Frequency Estimation in OFDM Direct-Conversion Receivers Using a Repeated Preamble
| Autor: | Marco Moretti, Antonio A. D Amico, Leonardo Marchetti, Michele Morelli |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
direct-conversion receiver
Frequency recovery I/Q imbalance OFDM Electrical and Electronic Engineering Orthogonal frequency-division multiplexing Computer science Estimator 020302 automobile design & engineering 020206 networking & telecommunications 02 engineering and technology Preamble Quadrature (mathematics) Direct-conversion receiver 0203 mechanical engineering Transmission (telecommunications) Carrier frequency offset 0202 electrical engineering electronic engineering information engineering Electronic engineering Time domain Algorithm |
| Zdroj: | IEEE Transactions on Communications. 64:1246-1258 |
| ISSN: | 1558-0857 0090-6778 |
| DOI: | 10.1109/tcomm.2016.2515083 |
| Popis: | This paper investigates the problem of carrier frequency offset (CFO) recovery in an OFDM receiver affected by frequency-selective in-phase/quadrature (I/Q) imbalances. The analysis is based on maximum-likelihood (ML) methods and relies on the transmission of a training preamble with a repetitive structure in the time domain. After assessing the accuracy of the conventional ML (CML) scheme in a scenario characterized by I/Q impairments, we review the joint ML (JML) estimator of all unknown parameters and evaluate its theoretical performance. In order to improve the estimation accuracy, we also present a novel CFO recovery method that exploits some side-information about the signal-to-interference ratio. It turns out that both CML and JML can be derived from this scheme by properly adjusting the value of a design parameter. The accuracy of the investigated methods are compared with the relevant Cramer–Rao bound. Our results can be used to check whether conventional CFO recovery algorithms can work properly or not in the presence of I/Q imbalances and also to evaluate the potential gain attainable by more sophisticated schemes. |
| Databáze: | OpenAIRE |
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