| 摘要 |
PROBLEM TO BE SOLVED: To improve the degree of convergence of a signal point, to stabilize and normalize control, and to prevent the deterioration of an inter-polarization interference compensator. SOLUTION: This demodulator for subjecting a received signal to semi- synchronous detection into two sequences of in-phase component and quadrature component is provided with analog parts 21, 22, 41, 42, 31 and 32 which form a two-sequence baseband signal by mixing the received analog signal and eliminating a high frequency component, a digital phase rotation elimination circuit 80 which eliminates phase rotation from a digital signal obtained by converting the two-sequence baseband signal of the analog parts, and a 1st automatic gain control circuit 170 which makes the mean power difference of the two- sequence baseband signal converted into the digital signal zero between the analog parts and the digital phase rotation elimination circuit. |
