MIMO-OTSM: Low Complexity Channel Estimation and MRC Detection Under High Mobility Scenarios

This paper presents a low-complexity detection method tailored for use in MIMO systems employing Orthogonal Time Sequency Multiplexing (OTSM) modulation, specifically designed to perform efficiently despite hardware challenges such as carrier frequency offset (CFO) and IQ imbalance. This de-tector utilizes maximum ratio combining (MRC) to progressively improve the signal to interference plus noise ratio (SINR) through the iterative combination of symbol-vectors across multiple di-versity branches, thereby significantly reducing both multipath and inter-antenna interference. To overcome CFO, it employs sub-channel estimation in the delay-time domain, utilizing sub-sampled estimation at specific pilot intervals. The detector's frame design includes an adequate guard interval to prevent inter-block and pilot-data interference, allowing for efficient parallel detection throughout the data frame. The methodologies proposed here ensure robust, low-complexity performance in a range of real-world radar and communication settings. Compre-hensive testing demonstrates the detector's effectiveness in spa-tially correlated MIMO-OTSM systems, highlighting its potential to improve wireless communication and radar technologies.