Elena Simona Lohan

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In positioning applications, where the line of sight (LOS) is needed with high accuracy, the accurate delay estimation is an important task. The new satellite-based positioning systems, such as Galileo and modernized GPS, will use a new modulation type, that is, the binary offset carrier (BOC) modulation. This type of modulation creates multiple peaks(More)
Author(s) Lohan, Elena Simona; Burian, Adina; Renfors, Markku Title Low-complexity unambiguous acquisition methods for BOC-modulated CDMA signals Citation Lohan, Elena Simona; Burian, Adina; Renfors, Markku 2008. Low-complexity unambiguous acquisition methods for BOC-modulated CDMA signals. International journal of satellite communications vol. 26, num. 6,(More)
The ever-increasing public interest on location and positioning services has originated a demand for higher performance Global Navigation Satellite Systems (GNSSs). In order to achieve this incremental performance, the estimation of Line-Of-Sight (LOS) delay with high accuracy is a prerequisite for all GNSSs. The Delay Lock Loops (DLLs) and their enhanced(More)
Recent proposals for the modernized GPS and Galileo receivers suggested the use of a new modulation type, namely the Binary-Offset-Carrier (BOC) modulation, in order to get a better spectral efficiency and reduced interference compared to the traditional BPSK modulation. The acquisition and tracking of the code phase delay and Doppler shift is typically(More)
Rake receiver is the most common receiver employed in Wideband CDMA (WCDMA) systems. Traditionally Multiple Access Interference (MAI) in spread spect rum systems is modelled as white Gaussian noise. This presumption is valid when the number of users is large and interference signals have large spreading factors. But the WCDMA air interface for the 3rd(More)
A Bayesian method for dynamical off-line estimation of the position and path loss model parameters of a WLAN access point is presented. Two versions of three different on-line positioning methods are tested using real data. The tests show that the methods that use the estimated path loss parameter distributions with finite precisions outperform the methods(More)
In mobile positioning, it is very important to estimate correctly the delay between the transmitter and the receiver. When the receiver is in line-of-sight (LOS) condition with the transmitter, the computation of the mobile position in two dimensions becomes straightforward. In this paper, the problem of LOS detection in WCDMA for mobile positioning is(More)
Delay estimation in direct sequence CDMA (DS-CDMA) systems is necessary for accurate code synchronization and for applications such as mobile phone positioning. Multipath propagation is among the main sources of error in the DS-CDMA delay estimation process, together with multiple access interference and Non Line-Of-Sight (NLOS) propagation. This paper(More)
The estimation with high accuracy of the line-of-sight delay is a prerequisite for all global navigation satellite systems. The delay locked loops and their enhanced variants are the structures of choice for the commercial GNSS receivers, but their performance in severe multipath scenarios is still rather limited. The new satellite positioning system(More)
The Binary Offset Carrier (BOC) modulation which has been proposed for future Galileo and GPS M-code signals, provides a higher spectral separation from BPSK-modulated signals, such as GPS C/A code. The absolute value of the autocorrelation function of a BOC signal has a narrower main lobe, which may increase the resolution of delay estimates, but also(More)