On the achievable secrecy transmission rates by Alamouti space‐time block coding in time‐selective fading channels

In this letter, the authors study the security performance of Alamouti space‐time block coding (STBC) with two different linear detection strategies, linear maximum likelihood (LML) and zero‐forcing (ZF), over time‐selective Rayleigh fading channels. Specifically, the connection and secrecy outage probabilities for general temporal correlation when the legitimate receiver and eavesdropper adopt the LML and ZF detectors are first derived. Then the secrecy transmission rates for various combinations of LML and ZF detectors at the legitimate receiver and eavesdropper are derived. The authors also found that the optimal control of the codeword rate and secrecy rate can maximize the secrecy transmission rates.