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)
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 grea...