A low-complexity suboptimal algorithm for joint subcarrier assignment in downlink OFDMA system

Multiuser orthogonal frequency division multiple access (MU-OFDMA) technique has attracted much attention for broadband wireless access in future generation wireless communication systems. To achieve high data rate under constraint conditions, systems require proper resource allocation. This demands, sophisticated signal processing algorithms, which are computationally complex. This paper proposed a low complexity suboptimal joint algorithm for resource allocation (task-1) and subcarrier assignment (task-2). The power allocation is carried out using the water-filling algorithm. The proposed algorithm is compared with existing Hungarian algorithm (HA) and amplitude craving greedy (ACG) algorithm for spectral efficiency, fairness among the users and computational complexity. The simulations results show that the proposed algorithm performs close to the HA. It maintains high fairness among the users and has reduced computational complexity compare to the existing algorithms.