A novel adaptive spectrum forming filter:Application in cognitive ultra-wideband  

作　　者：LI Bin ZHOU Zheng ZOU WeiXia 

机构地区：[1]Key Lab of Universal Wireless Communications, MOE. Wireless Network Lab, Beijing University of Posts and Telecommunications, Bcijing 100876, China

出　　处：《Science China(Information Sciences)》2010年第12期2584-2599,共16页中国科学（信息科学）（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 60772021,60972079,60902046);the National High-Tech Research & Development Program of China (Grant No. 2009AA01Z262);the Important National Science & Technology Specific Projects (Grant No. 2009ZX03006-006/-009);the BUPT Excellent Ph.D. Students Foundation (Grant No. CX201013);supported by the Ministry of Knowledge Economy,Korea,under the ITRC support program supervised by the Institute for InformationTechnology Advancement (Grant No. IITA-2009-C1090-0902-0019)

摘　　要：Ultra widcband impulse radio （UWB-IR） has important applications in high data rate communications, high precision positioning and penetrating target detection. Combincd with cognitive radio （CR）, UWB can also greatly alleviate the current spectrum scarcity. However, the cxisting UWB waveforms are faced with two challenges. The spectrum utilization of UWB signal is rather low, which reduces the communication reliability. Meanwhile, it appears difficult for UWB-IR to avoid spectrum collision with other incumbent services. So UWB will inevitably interfere other legal wireless systems. Motivated by these considerations, we model the UWB waveform design into an interpolation problem. Based on radial basis function neural network, a novel UWB pulse is presented in this paper. This UWB pulse is then realized though reasonable simplification on the already proposed theoretical network. The designed UWB pulses can adaptively track the external spectral environment where UWB devices work and reconfigure its emission spectrum according to the state of primer users without any modification on hardware. The frequency utilization is maximized when there is no active primary user. The adequate spectrum avoidance has also been achieved without much spectrum utilization degradation within the non-primary bands. Simulation and analysis show that our UWB-IR pulse is much superior to the other existing UWB signals in the frequency utilization, spectrum avoidance and in the transmission performance.Ultra widcband impulse radio （UWB-IR） has important applications in high data rate communications, high precision positioning and penetrating target detection. Combincd with cognitive radio （CR）, UWB can also greatly alleviate the current spectrum scarcity. However, the cxisting UWB waveforms are faced with two challenges. The spectrum utilization of UWB signal is rather low, which reduces the communication reliability. Meanwhile, it appears difficult for UWB-IR to avoid spectrum collision with other incumbent services. So UWB will inevitably interfere other legal wireless systems. Motivated by these considerations, we model the UWB waveform design into an interpolation problem. Based on radial basis function neural network, a novel UWB pulse is presented in this paper. This UWB pulse is then realized though reasonable simplification on the already proposed theoretical network. The designed UWB pulses can adaptively track the external spectral environment where UWB devices work and reconfigure its emission spectrum according to the state of primer users without any modification on hardware. The frequency utilization is maximized when there is no active primary user. The adequate spectrum avoidance has also been achieved without much spectrum utilization degradation within the non-primary bands. Simulation and analysis show that our UWB-IR pulse is much superior to the other existing UWB signals in the frequency utilization, spectrum avoidance and in the transmission performance.

关 键 词：UWB-IR cognitive radio pulse design RBF network spectrum efficiency spectrum avoidance 

分 类 号：TN925[电子电信—通信与信息系统]