Interference Protection on Legacy Devices with Cognitive Radio using Smart Antennas

The scarcity of the radio spectrum now encourages the use of cognitive radios so that highly sought frequency bands could be shared between a secondary and a primary (legacy) network. This paper presents a new interference estimation technique for a smart antenna equipped MANET (Mobile Ad hoc NETwork), acting as a secondary network, to estimate its interference to fixed primary network devices by means of uncertainty ellipses surrounding the coarse probabilistically estimated location of those devices. The MANET can thus assess by simulation the impact of its future spectrum sharing with the primary network and takes countermeasures accordingly. Simulation results demonstrate the advantage of using this new technique compared to our previous technique that uses uncertainty circles.