Uplink Capacity Enhancement in IEEE 802.22 Using Modified Duplex Approach

Efficient usage of spectrum is highly needed for wireless communication application. Cognitive radio (CR) is capable of using unused spectrum at any time/location by without causing any interference to neighbour. IEEE 802.22 wireless regional area network (WRAN) standard operation principles are based on CR technology and it follows time division duplex/Orthogonal frequency division multiplex as a multiple access scheme. Main problem with these access schemes are large turnaround time or idle time exist in the network. Due to the presence of large turnaround time in a network, severe cross time slot interferences and throughput inefficiency are observed in WRAN network. To combat this effect, modified duplex schemes are developed in this article. From the simulation results, it is observed that proposed technique considerably reduces idle time of the network, and additional data are transmitted through available elapsed time. Hence overall system throughputs are improved in the proposed system.