| 摘要 |
PURPOSE:To provide a carrier reproduction circuit in which a frequency estimation error owing to the phase difference of a sampling clock is reduced at the time of reproducing a carrier from an offset quadrature phase shift peying (O-QPSK) modulated wave on the carrier reproduction circuit of an O-QPSK modulation wave, in which the preamble parts of burst signals in two systems that are orthogonal phase-modulated by an (O-QPSK) system are set in prescribed bit patterns. CONSTITUTION:In a costas loop reproducing the carrier in the QPSK system, a delay unit 14 matches the phases of the burst signals inputted to two orthogonal channels. A phase comparator for bit timing reproduction part 19 adds a carrier detection value detected by an arc tangent calculation circuit 191 and a carrier detection value delayed by a one period delay unit 192 in an adder 193 and outputs the carrier detection value. A switch circuit 22 switches/ outputs the outputs of phase comparators 18-20 and inputs them to a loop filter 23. |
