用於頻譜預編碼式正交分頻多工系統之功率負載技術

Spectrally Precoded OFDM With Power Loading

劉星宏(Hsing-Hung Liu)

指導教授 ： 鐘嘉德

國立臺灣大學/電機資訊學院/電信工程學研究所/碩士(2008年)

https://doi.org/10.6342/NTU.2008.00507

摘要

在本篇論文中，我們將頻譜預編碼式正交分頻多工系統 (Spectrally Precoded OFDM，簡稱 SP-OFDM) 與功率負載技術 (Power Loading，簡稱 PL) 做結合，目的是希望能在有效降低系統位元錯誤率的情況下，同時提供極佳的頻譜效率 (spectral efficiency)。在此系統中，我們加入了反覆式近似最小錯誤率 (Iterative Approximate Minimum BER，簡稱 IAMBER)、相等增益 (Equal Gain，簡稱 EG) 與最小均方誤差 (Minimum Mean Square Error，簡稱 MMSE) 功率負載技術，它們的特點是我們的資料在經過頻譜預編碼處理前後都會做功率負載的動作。另外，我們所提出的反覆式近似最小錯誤率功率負載技術對 [8] 中的近似最小錯誤率功率負載技術 (Approximate Minimum BER，簡稱 AMBER) 做了演算法上的修正。最後，我們會在雙路徑衰減通道下，討論各種頻譜預編碼在加入不同的功率負載技術後，其系統的平均位元錯誤率表現、頻帶外功率特性與複雜度的比較。

關鍵字

頻譜預編碼 ； 正交分頻多工系統 ； 功率負載技術 ； 頻譜效率 ； 雙路徑衰減通道

並列摘要

In this thesis, we combine spectrally precoded OFDM (SP-OFDM) with power loading (PL) in order to improve BER performance and provide very high spectral efficiency. We add iterative approximate minimum BER (IAMBER), equal gain (EG) and minimum mean squared error (MMSE) power loading to SP-OFDM system, and especially we do the power loading for the data before and after spectrally precoding. Besides, the proposed IAMBER power loading algorithm corrects the approximate minimum BER (AMBER) power loading in [8]. Eventually, on two-ray fading channels, we will compare average BER performance, fractional out-of-band power characteristics and complexity of the spectral codes with different power loading algorithms.

並列關鍵字

Spectral precoding ； orthogonal frequency division multiplexing (OFDM) ； power loading ； spectral efficiency ； two-ray fading channels

參考文獻

[2] C. D. Chung, “Spectral precoding for rectangularly pulsed OFDM,” IEEE Trans. Commun., accepted for publication, 2006.

[3] C. D. Chung, “Spectrally precoded OFDM,” IEEE Trans. Commun., vol. 54, no.

[4] I. Cosovic, S. Brandes, and M. Schnell, “Subcarrier weighting: A method for sidelobe suppression in OFDM systems,” IEEE Commun. Lett., vol. 10, pp. 444-446, Jun. 2006.

[5] S. Brandes, I. Cosovic, and M. Schnell, “Reduction of out-of-band radiation in OFDM systems by insertion of cancellation carriers,” IEEE Commun. Lett., vol. 10, pp. 420-422, Jun. 2006.

[6] J. A. C. Bingham, “Multicarrier modulation for data transmission: An idea whose time has come,” IEEE Comm. Mag., vol. 28, pp. 5–14, May 1990.