Adaptive minimum selection combining scheme over ISI communication channel in non-Gaussian noise

An adaptive minimum selection combining (MSC) scheme is proposed for time varying, intersymbol interference fading communication channel in presence of impulsive noise. The receiver adaptively selects and combines minimum number of diversity branches to reduce the complexity and to save the power. We use the maximum likelihood (ML) metric to choose the branches instead of the instantaneous signal to noise ratio. Due to the time variations of the channel, the ML metric of each diversity branch is compared to a dynamically adjusted threshold. The sign algorithm (SA) is used to estimate the channel because it gives a robust estimate when the noise becomes more impulsive. Equalization and data detection are performed after combining using maximum likelihood sequence estimation implemented by Viterbi algorithm (MLSE-VA). The minimum survivor technique is employed to reduce the complexity of the receiver.