Patent ID: 6459884
Filing Date: 2002-10-01
Classification: H04B,H04W

Abstract:
A method of estimating characteristics of a radio channel over which a reference signal is transmitted consecutively together with an additional signal, other than the reference signal, with a sequence of spread spectrum codes multiplied, with each of the reference signal and the additional signal, said method comprising:a first step of receiving the reference signal and the additional signal from the radio channel and demodulating the reference signal and the additional signal received into a baseband signal; a second step of obtaining in the baseband signal a correlated value of at least a first part of the reference signal which is closer to the additional signal on a time axis with the sequence of spread spectrum codes to produce a first correlated value; a third step of obtaining in the baseband signal a correlated value of the additional signal with the sequence of spread spectrum codes to produce a second correlated value; a fourth step of processing the first correlated value and the second correlated value to determine data represented by the additional signal; a fifth step of removing the data from the additional signal so as to restore a second part of the reference signal which would have appeared unless multiplied with the sequence of spread spectrum codes; and a sixth step of estimating the characteristics of the radio channel on the basis of the reference signal including the first part and the second part from which the data have been removed.