| 摘要 |
<p>In a radio communication system a receiving terminal has a number of traffic receivers, each of which can respectively receive a different communication channel. Each channel is capable of receiving data signals, and in order to assess the quality of reception of a channel in the absence of a received data signal, a locally generated test signal is combined with the output of an aerial which is common to all traffic receivers, and the combined signal is injected into a test receiver which is tuned to each radio channel in turn. The test signal is extracted from the test receiver and after demodulation is compared directly with the locally generated data signal so that a data error can be established for each channel. Thus when a new communication link is to be opened, it can be allocated a channel having an acceptably good reception characteristic. <IMAGE></p> |
