Patent ID: 7443826

Claim:
A transceiver for processing code division multiple access signals received through at least one multipath propagation channel to produce at least one relative frequency error estimate, comprising: a processor for receiving and processing the signals using a local frequency reference oscillator to obtain representative complex numerical samples for processing; channel estimators for correlating the complex numerical samples with shifts of a locally generated despreading code and producing a number of complex channel estimates, each corresponding to a different delayed ray of the at least one multipath propagation channel; frequency error estimators for computing a frequency error estimate for each ray based on successive values of a respective one of the channel estimates; and at least one summer for performing a weighted summation of the frequency error estimates to provide at least one relative frequency error estimate, wherein the relative frequency error estimate is used to control the frequency of a local frequency reference oscillator, and further comprising: a rake combiner for despreading a desired signal using shifts of a locally generated wanted signal despreading code to produce one complex sample per data symbol per shift and for performing a weighted summation of the complex samples per shift using weighting factors based on the channel estimates to produce a rake-combined value for each data symbol; a decoder for decoding the per-symbol rake-combined values using a soft error correction decoder to reproduce wanted information bits; and an error detection decoder for performing an error check on the decoded information bits and to generate an error or no-error indication, wherein the relative frequency error estimate is only used to control the local reference oscillator when a no-error indication is generated.