A co-channel interference and nonlinear distortion cancellation for DS/CDMA in optical link

A multi-stage cancellation technique is proposed to cancel co-channel interference and nonlinear distortion of microcellular radio CDMA (CDMA) optical access network. A radio CDMA optical access is a network access technique which uses microcellular radio CDMA signals in wireless channel and connects the base stations and central stations (CS) through optical transmission. In such system, co-channel interference from channel multiple and nonlinear distortion due to laser diode nonlinearity limit the number of mobile CDMA channels. A multi-stage interference cancellation technique to cancel the co-channel interference and the nonlinear distortion is analyzed theoretically. A memoryless third-order polynomial memory is used to present the laser diode (LD) nonlinearity. The analytical method and its results are also applicable to other general nonlinear CDMA system.