Low-complexity equalization algorithm for orthogonal time frequency space based on iterative enhancement

Orthogonal Time Frequency Space (OTFS) modulation technology can effectively address the significant challenges brought by fast time-varying channels to signal detection at the receiver, thus providing reliable system transmission performance for high-mobility communication environments. To tackle the problem of high complexity in common OTFS receiver signal detection algorithms, we propose an iterative enhanced detection algorithm based on the delay-time domain. In the delay-time domain, the channel sub-matrix exhibits diagonal characteristics, and the transmission signal and channel matrix appear in the form of vector dot products, effectively reducing the complexity of the receiver signal detection algorithm design. Based on this property, simultaneous utilization of iterative enhanced detection method is employed for interference elimination and Maximum Ratio Combining (MRC) estimation symbol of Least Square Minimum Residual (LSMR) equalizer, aiming to obtain channel delay multipath diversity gain and reduce detector computational complexity. Simulation analysis results demonstrate that compared to standard OTFS signal detection algorithms, such as Minimum Mean Square Error (MMSE) and Message Passing (MP), this detection scheme exhibits certain advantages in terms of computational complexity and system demodulation performance.