Nonlinear correlator for DS/SSMA communications in impulsive channels

A nonlinear correlator for the reception of multiple-access transmissions in impulsive channels is presented. In this detector, a practical performance measure, i.e., the output signal-to-noise ratio, for optimizing the nonlinearity is addressed and a learning algorithm is developed to adjust the nonlinearity in accordance with the noise characteristic. The performance in single- and synchronous two-user channels is evaluated. To further alleviate the "near/far" effect caused by the multiple-access interference, an interference cancellation scheme is incorporated in the detector. Computer simulations show that this new correlator has a robust performance.