Synchronous demodulation apparatus of base transceiver station in interim standard-2000 system

1. A synchronous demodulation apparatus of a base transceiver station in a communication system, comprising:

a first synchronous demodulation unit for receiving received signals each of which includes a pilot channel signal and a traffic channel signal, demodulating the received signals to generate demodulated signals, and outputting the demodulated user signals;

a channel estimation unit for estimating channel parameters for each of the mobile stations based on the pilot channel signals transmitted from the mobile stations, and generating estimated channel parameters;

a received signal delay unit for delaying the received signal and outputting a delayed signal which is delayed in one symbol from the received signal;

an interference signal regeneration unit for generating interference signals based on the demodulated user signals and the estimated channel parameters, removing interference signals from the delayed signals, and outputting interference-cancelled-signals in which the interference signals are removed; and

a second synchronous demodulation unit for demodulating the interference-cancelled-signals and outputting demodulated signals,

wherein each of the channel parameters includes an amplitude distortion and a phase distortion.

2. The synchronous demodulation apparatus as recited in claim 1 , wherein the interference signal regeneration unit includes:

multipliers, each of which multiplies the demodulated user signal (d' 1,. . ., d' k ) by the channel parameter (A 1 (t−T b ),. . . , A k (t−T b ) so as to generate and output a phase distorted signal;

despreaders, each of which despreads the phase distorted signal and generates a despread signal (s' 1 (t−T b ),. . ., s' k (t−T b )) based on the phase distorted signal;

adders, each for adding the despread signals (s' 1 (t−T b ),. . ., s'( k (t−T b )) except for the despread signal corresponding to its order so as to generate and output an interference signal; and

subtractors, each each of which removes the interference signal from the delayed signal (r(r−T b )) and outputs the interference-cancelled-signal to the second demodulation unit.

3. A synchronous demodulation method applied to a base transceiver station in a communication system, the method comprising the steps of:

a) receiving received signals each of which includes a pilot channel signal and a traffic channel signal, demodulating the received signals to generate demodulated signals, and outputting the demodulated user signals;

b) estimating channel parameters for each of the mobile stations based on the pilot channel signals transmitted from the mobile stations, and generating estimated channel parameters;

c) delaying the received signal and outputting a delayed signal which is delayed in one symbol from the received signal;

d) generating interference signals based on the demodulated user signals and the estimated channel parameters, removing interference signals from the delayed signals, and outputting interference-cancelled-signals in which the interference signals are removed; and

e) demodulating the interference-cancelled-signals and outputting demodulated signals,

wherein each of the channel parameters includes an amplitude distortion and a phase distortion.