| 摘要 |
PURPOSE:To suppress the degradation of a C/N in a weak electric field by improving the degree of multi-carrier separation at a receiver in a multi-carrier system. CONSTITUTION:An IF signal is provided by impressing a received signal 1 to a frequency converter 2 together with the output of a local oscillator 3 and converting the signal to a low frequency. The IF signal is multiplied by a frequency component signal from a fixed oscillator 6 by a multiplier 5, a differential component signal between the frequency of the IF signal and that of the frequency component signal from the fixed oscillator 6 is extracted by a BPF 7, and the differential component signal is impressed to a delay circuit 8. An adder 9 adds the input and output of the delay circuit 8. On the other hand, a subtracter 10 calculates difference between the input and output of the delay circuit 8. The outputs of the adder circuit 9 and subtraction circuit 10 are demodulated respectively in signal processing steps 4-1 and 4-2 and are synthesized by a synthesizing circuit 11 as needed. |
