基於錯誤率效用函數之遞增轉傳技術

Incremental Relaying Based on Error-Rate Utility Function

施厚成(Hou-Cheng Shih)

指導教授 ： 李彥文

國立暨南國際大學/科技學院/電機工程學系通訊工程碩士班/碩士(2016年)

摘要

在無線通訊系統中，應用合作式通訊系統 (Cooperative Communications) 架構可以產生空間分集 (Spatial diversity) 的增益特性，其特性改善系統在衰減通道中傳送之錯誤率效能，然而傳統合作式通訊架構通常會使用全部的中繼端 (Relay)幫忙轉傳訊號，但是這樣傳統傳輸架構將會降低在頻譜上的使用效率。近來研究提出增量中繼端 (Incremental relaying, IR) 透過降低中繼端使用次數來增加頻譜使用率，其方式在目的端設置一組訊雜比 (Signal to Noise Ratio, SNR) 門檻值 (Threshold) 檢測訊號判斷是否需要中繼端幫忙轉傳訊號。
本論文提出利用瞬時錯誤率 (Instantaneous error rate) 運用放大後傳送(Amplify-and-Forward, AF) 協定與正交振幅調變 (M-ary Quadrature Amplitude Modulation, M-QAM) 以及相位偏移調變 (M-ary Phase Shift Keying, M-PSK) 與先前提出之增量中繼所使用的中繼端次數比較。模擬結果顯示，我們所提出的方法在QPSK和16QAM 系統中，得到比傳統基於訊雜比 (signal-to-noise ratio, SNR)之放大後轉傳增量中繼 (IR-AF) 在相同錯誤率表現下更為有效的判斷中繼端使用時機。

關鍵字

合作式通訊 ； 放大後轉傳增量中繼 ； 瞬時錯誤率

並列摘要

In wireless communications, the application of various cooperation techniques can offer additional spatial diversity. It can be shown that the corresponding error-rate performance can be much improved under the fading channel environment. However, in order to achieve this enhancement, traditional cooperation techniques usually use all active relay branches for transmission, which may reduce the spectral efficiency. Incremental relaying (IR) has been proposed recently to increase spectral-efficiency through reducing the relay-forwarding action. A signal-to-noise ratio (SNR) threshold value is included at the destination which helps to determine whether the relay is needed to forward the overheard signals.
In this thesis, we propose a new IR method based on instantaneous error-rate and Amplify-and-Forward (AF) protocol for M-ary Quadrature Amplitude Modulation (M-QAM) and M-ary Phase Shift Keying (M-PSK) signals. We compare both the error-rate performance and relay usage of our proposed IR method and the previous SNR-based IR method. Simulation results show that the proposed method has better relay usage as compared with the conventional one for both QPSK and 16-AQM signals under a similar error rate.

並列關鍵字

Cooperative Communications ； IR-AF ； Instantaneous error rate

參考文獻

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