Zak-OTFS With Time-Domain Offset Gradient Descent Equalization

Orthogonal Time Frequency Space (OTFS) modulation has emerged as a powerful strategy to address the challenges posed by doubly selective channels in high-mobility wireless communication systems. In this study, we introduce an innovative Zak-OTFS transmission framework that integrates channel estimation (CE) alongside an offset gradient descent (OGD) equalization method. The proposed scheme leverages a time-domain training sequence (TS) assisted transmission approach, using the Zak transform to formulate a system with customizable and optimized characteristics suited for varying channel environments. Furthermore, the OGD equalization technique effectively minimizes computational demands by eliminating the need for matrix inversion. Through comprehensive simulations, we demonstrate that our approach achieves comparable performance to the minimum mean-squared error (MMSE) equalization method in integer Doppler case and superior performance in fractional Doppler case, while maintaining considerably lower computational requirements in both cases. This work offers an efficient solution to improve OTFS modulation in complex channel scenarios, positioning it as a strong candidate for next-generation wireless communication systems.