高空平台通信系统覆盖范围广、组网成本低、通信容量大，适合为地面用户提供可靠的多媒体广播多播业务。该文针对高空平台与地面系统协同广播的场景，提出了一种兼顾能效与谱效的下行多址接入和资源分配优化算法。根据活跃用户的位置分布，首先以提高发射能效为目标为每个业务选择合适的信道资源，然后根据同类信道内不同业务的服务质量要求，采用联合正交与非正交多址接入的混合下行多址接入策略，以实现频谱效率和接收端复杂度的折中。仿真结果表明：相比传统的正交多址接入和单一信道传输算法，该算法在复杂度损失较小的情况下显著节约了发射成本，且具有更高的资源配置灵活性。
Highaltitude platform (HAP) communication systems provide wide coverage, low networking costs, and large capacities for reliable multimedia broadcast/multicast services (MBMS) for terrestrial users. This paper presents an algorithm that jointly optimizes the downlink multiple access and the resource allocation for cooperative broadcasting using an integral HAP/terrestrial system which takes into account both the energy and spectrum efficiencies. The location distribution of active users is used to select the appropriate channel resources for each service that minimizes the energy use. Then, a hybrid orthogonal and non-orthogonal multiple access system is designed to satisfy the quality of service requirements for each service in the same channel to balance the spectral efficiency and the receiver complexity. Simulations verify that this algorithm is more efficient than the traditional orthogonal multiple access (OMA) strategy and single channel transmission algorithms. This algorithm has less complexity loss, significantly reduces transmission costs and provides more flexible radio resource management.
[1] MOHAMMED A, MEHMOOD A, PAVLIDOU F N, et al. The role of high-altitude platforms (HAPs) in the global wireless connectivity[J]. Proceedings of the IEEE, 2011, 99(11):1939-1953.
[2] ARANITI G, IERA A, MOLINARO A. The role of HAPs in supporting multimedia broadcast and multicast services in terrestrial-satellite integrated systems[J]. Wireless Personal Communications, 2005, 32(3-4):195-213.
[3] ARANITI G, IERA A, MOLINARO A, et al. On the optimization of power assignment to support multicast applications in HAP-based systems[C]//Proceedings of 201017th IEEE International Conference on Telecommunications. Doha, Qatar:IEEE, 2010:219-226.
[4] ARANITI G, IERA A, MOLINARO A. A power based algorithm for efficient radio resource management policy in integrated terrestrial/HAP MBMS systems[C]//IEEE Globecom 2008-2008 IEEE Global Telecommunications Conference. New Orleans, USA:IEEE, 2008:1-5.
[5] SUDARWAN R U, ISKANDAR. Performance analysis of DVB-H over high altitude platform station system (HAPS)[C]//Proceedings of 20151st International Conference on Wireless and Telematics. Manado, Indonesia:IEEE, 2015:1-5.
[6] 3GPP TS 36.212. Multiplexing and channel coding:V14.8.0[S]. 2018.
[7] ISLAM S M R, AVAZOV N, DOBRE O A, et al. Power-domain non-orthogonal multiple access (NOMA) in 5G systems:Potentials and challenges[J]. IEEE Communications Surveys & Tutorials, 2017, 19(2):721-742.
[8] 3GPP TR 36.776. Study on LTE-based 5G terrestrial broadcast:V1.0.0.[S]. 2018.
[9] ZHOU F H, WU Y P, HU R Q, et al. Energy-efficient NOMA enabled heterogeneous cloud radio access networks[J]. IEEE Network, 2018, 32(2):152-160.
[10] JIN H P, PENG K W, SONG J. A spectrum efficient multi-user transmission scheme for 5G systems with low complexity[J]. IEEE Communications Letters, 2015, 19(4):613-616.
[11] PARK S I, LEE J Y, LIM B M, et al. Field comparison tests of LDM and TDM in ATSC 3.0[J]. IEEE Transactions on Broadcasting, 2018, 64(3):637-647.
[12] ZHU L P, ZHANG J, XIAO Z Y, et al. Optimal user pairing for downlink non-orthogonal multiple access (NOMA)[J]. IEEE Wireless Communications Letters, 2019, 8(2):328-331.
