Abstract
For a multiple-input-single-output secure channel, we consider the transmission strategies, including transmission rate and beamformer against opportunistic attack, which eavesdrops or generates jamming signal with certain probabilities. Based on the perfect and partial channel state information of jamming channel, we design the transmission strategies against the jamming, eavesdropping, and both attacks. Then, we provide the optimal transmission strategy in terms of expected secrecy rate for the given attack strategy.