Optimal BER Minimum Precoder Design for OTFS-Based ISAC Systems

TL;DR

This paper proposes a novel precoder design for OTFS-based ISAC systems that minimizes BER by optimizing power and sensing performance, using an iterative method to solve a non-convex problem.

Contribution

It introduces a delay-Doppler domain precoder design for BER minimization in OTFS-ISAC systems, addressing non-convexity with an iterative solution.

Findings

Proposed precoder effectively reduces BER in OTFS-ISAC systems.

Simulation confirms the precoder's ability to balance sensing and communication performance.

Demonstrates the interplay between sensing and communication in dual-functional precoder design.

Abstract

This paper investigates the bit error rate (BER) minimum pre-coder design for an orthogonal time frequency space (OTFS)-based integrated sensing and communications (ISAC) system, which is considered as a promising technique for enabling future wireless networks. In particular, the BER minimum problem takes into account the maximized available transmission power and the required sensing performance. We devise the precoder from the perspective of delay-Doppler (DD) domain by exploiting the equivalent DD channel. To address the non-convex design problem, we resort to minimizing the lower bound of the derived average BER. Afterwards, we propose a computationally iterative method to solve the dual problem at low cost. Simulation results verify the effectiveness of our proposed precoder and reveal the interplay between sensing and communication for dual-functional precoder design.