Power allocation for sum rate maximization in non-orthogonal multiple access system

Non-orthogonal multiple access (NOMA) can increase the spectral efficiency and could play an important role in improving the capacity of 5G networks. In this paper, an optimization problem is formulated to maximize the overall sum rate in a sub-carrier based NOMA system. The optimal transmission power of each user is obtained based on the users' instantaneous channel state information under the total power and the minimum rate constraints. Moreover, two closed-form suboptimal solutions are also proposed for a two-user scenario to reduce the complexity of the optimal solution. The suboptimal approaches are also extended to multiuser scenario by pairing users for subbands transmission. Simulation results show that the derived sub-optimal solutions provide better performance than the orthogonal frequency division multiple access (OFDMA) in terms of coverage probability and sum rate. Moreover, the results show that the proposed sub-optimal solutions achieve a comparable results to the optimal one with lower complexity.

[1]  Muhammad Imran,et al.  Non-Orthogonal Multiple Access (NOMA) for cellular future radio access , 2017 .

[2]  Li Ping,et al.  Comparison of orthogonal and non-orthogonal approaches to future wireless cellular systems , 2006 .

[3]  Anass Benjebbour,et al.  System-level performance of downlink NOMA for future LTE enhancements , 2013, 2013 IEEE Globecom Workshops (GC Wkshps).

[4]  Pingzhi Fan,et al.  On the Performance of Non-Orthogonal Multiple Access in 5G Systems with Randomly Deployed Users , 2014, IEEE Signal Processing Letters.

[5]  Anass Benjebbour,et al.  Concept and practical considerations of non-orthogonal multiple access (NOMA) for future radio access , 2013, 2013 International Symposium on Intelligent Signal Processing and Communication Systems.

[6]  Yik-Chung Wu,et al.  Orthogonal frequency division multiple access fundamentals and applications , 2010 .

[7]  Yoshihisa Kishiyama,et al.  Performance of non-orthogonal access with SIC in cellular downlink using proportional fair-based resource allocation , 2012, 2012 International Symposium on Wireless Communication Systems (ISWCS).

[8]  Joerg Schaepperle,et al.  Enhancement of throughput and fairness in 4G wireless access systems by non-orthogonal signaling , 2009, Bell Labs Technical Journal.

[9]  Jinho Choi,et al.  Non-Orthogonal Multiple Access in Downlink Coordinated Two-Point Systems , 2014, IEEE Communications Letters.

[10]  Yoshihisa Kishiyama,et al.  A novel architecture for LTE-B :C-plane/U-plane split and Phantom Cell concept , 2012, 2012 IEEE Globecom Workshops.

[11]  Stephen P. Boyd,et al.  Convex Optimization , 2004, Algorithms and Theory of Computation Handbook.

[12]  Jeffrey G. Andrews,et al.  Adaptive resource allocation in multiuser OFDM systems with proportional rate constraints , 2005, IEEE Transactions on Wireless Communications.

[13]  Li Ping,et al.  Comparison of orthogonal and non-orthogonal approaches to future wireless cellular systems , 2006, IEEE Vehicular Technology Magazine.

[14]  Bongyong Song,et al.  A holistic view on hyper-dense heterogeneous and small cell networks , 2013, IEEE Communications Magazine.

[15]  Xiaohu You,et al.  Energy-Efficient Resource Allocation in OFDM Systems With Distributed Antennas , 2014, IEEE Transactions on Vehicular Technology.

[16]  Geng Wu,et al.  5G Network Capacity: Key Elements and Technologies , 2014, IEEE Vehicular Technology Magazine.