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Low Complexity High Resolution Maximum Likelihood Channel Estimation in Spread Spectrum Navigation Systems

Groh, Ingmar and Staudinger, Emanuel and Sand, Stephan (2011) Low Complexity High Resolution Maximum Likelihood Channel Estimation in Spread Spectrum Navigation Systems. 74th IEEE Vehicular Technology Conference (VTC-FAll), 5-8 Sep 2011, San Francisco, CA, USA.

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Abstract

Traditionally, the low complexity maximum likelihood (ML) estimation of several closely-spaced superimposed signal replicas in a communications or navigation receiver is per-formed using expectation maximization (EM) or space alternating generalized expectation maximization (SAGE) methods. However, the componentwise decomposition of a multidimensional log-likelihood function according to the EM or SAGE algorithm fails for realistic time-variant channels. Thus, we consider the minimization of a multidimensional log likelihood function for the closely-spaced channel delays. To get this log-likelihood function, we use a decomposition of the highly time-variant channel path phasors based on Slepian’s subspaces. The obtained log-likelihood function enables a coherent averaging over several hundred codewords even for high-mobility receivers. Therefore, we avoid the squaring loss (SL) that appears for the conventional incoherent averaging and incoherent log likelihood functions. Our simulations show that the minimization of coherent log-likelihood functions based on Slepian’s functions yields a root mean square error (RMSE) of the line of sight (LOS) delay estimation that approximates the Cramer-Rao bound (CRB) rather closely.

Item URL in elib:https://elib.dlr.de/69861/
Document Type:Conference or Workshop Item (Speech)
Title:Low Complexity High Resolution Maximum Likelihood Channel Estimation in Spread Spectrum Navigation Systems
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Groh, IngmarUNSPECIFIEDUNSPECIFIED
Staudinger, EmanuelUNSPECIFIEDUNSPECIFIED
Sand, StephanUNSPECIFIEDUNSPECIFIED
Date:2011
Refereed publication:Yes
Open Access:No
Gold Open Access:No
In SCOPUS:No
In ISI Web of Science:No
Status:Published
Keywords:spread spectrum system, synchronization, maximum likelihood estimation, multipath mitigation
Event Title:74th IEEE Vehicular Technology Conference (VTC-FAll)
Event Location:San Francisco, CA, USA
Event Type:international Conference
Event Dates:5-8 Sep 2011
Organizer:IEEE Vehicular Technology Society
HGF - Research field:Aeronautics, Space and Transport (old)
HGF - Program:Space (old)
HGF - Program Themes:W KN - Kommunikation/Navigation
DLR - Research area:Space
DLR - Program:W KN - Kommunikation/Navigation
DLR - Research theme (Project):W - Vorhaben GNSS2/Neue Dienste und Produkte (old)
Location: Oberpfaffenhofen
Institutes and Institutions:Institute of Communication and Navigation > Communications Systems
Deposited By: Sand, Dr Stephan
Deposited On:07 Oct 2011 09:25
Last Modified:29 Nov 2016 11:58

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