Weighted TSVR Based Nonlinear Channel Frequency Response Estimation for MIMO-OFDM System

Shuo Li,Lidong Wang,Xiaoyu Wang,Wei Zhang,Weimin Lei

doi:10.1109/access.2020.3045706

Abstract

A channel frequency response estimation method based on weighted twin support vector regression (TSVR) for pilot-aided multi-input multi-output (MIMO) orthogonal frequency division multiplexing (OFDM) system is proposed in this work. Nonlinearity of channel in wireless communication system is considered. The channel is fading in time domain produced by Doppler effect and in frequency domain by propagation multipath. An improved TSVR-weighted TSVR is adopted to estimate channel parameters in MIMO-OFDM system. The weights obtained by wavelet transform method are used to improve the regression performance of TSVR. The characteristic of the proposed algorithm is that different training samples are given weights calculated according to the distance from the samples to the mean values filtered by wavelet transform method. Due to the regression characteristics of TSVR, the channel frequency response estimation algorithm proposed in this work has good estimation performance and anti noise ability. Experimental results show that compared with the classical pilot aided channel estimation method, the proposed algorithm has better performance in estimating mean square error.

Highlights

H IGH data rate wireless communication is a research hotspot in the emerging wireless local area networks, home audio/visual network and the fifth generation (5G) wireless cellular systems
An improved nonlinear channel frequency response estimation in Multiinput multi-output (MIMO)-Orthogonal frequency division multiplexing (OFDM) systems based on wavelet transform based weighted TSVR (WTWTSVR) is proposed in this paper
SIMULATION RESULTS the simulation experiments are presented to demonstrate the performance of the proposed weighted twin support vector regression (TSVR) based nonlinear channel frequency response estimation algorithm for MIMO-OFDM system

Summary

INTRODUCTION

H IGH data rate wireless communication is a research hotspot in the emerging wireless local area networks, home audio/visual network and the fifth generation (5G) wireless cellular systems. Shuo Li et al.: Weighted TSVR Based Nonlinear Channel Frequency Response Estimation for MIMO-OFDM System channel is divided into orthogonal subchannels, and highspeed serial data is converted into low-speed parallel data for transmission. A nonlinear Kalman filter-based high-speed channel estimation algorithm for OFDM systems was proposed in [23]. The weights calculated by data variance are given to the training data and the regression performance can be improved Inspired by this idea, an improved nonlinear channel frequency response estimation in MIMO-OFDM systems based on WTWTSVR is proposed in this paper. The contributions of this work are described as: the novel improved TSVR based channel frequency response estimator is proposed for nonlinear parameter estimation in MIMO-OFDM systems.

MIMO-OFDM SYSTEM MODEL

CHANNEL ESTIMATION ALGORITHM

SIMULATION RESULTS

CONCLUSIONS