Secure Information Transmission and Power Transfer in Cellular Networks

This letter studies simultaneous data transmission and power transfer for multiple information receivers (IRs) and energy-harvesting receivers (ERs) in cellular networks. We formulate an optimization problem to minimize the total transmit power across a network subject to the following three sets of constraints: 1) data reliability by maintaining the required level of signal-to-interference-plus-noise ratio (SINR) for all IRs; 2) information security by keeping all the SINR levels of the intended IRs measured at each ER below a predefined value, which helps prevent possible eavesdroppers, i.e., ERs, from detecting the information aimed for the IRs; and 3) energy harvesting by guaranteeing the required level of received power at each ER. Using a semidefinite relaxation technique, the proposed problem is then transformed into a convex form that is proved to always yield a rank-one optimal solution.