Design Methodology for Multichannel Communication Systems

Abstract

A methodology for understanding and modeling the interaction of multiple CDMA signals in a nonlinear multichannel environment is introduced and verified. The analysis is based on understanding the statistical properties of input signals and developing a modeling technique that enables distortion to be estimated. This is coupled with the introduction of a new behavioral modeling technique that captures the black box characteristics of multichannel amplifiers. In addition, a performance analysis that relates nonlinear distortion to probability of bit error (BER) is introduced. The analysis presented here provides an insight into communication system design by relating distortion to system performance. The methodology is verified using simulations and measurements performed on a nonlinear power amplifier. A nonlinear model was extracted and used in developing the statistical model by which distortion is estimated. The resulting estimates of distortion were verified using measurements of distortion performed on the amplifier using the IS-95 CDMA system standard.