Advances in Wireless Networks: Topology, Signal Structure, and Feedback

公众对无线通信应用程序的参与正在改变世界各地人们的生活方式；从正在改变发展中经济体的移动银行系统，如M-PESA，以及使“公民新闻”成为可能，到对体育赛事的现场报道、视频电话和无处不在的信息获取。无线应用的日益普及，以及各种无线机器对机器通信应用的出现（其中一些属于设想的物联网）正在推动对无线接入的需求，超出当前一代无线网络的能力。事实上，普遍的共识是，到2020年，无线网络将寻求服务比当前网络多10-100倍的设备，传输1000倍的数据流量，将延迟减少5倍，并将能耗（以焦耳/比特计）减少100倍。现在人们普遍认识到，当前（第四代）网络的增量增强将无法实现这些目标，现在是时候设想第五代和未来的架构了。

The public’s engagement with applications enabled by wireless communications is transforming the way in which people around the world live their lives; from the mobile banking systems, such as M-PESA, that are transforming developing economies and the enabling of “citizen journalism”, to live coverage of sporting events, video phone calls, and ubiquitous access to information. The increasing popularity of wireless applications, and the emergence of a wide variety of wireless machine-to-machine communication applications (some of which fall under the umbrella of the envisioned Internet of Things) are driving demand for wireless access beyond the capabilities of the current generation of wireless networks. Indeed, the common consensus is that by 2020 wireless networks will be seeking to serve 10-100 times as many devices as current networks, to deliver 1000 times the data traffic, to reduce the latency by a factor of 5, and to reduce the energy consumption (in joules-per-bit) by a factor of 100. It is now widely recognized that incremental enhancements of the current (fourth) generation of networks will not be able to achieve these targets and that the time has come to envision the architectures of a fifth and future generations.