在同調環境下的可適性圓形天線陣列波束成型技術

Adaptive Uniform Circular Array Beamforming under Coherent Environment

沈家興(Chia-Hsin Shan)

指導教授 ： 李枝宏

國立臺灣大學/電機資訊學院/電信工程學研究所/碩士(2007年)

https://doi.org/10.6342/NTU.2007.02373

摘要

ㄧ般而言，假如想要接收信號和干擾沒有相關性或者不同調，可適性天線陣列可以接收想要接收的信號，而且可以把干擾信號消除。一旦出現同調干擾將會有信號抵銷的現象。理由是在輸出功率最小化的過程中不僅抑制了干擾同時也使得同調干擾消除想要接收的信號；通常同調干擾的發生在於牽涉到多重路徑傳輸或者是智慧型干擾。

為了防止信號抵銷現象很多方法被提出來，但是這些方法只適用在均勻線性陣列(ULA)，例如空間平均法(SS)與權重式空間平均法(WSS)，ITAM。而在圓形天線陣列上，它的方向向量不具有vandermonde的架構，所以上述的方法不適用於圓形天線陣列。在本篇論文中，利用估計出同調干擾入射方向，同調干擾從轉換接收的資料中被削除，為了抑制不同調的干擾，藉由轉換接收資料下的最小輸出功率限制在想要接收信號的單位增益下。這裡有兩種方法，DMV和SMV。把這兩個的方法進一步的延伸到寬頻的架構中，且把這些方法實現在GSC的架構中。最後並比較在LCMV和GSC的效能。

關鍵字

圓形天線陣列 同調

並列摘要

Gernerally, if there is no correlation or incoherent between the desired signal and the interference, adaptive antenna array can receive desire signals and suppress the interference. But there will be signal cancellation in the presence of coherent interference. The reason is that the output power minimination process not only suppresses the interference but also uses the coherent interference to cancel desire signals. Coherent interference usually occur in involving mutipath propagation or smart jammer.

Many approaches, such as Spatial Smoothing, Weight Spatial Smoothing, ITAM, are proposed for solving the signal cancellation due to coherent interference, but these methods can only be applied to Uniform Linear Array. However, the direction vectors of Uniform Circular Array don’t have the vandermonde structure. The above methods can not be applied to Uniform Circular Array (UCA). In this thesis, exploiting the estimates of coherent interference incident directions, coherent interference are eliminated from the transformation of received array data , to suppress incoherent interference, the output power is minimized by the transformation of received data subject to unit gain of the desired signal. Two methods, namely DMV and SMV, are extended to the structure of the wideband UCA and are accomplished to the structure of the generalized sidelobe canceller (GSC). Finally, we compare the performance between LCMV and GSC.

並列關鍵字

Uniform Circular Array coherent

參考文獻

[1] 蕭碩瑋,” 強健式圓形天線陣列多重波束成型技術,” 國立台灣大學電信工程學研究所碩士學位論文,June 2006.

[14] 陳治宇,”強健式寬頻陣列多重波束成型技術,”國立台灣大學電信工程學研究所碩士學位論文,June 2005.

[20] 徐振球,”在同調環境下的可適性寬頻波束成型技術,”國立台灣大學電信工程學研究所碩士學位論文,June 2005.

[2] M, Hatem EI-Ayadi,Emad K. AI-Hussaini and Eid A. EI-Hakeim,’’,A Generalized Solution to the Adaptive Nulling Problem in the Presence of Coherent Jammers’’IEEE Trans. Antennas and Propagation, vol.40, no.12, pp.1568-1571, Dec. 1992.

[3] Yang-Ho Choi ,’’Improved adaptive nulling of coherent interference without spatial smoothing,’’IEEE Trans. Signal Processing, Vol.52, NO.12, pp.3464-3469, Dec. 2004.