Efficient Methods for Resource Allocation and Interference Alignment in OFDMA Systems

• Main Authors: Mei-Chun Lin, 林玫君
• Other Authors: Yung-Fang Chen
• Format: Others
• Language: en_US
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/44830300848296320415

碩士 === 國立中央大學 === 通訊工程學系 === 101 === This paper considers resource allocation methods to achieve the maximum system throughput for a MIMO OFDMA system with an interference alignment technique. Interference alignment is considered as an important technique that could eliminate inter-cell interference and inter-user interference, and would enhance the system throughput. Before performing interference alignment, the system has to select paired user equipments that could align the interference signals. Consequently, each user equipment could receive the desired signal without interference. Owing to the design of interference alignment beamforming, the resource allocation problem becomes different and difficult. Based on the structure of interference alignment considered in this paper, the selection of the paired user equipments for each resource block is further investigated. This paper first presents the user equipment selection based on interference alignment. A proposed interference alignment-based selection scheme with a low computational complexity is developed by using the receive beamforming vectors, so that each resource block may be assigned to the paired user equipments that would have better system throughput. In addition, we design Sequential search scheme and Compete-and-compare scheme to further improve the performance. The paired user equipments are adjusted dynamically to achieve the maximum system throughput. Simulation results demonstrate that the proposed interference alignment-based selection scheme outperforms the existing algorithms. The performance of Sequential search scheme and Compete-and-compare scheme is very close to that of the optimal solution with an exhaustive search while the computational complexity is greatly reduced. The number of iterations in Sequential search scheme and Compete-and-compare scheme to obtain a solution is also pretty small.