CIF: Small: Limited Feedback and Information Exchange for Wireless Systems

商业蜂窝网络最近经历了数据服务需求的急剧增长。满足这一需求将需要这种网络能够实现的频谱效率的实质性（数量级）提高。这将要求网络中各节点之间进行比当前系统更广泛的信息交换和合作。本研究基于反馈和信息交换的实用方法，探讨了蜂窝网络中节点间合作的可能途径。本研究的主要主题是交换和利用无线网络中有关信道、干扰和服务质量的有限状态信息的技术。重点是两个场景：点对点衰落链路的反馈和两个合作基站之间的信息交换。第一种方案旨在解决小区内移动设备的衰落所施加的限制，而第二种方案旨在解决小区边界上的干扰所施加的限制。目标之一是对衰落信道中信道状态反馈和接收机状态反馈之间的权衡获得基本的理解。在双单元场景下，研究了协同资源分配和协同编解码策略。重点是理解作为信息交换量的函数的合作的好处，以及跨时间、频率和空间的相关资源分配。研究人员还研究了合作编码/解码与预编码器优化的自适应技术的结合，这种技术不依赖于信道测量的显式交换。

Commercial cellular networks have recently experienced a dramatic increase in demand for data services. Satisfying this demand will require substantial (order-of-magnitude) increases in the spectral efficiency that can be achieved by such networks. This will require much more extensive information exchange and cooperation among nodes in the network than in current systems. This research investigates possible approaches for cooperation among nodes in a cellular network based on practical methods for feedback and information exchange.The main theme of this research is on techniques for exchanging and exploiting limited state information about channels, interference, and quality of service in a wireless network. The focus is on two scenarios: feedback for point-to-point fading links, and information exchange between two cooperative base stations. The first scenario is meant to address limits imposed by fading for mobiles well within a cell, whereas the second scenario addresses limits imposed by interference at a cell boundary. One of the goals is to gain fundamental understanding into the trade-off between channel state feedback and receiver state feedback for fading channels. For the two-cell scenario, cooperative resource allocation and cooperative coding and decoding strategies are investigated. The emphasis is on understanding the benefits of cooperation as a function of the amount of information exchanged, and on associated resource allocation across time, frequency, and space. The investigators also study the combination of cooperative coding/decoding with adaptive techniques for precoder optimization, which do not rely on the explicit exchange of channel measurements.