Adaptive co-channel interference cancellation and signal separation method

Abstract

A method for co-channel interference suppression and signal separation was proposed in a previous work. It uses the amplitude variation of the composite signal to estimate the parasitic phase modulation impinged on the strong desired signal by the weak interference signal. This estimate is then used to cancel out the distortion of the composite signal, revealing the desired signal. In the cancellation process, amplitude estimates for both signals were obtained from measurements. Errors in estimating these magnitudes limit the quality of cancellation and signal separation performance. An adaptive method is proposed which improves these estimates and, hence, results in a better cancellation of interference. A criterion for performance measure was chosen to be the variance of the envelope of the weak signal estimate and is shown to be directly related to the cancellation quality. A random search algorithm was used to vary the signal magnitude estimates to achieve better estimates. Numerical simulation experiments were performed to prove the concept, including Gaussian noise. >