An Interpolation Technique for Channel Estimation in OFDM Systems

In this paper we investigate the bit error rate (BER) performance of orthogonal frequency division multiplexing (OFDM) wireless communication system with the implementation of the LS-Interpolation-based on pilot symbol-assisted channel estimation algorithm over the frequency selective multi-path Rayleigh fading channel. The Least square (LS) method is used for estimation of channel at the pilot frequencies, using different interpolation techniques such as spline cubic interpolation, cubic interpolation, low-pass interpolation and FFT interpolation, linear interpolation are employed to interpolate the channel at data frequencies. In signal mapping, the OFDM system incorporates M-ary phase-shift keying (M-PSK) and M-ary quadrature amplitude modulation (M-QAM) digital modulation techniques. Matlab simulations are carried out to analyze the performance of the developed OFDM system with the employment of pilot based channel estimation algorithms for various digital modulations in Rayleigh fading channel. A comparative analysis of the proposed interpolation with conventional one dimensional interpolation techniques shows its performance.