UNIVERSITY OF HOUSTON SYSTEM

There is a growing need for wireless networks that can sustain high data rates, are robust to interference, make efficient use of battery resources, and offer secure communications. This project introduces cooperative beamforming (CB), a novel technique that enables high throughput and power efficient communications in a secure manner. CB consists of two stages. In the first stage, the sources share their data with neighboring nodes via low-power communications. Various approaches for such information sharing are considered, with a goal to minimize queuing delays, conserve energy, and achieve high throughput. In the second stage, the cooperative nodes apply a weight to the signal received during first stage, and transmit. The weights are such that a specific objective criterion (e.g., signal to interference at the destination) is maximized. In CB, although each node uses low power, all nodes together can deliver high power to a faraway destination. This increase in power offsets power reduction due to propagation attenuation. CB can be viewed as an alternative to multihop transmission and, unlike multihop transmission, does not deplete the power resources of other nodes. Since CB can achieve long distance communication, new paths can be found to improve the overall network performance. Also, CB improves network security by avoiding eavesdroppers; unlike traditional cryptographic-based protocols that operate at higher layers and are sensitive to the broadcast nature of the transmission medium, CB improves security at the physical layer. CB will be implemented on a hardware network testbed to demonstrate how the developed techniques can revolutionize wireless communications.

Clarification of Codes