Spatial Spectrum Holes in Cognitive Radio with （空间在认知无线电频谱孔）.pdfVIP

Spatial Spectrum Holes in Cognitive Radio with Relay Transmission† ∗ Guodong Zhao , Jun Ma, Geoffrey Ye Li Anthony Soong Chenyang Yang School of ECE Wireless Advanced Research ∗School of EIE Georgia Institute of Technology Huawei Technologies Beihang University Atlanta, GA, USA Plano, TX, USA Beijing, China {gdzhao, junma, liye}@ asoong@ cyyang@ Abstract— In this paper, we propose a relay-assisted transmis- While all above techniques are to detect and access SHs sion scheme in cognitive radio (CR) to exploit spatial spectrum either in different time slots or in different locations with PUs, holes, which are generated by relay techniques. The proposed the possibilities that a CR system coexists with a primary sys- scheme enables CR users to coexist with primary users at the same time in the same geographic area and spectrum band. tem at the same time in the same geographic area and spectrum Compared to conventional schemes, a higher spectrum efficiency band have not been well investigated. In [10], beamforming is achieved by our method. We further analyze the successful techniques have been applied in point-to-point CR systems. communication probability and present numerical results to show In our previous work in [11], spatial SHs generated in CR advantages of our method. networks have been studied if CR users a