以軟體無線電平台實現 IEEE 802.16同步機制

一直以來，正交分頻多工技術中的時間與頻率同步 (Synchronization)是必須審慎面對的問題。由於時間 (Timing) 與頻率偏移 (Frequency Offset) 會造成資料錯誤以及次載波 (Sub-Carrier) 之間的干擾，進而造成系統整體的效能嚴重衰減。為了降低這個效應，我們在此對使用四種不同結構的符元 (Preamble)來估測時間、頻率偏移量，並且觀察這四種不同結構的符元對於偵測同步的精準度效能做探討。本論文將於多核心 (Multi-core) 軟體定義無線電 (Software-defined Radio) 平台實現採用符元來結合時間、頻率同步機制的IEEE 802.16 基頻通訊系統。於軟體定義無線電平台中，型號C6000的數位訊號處理器 (DSP) 核心 (Core) 是使用Code composer Studio作平台與DSP application programming interfaces (API)為介面做開發。採用符元來結合時間、頻率同步機制的IEEE 802.16 基頻通訊系統的成果將於最後做驗證與呈現。

關鍵字

軟體定義無線電；多核心；符元；同步；全球微波互通存取

並列摘要

In the last several decades there has been a tremendous wave of interest in how to avoid the impact of synchronization errors, such as using preamble symbols. But the sensitivity of synchronization error is depending on taking different preamble symbol structure. In this thesis, first, we study the characteristics of these functions and how these are related to different preamble structure. Then, present an implementation method of an OFDM synchronization algorithm on the Multi-core Software-Defined Radio (SDR) platform. At last we combine the preamble-based synchronization mechanism into the one of most popular wireless access technology IEEE 802.16 Worldwide Interoperability for Microwave Access (WiMAX) baseband transceiver. In this paper, we present the results of combining preamble-based synchronization mechanism into WiMAX baseband transceiver system based on SDR platform and the effect of sensitivity of synchronization error. All the sub-modules in this paper are first simulated in Matlab, Simulink, and Real-Time Workshop. Then programming with such tools as the Code composer Studio for C6000 integrated development environment (IDE) from Texas Instruments, and the DSP application programming interfaces (API). The results of implementation show that receiver of WiMAX system applying the preamble-based synchronization mechanism can find the right symbol timing point and carrier frequency offsets which can be corrected.

並列關鍵字

Software-defined Radio ； WiMAX ； Multi-core ； Preamble ； Synchronization ； IEEE 802.16 ； SDR

參考文獻

[1] T. M. Schmidl and D. C. Cox, “Robust frequency and timingsynchronization for OFDM,” IEEE Trans. Commun., vol. 45, no. 12, pp.1613-1621, December 1997.

[2] H. Minn, M. Zeng, and V. K. Bhargava, “On timing offset estimation forOFDM systems,” IEEE Commun. Lett., vol. 4, no. 7, pp. 242-244, July 2000.

[3] Byungjoon Park and Hyunsoo Cheon, "A simple preamble for OFDM timing offset estimation", Digital Object Identifier, IEEE, pp.729-732,Sept 2002

[4] Wang Qiang, Tao Chen, and Huang Wei “Efficient implementation of synchronization in OFDM system based on FPGA”, Digital Object Identifier, IEEE, pp.178-181,Feb 2007

[5] Hong Chen, Pottie, and G . J . " A comparison of frequency offset tracking algorithms for OFDM " Global Telecommunications Conference , 2003 . GLOBECOM '03. IEEE Volume 2 , 1－5 Dec . 2003.

國際替代計量

以軟體無線電平台實現 IEEE 802.16同步機制

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