In-phase/quadrature (I/Q) imbalances are front-end impairments which may greatly complicate the synchronization task in a low-cost direct-conversion receiver (DCR). In this paper we investigate the possibility of using the space-alternating generalized expectation-maximization (SAGE) algorithm to recover the carrier frequency offset in OFDM terminals with a DCR architecture. Our study leads to a novel scheme that operates in a recursive fashion and exploits a conventional OFDM training preamble composed by several repeated parts. At each iteration, interference arising from I/Q impairments is subtracted from the received samples before updating the frequency estimate. The performance of the new scheme is assessed in terms of estimation accuracy and processing load by considering a wireless local area network (WLAN) compliant with the IEEE 802.11a standard. The main goal is to check whether the SAGE approach exhibits some advantages compared to existing alternatives.
Autori interni: | |
Autori: | Morelli, Michele; Moretti, Marco |
Titolo: | A SAGE Approach to Frequency Recovery in OFDM Direct-Conversion Receivers |
Anno del prodotto: | 2014 |
Digital Object Identifier (DOI): | 10.1109/LCOMM.2014.012714.140092 |
Appare nelle tipologie: | 1.1 Articolo in rivista |