Subcarrier Allocation in OFDMA with Time Varying Channel and Packet Arrivals

Abstract:
This study considers the design of efficient low-complexity algorithms for dynamic allocation of subcarriers to users in a multiuser transmitter using Orthogonal Frequency Division. The effects upon throughput and delay performances of several canonical algorithms of varying the number of users, the number of subcarriers, and the statistical characteristics of incoming packets are investigated. Consequently, a subcarrier allocation algorithm with low computational complexity and satisfactory performance in almost all cases of interest is developed. The significance of channel v.s. queue state information with respect to various statistical properties of packet arrival processes is explored through extensive simulations. The results carry implications for the amount of channel estimation and feedback necessary. Finally, a new experimental method is proposed and applied for obtaining the stability regions of the algorithms in consideration.