An adaptive interference canceller using Kalman filtering

This paper describes an adaptive interference cancelling procedure based on the Kalman filtering theory. The procedure is shown to have a rapid convergence rate and provide a high signal-to-interference ratio (SIR) when dealing with sources of interference located in the sidelobe region of an array antenna. The procedure also deals successfully with interferences even when they are separated from the target of interest by a very small fraction of a standard beamwidth. In such a case, however, the convergence process tends to be somewhat slow, depending on the SIR and number of adapted weights. To constrain the processor from responding to a target signal, a set of orthogonal beams are used to provide the desired input data, and the main beam is excluded from the procedure for calculating the weights of the adaptive interference canceller.