Frequency estimation in the uplink of an orthogonal frequency-division multiple-access system is a challenging task due to the presence of multiple carrier frequency offsets. Many existing solutions are too complex for practical implementation, while others are restricted to a specific subcarrier assignment strategy. Motivated by the above consideration, in this letter we propose a novel frequency estimator that allows flexible subcarrier assignment while requiring a low computational burden. Our scheme exploits the repetitive structure of the users' training sequences, which are properly designed so as to minimize the multiple-access interference arising in the presence of frequency errors. Computer simulations are used to assess the effectiveness of the proposed method and to make comparisons with competing alternatives.
A Low-Complexity Scheme for Frequency Estimation in Uplink OFDMA Systems
SANGUINETTI, LUCA;MORELLI, MICHELE
2010-01-01
Abstract
Frequency estimation in the uplink of an orthogonal frequency-division multiple-access system is a challenging task due to the presence of multiple carrier frequency offsets. Many existing solutions are too complex for practical implementation, while others are restricted to a specific subcarrier assignment strategy. Motivated by the above consideration, in this letter we propose a novel frequency estimator that allows flexible subcarrier assignment while requiring a low computational burden. Our scheme exploits the repetitive structure of the users' training sequences, which are properly designed so as to minimize the multiple-access interference arising in the presence of frequency errors. Computer simulations are used to assess the effectiveness of the proposed method and to make comparisons with competing alternatives.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
