Abstract

LIZARRAGA, E.M; DOWHUSZKO, A.A; SAUCHELLI, V.H  and  GALLINA, S.H. An efficient spectral shaping method for ofdm systems using correlated interpolation of symbols. Lat. Am. appl. res. [online]. 2013, vol.43, n.3, pp. 261-267. ISSN 1851-8796.

The generation of suitable orthogonal frequency division multiplexing (OFDM) signals on the grounds of fully digital signal processing is considered. The main objective is to obtain a discrete-time signal with adequate allocation of power emissions in both, in-band portion (i.e., the allocated band for communication) and out-of-band portion (i.e., the band allocated to adjacent channels) of the spectrum. The proposed method prevents the transmitter from using traditional filtering techniques, to keep under control power emissions in the system. In addition, the adaptability feature of our proposal makes its implementation attractive within cognitive radio (CR) and software defined radio (SDR) OFDM-based systems. Our spectral shaping approach is based on an optimum interpolation, obtained from the combination of an inverse fast Fourier transform (IFFT) and a spectral precoding operation, both of them transparent from the perspective of a conventional (legacy) OFDM receiver.

Keywords : Correlated Interpolation; IFFT; Double-Length; OFDM; N-Continuous; Symbol Merging; Spectral Precoding; Spectral Shaping.