應用於無線感測網路之多模式低複雜度收發機設計

近年無線感測網路的應用日趨增加，包含軍事、醫療照護和保安監控等，在感測器的設計上，除了要著眼於降低功率消耗以解決電池能量有限和充電不易的問題，支援多種資料傳輸率以滿足不同傳輸要求的特性也是必需的。本論文提出一個多模式無線通訊收發系統，擷取IEEE802.15.4的規格參數特性和空間調變(Spatial Modulation)的技術，使用2.4GHz的頻帶和OQPSK調變，建立新的收發系統規格包含了五種傳輸模式，支援不同的資料傳輸率，範圍從250Kbps到3Mbps，以滿足不同的傳輸需求。我們為單天線和多天線傳輸模式建立基頻通道模型，加入了多路徑衰減通道效應、載波頻率偏移(CFO)和雜訊。在接收端部分主要分成三個部分，粗略同步、精確同步和資料還原。粗略同步包含利用前置序列的重覆性去做符元邊界偵測和CFO的粗略估測。精確同步包含針對CFO估測誤差的修正與相位補償、通道估測和殘餘相位誤差追蹤。在資料還原部分，是要將補償後的訊號還原回資料位元，針對單天線傳輸模式使用解展頻架構，針對多天線傳輸模式則使用多輸入多輸出偵測，我們使用最大相似(Maximum Likelihood, ML)偵測以用於OQPSK調變訊號與空間調變傳輸。最後我們針對五個收發模式做位元錯誤率的系統效能模擬，並將演算法進行硬體電路架構設計，完成系統的定點數模擬。

關鍵字

空間調變；收發機； OQPSK ； ML Detection

並列摘要

This thesis presents an OQPSK transceiver with five modes including Spatial Modulation mode for wireless sensor network applications. The communication system uses 2.4GHz carrier frequency with various data rates ranging from 250Kbps to 3Mbps. The transceiver supports SISO transmission in four modes and 2×2 MIMO transmission with spatial modulation. At the receiver, we design symbol timing detection, carrier frequency offset estimation and compensation, residual phase error tracking, channel estimation, data recovery. For data recovery block, correlator is used for despreading in SISO transmission mode and joint-ML Detection is used for spatial modulation detection in 2×2 MIMO transmission mode. We simulate the bit error rate of five transmission modes under multipath fading channel effects, CFO and noise. It shows that our receiver can work in the low-SNR regime with low-rate modes and also supports 3Mbps with spatial modulation. The algorithms are then transferred into hardware architecture. The fixed-point simulation is carried out to obtain the proper word-lengths of all data paths.

並列關鍵字

Spatial Modulation ； Transceiver ； OQPSK ；最大相似偵測

參考文獻

[1] ”Part 15.4: Low-Rate Wireless Personal Area Networks(LR-WPANs),”IEEE Std 802.15.4TM – 2011

[3] R. Tabish, F. Touati, “A Comparative Analysis of BLE and 6LoWPAN For U-HealthCare Applications”,2013 GCC Conference and Exhibition, pp.286-291, Nov 2013

[7] Keiji Tachikawa, “W-CDMA Mobile Communication System”, Wiley, 2002

[8] R. Mesleh, H. Haas, Y. Lee, and S. Yun, “Interchannel interference avoidance in MIMO transmission by exploiting spatial information”, in Proc. 16th IEEE Int. Symp. PIMRC, Berlin, Germany, 2005, vol.1, pp.141-145

[9] M. Di Renzo, H. Hass, A. Ghrayeb, et al., “Spatial Modulation for Generalized MIMO: challenges, opportunities, and implementation”, Proc. IEEE, vol.102, no. 1, pp.56-103, Jan 2014

國際替代計量

應用於無線感測網路之多模式低複雜度收發機設計

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