Optimized Dynamic Resource Allocation in Frequency and Spatial Domains

Abstract

We propose an effective resource allocation method to handle OFDMA and multiuser MIMO. This method offers two optimization techniques. In the frequency domain, those subcarriers that are useful for one subscriber station (SS) are allocated to that SS. In the spatial domain, several SSs are selected for spatial multiplexing. In frequency selective fading environments, the number of transmittable bits increases since the frequency and spatial resources can allocated efficiently. We define a permission table that indicates the allocation status. It is optimized using a genetic algorithm. The table is associated with GA chromosomes. They are renewed so as to improve two criteria, total throughput and minimum throughput among SSs. Calculations show that the proposed method improves the total throughput performance by up to around 50% compared to random resource allocation. The minimum throughput of each SS can also be improved with a small penalty in total throughput.