Publication year: 2012
Source:Physical Communication, Volume 5, Issue 3
Hai Lin, Tomoya Onishi, Rina Kume, Katsumi Yamashita
The paper proposes a novel joint estimation of the frequency offset, frequency-independent I/Q imbalance, and frequency-dependent I/Q imbalance, using periodic pilots in orthogonal frequency division multiplexing (OFDM) based wireless local area networks (LANs). Although a low-complexity frequency offset estimation in the presence of I/Q imbalance can be obtained via a periodic pilot, the corresponding closed-form solution encounters a sign ambiguity. A method based on a power comparison between the signal and image interference is then proposed to detect the sign. Meanwhile, since one periodic pilot only is unable to estimate I/Q imbalance in the absence of a frequency offset, we also propose an estimation method based on two different periodic pilots available in the preamble. The validity and superiority of the proposed method are demonstrated by computer simulations.
Source:Physical Communication, Volume 5, Issue 3
Hai Lin, Tomoya Onishi, Rina Kume, Katsumi Yamashita