分布式天线组阵优选设计

Optimal Design for Distributed Antenna Arraying System

分布式天线组阵是指利用现有的天线资源,使用较低成本实现超大的天线口径。针对分布式天线组阵中,不同口径天线接收信号信噪比差异较大,任意天线是否均可引入天线阵中,加入较低接收信噪比的信号进行组阵合成能否提高最终合成信号的误码率性能等问题,提出了分布式天线组阵的优选准则。该准则依据载频、时延以及相位这三者估计算法的性能及其克拉美罗性能下界,证实当接收信号信噪比低于载频估计的异常值效应门限时,受载频差估计精度急剧恶化的影响,将该信号加入天线阵中进行合成将引起最终合成信号误码率性能的恶化。系统仿真算例验证了结论的正确性,为我国未来深空探测任务提供可靠的保障。

In a distributed antenna arraying system, an effective large aperture with low cost can be realized by utilizing the existing antenna resources. For the receiving signal-to-noise ratios （SNRs） of antennas with different apertures in distributed antenna arraying system vary in a large range, a question is raised that is the combined performance improved with arbitrary antennas added into the distributed antenna arraying system？ An optimal design criterion is proposed to solve this issue. Based on the estimation algorithm＇s performance and the Cramer-Rao bounds （CRBs） of carrier frequency, delay and carrier phase, the criterion proves, that the combined BER performance is degraded when antennas with receiving signal＇s SNR lower than the outlier effect threshold of carrier frequency estimation are added to the distributed antenna arraying system. Theoretical analysis and simulation results verify the above conclusion.