An optimal link power set for a mobile communication network with directive/adaptive antennas

Abstract

The mobile communication (non-centralized) network with directive/adaptive antennas plays an important role in the digital battlefield in the future. Every user in this non-centralized network has directive or adaptive antennas for transmitting and receiving communication signals. One of the most important design problems in this network is that the communication link between a communication transmitter (CT) and a communication receiver (CR) is not detected by an unfriendly interceptor (UI). Without knowing the exact location of the CR, a CT needs to search for the CR in different directional bins (each has an angle equal to antenna beam width) at different time slots. An ascending search power algorithm between a CT and a CR is developed such that the probability of intercept is minimized when the CT searches for the CR in each directional bin. Instead of using the maximum transmission power level, a CT first uses the lowest transmission power level to search for the CR in the directional bin which has the highest probability of CR location. If the first search attempt is unsuccessful, then CT uses the second lowest transmission power level to search for the CR in the same direction, etc. The optimal link power levels in every directional bin are obtained by minimizing the probability of intercept when a CT searches for a CR using the above protocol. The optimal solutions are analyzed by approximating the probability of link and intercept as unit step functions, and two examples are presented.