Enhanced cooperative diversity communications

在过去的十年里，对无线数据服务的需求出现了爆炸性的增长。特别是，从无线语音到无线互联网数据和无线视频的演变导致对无线容量的需求呈指数级增长。然而，提高无线传输速率通常是非常困难的，因为无线信道受到包括衰落在内的许多伪像的影响，这显著降低了信号的质量。缓解这种挑战的关键方法之一是在发射机和/或接收机处实现多天线。然而，在许多应用中，例如在蜂窝、自组织和传感器网络中，由于终端的尺寸、功率和成本的限制，实现多个天线并不总是可行的。为了解决这一问题，一种新的技术被提出，称为合作分集，它最近引起了人们的极大兴趣。协作分集的基本思想是多个单天线终端相互协作以减轻衰落。也就是说，多个终端相互帮助，以便在无线衰落信道上更可靠地发送它们自己的信号和其他终端的信号。协作网络的基本性质和性能最近在许多出版物中得到了研究。然而，仍有一些重要问题有待解决。在提出的研究中，这些问题将被解决，以增强基于协作分集的无线通信系统。例如，我们将研究协作分集网络中最优系统资源分配和有效合并发送信号分组的方法等问题。研究的最终目标是优化协作分集系统。这项研究的结果将使无线通信公司能够降低费用，帮助他们实现利润最大化。由于加拿大有许多无线通信公司，因此这项研究将为加拿大带来直接的经济效益。此外，这项研究将为本科生和研究生提供基本的和最先进的传播理论，从而为他们的培养做出重大贡献。

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.