Performance Evaluation of Doubly Selective Fading in FBMC with Higher Order QAM for 5G Wireless Communications and Beyond

Abstract

Filter bank multi‐carrier (FBMC) modulation has gained significant attention as a potential candidate for physical data communication in the fifth generation (5G) and beyond wireless networks. Wireless channels, characterized by high mobility and abundant scatters, are prone to time-selective fading and frequency-selective fading that has been known as a "doubly selective channel." Broadband transmission systems encounter formidable challenges in channel estimation and equalization within such channels. The presence of high mobility gives rise to inter-carrier interference (ICI), while multipath transmission introduces inter-symbol interference (ISI). This thesis compared the performance of different channel estimation techniques in FBMC. Moreover, Iterative interference cancellation scheme is considered to address interference issues at pilot and data positions. Additionally, a suboptimal Minimum Mean Square Error (MMSE) equalization method, guided by a threshold judgment based on the variability of interference power was presented. This method utilizes normalized interference power thresholds to estimate the ISI dimension, minimizing equalization data and effectively mitigating the impact of ISI for efficient equalization. This research significantly contributes to the evolution of channel estimation techniques in FBMC, ultimately bolstering the reliability and performance of data communication in 5G wireless networks. In this thesis the performance of FBMC high order QAM in doubly selective fading channel is investigated with various performance. According to this, FBMC showed a much higher efficiency of ρ = 0.97 providing data rate approximately 50 % higher than in f-OFDM. Based on that the performance of FBMC is always the best one but its performances is comparable with now very the UFMC ones by providing maximum capacity value is 3.5 higher than the OFDM one but it is only 5% higher than UFMC. It can be observed from the result that FBMC revealed high performance compared to other multicarrier modulation techniques.