Fairness based Improved Subcarrier Allocation Algorithms for OFDMA based Next Generation Networks

Multiuser Orthogonal frequency division multiplexing (MU-OFDM) is one of the promising techniques for future cellular and wireless networks for achieving high downlink capacities. The objective of the next generation cellular and wireless networks, which are based on (MU-OFDM) is to increase the network efficiency by maximizing the total throughput of the system and minimizing the overall transmit power for a given quality of service (QOS). The sum capacity of MU-OFDM is maximized when each subchannel is assigned to the user with the best channel-to-noise ratio for that subchannel. Ever increasing demand for high throughput, low delay and low Outage probability can be met by using Adaptive Resource Allocation in OFDM Technology. In optimal resource allocation algorithms the subcarrier and power allocation should be done simultaneously but it is computationally complex. In order to reduce the complexity of resource allocation algorithms the subcarrier and power allocation is done separately and this is called sub-optimal subcarrier allocation and sub-optimal power allocation. Z. Shen et al. in [9] has given both sub-optimal subcarrier allocation and sub-optimal power allocation algorithms. In this paper we have proposed two methods of subcarrier allocation based on subcarrier allocation method in [9], and compared them with subcarrier allocation