| 摘要 |
PURPOSE: A wireless local loop system is provided to solve the problems of overlap phenomenon generated between adjacent cells and call trouble of a subscriber positioned in a call shadowing area by easily changing FA(Frequency Assignment). CONSTITUTION: An LNA(Low Noise Amplifier)(113) removes noise of signals received via an antenna. A pair of BPFs(Band Pass Filter)(114,115) filter the only signals of specific frequency band in the signals passing through the LNA(113). The first switch(116) is connected with an output end of the LNA(113) for selectively outputting the output signal of the LNA(113) to one of the BPFs(114,115). The second switch(117) outputs the signal outputted from the BPFs(114,115) to a DCC(Down Converter Card)(112). A UCC(Up Converter Card)(121) raises frequency of a signal to be transmitted. An HPA(High Power Amplifier)(122) amplifies the signal. A pair of Txfus(Transmitter front end units)(123,124) output the amplified signal via the antenna. The third switch is connected with an output end of the HPA(122) for selectively outputting the output signal of the HPA(122) to one of the Txfus(123,124). The fourth switch(126) outputs the signal outputted from the Txfus(123,124) via the antenna. An RFC(RF control card)(130) connects a receiver(110) with a transmitter(120). |
