New Optimal and Suboptimal Resource Allocation Techniques for Downlink Non-orthogonal Multiple Access

This paper investigates several new strategies for the allocation of radio resources (bandwidth and transmission power) using a non-orthogonal multiple access (NOMA) scheme with successive interference cancellation (SIC) in a cellular downlink system. In non-orthogonal access with SIC, the same subband is allocated to multiple users, which requires elaborate multiuser scheduling and subband assignment techniques, compared to orthogonal multiplexing. While taking into account various design issues, we propose and compare several optimum and suboptimum power allocation schemes. These are jointly implemented with multiple user scheduling strategies. Besides, a minimization of the total amount of used bandwidth is targeted. Also, to increase the total achieved system throughput, a hybrid orthogonal-non orthogonal scheme is introduced. This hybrid scheme enables a dynamic switching to orthogonal signaling whenever the non-orthogonal cohabitation in the power domain does not improve the achieved data rate per subband. Extensive simulation results show that the proposed strategies for resource allocation can improve both the spectral efficiency and the cell-edge user throughput, especially when compared to previous schemes employing either orthogonal signaling or NOMA with static & Joumana Farah [email protected] Marie-Rita Hojeij [email protected] Charbel Abdel Nour [email protected] Catherine Douillard [email protected] 1 Department of Telecommunications, Faculty of Engineering, Holy-Spirit University of Kaslik, P.O. Box 446, Jounieh, Lebanon 2 Department of Electronics, Lab-STICC UMR 6285 Technople Brest Iroise, Telecom Bretagne, CS 83 818, 29238 Brest Cedex, France 3 Department of Electricity and Electronics, Faculty of Engineering, Lebanese University, Roumieh, Lebanon 123 Wireless Pers Commun (2016) 87:837–867 DOI 10.1007/s11277-015-2629-2