定价： 0元 / 折扣价： 0 元

This standard provides recommended practices for the determination of uncertainty in the estimation of error vector magnitude (EVM) of a measured digitally modulated wireless communication signal. Such practices include several methods for validating a user's measurement of a specific reference waveform by comparison to a reference measurement. The methods differ based on the level of rigor desired by the user and the accessibility to timing and waveform recording capabilities of the available… read more hardware. Methods for evaluating measurement uncertainty in EVM are also presented. Some of the methods described here focus on measurements and uncertainties related to the use of laboratory-based measurement equipment such as vector receivers, real-time and equivalent-time sampling oscilloscopes and other types of waveform recorders that have access to the measured waveform. This allows time-alignment and gain normalization of measured waveforms prior to the calculation of EVM. Other methods focus on specialized receivers that report symbols directly. As part of the assessment of the measurement hardware and associated uncertainty analyses, this practice includes a mathematically rigorous method for the determination of EVM. read less

定价： 113元 / 折扣价： 97 元

This recommended practice is a guide to evaluating the electromagnetic immunity of medical devices to radiated radio-frequency (RF) emissions from common RF transmitters (e.g., two-way radios; walkie-talkies; mobile phones; wireless-enabled tablets, e-readers, laptop computers, and similar devices; radio-frequency identification (RFID) readers; networked mp3 players; two-way pagers; and wireless personal digital assistants [PDAs]). This protocol does not provide a comprehensive test or offer… read more any guarantee, but it is a basic evaluation that can help identify medical devices that might be particularly vulnerable to interference from common RF transmitters. The ad hoc test protocol can be used to evaluate existing or newly purchased medical devices or can be implemented for the purpose of prepurchase evaluation. This recommended practice applies to medical devices used in health-care facilities, but it can also be adapted to medical devices in home health-care or mobile health-care settings. It does not apply to implantable medical devices (e.g., pacemakers and defibrillators), transport environments such as ambulances and helicopters, or RF transmitters rated at more than 8 W of output power. Testing with transmitters greater than 8 W in health-care facilities is not recommended because of possible adverse effects on critical-care medical devices that are in use in nearby areas of the facility. Finally, this recommended practice does not address in-band RF interference where the fundamental frequency of an RF transmitter overlaps with frequencies used by a hospital wireless network or monitoring or used by other medical device wireless links. read less

定价： 110元 / 折扣价： 94 元