Performance Analysis of BEM-based Channel Estimation for OTFS with Hardware Impairments

TL;DR

This paper analyzes how hardware impairments affect the performance of OTFS systems with low-complexity BEM-based channel estimation, providing theoretical insights and validation through numerical results.

Contribution

It introduces a theoretical derivation of the MSE of BEM-based channel estimation under hardware impairments and evaluates their impact on OTFS system performance.

Findings

Hardware impairments significantly degrade OTFS performance.

Theoretical MSE analysis matches numerical simulations.

Minor hardware impairments can cause notable performance drops.

Abstract

This letter studies the low-complexity channel estimation for orthogonal time frequency space (OTFS) in the presence of hardware impairments. Firstly, to tackle the computational complexity of channel estimation, the basis expansion model (BEM) is utilized. Then, the mean square error (MSE) of the estimated channel is theoretically derived, revealing the effects of hardware impairments on channel estimation. Based on the estimated channel, the minimum mean square error (MMSE) detector is adopted to analyze the impacts of imperfect hardware on the bit error rate (BER). Finally, the numerical results validate the correctness of our theoretical analysis of the MSE for channel estimation and lower bound of the BER, and also demonstrate that even minor hardware impairments can significantly degrade the performance of the OTFS system.