Resource allocation in multiuser OFDM systems — A survey

OFDM (Orthogonal Frequency Division Multiplexing) is one of the famous technologies that supports very high data rate. It is one of the best techniques to overcome adverse effects of multipath spread. OFDMA (Orthogonal Frequency Division Multiple Access) is an extension of OFDM. It permits many users to transmit simultaneously on the different subcarriers per OFDM symbol. This paper deals with how the resources like bandwidth, power, subcarrier and bit allocations can be done efficiently to improve the spectral efficiency and to achieve the maximum system capacity. Allocating the total available power and maintaining fairness among users is a difficult task. It is necessary to maintain tradeoff between system capacity, computational complexity and fairness. Several optimization techniques are used to minimize the overall transmit power of a multiuser OFDM system. This paper surveys different resource allocation algorithms developed for the downlink of multiuser OFDM systems.