Performance Evaluation of Polynomial Based Channel Estimation for OFDM Systems on Time-Varying Frequency-Selective Fading Channels

Channel estimation based on Pilot Symbol Assisted Modulation (PSAM) has been investigated for OFDM systems on time-varying frequency-selective channels in different literature. The varying properties of the channel degrades the performance of the OFDM system which is perceived as special case of multicarrier transmission. This paper investigates the performance of PSAM polynomial interpolation based channel estimation for OFDM systems on time-varying frequency-selective channels. The PSAM polynomial interpolation channel estimation is based on block type pilot arrangement. The SER performance of the OFDM system, and computational time complexities of the PSAM polynomial channel estimation are analysed for different fading rates, frame lengths and polynomial orders (P-orders). The SER performance is documented assuming 16-QAM as the modulation scheme in the OFDM system. From the computer simulation results, we summarize that the SER performance of polynomial based channel estimator is highly dependent on the SNR and the fading rate. Although, low P-orders exhibit good SER performance most significantly at low SNR. Also, the lower the P-orders the better SER performance and computational time complexity trade-off because high P-orders exhibit more computational delay and time complexity.