Low-frequency nonlinear memory effects in M-ary QAM communications systems

作者：Allegue Martinez Michel^*; Madero Ayora Maria J; Reina Tosina Javier; Navarro Lazaro J; Crespo Cadenas Carlos

来源：Microwave and Optical Technology Letters, 2012, 54(3): 826-829.

DOI：10.1002/mop.26608

• behavioral models
• nonlinear distortion
• memory effects
• power amplifier

This article focuses on low-frequency nonlinear memory effects caused by a power amplifier (PA). Two models have been adopted for the PA to perform simulations of an M-ary communications system, the memory polynomial model and a dynamic Volterra-based model, both were able to predict the desired effects. An experimental setup allowing the identification of the coefficients using time-domain data acquisitions has been used, with the capability to represent the distorted signal in the constellation plane and to make error vector magnitude measurements. A good agreement between simulations with the adopted models and measurements has been obtained, showing the degradation of the communications system due to low-frequency nonlinear memory effects. A significant distortion and E-b/N-o losses are observed when a symbol rate of 17 ksym/s (low frequency zone) is used, when compared with the behavior of the system at 2 Msym/s.

• 出版日期2012-3