IEEE 802.16 MIMO-OFDM系統的通道估測

Channel Estimation for MIMO-OFDM System in IEEE 802.16

洪得發(De-Fa Hong)

指導教授 ： 彭先覺

國立虎尾科技大學/電機資訊學院/電機工程研究所/碩士(2010年)

摘要

在無線區域網路中，為了提供較高的資料傳輸速率，會利用多天線的架構，這種架構即是多重輸入輸出技術，而多輸入多輸出通道也是研究此技術的重要一環。正交分頻多工是一種多載波調變技術，正交分頻系統係具有高傳輸能力與頻寬效應，對於多路徑衰減和延遲有較佳的穩定性，所以在無線通訊普遍地使用。其利用快速傅利葉轉換做調變，達到效能的提升，並且利用保護區間有效的解決多路徑效應產生的符碼相互干擾與衰減。將多輸入多輸出與正交分頻多工技術結合成多輸入多輸出正交分頻多工系統，為因應通訊系統之高品質高速傳輸需求之必然趨勢。本篇論文以MATLAB-SIMULINK軟體搭配IEEE 802.16所規範的架構，建立多輸入多輸出正交分頻多工的系統模組與通道估測。系統採用最小平方法搭配不同內插法對通道進行估測，估測後的通道配合最大概似等化器還原訊號。最後，分析系統在不同的訊號對干擾雜訊比下的位元錯誤率。

關鍵字

多輸入多輸出正交分頻多工 ； IEEE 802.16 ； 最小平方法 ； 位元錯誤率

並列摘要

The multiple antenna technologies are being considered as a possible solution to pro¬vide high date rate over wireless communications. A statistical discrete-time model is considered for the future high-throughput wireless local area network（WLAN） that uses multiple antennas at both the transmitter and the receiver. This multi-in¬put multi-output（MIMO） channel model is mainly introduced by the WLAN high-throughput working group. Orthogonal frequency division multiplexing（OFDM） is a multi-carrier modulated technolgy, and it is widely applied in wireless communications systems due to its high rate transmission capability with high bandwidth efficiency and its robustness with regard to multi-path fading and delay . OFDM utilizes the fast fourier transform（FFT） and guard interval to solve inter-symbol lnterference（ISI） that multi-path effect caused. Combining MIMO and OFDM technologies to be an MIMO-OFDM system is certainty. This thesis is to simulate the MIMO-OFDM system in IEEE 802.16 using Matlab Simulink. In this system, the LS（Least Square）method with different interpolation methods is adopted to estimate channels. After channel estimation, the ML（Maximum Likelihood）equalizer is used to compensate for the signal . Finally, the bit error rate（BER）in this system is analyzed in the different signal to noise rate（SNR）.

並列關鍵字

MIMO-OFDM ； IEEE 802.16 ； LS ； BER

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