Polynomial based Channel Estimation Technique with Sliding Window for M-QAM Systems

S S,F A,M O,O O

doi:10.14569/ijacsa.2016.071147

Abstract

Pilot Symbol Assisted Modulation (PSAM) channel estimation techniques over Rayleigh fading channels have been analysed in recent years. Fluctuations in the Rayleigh fading channel gain degrades the performance of any modulation scheme. This paper develops and analyses a PSAM Polynomial interpolation technique based on Least Square (LS ) approxi-mations to estimate the Channel State Information (CSI) for M-ary Quadrature Amplitude Modulation (M-QAM) over flat Rayleigh fading channels. A Sliding window approach with pilot symbol adjustment is employed in order to minimize the computational time complexity of the estimation technique. The channel estimation performance, and its computational delay and time complexity is verified for di?erent Doppler frequen-cies ( fd), frame lengths (L), and Polynomial orders (P-orders). Simulation results show that the Cubic Polynomial interpolation gives superior Symbol Error Rate (SER) performance than the Quadratic Polynomial interpolation and higher P-orders, and the performance of the Polynomial estimation techniques degrade with increase in the P-orders.

Highlights

Channel estimation assuming a Rayleigh fading channel with Additive White Gaussian Noise (AWGN) is an essential aspect of wireless communication
Pilot Symbol Assisted Modulation (PSAM) channel estimation techniques have been proposed in literature using Gaussian, Wiener, Sinc, Linear interpolations, and many more interpolation techniques to analyse and compensate for the effect of fading errors in order to improve the performance of the modulation scheme [2]–[8]
This paper proposes a Polynomial interpolation channel estimation technique based on Least Square (LS ) approximations for Mary Quadrature Amplitude Modulation (M-QAM) assuming a flat Rayleigh fading channel

Summary

Introduction

Channel estimation assuming a Rayleigh fading channel with Additive White Gaussian Noise (AWGN) is an essential aspect of wireless communication. Pilot Symbol Assisted Modulation (PSAM) channel estimation techniques have been proposed in literature using Gaussian, Wiener, Sinc, Linear interpolations, and many more interpolation techniques to analyse and compensate for the effect of fading errors in order to improve the performance of the modulation scheme [2]–[8]. The major focus has been on the trade-off between the computational time complexity and gain performance of these channel estimation techniques over Rayleigh fading channels. This paper proposes a Polynomial interpolation channel estimation technique based on Least Square (LS ) approximations for M-QAM assuming a flat Rayleigh fading channel. Result is shown comparing the developed Polynomial interpolation technique with some existing channel estimation techniques found in [4], [7] and [9].

System Model

PSAM Polynomial Interpolation

Results and Discussion

Conclusion