空時分組碼MC-CDMA系統(tǒng)盲干擾抑制
Blind Interference Suppression for a Space-Time Block Coded MC-CDMA System
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摘要: 該文考慮空時分組碼多載波碼分多址(MC-CDMA)系統(tǒng)的盲干擾抑制。通過研究多徑信號頻域碼空間和數(shù)據(jù)矢量空間，采用噪聲子空間技術(shù)進(jìn)行盲信道估計。使用一種修改的ULV更新算法進(jìn)行噪聲子空間跟蹤，該算法不需要相關(guān)矩陣的秩估計，直接估計噪聲子空間。為了抑制多址干擾(MAI)，提出一種基于投影的輔助矢量(PAV)算法，用前一級濾波矢量的輸出重構(gòu)最大比合并(MRC)濾波矢量，將重構(gòu)濾波矢量到由基本濾波矢量和前幾級輔助矢量張成子空間上的正交投影作為輔助矢量，將前一級濾波矢量和新產(chǎn)生輔助矢量線性合并得到新的濾波矢量。仿真結(jié)果驗證了該文算法的有效性。
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關(guān)鍵詞:
- 多載波碼分多址;空時碼;盲干擾抑制;信道估計
Abstract: This paper considers blind interference suppression for a space-time block coded MultiCarrier CDMA (MC-CDMA) system. By investigating the code space in frequency domain and the data vector space of the multipath signals, the noise-subspace-based approach is used to perform blind channel estimation. A modified ULV updating algorithm is applied to performing noise subspace tracking. The algorithm does not require rank estimation of the correlation matrix, and estimate directly the noise subspace. To suppress Multiuser Access Interference (MAI), a Projection-based Auxiliary Vector (PAV) algorithm is proposed. A reconstructed Maximum Ratio Combining (MRC) filtering vector can be evaluated by using the outputs of the last filtering vector. Taking the orthogonal projection of the reconstructed filtering vector onto the space spanned by the basic filtering vector and the previously derived auxiliary vector as an auxiliary vector, a new filtering vector can be formed by linearly combining the last filtering vector and newly generated auxiliary vector. Simulation results show the effectiveness of the proposed algorithms. -
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