A Low-Complexity Bio-medical Signal Receiver for Wireless Body Area Network

近年來，無線通訊技術越來越蓬勃發展，且社會有越來越高齡化的趨勢，因此無線通訊也漸漸應用在醫療監控方面，有如居家監控、遠距醫療、生理訊號感測、近身智慧型裝置等等，諸如此類的設計都講求低功耗、低成本及低複雜度，因此我們希望可以建構出一套無線化、微小化的智慧型生理訊號監護系統，可多人同時使用，讓使用者彼此間的生理訊號不會互相影響，量測到的生理訊號經過無線傳輸後送至智慧型判斷，當發生異常警訊時會發出警訊，可大幅降低醫療人力與資源，本論文主要是研究以無線傳輸方式傳送生醫訊號的接收端基頻部份，並設計與實現之。如同其他無線傳輸標準，本論文亦考慮非理想通道效應，如高斯雜訊、載波頻率偏移及相位雜訊等影響，針對這些通道效應設計了低複雜度的接收端基頻部分，包括封包偵測、載波頻率偏移與補償、能量偵測、符元邊界同步及解展頻等演算法設計，一旦設定的演算法功能確定後，便可利用硬體描述語言與FPGA來做硬體的實現與驗證。In recent years, the wireless communication technology has been developed with a very high speed. In accordance to the tendency towards an aging society, the wireless communications technology has been used in medical monitoring gradually, such as home health monitoring, telemedicine, bio-sensing, smart device near body and so on. Such devices are all with characteristics of low power consumption, low cost, and low complexity. Thus, we want to construct a smart bio-sensing system, which is wireless, tiny, and can be provided for more than one person to use at the same time. The bio-signal between users will not be interfered with each other. The sensing bio-signal will be sent to the smart analyzing system by wireless transmission. Once the unusual signal is detected, the smart analyzing system will send out a warning signal. The system can save a lot of medical officers and resources. This thesis accomplished the baseband receiver for wireless bio-medical signal transmission.Like the other wireless transmission standard, this thesis also considered the channel effect like AWGN, carrier frequency offset, and phase noise. To reduce the complexity of the baseband receiver, many algorisms have been carefully investigated, such as packet detector, the compensation and estimation for carrier frequency offset, energy detector, boundary synchronism, and dispreading. After the algorisms for various functions are determined, then it is verified and accomplished by Verilog and FPGA.誌謝 I 摘要 II ABSTRACT III 目錄 IV 圖目錄 VI 表目錄 VIII 第一章 緒論 1 1-1 簡介 1 1-2 研究動機與方法 2 1-3 內容大綱 3 第二章 接收端技術介紹 4 2-1 傳輸頻帶介紹 4 2-2 展頻通訊概念 6 2-2-1 直序展頻與跳頻展頻 8 2-2-2 展頻碼 11 2-3 通道效應 15 2-3-1 載波頻率偏移 16 2-3-2 相位雜訊 16 2-3-3 取樣時脈偏移 16 第三章 接收端演算法設計 18 3-1 接收端架構 18 3-2 封包偵測 20 3-3 載波頻率偏移估計與回復 23 3-3-1 最大概似頻率偏移估計法 23 3-3-2 時域上的頻率補償邊界 25 3-4 能量偵測 26 3-5 符元邊界同步 26 3-6 解展頻 28 第四章 MATLAB軟體模擬結果 30 4-1 載波頻率偏移補償模擬結果 30 4-2 浮點數與定點數模擬結果 31 4-3 使用者人數模擬結果 32 第五章 接收端硬體設計與架構 36 5-1 設計流程 36 5-2 硬體區塊架構設計 38 5-2-1 封包偵測 38 5-2-2 載波頻率偏移估計與補償 38 5-2-3 能量偵測 45 5-2-4 符元邊界同步 46 5-2-5 解展頻 47 5-3 硬體實現結果與比較 47 第六章 結論及未來展望 50 參考文獻 5