【作者】 周健；

【导师】 赵洪新；

【作者基本信息】 东南大学 ， 电磁场与微波技术， 2018， 硕士

【摘要】 随着物联网的高速发展,低功耗的无线网络在工程应用中的地位愈发重要。针对不同的物联网应用,多种相应的低功耗无线技术被研究和使用。其中,需要低功耗、低通信速率和大容量自组织网络的无线通信网广泛使用ZigBee技术。但是标准的ZigBee模块受限于模块中接收机较大的噪声系数和发射机较小的辐射功率,满足不了远距离通信的要求。本文结合射频和通信技术,设计了一款基于ZigBee技术的远距离、低功耗收发信机。论文的主要工作有:1、提出了一种提高ZigBee通信距离的低功耗解决方案。分析ZigBee技术中数字基带调制方式和标准模块中的接收机类型,估算出ZigBee片上芯片系统中接收机的整机噪声系数。通过在接收前端增加低噪声放大器模块来降低整机的噪声系数以提高接收机灵敏度;同时在片上系统的发射末端增加功率放大器子模块以提高发射信号最大辐射功率且保证发射信号的质量。2、实现了远距离低功耗的ZigBee收发信机。不仅完成了硬件开发,而且基于ZigBee技术进行了协议的二次开发,保证了增加额外射频模块后,系统依然能够达到低功耗的目标。为实现二次协议的应用,本文自主开发了底层软件和上位机测试软件。特别是,自主开发的底软占用处理器资源少、灵活性强,有利于系统后续维护和升级。3、利用自主编写的底层和上层软件,完成了二次协议验证和外场通信试验。首先验证了协议的可靠性,分析了同频段的ZigBee、WIFI和蓝牙三种通信协议之间的共存特性;基于二次协议的整机性能测试结果表明,收发信机功耗、发射信号质量和接收灵敏度等指标符合设计要求;以测试结果为基础,对典型外场环境进行建模,完成点对点通信测试,测试数据和仿真数据对照分析表明,本文提出的ZigBee通信远距离低功耗方案具有可行性。本文研制的ZigBee收发信机可以拓展ZigBee技术的应用范围,使其也能满足通信节点之间远距离数据传输的使用。更多还原

【Abstract】 With the rapid growth of Internet-of-Things(IoT),low-power wireless networks become more and more important.IoT has different applications,in response,various low-power technologies have been adopted and developed.One of these technologies,ZigBee has been widely applied in low-power,low-speed,and large capacity self-organizing network.However,standard ZigBee module cannot satisfy the requirements of long-range communication,because of its comparatively higher noise figure of receiver and lower radiated power of transmitter.A Long-distance and Low-power Transceiver based on ZigBee technology has been developed,with distance enhancement technology.The main work of the paper includes:(1)A system scheme for Long-distance and Low-power ZigBee Transceiver is provided.The noise figure of receiver in the system-on-chip(SoC)for ZigBee is estimated by analyzing the modulation of digital baseband and the architecture of receiver in SoC.With noise figure reduced by adding LNA,the sensitivity will be increased,meanwhile the maximum power of radiation by adding PA at the end of transmitter.The linearity of the signal should be promised after adding PA.(2)A Long-distance and Low-power ZigBee Transceiver has been designed.Due to the requirement of point-to-point,point-to-multipoint communication and low-power consumption,the ZigBee protocol is trimmed.The experiment datum indicates that the protocol has a good performance in the transceiver.(3)The literature on coexistence is analyzed between ZigBee,BLE and WIFI due to share of the same band.Then,the power consumption,sensitivity and emission characteristics are measured.The modeling analysis of the system at outfield is presented in this paper,what’s more,point-to-point communication has been tested at the outfield.The experiment datum indicates the system scheme is practical.In this paper,a ZigBee transceiver is designed with Low-power and Long-distance features,it can expand ZigBee application scope,especially in the application scenarios where long-range communication is required.更多还原