Energy and data cooperation in energy harvesting multiple access channels

A typical wireless device is limited by its fi nite battery, and energy limitation is as a critical bottleneck on wireless network performance. In addition to the EM radiation caused by high power wireless devices, the batteries used in those devices need to be recharged frequently, causing fast depletion of earth's resources; and are discarded after a while, causing environmental pollution. Moreover, in some scenarios, such as sensor networks deployed in rural areas, it is simply not feasible to replace the batteries of the wireless nodes, hence using nodes which can replenish their energy is of paramount importance in prolonging the network lifetime. As a result, the concept of green communication and the idea of designing communication protocols based on energy harvesting constraints of individual nodes have recently received tremendous attention. With this motivation in mind, this thesis is devoted to designing cooperation and transmit scheduling techniques for networks powered soleley by harvested energy. We study energy cooperation in a two user multiple access channel and a two user cooperative multiple access channel with and without battery limitations. We characterize, and optimize the departure region for a two user multiple access channel, under six di fferent models, with varying levels of cooperation and energy storage capabilities. We aim to find the optimum energy management policies of the transmitters to maximize the achievable departure region over a fi nite transmission duration.