Patent ID: 6246281
Filing Date: 2001-06-12
Classification: H04L

Abstract:
An absolute phasing circuit, comprising:a frame synchronization circuit for comparing a signal point arrangement of baseband demodulation signals I and Q demodulated from a received P-phase shift keying modulated signal wherein P is n-th power of 2 and n is an integer of 3 or greater by a demodulation circuit with an original signal point arrangement on a transmitting side, detecting a phase rotation angle of the reception phase relative to the original signal point arrangement, and outputting a phase rotation signal corresponding to the detected phase rotation angle;phase rotation means for rotating a phase of the baseband demodulation signals I and Q demodulated by the demodulation circuit by an amount corresponding to an odd multiple of (2.pi./P) radian; andlogic conversion means for receiving the baseband demodulation signals I and Q demodulated by the demodulation circuit and phase rotated baseband demodulation signals i and q output from said phase rotation means, selectively converting the baseband demodulation signals in accordance with the phase rotation signal, and outputting baseband demodulation signals having a signal point arrangement same as the signal point arrangement on the transmitting side.