ADAPTIVE CHANNEL ESTIMATOR OF IMT 2000 UNDER VARYING RADIO CHANNEL ENVIRONMENT

摘要

PURPOSE: A device for estimating an optimum channel according to a channel variation of a mobile communication system is provided to make a detection of an optimum coherent possible in accordance with a channel environment by deciding a length of a pilot symbol to be waited to a channel estimator variably in accordance with a status of a fading channel. CONSTITUTION: A received spread signal transmitted from a transmitter and received to a receiver is inputted in a DPDCH(Dedicated Physical Data Channel) filter(101) and a DPCCH(Dedicated Physical Control Channel) filter(102). The DPDCH filter(101) is matched to a DPDCH in a received signal and performs a reverse diffusion of a received signal. The DPCCH filter(102) is matched to a DPCCH in the received signal and performs a reverse diffusion of the received signal. The reverse diffused DPCCH signal outputted in the DPCCH filter(102) inputs a reverse diffused DPCCH pilot symbol in a channel estimator(104) through the first arithmetic unit(103). A Doppler frequency estimator(111) estimates a Doppler frequency of the received signal and detects a variation of a movement velocity of a mobile station. A symbol length decision(112) decides a symbol length adapted to the Doppler frequency and transmits the length to the channel estimator(104) and delays(101a,103a).