Narrow-band interference cancellation in spread-spectrum communication systems using chaos

A novel approach based on chaos theory is proposed to enhance narrow-band interference cancellation for spread spectrum communications. The method uses a chaotic system to generate binary sequences for spreading codes in a direct sequence spread spectrum system. Interference cancellation is therefore a problem of parameter estimation in chaotic noise. Because of the inherently deterministic nature of a chaotic signal, the interference cancellation capability can be improved by using a dynamic-based estimation technique called the minimum phase space volume (MPSV) method. Since the PSV complexity measure is usually a nonlinear function of the parameters, a genetic algorithm (GA) is incorporated into the MPSV method to form the GA-MPSV technique for narrow-band interference cancellation. Simulation results show that the chaotic approach consistently outperforms the conventional statistical method over a wide range of signal-to-interference ratios (SIR) in point-to-point communications, multiple user systems and multipath environments.