Decorrelative successive interference cancellation for cyclic interleaved frequency division multiplexing

Cyclic interleaved frequency division multiplexing (CIFDM) stands out as a promising solution for enhancing diversity reception over frequency-selective channels. Within the CIFDM framework, cyclic interleaving at the transmitter, followed by multipath detection at the receiver, collaboratively contributes to performance improvement. A recent advancement in this domain is the introduction of CIFDM-successive interference cancellation (CIFDM-SIC) (Anuthirsha and Stuwart in ETRI J, 1--11, 2024), a multipath multistage detection method. However, CIFDM-SIC leaves room for improvement, as it only partially mitigates multipath interference resulting from the semi-orthogonality of codes in CIFDM. To address this limitation, our current approach introduces a CIFDM-decorrelative successive interference cancellation (CIFDM-dSIC) method. In the proposed CIFDM-dSIC, a decorrelation process is employed to effectively eliminate non-orthogonal interference components arising from the cross-correlation of codes in the SIC output stages. Specifically, after the completion of the entire SIC operation, interference at each output stage, except the last one, is eliminated through path-specific decorrelation of the effective spreading codes. We have conducted a comprehensive evaluation of the performance of CIFDM-dSIC under various scenarios, comparing it with both existing CIFDM and traditional interleaved frequency division multiplexing methods. Simulation results unequivocally establish the dominance of the proposed CIFDM-dSIC, affirming its reliability in terms of bit error rate and diversity reception.