Optimizing PAPR, BER, and PSD Efficiency: Using Phase Factors Generated by Bacteria Foraging Algorithm for PTS and SLM Methods

The orthogonal time–frequency space (OTFS) waveform is a modulation scheme for wireless communication that achieves high spectral efficiency by exploiting multipath propagation, offering robustness to Doppler shifts and delay spread. A high peak-to-average power ratio (PAPR) is considered to be a significant issue in the OTFS waveform, drastically reducing the performance of the framework. PAPR affects system performance by causing power amplifiers to operate inefficiently at high power levels, leading to increased power consumption, distortion, and reduced spectral efficiency. In this study, we combined the partial transmission sequence (PTS) and selective mapping (SLM) with the bacterial foraging algorithm (BFA), which is also known as the SLM-BFA and PTS-BFA. An extensive search for the optimal phase factors in the PTS and SLM can be computationally expensive. BFO mimics the foraging behavior of bacteria to efficiently navigate the search space. BFO intelligently finds the optimal phase factors, reducing the computation and PAPR values of the OTFS. The performance of the proposed hybrid schemes was simulated for Rayleigh and Rician channels for 64 and 256 subcarriers, respectively. Parameters such as PAPR, bit error rate (BER), and power spectral density (PSD) were analyzed and compared with those of conventional SLM and PTS methods. The projected hybrid methods obtained a significant PAPR gain of 7.9 and 11.9 dB for 64 subcarriers and 7.5 dB and 8.9 dB for 256 subcarriers with Rayleigh and Rician channels, respectively. Further, it is seen that the proposed methods effectively retained the BER performance of the framework with trivial intricacy. In conclusion, using PTS and SLM techniques, which have been improved by the BFA, makes OTFS waveform communication systems work better. These methods effectively mitigate the PAPR issue and improve the system efficiency and spectral utilization. The synergy between the PTS, SLM, and BFA offers a promising approach for overcoming the challenges in OTFS modulation, contributing to the advancement of robust and efficient wireless communication technologies.