NeTS: Small: Doubling Cellular Capacity by Full Duplex Communications

由于发送器和接收器电路之间的串扰，传统无线电收发机通常不能在同一频带上接收和发送。由于空中接收的信号比发射的信号弱一百万倍或更多，在发射机的内部干扰下检测接收的信号即使不是不可能的，也是非常困难的。因此，为了避免这种干扰，今天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上发送和接收。在该项目中开发的全双工技术允许收发信机在同一频段内接收和发送，同时有可能使数据速率翻倍。鉴于无线产业的巨大市场规模，再加上对解决“频谱紧张”解决方案的迫切需求，全双工技术因此产生了巨大的社会和商业影响。该项目解决了在蜂窝网络中整合全双工无线电以释放这项技术的全部潜力时的基本挑战。具体地说，该项目由三个相互关联的部分组成：(I)无线电前端设计，允许多个天线增益与全双工操作相结合；(Ii)全双工基站的智能调度器，以最小的相互干扰协调最大的传输集合，同时保持移动之间的公平性；(Iii)充分利用全双工启用的中继终端的联合路由和调度算法。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的实验进行验证。

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.