【作者】 陈涛；

【导师】 谭学治；

【作者基本信息】 哈尔滨工业大学 ， 电子与通信工程（专业学位）， 2018， 硕士

【摘要】 警用数字集群(Police Digital Trunking,PDT)是我国用于公共安全或者专业集群通信领域中的一种专用无线通信标准。该通信标准是由国家公安部牵头,海能达主导,联合国内主要无线专网通信厂家,针对中国国情和应用特点而制定的一种覆盖广、效率高、灵活性强的无线集群标准。本文研究了基于软件无线电技术的数字多载波射频拉远单元(Radio Remote Unit,RRU),完成了其接收和发射方案的设计和实现。和传统专网基站系统相比,该方案能有效降低基站设备的体积、功耗和成本,具备更加灵活的形态,易于扩展和维护。在接收端提升了系统的接收灵敏度,提高了上行覆盖能力,解决了上下行覆盖不平衡的问题。通过动态监测上行信号强度的分布情况进行统计分析,对当前无线环境进行建模,使当前射频电路的链路方案更加适合当前无线环境。在这种情况下可以有效改善多载波接收链路接收动态范围不够大的问题,采用比较经济的办法达到了更好的效果。在发射端采用预失真和Doherty功放的架构实现多载波发射,在保证线性度的情况下实现了在同一发射链路产生多载波信号,并且综合效率达到35%以上。采用该实现方式,载频间隔可以设置更近,这样也间接提升了频谱利用率。同时该方案解决了在载频合路上受限于窄带腔体合路器的约束,能够有效降低功率放大器到天线的插损,在同等发射功率的情况下,显著提升系统的射频发射效率。基于软件无线电技术的多载波数字集群RRU,符合无线通信系统朝着小型化、灵活化、高速化、光纤化的发展方向,这也是未来数字集群通信技术发展的方向。通过本文的研究更加清晰的验证了多载波数字集群收发射链路架构的可实现性和优越性,随着技术更进一步的发展、研究突破更多技术难题,多载波数字集群系统具备着非常广阔的应用前景。更多还原

【Abstract】 Police Digital Trunking is a kind of special wireless communication standard used in the field of public safety or professional trunking communication in our country.This communication standard is led by the Ministry of Public Security and led by Hytera,together with major domestic wireless network communication manufacturers.according to China’s national conditions and application characteristics developed a wide coverage,high efficiency and flexibility of the wireless cluster standards.This paper studies digital multi-carrier on software radio technology,completed the design and implementation for radio remote unit.Compared with traditional private network base station systems,PDT can effectively reduce the volume,power consumption,and cost of base station equipment.It has a more flexible form and is easy to expand and maintain.On the receiving link,the system’s receiving sensitivity is improved,and the uplink coverage capability is improved,thus solving the problem of unbalanced uplink and downlink coverage.Through dynamic monitoring of the distribution of uplink signal strength for statistical analysis,the current wireless environment is modeled so that the current radio circuit link scheme is more suitable for the current wireless environment.In this case,it is possible to effectively improve the problem that the multi-carrier receiver does not receive a large dynamic range,and a more economical approach achieves better results.Multi-carrier transmission is realized at the transmitter using a pre-distortion and Doherty power amplifier architecture,and multi-carrier signals are generated on the same transmission link with guaranteed linearity,and the overall efficiency reaches over 35%.With this implementation,the carrier frequency interval can be set closer,which also indirectly improves the spectrum utilization.At the same time,the solution solves the constraint that the narrow-band cavity combiner is limited on the carrier frequency,which can effectively reduce the insertion loss from the power amplifier to the antenna,and significantly improves the system’s RF emission efficiency under the same transmit power.The multi-carrier digital trunk transceiver based on software radio technology is in line with the development direction of miniaturization,flexibility,high speed,and fiber optics in wireless communication systems.This is also the direction of future digital trunking communication technology development.Through the research of this paper,the feasibility and superiority of multi-carrier digital trunk transceiver architecture are more clearly verified.With the further development of technology,research and breakthrough more technical problems,multi-carrier digital trunking system has a very broad application prospects.更多还原