Detection Techniques for SISO/MIMO-OTSM Systems with Hardware Impairments Under High Mobility Scenarios

This paper presents a novel low-complexity detector tailored for radar and communication (RadCom) applications within multiple-input multiple-output (MIMO) systems employing Orthogonal Time Sequency Multiplexing (OTSM) modulation, particularly in the presence of hardware impairments such as carrier frequency offset (CFO) and IQ imbalance. Leveraging maximum ratio combining (MRC), the detector iteratively enhances the signal-to-interference-plus-noise ratio (SINR) by amalgamating symbol-vectors from diverse diversity branches. The approach adeptly mitigates challenges arising from multi-path interference and inter-antenna interference. To tackle CFO-related issues, the detector employs sub-channel estimation in the delay-time domain, utilizing sub-sampled estimation at discrete pilot intervals. The frame design incorporates a sufficiently sized guard interval, eliminating inter-block interference and pilot-data interference, thereby facilitating low-complexity parallel detection across the entire data frame. The proposed techniques demonstrate robust performance and reduced complexity in various practical radar and communication scenarios. Extensive experimental validation underscores the effectiveness of the proposed detector in MIMO-OTSM systems, showcasing its potential to enhance wireless communication and radar applications.