結合多天線感測機制之感知無線電演算法設計與驗證

感知無線電技術的開發可感測頻域中是否有閒置頻譜，進而對頻譜進行再利用，達到頻譜使用效率的提昇。然而，傳統上使用單根天線的頻譜感測器無法感測出訊號源的入射方向，因此無法善用空域稀疏特性，以進一步達到感知容量的再提昇。除此之外，若考慮在傳送寬頻帶中有多個主要使用者(Primary User, PU)同時存在，單天線頻域感器就無法偵測出受到鄰近高功率訊號干擾的PU低訊功率訊號，進而造成偵測率低以及感知系統的不可靠。為解決上述問題，本論文將多天線接收技術與頻域感測技術結合，提出二種低複雜度二維空－頻帶感知器演算法。模擬結果顯示，本論文提出之感測方法可使弱PU在強干擾訊號的影響下仍能被偵測出。最後，本論文採用Xilinx的System Generator實現空－頻帶感知器演算法，驗證本論文提出的演算法適用於硬體電路的實現。

關鍵字

感知無線電；空域稀疏性；入射角度；二維空－頻帶感知器

並列摘要

Cognitive radio technology aims to sense the white space in the target spectrum resource, and then reuse the spectrum, to improve the bandwidth efficiency. However, the conventional frequency sensor with one antenna cannot measure the direction of arrival of the signal of interest, and thus the space sparsity cannot be made use of, and the sensing capacity cannot be further to be improved. Besides, considering the case of multiple primary users occupy the same transmission band, the single-antenna technique cannot detect the low-power signal which is corrupted by the neighboring-band interference with high power. Therefore, this would result in low detection rate and low reliability of the cognitive radio system. To solve the above problem, in this paper we propose two types of low complexity two-dimensional space-frequency band sensor algorithms. Simulation results are included to demonstrate the proposed algorithm can favor the low-power user which is corrupted by the high-power interference. Finally, we adopt System Generator to implement the proposed space-frequency band sensor.

並列關鍵字

Cognitive radio ； spatial sparsely ； direction of arrival ； 2D space-frequency spectrum sensing

參考文獻

[1] T. Yucek, and H. Arslan, “A survey of spectrum sensing algorithms for cognitive radio applications, ” IEEE Commun. Surveys & Tutorials, vol. 11, no. 1, pp. 116-130, First Quarter, 2009.

[2] K.-L. Du, and W. H. Mow, “Affordable cyclostationarity-based spectrum sensing for cognitive radio with smart antennas ” IEEE Trans. Vehicular Tech., vol. 59, no.4, pp. 1877 – 1886, May 2010.

[4] Meng-Lin Ku, Li-Chun Wang, and Yu-Ted Su, “Optimal Multiuser Beamforming and Power Allocation for Hierarchical Cognitive Radio Systems,” in Proc. IEEE International Symposium on Information Theory and its Applications (ISITA), pp. 946-951, Oct. 2010.

[8]G. Ganesan and Y. Li, “Agility improvement through cooperative diversity in cognitive radio,” in Proc. IEEE Global Telecomm. Conf.(Globecom), vol. 5, St. Louis, Missouri, USA, Nov./Dec. 2005, pp.2505–2509.

[10] D. Cabric, A. Tkachenko, and R. Brodersen, “Spectrum sensing measurements of pilot, energy, and collaborative detection,” in Proc.IEEE Military Commun. Conf., Washington, D.C., USA, Oct. 2006, pp. 1–7.

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結合多天線感測機制之感知無線電演算法設計與驗證

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