Novel Windowing Scheme for Cognitive OFDM Systems
IEEE Communications Letters Vol. 2, Nº 3, pp. 251 - 254, June, 2013.
ISSN (print): 1089-7798
ISSN (online): 1089-7798
Journal Impact Factor: 1,268 (in 2014)
Digital Object Identifier: 10.1109/WCL.2013.020513.120848
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In this paper a new shaping window is designed to force the side-lobe of OFDM transmission to decay faster than conventional raised-cosine windowing. The proposed window is a soft-window based on the characteristics of functions with vestigial symmetry, which are common in digital data transmis- sion. By using the vestigial symmetry and enforcing several null derivatives at the extremes of the window, it is possible to control the fast out-of-band decay. Results show that by using a lower roll-off factor (10%) the proposed window can achieve the same performance of raised-cosine (100%) with around 90% overhead savings, making it of interest for OFDM cognitive radio.