Joint Space-Frequency Iterative Interference Suppression in Multiuser MIMO-OFDM Systems

In uplink multiuser multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) systems, inter-user interference includes co-channel interference (CCI) due to spatial multiplexing and inter-carrier interference (ICI) due to carrier-frequency offset (CFO). In this letter, a space-frequency joint processing scheme is proposed to suppress the two-dimensional interference alternatively and iteratively. Moreover, by the studies of convergence behavior of iterations, a sufficient condition for convergence is presented. The theoretical analysis and simulation results both show that this iterative scheme can effectively suppress inter-user interference with low complexity.