Efficient waveform design improves MIMO OFDM radar and communication systems

Efficient Transmit Waveform Design for MIMO-OFDM DFRC Systems with 1-Bit DACS

Information Theory

Summary

This paper tackles the challenge of designing special signals that can both detect objects and send data using simple 1-bit digital converters, which are cheaper but harder to work with. The authors created a mathematical way to maximize the accuracy of detecting targets while also keeping communication errors low, using a challenging optimization problem. They proposed a new algorithm that efficiently solves this problem by switching between different signal views (time and frequency) and cleverly handling constraints to make the process faster and more reliable. Simulations show promising results for combining radar and communication in one system with these constraints.

What this means in practice

Authors

Chenfei Huang, Mingjie Shao, Ya-Feng Liu

Abstract

This paper studies efficient waveform design for MIMO-OFDM dual-functional radar-communication (DFRC) systems with 1-bit digital-to-analog converters (DACs), which remains underexplored in the literature. We formulate the DFRC waveform design problem by maximizing the trace of the target angular Fisher information matrix (FIM), subject to symbol-error probability constraints realized via constructive interference (CI) and a time-domain 1-bit transmit alphabet constraint. The resulting problem is a large-scale nonlinear integer programming problem. We develop an inexact alternating direction method of multipliers (ADMM) algorithm with alternating time- and frequency-domain updates. The proposed scheme enables subcarrier-wise optimization in the frequency domain and closed-form primal and dual updates in the time domain. In particular, the CI constraints are deliberately retained in both the time- and frequency-domain subproblems to promote the feasibility of intermediate iterates and improve the convergence behavior of ADMM. Simulation results demonstrate promising DFRC performance.
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