naa a22 4500 510799108 CHVBK 20180411083347.0 cr unu---uuuuu 180411e20130901xx s 000 0 eng 10.1007/s11277-013-1095-y doi (NATIONALLICENCE)springer-10.1007/s11277-013-1095-y Wu Wei-Chiang Changhua, Taiwan, Republic of China aut Non-intrusive Cognitive Radio Using Adaptive Nulls-Steering [Elektronische Daten] [Wei-Chiang Wu] In this paper, we propose an adaptive non-intrusive cognitive radio network based on smart antenna technologies. The cognitive transmitter (CT), which is equipped with antenna array, first estimates and tracks the composite steering vectors of each primary (licensed) user. In what follows, CT forms transmit beamforming to place nulls to primary receivers based on the estimated spatial signatures. Moreover, we extensively analyze performance degradation caused by spatial signatures mismatch (estimation error) and verify that the proposed robust nulls-steering beamformer can comprehensively alleviate the mismatch effect. Simulation results demonstrate convergence of the proposed gradient-based recursive least squares algorithm. Furthermore, we have shown that outage probability can be kept extremely low under appropriate array size, which ensures the practicability of the proposed scheme. Springer Science+Business Media New York, 2013 Cognitive radio nationallicence Non-intrusive nationallicence Adaptive nulls-steering nationallicence Mismatch nationallicence Robust beamforming nationallicence Recursive least squares (RLS) nationallicence Wireless Personal Communications Springer US; http://www.springer-ny.com 72/2(2013-09-01), 1549-1563 0929-6212 72:2<1549 2013 72 11277 https://doi.org/10.1007/s11277-013-1095-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11277-013-1095-y text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Wu Wei-Chiang Changhua, Taiwan, Republic of China aut NATIONALLICENCE 773 0- Wireless Personal Communications Springer US; http://www.springer-ny.com 72/2(2013-09-01), 1549-1563 0929-6212 72:2<1549 2013 72 11277 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer