Iterative MMSE Detection for Orthogonal Time Frequency Space Modulation

In this article, a successive interference cancellation (SIC) based minimum mean squared error (MMSE) signal detection is investigated for orthogonal time frequency space (OTFS) modulation. In this proposed detection technique, the transmit symbols will be detected on the basis of layers, and different multipath components of the same layer signal together with its interference will be coherently combined and suppressed through MMSE filtering. The performance will be further improved from an iterative operation on SIC-MMSE detection. The complexity of calculating MMSE filter coefficients can be reduced when detection is performed in the time domain due to its simpler channel structures. Simulation shows that our proposed SIC-MMSE detection can outperform maximum-ratio-combing (MRC) thanks to its inherent balances on matched filter and zero-forcing detector.