Successive Interference Cancellation for Multi-user MIMO-OFDM Ad-Hoc Networks: A Performance-Complexity Tradeoff

In this paper, we consider a multi-user ad-hoc framework which is established on a Multiple Input-Multiple Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) infrastructure. The reception is accomplished by utilizing the Successive Interference Cancellation (SIC) approach. Particularly, we emphasize on the performance-complexity tradeoff of SIC by implementing two well-known equalizers, namely Zero-Forcing (ZF) and Minimum Mean Squared Error (MMSE). Our main objective is the provision of the system robustness in terms of the error resilience and the computational complexity efficiency. Thereby, a novel hybrid-SIC is proposed, which jointly performs either ZF-SIC or MMSE-SIC according to the instantaneous channel statistics, on an OFDM subcarrier basis. Furthermore, a complexity analysis is provided whereas upper and lower complexity bounds for the proposed scheme are also derived. Finally, the analysis is accompanied with detailed Bit-Error-Rate (BER) numerical results, which along with the corresponding complexity results, demonstrate the usefulness of the proposed scheme.