Security-Reliability Trade-Off Analysis in Adaptive Transmit Antenna Selection Systems With Limited Feedback

We investigate the security-reliability trade-off (SRT) performance of a cellular wireless network under illegal eavesdropping, where only the quantized main channel state information (CSI) from the destination is available at the multiantenna source. Due to the limited feedback, the employment of antennas with poor channel quality marginally enhances the system performance, but increases the channel quantization error. Accordingly, an adaptive transmit antenna selection (ATAS) scheme is introduced, where the transmit antennas with channel gain exceeding a predefined threshold can be employed. We conduct SRT analysis by deriving the expressions of the outage probability (OP) and intercept probability (IP) for our ATAS scheme and propose the sum of OP and IP optimization of ATAS (SOIO-ATAS) algorithm to realize the balance and tradeoff between security and reliability. Numerical simulation results demonstrate the advantage of proposed ATAS scheme over the benchmarks in terms of SRT performance. Moreover, the SRT performance can be enhanced by adjusting the channel gain threshold.