Performance of iterative Successive interference cancellation receiver for LDPC coded OTFS

Abstract

Orthogonal Time Frequency Space (OTFS) modulation is a recently developed transmission technology, where contellation symbols are placed in the delay Doppler lattice. It is shown in literature that, OTFS is more resilient to inter carrier interference than OFDM. However, the required signal processing complexity of OTFS at the receiver side is much higher than that of OFDM. In this work we present the performance of an iterative SIC receiver for LDPC coded OTFS based on a earlier developed MMSE receiver. It is observed that improvement up to 7.5 dB can be achieved using the proposed receiver. It is also shown that the proposed SIC receiver has lower complexity than a message passing receiver available in literature, yet provides comparable performance for lower order modulation and low SNR. For higher order modulations and at high SNR the proposed receiver achieves better reliability, i.e. coded block error rates up to 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> , which is aligned with the higher reliability requirement of 6G mobile communication systems.