A comparision of frequency/amplitude modulation scheme in cognitive radio envoirnment

The electromagnetic spectrum is a natural resource and it is utilized by taking license from governments in every part of the world. The licensed/primary users are not transmitting all the time and consequently degrade spectrum utilization that can be improved by the exploitation of spectrum to secondary/unlicensed users. The spectrum can be utilized in an effective and reliable manner by the use of cognitive radio technology. Cognitive radio is software defined radio with an additional capability to sense environment and consequently configures itself intelligently according to changes in the surroundings. In this paper we have presented a model that allows secondary users to transmit in a FM/AM radio environment without violating the interference temperature limit and tried to evaluate which one among FM/AM is more proficient for an efficient utilization of spectrum. We have modeled the radio environment in MATLAB where primary users transmit after random intervals and the vacant spaces during these intervals are used by secondary users.