Patent ID: 6697440
Filing Date: 2004-02-24
Classification: H04L

Abstract:
A demodulating apparatus of a receiver having demodulating means for demodulating a PSK modulated signal obtained by time-multiplexing digital signals modulated in various PSK modulation systems by using a carrier regenerated by carrier regeneration means, and for outputting an I-Q symbol stream data of a symbol unit comprising:regeneration means for regenerating a predetermined pattern for a portion of outputs of the demodulating means obtained by 2-phase-modulating a digital signal of the predetermined pattern on a transmission side; inverting means for selectively inverting a code of I-Q symbol stream data output from said demodulating means depending on a value of the predetermined pattern regenerated by said regeneration means; a phase error table showing a phase error from an absolute phase for a received signal point in a predetermined quadrant; and phase error detecting means for converting a received signal point in an I-Q phase indicated by an output of said inverting means into a predetermined quadrant by performing a process depending on a current quadrant, reading phase error data corresponding to the converted received signal point from said phase error table, and adjusting the read phase error data based on conversion, wherein said phase error detecting means amends a phase of a regenerated carrier according to the phase error data adjusted by said phase error detecting means.