T Quality Image Transmission through AWGN Channel using Polar Codes

Polar coded grayscale image communication over additive white Gaussian noise (AWGN) channels using orthogonal frequency division multiplexing (OFDM) system is demonstrated in this paper. The OFDM technique is effective multicarrier technique used in the high-speed transmission system. Polar codes are recently applied to the binary memoryless channel and binary erasure channels for achieving near to Shannon channel capacity. However, besides these two channels, the analysis of polar codes over other channels is still open to scrutiny. The additive white Gaussian noise (AWGN) channel is evaluated by transmitting still images through M-ary QAM modulated OFDM system using polar codes. By comparing with the Bose – Chaudhuri – Hocquenghem (BCH) codes in the same scenario, our results suggest that polar codes have better performance than that of BCH codes. We introduce the polar coded adaptive modulation OFDM system in which the modulation order of QAM is selected in accordance with the channel conditions and channel BER upper threshold value. The result shows that better spectral bandwidth utilization can be achieved by adapting the order of modulation in the polar coded OFDM system. We also concatenate the BCH code with polar code in same scenario using fixed 64-QAM modulation scheme. The obtained results confirm improvement in the behavior of channel BER and visual quality of transmitted images for the entire range of channel Eb/No in comparison to use of polar codes. Overall, it is concluded that polar codes are a good selection for wireless image communication.