This paper presents an analytical framework which lays the foundation for distributed massive multiple-input multiple-output (MIMO) supported wireless power transfer for wearable devices. In our approach, we consider multiple users, each wearing a number of wireless sensors along with one body worn hub which acts as a relay to forward information from the on-body sensors to nearby access points (APs). Each AP is equipped with a large number of antennas and is not only responsible for receiving data sent from the hubs, but also supplying wireless power to them. Interaction between hubs and APs is not exclusive to a single pairing, with APs assigned to supply energy to and receive data from more than one hub. More precisely, APs perform the downlink energy transmission and the uplink data transmission using maximum-ratio combining. Analytical approximations of the outage probability and spectral efficiency are derived. Based on these analytical results, two modes of operation are investigated. These are outage probability prioritized and spectral efficiency prioritized. For each mode, max-min power controls are proposed to ensure a uniformly good service throughout the area of coverage. By contrasting with the IEEE 802.15.6 standard, the numerical results illustrate that while using collocated massive MIMO may provide unsatisfactory performance, the distributed setting shows much promise for enabling wireless power transfer for wearable devices.

中文翻译：

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使用分布式大规模 MIMO 的无线供电可穿戴设备

本文提出了一种分析框架，该框架为可穿戴设备的分布式大规模多输入多输出 (MIMO) 支持的无线电力传输奠定了基础。在我们的方法中，我们考虑多个用户，每个用户都佩戴多个无线传感器以及一个穿戴式集线器，该集线器充当中继器，将信息从身体传感器转发到附近的接入点 (AP)。每个AP都配备了大量的天线，不仅负责接收集线器发来的数据，还为集线器提供无线电源。集线器和 AP 之间的交互不仅限于单个配对，AP 被分配为多个集线器提供能量并从多个集线器接收数据。更准确地说，AP使用最大比合并来执行下行能量传输和上行数据传输。得出中断概率和频谱效率的分析近似值。基于这些分析结果，研究了两种操作模式。这些是优先中断概率和优先频谱效率。对于每种模式，提出了最大-最小功率控制，以确保在整个覆盖区域内提供一致的良好服务。通过与 IEEE 802.15.6 标准的对比，数值结果表明，虽然使用并置的大规模 MIMO 可能提供不令人满意的性能，但分布式设置显示出为可穿戴设备实现无线电力传输的大希望。对于每种模式，提出了最大-最小功率控制，以确保在整个覆盖区域内提供一致的良好服务。通过与 IEEE 802.15.6 标准的对比，数值结果表明，虽然使用并置的大规模 MIMO 可能提供不令人满意的性能，但分布式设置显示出为可穿戴设备实现无线电力传输的大希望。对于每种模式，提出了最大-最小功率控制，以确保在整个覆盖区域内提供一致的良好服务。通过与 IEEE 802.15.6 标准的对比，数值结果表明，虽然使用并置的大规模 MIMO 可能提供不令人满意的性能，但分布式设置显示出为可穿戴设备实现无线电力传输的大希望。