Theoretical limits on time delay estimation for ultra-wideband cognitive radios

Author

Gezici, Sinan ; Celebi, Hasari ; Arslan, Huseyin ; Poor, H. Vincent

Author_Institution

Dept. of Electr. & Electron. Eng., Bilkent Univ., Ankara

Volume

2

fYear

2008

fDate

10-12 Sept. 2008

Firstpage

177

Lastpage

180

Abstract

In this paper, theoretical limits on time delay estimation are studied for ultra-wideband (UWB) cognitive radio systems. For a generic UWB spectrum with dispersed bands, the Cramer-Rao lower bound (CRLB) is derived for unknown channel coefficients and carrier-frequency offsets (CFOs). Then, the effects of unknown channel coefficients and CFOs are investigated for linearly and nonlinearly modulated training signals by obtaining specific CRLB expressions. It is shown that for linear modulations with a constant envelope, the effects of the unknown parameters can be mitigated. Finally, numerical results, which support the theoretical analysis, are presented.

Keywords

cognitive radio; ultra wideband communication; Cramer-Rao lower bound; carrier-frequency offsets; channel coefficients; generic UWB spectrum; linearly modulated training signals; nonlinearly modulated training signals; time delay estimation; ultra wideband cognitive radios; Bandwidth; Cognitive radio; Contracts; Delay effects; Delay estimation; Frequency estimation; Radio transmitters; USA Councils; Ultra wideband technology; Wireless communication; Cramer-Rao lower bound (CRLB); Ultra-wideband (UWB) cognitive radio; carrier frequency offset (CFO); dispersed spectrum utilization; time delay estimation;

fLanguage

English

Publisher

ieee

Conference_Titel

Ultra-Wideband, 2008. ICUWB 2008. IEEE International Conference on

Conference_Location

Hannover

Print_ISBN

978-1-4244-2216-6

Electronic_ISBN

978-1-4244-1827-5

Type

conf

DOI

10.1109/ICUWB.2008.4653380

Filename

4653380