Al Kalaa Mohamad Omar, Seidman Seth J
Center for Devices and Radiological Health (CDRH), U.S. Food and Drug Administration, Silver Spring, MD 20993.
IEEE Trans Electromagn Compat. 2020 Aug 1;62(4):1468-1476. doi: 10.1109/temc.2020.2983326.
This article details the experimental work conducted at the Electromagnetic Compatibility and Wireless Laboratory, U.S. Food and Drug Administration, to investigate the use of LAA signals for wireless coexistence testing. A software defined radio platform was deployed to generate realistic LAA signals and measure the wireless coexistence impact on the LAA communication link. The equipment under test (EUT) used IEEE 802.11ac as an example incumbent technology in the 5 GHz band. The standardized radiated anechoic chamber method was used for testing. Results highlight the mutual coexistence impact of LAA in the 5 GHz band and suggest that selecting an LAA signal with the maximum possible channel time occupancy and the highest possible modulation and coding scheme (MCS) yields the most impactful coexistence situation on both the EUT and the LAA system. Additionally, an analysis of the internal LAA system states during coexistence testing is presented to document the inverse relationship between LAA transmit and wait times during coexistence and the adverse impact of challenging coexistence scenarios on successful channel access. Finally, the risk management process of wireless coexistence for medical devices is summarized and associated with coexistence testing.
本文详细介绍了美国食品药品监督管理局电磁兼容性与无线实验室开展的实验工作，以研究用于无线共存测试的许可辅助接入（LAA）信号。部署了一个软件定义无线电平台，以生成逼真的LAA信号，并测量无线共存对LAA通信链路的影响。被测设备（EUT）以IEEE 802.11ac作为5 GHz频段中的现有技术示例。采用标准化的电波暗室法进行测试。结果突出了5 GHz频段中LAA的相互共存影响，并表明选择具有尽可能最大信道占用时间和尽可能最高调制与编码方案（MCS）的LAA信号，会对EUT和LAA系统产生最显著的共存情况影响。此外，还给出了共存测试期间对LAA系统内部状态的分析，以记录共存期间LAA发射和等待时间之间的反比关系，以及具有挑战性的共存场景对成功信道接入的不利影响。最后，总结了医疗设备无线共存的风险管理过程，并将其与共存测试相关联。
