Energy Efficient Waveform Design and Subcarrier Allocation for Multicarrier MIMO JCAS

• Published in: IEEE Wireless Communications and Networking Conference : [proceedings] : WCNC pp. 1 - 6
• Main Authors: Hatami, Mohammad, Nguyen, Nhan Thanh, Juntti, Markku
• Format: Conference Proceeding
• Language: English
• Published: IEEE 24.03.2025
• Subjects: beamforming; Energy efficiency; energy efficiency (EE); Joint communications and sensing (JCAS); Lapping; Linear programming; Optimization; Programming; Radar; Resource management; Sensors; Signal to noise ratio; Transforms; waveform design
• ISSN: 1558-2612
• DOI: 10.1109/WCNC61545.2025.10978567

This work studies joint waveform design and subcarrier allocation in a multiuser multicarrier monostatic joint communications and sensing (JCAS) system. We aim to design the JCAS transmit waveform with subcarrier allocation that maximizes the energy efficiency (EE) of the multiuser communications subject to the constraints on the minimum communications and sensing signal-to-interference-plus-noise ratios (SINRs) and transmit power budget. The formulated EE design problem is a mixed-integer non-convex fractional program, which is highly challenging to solve directly. To overcome the challenges, we leverage alternating optimization (AO) and divide the original problem into two subproblems, namely, the waveform design and subcarrier allocation. For the non-convex fractional objective function in the waveform design, we propose an efficient method combining two typical techniques in fractional programming, namely, the quadratic and Dinkelbach transforms, along with successive convex approximation (SCA). For the subcarrier allocation, we leverage quadratic transform and penalty function method. Numerical results demonstrate the effectiveness of the proposed method, showing a significant improvement in energy efficiency compared to a baseline scheme.