Development of hybrid envelop memory polynomial based predistorter for RoF system

Abstract

Radio over Fiber (RoF), an empowering innovation for dissemination of wireless broadband service signals through simple optical connections experiences non-linear distortion. We have designed and implemented a novel predistorter model to reduce nonlinear distortion using hybrid envelop memory polynomial (HEMPM) for the RoF system. The link gives satisfactory performance in the range of GHz signal. The designed algorithm is superior to popular approaches like memory polynomial model (MPM) and envelop memory polynomial model (EMPM) in terms of order of the memory and degree of nonlinearity. As per author's the best knowledge, this is exclusively first time result obtained for HEMPM technique for RoF link and also, for MPM, EMPM based predistorter for RoF link using MATLAB – OptiSystem co-simulation. The results shows that adjacent channel power (ACP) is suppressed by ∼0.45dBm, ∼28.4dBm and ∼7.65dBm of MPM & EMPM and HEMPM model for K=5 &Q=2 whereas for K=7 &Q=3 the value of suppressed power is ∼36.3dBm, ∼47.7dB and ∼05.8dBm, respectively as compared to input signal. NMSEs for (K=7) and memory length (Q=3) reduced by ∼−5.003dBm for HEMPM model and increased by ∼−4.13dBm for MPM model. The EVM is increased from ∼1.56% to ∼1.96% for HEMPM model and increased from ∼4.38% to ∼14.73% for MPM model for K=7 &Q=3.