Date Added: Jun 2011
Cognitive Radio built on top of spectrum sensing is promised to provide more capacity for users wherever and whenever needed and improve radio spectrum utilization in clever and fair manner. However, practical spectrum sensors have to be implemented and they should provide sufficient protection to legacy users of radio spectrum. This leads to trade-offs between primary user protection ratio, device form factor, cost and power consumption. In this paper, the authors have derived requirements for antenna efficiency, sensitivity and linearity of practical spectrum sensors. These are verified by field measurements using spectrum sensor embedded to a mobile phone.