Queue Management and Interference control for Cognitive Radio

Abstract

In this report I will look at the possibility of using a sensor network to control the interference to primary users made by secondary users. I'm going to use two Rayleigh fading channels, one to simulate the channel between the secondary transmitter and the sensor, and another to simulate the channel between the secondary transmitter and secondary receiver. I assume that the system is either using multiple antennas or that the secondary transmitter is moving relative to the sensor and primary user so that the channels share the same statistics. If the interference level gets too high at the sensor it should limit the transmission power at the secondary transmitter. And when it reaches a low level, the secondary transmitter can transmit with a higher power, depending on the channel between the two secondary users. I will study where the system stabilize. What the different variables control in the system. How the factor between the signal received at the sensor and the signal received at the secondary user are for different arrival rates. In the results i found out that small arrival rates have the highest efficiency compared to power at the secondary user and the sensor. When using a peak power constrain it helped stabilizing the system.