基于WBAN标准收发机研究与设计

发布时间：2018-03-24 05:17

本文选题：无线体域网　切入点：收发机　出处：《电子科技大学》2014年硕士论文

【摘要】：随着人口老龄化速度的加快和半导体产业的发展,用于人体健康应用的无线通信系统应运而生。从1996年体域网概念的最早提出到2012年IEEE802.15.6标准的正式确立,无线体域网(WBAN)系统设计与应用是近年来研究的热门课题。本文研究的主要内容是参考协议标准和目前日本和欧美的无线体域网应用,设计用于无线体域网的接收机和发射机。首先对比了WBAN的各个物理层,分析了各个物理层的应用环境、优势和不足,本文的收发机主要工作在其中的400MHz频段。400MHz在以人体为传播媒介的传输中衰减较小这一特点,决定了该频率主要用于植入芯片。收发机系统要求工作在400MHz~450MHz范围,带宽为1MHz,数据率为50kbps~150kbps,调制方式主要是π/2-DBPSK,π/4-DQPSK和GMSK。发射端要求最大输出功率大于0dBm,误差矢量模(EVM)因调制方式而异,约-11~-20dB,同时,要求发射机的相邻信道功率比为-26dB。接收端要求灵敏度为-84~-95dBm,邻道抑制为6~17dB,接收功率在-90dBm~-40dBm之间,此外,要求到达接收机输出端的信号SNR为12dB。本文列举了各种接收机和发射机结构,并分析了各自的优缺点,最终根据设计要求选择了低中频结构,折中了频带选择和信道选择,最终中频选择为2MHz。系统工作频段覆盖400MHz~450MHz,属于窄带系统,可以利用电感源级反馈结构低噪声放大器的低噪声系数和低功耗优势。混频器选用的是双平衡有源结构,提高系统的线性度和消除偶次谐波失真。混频器下变频到I/Q两路信号,中频信号经过复数滤波器,最后经过PGA放大输出。滤波器选用的是有源Gm-C结构,实现了中心频率为2MHz,带宽为1MHz,能满足信道选择和镜像抑制的复数滤波器。为了应对直流失调问题,PGA采用了DCOC辅助结构。对于发射机端,主要是对PA的考虑,本文选择的是AB类结构,能很好的满足设计要求。本次设计选用的是GSMC0.18um工艺,从电路设计到版图规划实现都是在cadence环境下设计完成,部分设计中用到MATLAB,主要仿真工具为Spectre/SpectreRF。最终仿真结果显示,接收部分噪声系数为5dB,增益覆盖范围25~100dB,发射端最大输出功率为10dBm,其他各项指标都能满足设计要求。
[Abstract]:With the acceleration of population aging and the development of semiconductor industry, wireless communication systems for human health applications have emerged. From the earliest concept of body area network in 1996 to the formal establishment of IEEE802.15.6 standard in 2012, The design and application of wireless body area network (WLAN) system is a hot topic in recent years. The main contents of this paper are the reference protocol standards and the current wireless body area network applications in Japan, Europe and the United States. The receiver and transmitter are designed for wireless body area network. Firstly, the physical layer of WBAN is compared, and the application environment, advantages and disadvantages of each physical layer are analyzed. In this paper, the transceiver mainly works in the 400MHz frequency band. 400MHz has less attenuation in the transmission using human body as the transmission medium, which determines that the frequency is mainly used for the chip implantation. The transceiver system requires that the transceiver system work in the 400MHz~450MHz range. The bandwidth is 1MHz and the data rate is 150kbps. the modulation mode is mainly 蟺 / 2-DBPSK, 蟺 / 4-DQPSK and GMSK. The maximum output power required by the transmitter is greater than 0dBm.The error vector mode (EVM) varies according to the modulation mode, about -11-20dB. at the same time, The adjacent channel power ratio of the transmitter is required to be -26dB. the sensitivity of the receiver is -84 ~ 95dBm, the adjacent channel suppression is 610dB, the receiving power is between -90dBmO and 40dBm. In addition, the signal SNR to the output end of the receiver is required to be 12dB.A variety of receiver and transmitter structures are listed in this paper. Their advantages and disadvantages are analyzed. Finally, the low intermediate frequency structure is selected according to the design requirements, and the intermediate frequency band selection and channel selection are compromised. The final intermediate frequency selection is 2MHz. The operating frequency band of the system covers 400MHz / 450MHz, which belongs to the narrowband system. The advantages of low noise coefficient and low power consumption of the low noise amplifier with inductance feedback structure can be utilized. The mixer uses a dual balanced active structure to improve the linearity of the system and eliminate even harmonic distortion. The mixer can be down-converted to the I / Q signal. The intermediate frequency signal passes through the complex number filter, and finally the output is amplified by PGA. The filter uses the active Gm-C structure. A complex filter with a central frequency of 2 MHz and a bandwidth of 1 MHz is realized. In order to cope with the DC misalignment problem, the DCOC auxiliary structure is adopted. For the transmitter, PA is mainly considered. This article chooses the AB class structure, can satisfy the design request very well. This design uses the GSMC0.18um process, from the circuit design to the layout plan realization is under the cadence environment design completes, MATLAB is used in part of the design, the main simulation tool is Spectre-SpectreRF.The final simulation results show that the received part of the noise coefficient is 5 dB, the gain coverage range is 25 ~ 100 dB, the maximum output power of the transmitter is 10 dBm. the other indexes can meet the design requirements.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN859

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