线形小区中分布式天线协同的定时捕获改进方法

An Improved Timing Acquisition Method with Cooperation of Distributed Antennas in Linear Cell

不精确的定时捕获造成分布式天线系统性能的严重下降,现有的改善分布式天线系统定时捕获性能的方法存在诸多不足。为进一步提高分布式天线系统定时捕获时的正确捕获概率,提出了一种基于分布式天线协同的定时捕获方法。该方法针对线形小区的平坦瑞利衰落信道场景,利用两根分布式接收天线接收来自单天线移动台的发射信号;随后,推导了两分布式接收天线的时延差先验信息,建立了协同定时捕获的协同条件;最后,根据门限检测方法在协同条件下进行定时捕获。分析与仿真结果表明,在定时捕获时,无论移动台处于协同区域的哪个位置,提出方法均能有效改善各分布式接收天线的正确捕获概率。

The inaccuracies of timing acquisition significantly degrade the performance of distributed antenna systerns （DAS）. In the existing methods, there are many insufficiencies to improve the timing acquisition performance. To accommodate and compensate these insufficiencies, a timing acquisition method with the cooperation of distributed receive antennas is proposed. In the fiat Rayleigh channels of linear cell, two distributed receive antennas are adopted to receive the signal transmitted from the mobile station （MS） with a single antenna. Then, a precondition of cooperation is exploited by utilizing the prior information of the time-delays difference from the two distributed receive antennas. With the exploited cooperation precondition, the timing acquisition based on the method of threshold detection is performed at each distributed antenna. Analysis and simulations show that the probability of correct acquisition for each distributed antenna can be improved according to the pro- posed method wherever the MS is located.