Ambient Internet of Things networks use low-cost, low-power backscatter tags in various industry applications. By exploiting those tags, we introduce the integrated sensing and backscatter communication (ISABC) system, featuring multiple backscatter tags, a user (reader), and a full-duplex base station (BS) that integrates sensing and (backscatter) communications. The BS undertakes dual roles of detecting backscatter tags and communicating with the user, leveraging the same temporal and frequency resources. The tag-reflected BS signals offer data to the user and enable the BS to sense the environment simultaneously. We derive both user and tag communication rates and the sensing rate of the BS. We jointly optimize the transmit/received beamformers and tag reflection coefficients to minimize the total BS power. To solve this problem, we employ the alternating optimization technique. We offer a closed-form solution for the received beamformers while utilizing semi-definite relaxation and slack-optimization for transmit beamformers and power reflection coefficients, respectively. For example, with ten transmit/reception antennas at the BS, ISABC delivers a 75% sum communication and sensing rates gain over a traditional backscatter while requiring a 3.4% increase in transmit power. Furthermore, ISABC with active tags only requires a 0.24% increase in transmit power over conventional integrated sensing and communication.

翻译：环境物联网网络在多种工业应用中采用低成本、低功耗的反向散射标签。通过利用这些标签，我们引入了集成感知与反向散射通信（ISABC）系统，该系统包含多个反向散射标签、一个用户（读取器）以及一个全双工基站（BS），该基站集成感知与（反向散射）通信功能。基站承担双重角色：检测反向散射标签以及与用户通信，并利用相同的时频资源。标签反射的基站信号同时为用户提供数据并使基站能够感知环境。我们推导了用户和标签的通信速率以及基站的感知速率。我们联合优化发射/接收波束赋形器和标签反射系数，以最小化基站总功率。为解决该问题，我们采用交替优化技术。我们以闭式解形式给出接收波束赋形器，同时分别利用半定松弛和松弛优化处理发射波束赋形器和功率反射系数。例如，当基站配备十根发射/接收天线时，与传统的反向散射相比，ISABC在总通信与感知速率上获得75%的提升，同时仅需增加3.4%的发射功率。此外，与传统的集成感知与通信相比，采用有源标签的ISABC仅需增加0.24%的发射功率。