In this paper we propose the use of QAM constellations, specifically 4, 16, and 64-QAM, in severely time-dispersive channels and with moderate CFOs (Carrier Frequency Offsets). We consider an SC-FDE (Single Carrier Frequency-Domain Equalization) and assume that previously to the equalization procedure a coarse CFO estimation and compensation is performed. Since the coarse CFO estimate can have a significant error leading to a residual CFO we present and evaluate a receiver with joint detection and carrier synchronization in order to guarantee a good BER. We employ frequency-domain iterative DFE (Decision Feedback Equalization) receivers denoted by IB-DFE (Iterative Block-Decision Feedback Equalization), which are combined with a DD (Decision-Directed) CFO estimator. Our aim is to determine the synchronization requirements for 4, 16, and 64-QAM and compare several methods for the DD CFO estimators when using these QAM constellations.
|Title of host publication||IEEE Vehicular Technology Conference|
|Publication status||Published - 1 Jan 2011|
|Event||73rd IEEE Vehicular Technology Conference (VTC Spring) - |
Duration: 1 Jan 2011 → …
|Conference||73rd IEEE Vehicular Technology Conference (VTC Spring)|
|Period||1/01/11 → …|