Low-Complexity Zero-Forcing Equalization for MIMO SC-FDMA Terahertz Communications

Multiple input-multiple output (MIMO) transmission diversity has proven to be a spectrally-efficient technique that multiplies the capacities of band-limited wireless channels. However, employing this technique to the inherently bandwidth-generous terahertz technologies results in massive data volumes, which calls for computationally-affordable signal processing techniques. In this paper, we propose an implementation for zero-forcing (ZF) equalizers in single-carrier frequency domain multiple access (SC-FDMA) MIMO systems operating at terahertz frequencies, where the high-speed processing of massive data is of paramount importance. The proposed method explores the sparseness of the MIMO channel matrix to reduce the computational complexity. Simulation results show that the proposed equalizer is comparable to the conventional ZF equalizer in terms of the bit error rate (BER), with a much lower computational complexity. The proposed equalization approach can be considered as a potentially significant step towards the implementation of real-time terahertz communications applications.