Evaluation of GFDM-OQAM Performance Using Variation of Equalizations and Roll-Off Factors

Future communication systems demand technology supporting high-speed communication, low latency, and high reliability. One approach to achieve this is by implementing Generalized Frequency Division Multiplexing (GFDM) technology in 5G cellular communication. The GFDM system employs modulation, with this study utilizing a 16-QAM modulation scheme through the Offset-QAM (OQAM) technique. OQAM has demonstrated enhanced spectral efficiency and reduced Inter Carrier Interference (ICI) and Inter Symbol Interference (ISI). This research examines two signal detection equalization techniques, namely Zero Forcing (ZF) and Minimum Mean Square Error (MMSE). The study also investigates three variations of the roll-off factor (α) 0.3; 0.5; and 1. The input comprises audio transmitted through an Additive White Gaussian Noise (AWGN) channel, with pulse shaping achieved by a Root Raised Cosine (RRC) filter. Findings reveal that GFDM-OQAM with MMSE outperforms the ZF approach. The results of the GFDM-OQAM ZF and GFDM-OQAM MMSE graphs at an SNR of 20 dB, with respective BER of 0.000391667 and 0.00034444, while the results of SER are 0.000734375 and 0.000645833, respectively. Optimal results for both ZF and MMSE are attained at minimum roll-off factor of α = 0.3. The choice of equalization techniques and the selection of roll-off factor significantly influence the reduction in BER and SER values by increasing SNR, indicating improved system performance.