Optimizing the rate 1/2; convolutional code for OFDM applications in terms of bit-error-rate and Peak-to-Average Power Ratio

Abstract

In this paper the performance of different convolutional code generator polynomials with constraint length 7 is examined in relation to OFDM transmissions. The performance is evaluated in terms to Bit Error Rate (BER) in white Gaussian noise and Peak-to-Average Power Ratio (PAPR). It is shown that convolutional codes with identical generator polynomials result in very poor BER performance, however surprisingly, identical polynomial combinations seem to possess the advantage of reducing slightly the PAPR. The standard convolution code (7, [171, 133]), commonly used in wireless systems, is shown to possess reasonably good BER and similar PAPR performance in comparison to other non-identical polynomial codes, but possesses a slightly higher average PAPR when compared to identical generator polynomial combinations.