NeTS: Small: Doubling Cellular Capacity by Full Duplex Communications

传统的无线电收发器通常不能在相同的频带上接收和发送，因为发射器和接收器电路之间存在串扰。假定通过空中接收的信号比发射的信号弱一百万倍或更多，则在来自发射机的内部干扰下检测接收的信号是非常困难的（如果不是不可能的话）。因此，为了避免这种干扰，当今的通信系统依赖于半双工传输，通常在不同的时间或在不同的频带中发送和接收。该项目开发的全双工技术允许收发器在同一频带内接收和发送，同时可能使数据速率加倍。考虑到无线行业巨大的市场规模，以及对解决“频谱紧缩”的解决方案的迫切需求，全双工技术因此提供了巨大的社会和商业影响。该项目解决了在蜂窝网络中集成全双工无线电时的基本挑战，以释放该技术的全部潜力。具体地说，该项目包括三个相互关联的组件：（i）无线电前端设计，其允许与全双工操作相结合的多个天线增益;（ii）用于全双工基站的智能调度器，其协调具有最小相互干扰的最大传输集合，同时保持移动台之间的公平性;（iii）充分利用全双工使能中继终端的联合路由和调度算法。所开发的技术跨越物理层、介质访问控制层和网络层，并联合协调空中接口和回程。理论和算法将通过空中和端到端实验进行验证。

Traditional radio transceivers are generally not able to receive and transmit on the same frequency band because of the crosstalk between the transmitter and the receiver circuits. Given that the received signal over the air is one million times or more weaker than the transmitted signal, it is very difficult, if not impossible, to detect the received signal under internal interference from the transmitter. Thus, to avoid this interference, today's communication systems rely on half duplex transmission, typically transmitting and receiving at different times or in different frequency bands. The full duplex technology developed in this project allows for transceivers to receive and transmit in the same frequency band, at the same time, potentially doubling data rates. Given the enormous market size of the wireless industry, combined with the pressing need for solutions to solve the 'spectrum crunch', full duplex technology thus offers tremendous societal and commercial impact. This project addresses the fundamental challenges when incorporating full duplex radios in a cellular network to unlock the full potential of this technology. Specifically, the project consists of three inter-related components: (i) a radio front-end design that allows multiple antenna gains in conjunction with full duplex operation; (ii) a smart scheduler for full duplex base stations that coordinates the maximum set of transmissions with least mutual interference, while maintaining fairness among the mobiles; (iii) a joint routing and scheduling algorithm that fully utilizes full duplex enabled relay terminals. The technologies developed span physical, medium access control, and network layers, and jointly coordinate the air-interface and the backhaul. The theory and algorithms will be validated by over-the-air and end-to-end experiments.