Green Transceiver Design for Integrated Sensing and Backscatter Communication with QoS Demands

With the mass inclusion of machines in network architectures, integrated sensing and communication (ISAC) is emerging as a key use-case of 6 G communication systems. The dual functionality of ISAC introduces prohibitive energy and spectrum costs, which are further exacerbated by the increasing scale of modern networks. This escalating demand highlights the urgent need for green network architectures that minimize power consumption and improve energy efficiency. Backscatter technology offers a promising avenue for alleviating resource constraints, as it utilizes existing radio-frequency signals, enhancing both spectrum and energy efficiency. However, the interference between the sensing and communication signals can further increase resource consumption. Hence, green communication, with a directed focus on power minimisation and energy efficiency, is essential for next-generation systems. In this paper, we present a green, quality-of-service (QoS) -aware transceiver design for integrated sensing and backscatter communication (ISABC) systems. The sensing and communication QoS constraints ensure the functional operation of target sensing and backscatter communication. We jointly optimize the radar signal, precoding vector, and receive combiners to minimize power consumption at the dual-function base station while meeting both sensing and communication requirements. The proposed green ISABC design demonstrates a 12 dB performance improvement compared to equivalent radar sensing and uplink communication systems.