Patent ID: 6625202
Filing Date: 2003-09-23
Classification: H04B

Abstract:
A mobile station for spread spectrum communication, comprising:a plurality of antennas arranged so that a cross-correlation of signals received thereby is small; a delay device, to which received signals from said antennas are input, for delaying the received signals so that the time differences of each of the received signals are more than one chip time of the spreading code; a high frequency combining circuit for combining each of the received signals output from the delay device; and a rake receiving circuit for receiving a combined signal output by said high frequency combining circuit, said combined signal being a multipath signal, separating said multipath signal using a plurality of de-spreading circuits into a plurality of path signals each having a different propagation delay time, said multipath signal being spread by a spread spectrum method according to a spreading code, demodulating each of the separated path signals, and combining the demodulated path signals by adjusting the time base of the demodulated path signals, wherein said delay device is a surface acoustic wave filter, which delays a received signal by converting the received signal to a surface acoustic wave signal consisting of a mechanical vibration, wherein said rake receiving circuit comprises: a path search circuit that processes de-spreading of the combined signal output from said high frequency combining circuit by using a reference spreading code, searches for the peak value of the path, wherein the amplitude of the de-spreaded signal is more than a threshold value, by controlling the phase of the reference spreading code, and finds time position and amplitude value of the peak, and a time window instruction circuit that finds the maximum peak wherein the amplitude value of the peak output from the path search circuit is the maximum, determines a time window of the peak search in the path search circuit according to the time position of the maximum peak while taking account of a time difference of a delay in said delay device, and identifies the time window to the path search circuit.