Optimal Pilot Design for OTFS in Linear Time-Varying Channels

TL;DR

This paper proposes optimal pilot placement and power allocation strategies for OTFS modulation in linear time-varying channels, significantly improving channel estimation accuracy and capacity.

Contribution

It introduces two new pilot allocation schemes and an optimized power distribution method to enhance OTFS performance in dynamic channels.

Findings

New pilot allocations reduce channel estimation error

Optimized power balance increases average channel capacity

Numerical results validate the proposed methods' effectiveness

Abstract

This paper investigates the positioning of the pilot symbols, as well as the power distribution between the pilot and the communication symbols in the orthogonal time frequency space (OTFS) modulation scheme. We analyze the pilot placements that minimize the mean squared error (MSE) in estimating the channel taps. This allows us to identify two new pilot allocations for OTFS. In addition, we optimize the average channel capacity by adjusting the power balance. We show that this leads to a significant increase in average capacity. The results provide valuable guidance for designing the OTFS parameters to achieve maximum capacity. Numerical simulations are performed to validate the findings.