Bio‐inspired hybrid algorithm to optimize pilot tone positions in polar‐code‐based orthogonal frequency‐division multiplexing–interleave division multiple access system.

Summary: In this paper, a hybrid bio‐inspired algorithm is proposed to enhance the performance of channel estimation of the orthogonal frequency‐division multiplexing–interleave division multiple access (OFDM–IDMA) system. This algorithm is a fusion of the lion algorithm and group search optimization algorithm named as SU‐LA, scrounger updated lion algorithm. It works on the optimal selection of pilot tone positions that ensure the attainment of the least value of mean square error. Polar code is used for error detection and correction along with Quadrature Amplitude Modulation (QAM) and 16 QAM techniques. Carrier frequency offset (CFO), user, and Eb/No factors are selected to analyze their impact on the BER performance in the presence of Rayleigh channel. It is observed that the proposed SU‐LA‐based system with the QAM technique achieves 91.23% enhancement in BER at zero CFO as compared to harmony search‐based system for Eb/No of 12 dB. Further, in the presence of 0.1 CFO, the proposed system retains BER performance. The experimentation is also carried with 16 QAM over various CFOs and the number of users. The BER performance of the proposed system is also superior to the particle swarm optimization (PSO) and genetic algorithm (GA)‐based system. The effect of peak‐to‐average power ratio (PAPR) and symbol time offsets is not considered. [ABSTRACT FROM AUTHOR]