| 摘要 |
<p>PURPOSE: To perform control by a automatic gain controller and automatic frequency controller of a receiver for an FSK signal of radio communication respectively by using a demodulation output. CONSTITUTION: When a bit decision means 107 decides the bits of the demodulation output of the FSK signal 101 obtained by a demodulating circuit 106, a threshold value crossing frequency calculating means 110 calculates how many times a bit dicision threshold value is crossed with the demodulation output within a certain time to estimate the electric field strength of the received FSK signal, thereby controlling the gain of a variable gain amplifier 103. Further, an error correction circuit is provided at the output stage of the bit deciding means 107, the ratio of BERs of a mark and a space is calculated on the basis of the error information of the error correcting circuit, and an error of the oscillation frequency of a voltage-controlled oscillator is estimated on the basis of the calculation result to control the voltage-controlled oscillator.</p> |
