An Aloha based throughput analysis for cognitive radio applications in TV bands

Since existing spectrum is limited and could not efficiently be used, new ways to solve this problem are brought forth. The unused bands currently allocated to TV broadcasting services can be opportunistically reassigned to support broadband networking services while continuing to provide broadcast TV The fragmented and unused TV channels have considerable amount of bandwidth potential and long transmission ranges. This paper considers an OFDM based wireless communications system using TV bands. To make a good use of spectral resources, two OFDM paradigms, ie., Fixed Carrier Spacing (FCS) and Fixed Carrier Number (FCN), have been investigated deeply for Aloha-Medium Access Control protocol in TV white spaces.