中文摘要：

目前物理层安全研究大多假设用户是静止的，并未考虑其移动性对安全性能所造成的影响．为此提出一种联合天线选择（TAS）与协作通信（Cop）的物理层安全传输方法TAS—Cop．首先，两个彼此相隔一定距离的基站都具有多根天线，利用天线选择技术，每个基站都选择能使合法接收用户信噪比最大的天线发送保密信息；其次，当用户在两个基站覆盖范围内移动时，彼此之间通过协作以寻求最佳的安全性能．在此基础上推导了瑞利衰落信道下的非零安全容量概率和容量中断概率的闭式表达，并设计了基站之间的最佳功率分配策略．仿真结果表明，与已有的TAS方法相比，TAS-Cop能更有效地满足当用户移动时的安全性能．

英文摘要：

The prevailing research on physical layer security assumes that users are static, while takes no account of user mobility. In view of user mobility, a novel transmit antenna selection and cooperative communication design （TAS-Cop） to enhance physical layer security was proposed. The scenario considered contains two cooperative base stations, which are equipped with multiple antennas respectively. Firstly, both of the two transmitters apply TAS technology to maximize the signal to noise ratio （SNR） at the legal receiver. Next, when the legal receiver moves in the coverage of the two base stations, the transmitters cooperate with each other such that the best security performance can be acquired. Based on Rayleigh fading channel, key security metrics such as the closed-form expressions for non-zero secrecy capacity probability and secrecy outage probability were derived. Following that, an optimal power allocation strategy between the two transmitters was presented. Numerical simulation results show thatthe proposed scheme can achieve better security performance when compared with existing TAS schemes with user mobility is taken into consideration.