线形小区中分布式天线协同的定时捕获改进方法

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。

An improved timing acquisition method with cooperation of distributed antennas in linear cell

The inaccuracies of timing acquisition significantly degrade the perfo rmance of distributed antenna systems (DAS). In the existing methods, there are many insufficiencies to improve the timing acquisition performance. To accommoda te and compensate these insufficiencies, a timing acquisition method with the co ope ration of distributed receive antennas is proposed. In the flat Rayleigh channel s of linear cell, two distributed receive antennas are adopted to receive the si gnal transmitted from the mobile station (MS) with a single antenna. Then, a pre condition of cooperation is exploited by utilizing the prior information of the time-delays difference from the two distributed receive antennas. With the expl oited cooperation precondition, the timing acquisition based on the method of th reshold detection is performed at each distributed antenna. Analysis and simulations show that the probability of correct acquisition for each di stributed antenna can be improved according to the proposed method wherever the MS is located.