81; The multiplex (MUX) divides 81 pairs of three analog if signals of mixer to close the road, thereby synthesizes the analog intermediate frequency composite signal and be separated in the up link.The analog intermediate frequency composite signal at first is transferred in the light integrated module 71 of far-end unit and handles; The light integrated module 71 usefulness analog intermediate frequency composite signals of far-end unit are modulated the light carrier with the downlink optical signal different wave length, form up modulated optical signal.Up modulated optical signal is transmitted through the fiber to the light integrated module 61 of near-end unit; The light integrated module 61 of near-end unit recovers the analog intermediate frequency composite signal from modulated optical signal; The multiplex (MUX) who then this analog intermediate frequency composite signal is transferred to the near-end unit divides mixer 51; The multiplex (MUX) divides mixer 51 the analog intermediate frequency composite signal to be separated into the analog if signal of different frequency range; And the analog if signal of different frequency range transferred to simulation up-conversion module 41, simulation up-conversion module 42, simulation up-conversion module 43 respectively; Simulation up-conversion module 41, simulation up-conversion module 42, simulation up-conversion module 43 are distinguished up-conversion to radio frequency with the analog if signal of different frequency range, obtain GSM radiofrequency signal, DCS radiofrequency signal, TD-SCDMA radiofrequency signal respectively.The GSM radiofrequency signal is coupled to corresponding base station 11 through coupler 21; The DCS radiofrequency signal is coupled to corresponding base station 12 through coupler 22; The TD-SCDMA radiofrequency signal is coupled to corresponding base station 13 through coupler 23, can accomplish the transmission of upward signal from antenna 141, antenna 142, antenna 143 to base station 11, base station 12, base station 13.
Among the present invention, descending light carrier and up light carrier adopt different wavelengths, in an optical fiber, carry out mixed transport through WDM technology.
Above content is to combine concrete execution mode to the further explain that the present invention did, and can not assert that practical implementation of the present invention is confined to these explanations.For the those of ordinary skill of technical field under the present invention, under the prerequisite that does not break away from the present invention's design, can also make some simple deduction or replace, all should be regarded as belonging to protection scope of the present invention.