太赫兹无线通信系统研究与基带设计

发布时间：2018-06-16 06:55

本文选题：太赫兹波 + 宽带无线通信　；参考：《电子科技大学》2017年硕士论文

【摘要】：太赫兹波的高度定向性与太赫兹频段的高带宽,使得太赫兹通信技术在宽带无线通信及个域网系统方面具有很强的应用价值。通过对太赫兹波在大气中传播问题的研究,可以发现,大气对于太赫兹波存在一个传输窗口,大概为200-300GHz的窗口。不过,要获得可行的太赫兹通信解决方案,需要克服很多严峻的技术障碍。第一,当有障碍物(比如:人、车辆)临时阻挡了发射机和接收机之间的、正在进行数据传输的通路时——从无线路由到平板电脑,由于太赫兹波在空气中传输是高度定向的,怎样变更无线信号的传输路径称为一个亟待解决的问题。第二,太赫兹无线数据链路的形式与今天室内无线通信系统截然不同,室内太赫兹通信系统链路的实现,不仅仅是现有技术的扩展,而且必须融入许多新的思路和理念。本文提出了一种适合于太赫兹点对点无线通信的基带电路设计,在基带链路基础搭建了330GHz太赫兹无线点对点通信系统。整个基带系统分为发射机和接收机两部分。发射机负责对完成信源编码的信号进行信道编码,加扰,加入同步序列,发射等处理,接收机完成模数转换,帧同步,解扰,信道译码。在发射端,PC完成信源编码,打包和压缩,经USB2.0接口将信号传输到FPGA,FPGA完成信道编码(信道编码使用(2,1,7)卷积码编码),加扰,加入同步序列(同步序列使用的是Golay序列,参考了802.11ad协议中的Ga64与Gb64序列)和基带发射(发射模块是VIRTEX6芯片(芯片型号:xc6vlx130t)自带的高速串行GTX发射器)。在接收端,解调回来的基带信号经过两倍率采样16bit量化进行模数转换,截取13bit的采样数据经过2倍率抽样的Golay序列相关器进行帧同步,同时通过比较相关值从两路抽样信号中选取信噪比最大的一路信号进行解扰与信道译码,信道译码采用(2,1,7)Viterbi译码算法(3bit软判决),将译码结束的一帧数据经过USB2.0传输到接收PC端,接收PC端完成信源译码,解压与收包;其中golay序列相关器,解扰器,viterbi译码器和usb接口控制器由FPGA实现。最终实验完成一种太赫兹无线通信基带链路的电路设计与FPGA实现,误码率可达10E-8,50MHz带宽,在330GHz信道上完成了720p视频传输的业务,传输距离11m。
[Abstract]:Due to the high directivity of terahertz wave and the high bandwidth of terahertz band, terahertz communication technology has strong application value in wideband wireless communication and personal area network system. By studying the propagation of terahertz waves in the atmosphere, it can be found that there is a transmission window for terahertz waves in the atmosphere, which is about 200-300 GHz. However, to achieve a viable terahertz communication solution, there are many serious technical obstacles to overcome. First, when obstacles (such as people, vehicles) temporarily block the path between the transmitter and the receiver that are transmitting data from wireless to the tablet, because terahertz waves are highly oriented in the air, How to change the transmission path of wireless signal is an urgent problem to be solved. Secondly, the form of THz wireless data link is very different from today's indoor wireless communication system. The realization of indoor terahertz communication system link is not only an extension of existing technology, but also must be incorporated into many new ideas and concepts. This paper presents a baseband circuit design for terahertz point-to-point wireless communication. A 330GHz terahertz wireless point-to-point communication system is built on the baseband link basis. The whole baseband system is divided into transmitter and receiver. The transmitter is responsible for channel coding, scrambling, adding synchronization sequence, transmitting and so on. The receiver completes A / D conversion, frame synchronization, descrambling and channel decoding. At the transmitter PC, the source code is encoded, packaged and compressed, and the signal is transmitted to FPGA via USB2.0 interface to complete the channel coding (channel coding is done with the convolutional code (the channel code is coded using a 2 / 2 / 1 / 7) convolutional code), scrambling, and adding a synchronous sequence (the synchronous sequence is a Golay sequence). Reference is made to the Ga64 and Gb64 sequences in the 802.11ad protocol and the baseband emitter (the transmitter module is VIRTEX6 chip (chip type: xc6vlx130t) with its own high-speed serial GTX transmitter. At the receiving end, the demodulated baseband signal is converted by a two-rate sampling 16bit quantization, and the sampling data of 13bit is intercepted for frame synchronization through a two-rate sampling Golay sequence correlator. At the same time, by comparing the correlation values, the first signal with the largest SNR is selected from the two sampling signals for descrambling and channel decoding. The channel decoding adopts a 3bit soft decision algorithm for channel decoding, and transmits a frame of data from the end of decoding to the receiving PC through USB2.0. The golay sequence correlator, descrambler Viterbi decoder and usb interface controller are implemented by the receiver PC. Finally, the circuit design and FPGA implementation of a terahertz wireless communication baseband link are completed. The BER can reach 10E-8N 50MHz bandwidth. The 720p video transmission service is completed on the 330GHz channel, and the transmission distance is 11m.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN92

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