Security-reliability tradeoff for secure wireless communications with channel estimation error

In this paper, we identify and analyze the tradeoff between security and reliability for wireless communications in the presence of eavesdropping attack. Typically, we assume that both destination and the eavesdropper can only obtain channel state information with estimation errors, instead of perfect channel estimation predominantly assumed in the literature. Linear minimum mean-square error estimation (LMMSE) is performed and the expressions for data throughput of the main link and the wiretap link are derived considering estimation errors. Next the probability that an outage event occurs over the main link, named outage probability, is given to represent the reliability. Meanwhile, the probability that an eavesdropper succeeds in intercepting the source signal, called intercept probability, is found to measure the security. Based on these, the security-reliability tradeoff performance is analyzed and it is shown that the transmission security (reliability) can be improved by loosening the reliability (security) requirement. Simulations are then provided to corroborate the proposed studies.