Fairness-Insured Aggressive Sub-Channel Allocation and Efficient Power Allocation Algorithms to Optimize the Capacity of IEEE802.16E OFDMA/TDD Cellular System

This paper addresses the problem of finding a suitable solution for the joint allocation of the sub-channel and transmit power for multiple users in an IEEE 802.16e OFDMA/TDD cellular system. We propose the FASA (Fairness insured Aggressive Sub-channel Allocation) algorithm, a dynamic channel allocation algorithm that considers all the users´ channel state information conditionally to maximize throughput while considering fairness. A dynamic power allocation algorithm, i.e., an improved CHC algorithm, is also proposed in this paper to be combined with the FASA algorithm. The improved CHC algorithm collects the extra downlink transmit power and then re-allocates it to other potential users. Simulation results show that the joint allocation scheme with the improved CHC power allocation algorithm provides an additional increase of sector throughput with simultaneous enhancement of the fairness. Furthermore, by addressing the difference between uplink and downlink scheduling in an IEEE 802.16e OFDMA TDD system, we employ the uplink channel information directly through channel sounding, which yields more accurate uplink dynamic resource allocation.