Symmetric Turbo Coded OFDM System for Multi-relay Coded-Cooperative Wireless Communication under Wideband Noise Jamming Environment

This research study proposes a novel anti -jamming technique based on a distributed symmetric Turbo coded orthogonal frequency division multiplexing (DSTC-OFDM) scheme for coded -cooperative wireless communication under wideband noise jamming environment. As a suitable benchmark for comparison, a conventional symmetric Turbo coded OFDM (STC-OFDM) scheme for non -cooperative wireless communication is also simulated and analyzed under the same jamming environment. The prime modulation technique employed is binary phase -shift keying while the decoding algorithm used is log maximum a -posteriori probability algorithm. The STC-OFDM (non -cooperative) scheme is compared to the DSTC-OFDM (coded -cooperative) scheme over the stated models of wireless communication channels under the same circumstances and noise jamming environment. According to Monte Carlo simulation results, the DSTC-OFDM scheme outperforms the STC-OFDM scheme by a gain that ranges between 1-7 dB for different values of jamming -to -signal ratio in the high SNR simulated region under the same conditions, i.e., the code rates R c =1/3 and data frame lengths l =512 data bits for both the proposed schemes. However, in the low SNR simulated region, the STC-OFDM scheme shows similar performance as the DSTC-OFDM scheme, under identical conditions. The proposed DSTC-OFDM scheme is further explored in coded -cooperation with multiple relays and the best relay selection technique under the jamming environment over a multipath frequency -selective Rayleigh fading channel.