Effect of pulsed interference on an ASK receiver

Wireless communication is vulnerable to intentional electromagnetic interference, and therefore it is important to understand the interfering mechanisms. In this paper we investigate the effect of pulsed interference – as compared to continuous interference – on a receiver of digital amplitude modulated signals. To correctly receive the signals, a threshold estimate has to be computed for the proper detection of the symbols. The threshold estimate is based on average received power over an arbitrary length of time. We show that the effect of pulsed interference on the threshold estimate is severe, as compared to that for continuous interference. For this reason, pulsed interference can be more disruptive than continuous interference on a wireless link. This conclusion is confirmed by bit-error-rate measurements on a wireless receiver of amplitude-shift keying modulated signals

Introduction of Wireless Services and Devices in a Hospital Environment Following a Risk-based EMC Approach

This paper emphasizes the need for a risk-based EMC approach in the hospital environment. A modern hospital with various kinds of wireless medical electronic equipment especially in the intensive care, operation theatre, neonatology, etc., pollutes the environment by creating electromagnetic interference with other equipment in the vicinity or even implanted equipment inside the patient. Even following the IEC 60601-1-2 product standard for medical equipment which is based on a rule-based approach, suppressing electromagnetic interference effectively is an arduous task. In the upcoming years, the number of wireless devices in a modern hospital will significantly increase and might cause EMC instability in this highly complex system. Hence, an urgent requirement for an advanced and smarter approach leads to the use of a risk-based EMC approach. The detrimental effect of intentional sources causing electromagnetic interference in the hospital environment is briefly discussed. The risk-based EMC approach has been applied in the Medisch Spectrum Twente hospital, where it was discovered that wireless devices such as digital mobile radio, cell phone, and radio frequency identification equipment critically affect equipment pumps and patient monitors