Patent ID: 7107031

Claim:
A method for a digital receiver exploiting second order statistics for adaptive co-channel interference rejection in wireless communication, having digitally I, in phase, and Q, quadrature, branches of a received transmitted signal as input to the receiver, a coarse synchronization and a coarse frequency offset compensation have being performed on said signal, and comprising a means for derotation, means for separation, means for filtering, means for estimating and means for detecting transmitted symbols in the received signal, characterized in that it comprises the following steps: derotating the signal in said means for derotation, outputting a complex valued time discrete base band representation of the received signal if a used modulation form is one dimensional, else if a used modulation form is multiple dimensional then construct, from possibly two vector valued signal sequences, a complex valued signal sequence and outputting said complex valued signal; separating said output signal in said means for separating it into its real and imaginary parts which vector is output from said means for separation containing the transmitted signal, co-channel interfering user signals, additive noise and other possible disturbance; estimating in said means for estimation, using the outputs from said means for separation, means for filtering, and from said means for detecting as input, and performing on one or more of the following quantities: fine synchronisation, fine frequency offset estimation or compensation, or data model estimation, outputting one or more of said quantities to said means for derotating, filtering, and detecting; filtering in said means for filtering, using the real value output from said means for separation and coefficients in said data model output from the means for estimation and performing a whitening operation on the signal additionally taking into account a second order properties of noise and co-channel interference, the filtered signal being output to the means for estimation and detection; and detecting transmitted symbols in said means for detecting, making use of the output from said means for filtering and the data model from the means for estimation, thereby improving co-channel rejection in wireless communication, thus making it possible to increase the number of channels for frequencies used.