Link acquisition protocols for a mobile communication network with directive/adaptive antennas

A non-centralized fully distributed mobile communication network with directive or adaptive antennas is proposed in this thesis. Every node uses directive or adaptive antennas for transmitting and receiving communication signals. The spatial and temporal synchronization of transmitting and receiving antenna beams is accomplished by employing the Global Positioning System information and a double-ended spatial search algorithm. This research focuses on the problem of how a communication transmitter (CT) establishes the communication link with a communication receiver (CR). The communication link setup between a CT and a CR depends on the successes of both forward and reverse links. A two-way communication link protocol is defined as a basic agreement for the link activation in the network. Two link search algorithms, (1) a sequential ascending search power algorithm (SASPA) using an optimal set of link power levels and (2) a sequential Bayesian search algorithm (SBSA) using Bayes rule to update the CR location information, for additive white Gaussian noise channels, are proposed for a CT to search for its intended CR in both hostile and friendly communication environments. The optimal SBSA can be obtained by using dynamic programming but the computational complexity is unfeasibly high. All the link protocols, search algorithms and theories developed in this thesis are general, and can be applied to any realistic antenna patterns and to any particular receiver using any type of digital modulations. The experimental results that the CT uses a non-coherent matched filter receiver for spread-spectrum code acquisition and the unfriendly interceptor uses a wide-band energy detector for both link search algorithms are presented in this thesis.