Structured spatial interference rejection combining

Modern communication systems are often interference limited. By modeling the co-channel interference as spatially colored, temporally white Gaussian noise, it is straightforward to incorporate interference rejection in the metric of a sequence estimator. In general, estimates of both the channels and the spatial color of the co-channel interference and the noise are needed. In this work, a structured model for the spatial noise covariance matrix is proposed and maximum likelihood estimates of the parameters are derived. The choice of model order is also addressed. Simulation results show large gains due to the use of these structured estimates compared with the conventional, unstructured, approach.