Efficient Implementation of Subcarrier Allocation Schemes in N-Continuous OFDM Transmissions

Abstract

This work presents an efficient implementation of subcarrier allocation schemes in compliance with several orthogonal frequency division multiplexing (OFDM) standards such as LTE. The considered schemes were chosen for OFDM systems owing to its capabilities to overcome certain practical limitations, e.g. improving the required sampling rate or the coding performance. However, they imply an increased computation load based on the large number of subcarriers present in current and future standards. Then it is shown that by means of vector reordering, the fast Fourier transform (FFT) algorithm may be used to avoid the implementation of computationally demanding matrix-vector multiplications derived from the required domain transformation, from frequency to time. The proposed strategy is used in a digital transmitter to obtain a continuous signal, whose first N derivatives are also continuous to reduce the out-of-band power emission. Since a digital signal generation is considered, these results em- power hardware recon gurable applications.