On the secrecy of the cognitive interference channel with partial channel states

The secrecy problem in the state-dependent cognitive interference channel is considered in this paper. In our model, there are a primary and a secondary (cognitive) transmitter-receiver pairs, in which the cognitive transmitter has the message of the primary one as side information. In addition, the channel is affected by two channel state sequences, which are known at the cognitive transmitter and the corresponding receiver, separately. The cognitive transmitter should cooperate with the primary one, and it wishes to keep its message secure at the primary receiver. The achievable equivocation-rate regions for this channel are derived using two approaches: the binning scheme coding and superposition coding. Then, comparisons between the results using two coding approaches, in Gaussian case, shows that there is a trade-off between the achievable rate of the primary transmitter and the equivocation rate of the cognitive one. Moreover, the outer bounds on the capacity of the channel are derived. Copyright (c) 2016 John Wiley & Sons, Ltd.