Channel Estimation and Data detection of OTFS system in the presence of Receiver IQ Imbalance

Orthogonal time frequency space modulation (OTFS), which is very robust to doubly-dispersive channels under high mobility is an emerging waveform for 5G cellular applications. In this paper, we first derive the input-output vectorized relation of OTFS system in the delay-Doppler domain in presence of IQ imbalance. Next, we study the effects of receive IQ imbalance on the performance of OTFS system. We also study the channel estimation and data detection of OTFS system in the presence of receiver IQ imbalance using pilot based transmission. We use a two level threshold based technique for 1. Pilot aided channel estimation and for 2. IQ imbalance parameter estimation. We compare the performance analysis of receiver IQ imbalanced OTFS with the estimated one and observe that the error flooring effect is removed.