Enhanced cooperative diversity communications

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Over the past decade, there has been an explosive growth in demand for wireless data services. In particular, the evolution from wireless voice to wireless internet data and wireless video is causing exponentially increasing demand for wireless capacity. However, it is generally very hard to increase the wireless transmission rates, because the wireless channel suffers from many artifacts including fading, which significantly degrades the quality of the signal. One of the key methods to mitigate such challenges is to implement multiple antennas at the transmitter and/or at the receiver. In many applications, however, such as in cellular, ad hoc, and sensor networks, it is not always practical to implement multiple antennas due to the size, power, and cost limitations of the terminals. Addressing this problem, a new class of technology, called cooperative diversity, was proposed and it has recently drawn a great deal of interest. The basic idea of cooperative diversity is that several single-antenna terminals "cooperate" in order to mitigate the fading. That is, the multiple terminals help one another in order to send their own and other's signals more reliably over wireless fading channels. The basic properties and performance of cooperative networks have recently been studied in many publications. However, there still remain a number of important issues to be solved. In the proposed research, these problems will be solved to enhance the wireless communication systems based on cooperative diversity. For example, we will study the issues on optimum system resource allocation and efficient methods to combine transmitted signal packets in cooperative diversity networks. The final objective of the proposed research is to optimize cooperative diversity systems. The outcomes of this research will enable wireless communications companies to reduce the expenses and help them maximize profits. Since there are many wireless communications companies in Canada, this research will have a direct economic benefit for Canada. Furthermore, this research will significantly contribute to the training of undergraduate and graduate students by providing them with the fundamental and the state-of-the-art theories on communications.