All Analogue Full-duplex Dual-receiver Radio for Wideband Mm-wave Communications

智能手机、平板电脑和笔记本电脑广泛用于多用户视频会议、观看视频和电视、玩视频游戏、下载/上传大型文件和应用程序。通过无线网络交换的数据每年都在显著增加，因此数据速度需要随着需求而增加，以保持用户满意。无线电网络设计人员和频谱监管机构正面临着有效的资源规划以满足不断增长的需求的艰巨任务。考虑到频谱的限制，提供超高速无线系统只能通过一些突破性的技术来实现。全双工（FD）无线电是一种具有使速度加倍的潜力的技术，并且如果在毫米波段规划，则其可以提供巨大的带宽。HetNet中的宽带毫米波FD的巨大益处是众所周知的，包括无线网络中的小小区之间的非常快速的Gbit互操作。低成本的毫米波MMIC为基础的子系统的可用性与简单的基础设施设置FD无线电将宽带毫米波FD无线电领先于其竞争对手，即，复杂的低频宽带大规模多输入多输出（MIMO）系统在多个信道中运行。事实上，基于FD的低成本宽带基础设施网络对于不断寻找廉价解决方案以在复杂环境（如地下隧道、大型/高层建筑物和忙碌人口密集的城市区域）中提供非常高速的通信覆盖的移动的运营商来说将是非常有吸引力的。实际上，可以设想宽带毫米波FD无线电的数百万个毫微微小区在宽带毫米波FD技术的成熟的情况下在世界范围内操作，从而确保该技术的贡献者的大量收入（数十亿英镑的量级）FD无线电使用一个信道来转发，因此自干扰（SI）是其主要问题。在FD无线电中，所需的SI消除（SIC）取决于发射机功率和信号带宽。典型地，对于可靠的FD系统，60 dB至110 dB的SIC是必要的。在低频FD无线电中，这种大的抑制通常是在多个阶段实现的;即：在天线系统中，在接收机前端中，以及在具有数字信号处理（DSP）的基带中。假设10%的分数带宽，毫米波载波频率具有调制几GHz带宽的快速信号的潜力;例如：3 GHz带宽在30 GHz载波处可用。对于这样的宽基带，基于DSP的SIC不能是一种选择，因为目前没有用于在小型移动的/固定设备中实现的功耗敏感的DSP单元可用于处理几GHz带宽的快速信号。为了消除DSP的限制，已经提出了几种有前途的技术来减轻毫米波FD收音机中的SI，但他们仍在研究中，到目前为止，在literation.Recently有限的实际结果下，EPSRC的资助下，我们已经开发出一种新的SIC技术免费的DSP。在此基础上，我们演示了一个窄带（60 MHz）FD无线电在3.2 GHz的微波载波。我们的演示器在-5.6 dBm发射功率下实现了81.5 dB SIC。我们的新系统的无数字性能归功于双接收器架构，从而消除了对DSP级的需求。预计该特性对于实现所有模拟宽带毫米波FD系统是非常合适/重要的。该提议的新奇，将其与文献中的工作区分开来并且实际上远远高于文献中的工作，正在释放我们的新窄带FD无线电架构的潜力，以利用其几个优点，包括模拟基带SIC解决方案（即，免DSP）和通过发射机和双接收机之间具有高隔离度的三端口双天线系统的自多径反射干扰消除。在这项工作中，我们将把测试我们的经验，在开发我们的新的双接收器微波FD无线电，实现一个独特的DSP免费宽带毫米波FD无线电。

Smartphones, tablets and laptops are widely used for multi-user video conferencing, watching video and TV, playing video game, downloading/uploading large files and applications. Data exchanged over wireless networks is significantly increasing annually, and hence the data speed needs to be increased with the demand to keep users happy. Radio network designers and spectrum regulators are facing the daunting task of efficient resource planning to meet the growing demand. Considering spectrum limitation, providing ultra-speed wireless systems can only come through some breakthrough technologies. The full-duplex (FD) radio is one technology with the potential to double the speed and if planned at mm-wave bands, it can offer a huge bandwidth.The massive benefits of broadband mm-wave FD in HetNets are well-known including very fast Gbit inter-operation between small cells in wireless networks. The availability of low-cost mm-wave MMIC-based subsystems together with the simple infrastructure setups for FD radios would place broadband mm-wave FD radios ahead of its rival, namely, the complicated low frequency broadband massive multi-input multi-output (MIMO) systems operating in multiple channels. Indeed, the low-cost broadband infra-structure networks based on FD would be very attractive to mobile operators continuously looking for cheap solutions to provide very high-speed communication coverage in complex environments like underground tunnels, large/high-story buildings, and busy densely populated city areas. Indeed, millions of femtocells of wideband mm-wave FD radios can be envisaged to operate worldwide on the mature of the broadband mm-wave FD technology, ensuring substantial revenue (of the order of billions of pounds) for contributors to the technology.A FD radio uses one channel to transceive and hence self-interference (SI) is its major problem. In FD radios, the required SI cancellation (SIC) depends on transmitter power and signal bandwidth. Typically, a SIC of 60 dB to 110 dB is necessary for a reliable FD system. In low frequency FD radios, this large suppression is normally achieved in multiple stages; ie: in antenna system, in receiver front-end, and in baseband with digital signal processing (DSP).Assuming 10% fractional bandwidth, mm-wave carrier frequencies have the potential to modulate fast signals of a few GHz bandwidth; eg: 3 GHz bandwidth becomes available at 30 GHz carrier. For such a wide baseband, the DSP-based SIC cannot be an option, since no miniaturised power conscious DSP unit for implementation in small mobile/fixed devices is available presently to deal with fast signals of a few GHz bandwidth. To remove the DSP constraint, several promising techniques have been proposed to mitigate the SI in mm-wave FD radios, but they are still under research with limited practical results presented so far in the literature.Recently under an EPSRC grant we have developed a new SIC technique free from DSP. Based on this, we demonstrated a narrow band (60 MHz) FD radio at 3.2 GHz microwave carrier. Our demonstrator achieved a total of 81.5 dB SIC at -5.6 dBm transmit power. Our new system owes its digital-free performance to a two-receiver architecture purging the need for the DSP stage. This property is anticipated to be extremely suitable/important for realising all analogue broadband mm-wave FD systems.The novelty of this proposal, distinguishing it from and indeed levitating well above the work in the literature, is unlocking the potential of our new narrow band FD radio architecture to exploit its several advantages including an analogue baseband SIC solution (i.e., free from DSP) and a self-mutipath reflection interference cancellation via a three-port dual antenna system with a high isolation between transmitter and the dual-receiver. In this work we are to put to test our experiences in developing our new dual-receiver microwave FD radio to realise a unique DSP-free broadband mm-wave FD radio.