Performance Analysis of Pilot-Symbol Aided Channel Estimation (PSACE) in FBMC-OQAM System

Filter Bank Multicarrier with Offset Quadrature Amplitude Modulation (FBMC-OQAM) is a promising alternative to OFDM which utilizes pulse shaping to improve spectral efficiency, reduce spectral leakage and mitigate interference in fading channels. However, as channels become selective, orthogonality is destroyed, leading to severe interference level especially with larger numbers of subcarriers or higher modulation orders. This leads to more challenging channel estimation process and calls to address the impact of such factors on the estimated channel in FBMC system. Such void is yet to be thoroughly investigated in the literature. Therefore, in this paper, precise channel estimate, using Pilot-Symbol Aided Channel Estimation (PSACE), is first addressed in the context of FBMC-OQAM to assess its performance over frequency-selective fading 5G channel model. Then, we examine the impact of various factors like number of subcarriers, modulation orders and user mobility on the Bit Error Rate (BER), Mean Squared Error (MSE) and power dispersion metrics in different simulation scenarios. The numerical results reveal that the estimated channel matches the actual channel when the number of subcarriers is decreased, the modulation order is lowered, and the user speed is slowed down. However, when channel circumstances are dynamic or the user is actively moving around, the proposed system brings considerable improvement to channel estimation as seen, for instance, by 23 % reduction in MSE for the 256-subcarriers case.