Estimating impairment covariance matrix without estimating medium channel response

摘要

Disclosed is a method of determining an own-cell impairment covariance matrix for use in parametric modelling of impairments in an interference-suppressing CDMA receiver. The method comprises determining whether the channel response for the received CDMA signal is substantially flat (510, 520). If the channel response is determined to be substantially flat, processing delays are selected such that the delay difference between one or more pairs of processing delays is less that the CDMA chip duration (530). If the channel response is determined to not be substantially flat, the processing delays are selected such that the delay difference between any two of the processing delays is an integer multiple of a chip duration for the received CDMA signal. The method also includes estimating a net channel coefficient for each of the processing delays (540). An own-cell impairment covariance matrix for each of the processing delays as a function of the net channel coefficients and the processing delays is then calculated (550). A substantially flat channel response is one having a single dominant delay, a low delay spread or both. A receiver circuit for performing this method is also disclosed.