基于分布式天线的全双工中继系统最大化和速率波束成形设计

摘要

Distributed antenna based full-duplex relay system is capable of simultaneous transmission and reception in the same frequency band on two hops, and it provides uniform coverage for cell edge and deep shadow fading areas with increased spectral efficiency. In multiuser scenarios with non-ideal self interference cancellation, beamforming using multiple distributed antennas is proposed to suppress self interference and multiuser interference jointly. A system model for multiuser end-to-end sum-rate maximization under individual power constraints at distributed antennas is established first. Then, a dual-layer iterative algorithm is proposed to resolve the non-convexity of the problem. Simulation results validate the effectiveness of the proposal algorithm, showing that the proposed beamforming design can be used in distributed-antenna based full-duplex relay systems, to suppress both self interference and multiuser interference efficiently, and increase system spectral efficiency significantly.%基于分布式天线的全双工中继系统结合了全双工中继两跳同时同频传输的能力和分布式天线高效覆盖的特性，为提升小区边缘和严重阴影衰落区域的频谱效率提供了一种有效途径。在自干扰抵消非理想的多用户场景下，利用分布式多天线波束成形可实现对系统中自干扰和多用户干扰的联合抑制。为此，该文首先建立了在各分布式天线节点独立发射功率约束下最大化多用户端到端和速率的最优化系统模型，进而提出一种双层迭代算法，解决原问题的非凸性求解难题。仿真结果验证了算法的有效性，表明在多用户分布式天线全双工中继系统中，所提波束成形设计能够有效抑制自干扰和多用户干扰，显著提高系统频谱效率。