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Papers by Abdelmonaem Lakhzouri

Research paper thumbnail of Selection of the multiple-dwell hybrid-search strategy for the acquisition of Galileo signals in fading channels

2004 IEEE 15th International Symposium on Personal, Indoor and Mobile Radio Communications (IEEE Cat. No.04TH8754), 2004

... equivalent with BOC( 1,l) modulation, which has recently been proposed for GPS/Galileo agreem... more ... equivalent with BOC( 1,l) modulation, which has recently been proposed for GPS/Galileo agreements. ... 5: Comparison between different K-dwell structures (K = 1,. . . ,5) at various penalty factors ... 5-dwell structure, and the worst performance is obtained with a single-dwell structure ...

Research paper thumbnail of Measurement and Characterization of Satellite-to-Indoor Radio Wave Propagation Channel

Despite of the great advances in Global Positioning Sys- tem (GPS) technology, millions of people... more Despite of the great advances in Global Positioning Sys- tem (GPS) technology, millions of people still cannot be located when they are in indoor environment. The sig- nal transmitted from the Navstar satellites experiences severe attenuation while penetrating all the construction materials. The characteristics of the indoor propagation is still not well understood and the question whether the GPS signals

Research paper thumbnail of DMT based VDSL modem implementation using TMS320C64x

Proceedings. Sixth IEEE Symposium on Computers and Communications, 2001

The DSP based solutions have become the main concern of new modems design. At present, most of th... more The DSP based solutions have become the main concern of new modems design. At present, most of the voice band modems use a programmable solution and most of the telecommunication systems tend to do the same. For the xDSL modems, the same trend is expected and the DSP based implementation becomes the challenge for new designs. We investigate a programmable

Research paper thumbnail of STATISTICAL PROPERTIES OF URBAN WCDMA CHANNEL FOR MOBILE POSITIONING APPLICATIONS

International Journal on Wireless & Optical Communications, 2004

The goal of this paper is to report the results of a comprehensive statistical analysis of the ur... more The goal of this paper is to report the results of a comprehensive statistical analysis of the urban wireless channels, based on WCDMA field-measurements data. The applications of our study are in the area of WCDMA-based mobile phone positioning. The target here is the analysis of the Line-of-Sight (LOS) and Non Line-of-Sight (NLOS) situations and of the statistical distributions of their parameters, such as the delays and amplitudes. The distribution of the first arriving path is tested against several theoretical distributions, such as Rayleigh, Rician, and Nakagami-m distributions. The estimated delay of the first arriving path is compared to the LOS delay estimated via GPS, in order to detect NLOS situations. The estimation of the mobile speed, based on field-measurements data is also carried out and compared to the speed estimation based on the GPS link. The measurements were conducted in urban environment, downtown Helsinki.

Research paper thumbnail of Complex double-binary-offset-carrier modulation for a unitary characterisation of Galileo and GPS signals

IEE Proceedings - Radar, Sonar and Navigation, 2006

Research paper thumbnail of Highly efficient techniques for mitigating the effects of multipath propagation in DS-CDMA delay estimation

IEEE Transactions on Wireless Communications, 2000

Abstract—Delay estimation in direct-sequence code-division multiple-access (DS-CDMA) systems is n... more Abstract—Delay estimation in direct-sequence code-division multiple-access (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 ...

Research paper thumbnail of Feedforward Delay Estimators in Adverse Multipath Propagation for Galileo and Modernized GPS Signals

EURASIP Journal on Advances in Signal Processing, 2006

The estimation with high accuracy of the line-of-sight delay is a prerequisite for all global nav... 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 proposals specify higher code-epoch lengths compared to the traditional GPS signal and the use of a new modulation, the binary offset carrier (BOC) modulation, which triggers new challenges in the delay tracking stage. We propose and analyze here the use of feedforward delay estimation techniques in order to improve the accuracy of the delay estimation in severe multipath scenarios. First, we give an extensive review of feedforward delay estimation techniques for CDMA signals in fading channels, by taking into account the impact of BOC modulation. Second, we extend the techniques previously proposed by the authors in the context of wideband CDMA delay estimation (e.g., Teager-Kaiser and the projection onto convex sets) to the BOC-modulated signals. These techniques are presented as possible alternatives to the feedback tracking loops. A particular attention is on the scenarios with closely spaced paths. We also discuss how these feedforward techniques can be implemented via DSPs.

Research paper thumbnail of Extended Kalman Filter Channel Estimation for Line-of-Sight Detection in WCDMA Mobile Positioning

EURASIP Journal on Advances in Signal Processing, 2003

... abdelmonaem.lakhzouri@tut.fi Elena Simona Lohan Institute of Communications Engineering, Tamp... more ... abdelmonaem.lakhzouri@tut.fi Elena Simona Lohan Institute of Communications Engineering, Tampere University of Technology, PO Box 553, 33101 Tampere, Finland Email: elena-simona.lohan@tut.fi Ridha Hamila Etisalat ...

Research paper thumbnail of A Highly Efficient Generalized Teager-Kaiser-Based Technique for LOS Estimation in WCDMA Mobile Positioning

EURASIP Journal on Advances in Signal Processing, 2005

... abdelmonaem.lakhzouri@tut.fi Elena Simona Lohan Institute of Communications Engineering, Tamp... more ... abdelmonaem.lakhzouri@tut.fi Elena Simona Lohan Institute of Communications Engineering, Tampere University of Technology, PO Box 553, 33101 Tampere, Finland Email: elena-simona.lohan@tut.fi Markku Renfors Institute ...

Research paper thumbnail of An improved simulation model for Nakagami-m fading channels for satellite positioning applications

- This paper presents a simple and efficient simulation model for Nakagami-m fading channels. We ... more - This paper presents a simple and efficient simulation model for Nakagami-m fading channels. We first show, via measurement data, that the Nakagami-m distribution provides the best fit for the fading amplitudes of the satellite-to-indoor and satellite-to-outdoor ...

Research paper thumbnail of Hybrid search single and double-dwell acquisition architectures for Galileo signal

CDROM Proc. of IEEE IST Mobile & …, 2004

GPS and Galileo receivers must perform two dimensional searches, in time and in frequency, in ord... more GPS and Galileo receivers must perform two dimensional searches, in time and in frequency, in order to acquire the correct code phase and correct Doppler frequency. Accurate and fast acquisition plays an important role in achieving reli-able satellite-based ...

Research paper thumbnail of Spectral shaping of Galileo signals in the presence of frequency offsets and multipath channels

Abstract—Recently, the authors have proposed a new class of Binary-Offset-Carrier (BOC) modulatio... more Abstract—Recently, the authors have proposed a new class of Binary-Offset-Carrier (BOC) modulation, namely the Double-BOC (DBOC) mod-ulation which generalizes the main modulation types used in GPS and Galileo under a single, unified formula, and allows extra-flexibility ...

Research paper thumbnail of Indoor fading distributions for GPS-based pseudolite signals

2007 International Workshop on Satellite and Space Communications, 2007

During the past few years, accurate positioning of terminals has received much attention in wirel... more During the past few years, accurate positioning of terminals has received much attention in wireless communication. One reason is that of the requirement for emergency call positioning imposed by the authorities. The positioning algorithms based on the Navstar satellites have limitations in the indoor environment because the signal experiences severe attenuation in the indoor environment. The characteristics of the indoor propagation is still not well understood. In many cases, it is assumed that with the deployment of pseudolites, indoor navigation can show better performance. In this paper we analyze the indoor channel propagation using pseudolites, based on the measurement data collected in different scenarios.

Research paper thumbnail of Selection of the multiple-dwell hybrid-search strategy for the acquisition of Galileo signals in fading channels

2004 IEEE 15th International Symposium on Personal, Indoor and Mobile Radio Communications (IEEE Cat. No.04TH8754), 2004

... equivalent with BOC( 1,l) modulation, which has recently been proposed for GPS/Galileo agreem... more ... equivalent with BOC( 1,l) modulation, which has recently been proposed for GPS/Galileo agreements. ... 5: Comparison between different K-dwell structures (K = 1,. . . ,5) at various penalty factors ... 5-dwell structure, and the worst performance is obtained with a single-dwell structure ...

Research paper thumbnail of Measurement and Characterization of Satellite-to-Indoor Radio Wave Propagation Channel

Despite of the great advances in Global Positioning Sys- tem (GPS) technology, millions of people... more Despite of the great advances in Global Positioning Sys- tem (GPS) technology, millions of people still cannot be located when they are in indoor environment. The sig- nal transmitted from the Navstar satellites experiences severe attenuation while penetrating all the construction materials. The characteristics of the indoor propagation is still not well understood and the question whether the GPS signals

Research paper thumbnail of DMT based VDSL modem implementation using TMS320C64x

Proceedings. Sixth IEEE Symposium on Computers and Communications, 2001

The DSP based solutions have become the main concern of new modems design. At present, most of th... more The DSP based solutions have become the main concern of new modems design. At present, most of the voice band modems use a programmable solution and most of the telecommunication systems tend to do the same. For the xDSL modems, the same trend is expected and the DSP based implementation becomes the challenge for new designs. We investigate a programmable

Research paper thumbnail of STATISTICAL PROPERTIES OF URBAN WCDMA CHANNEL FOR MOBILE POSITIONING APPLICATIONS

International Journal on Wireless & Optical Communications, 2004

The goal of this paper is to report the results of a comprehensive statistical analysis of the ur... more The goal of this paper is to report the results of a comprehensive statistical analysis of the urban wireless channels, based on WCDMA field-measurements data. The applications of our study are in the area of WCDMA-based mobile phone positioning. The target here is the analysis of the Line-of-Sight (LOS) and Non Line-of-Sight (NLOS) situations and of the statistical distributions of their parameters, such as the delays and amplitudes. The distribution of the first arriving path is tested against several theoretical distributions, such as Rayleigh, Rician, and Nakagami-m distributions. The estimated delay of the first arriving path is compared to the LOS delay estimated via GPS, in order to detect NLOS situations. The estimation of the mobile speed, based on field-measurements data is also carried out and compared to the speed estimation based on the GPS link. The measurements were conducted in urban environment, downtown Helsinki.

Research paper thumbnail of Complex double-binary-offset-carrier modulation for a unitary characterisation of Galileo and GPS signals

IEE Proceedings - Radar, Sonar and Navigation, 2006

Research paper thumbnail of Highly efficient techniques for mitigating the effects of multipath propagation in DS-CDMA delay estimation

IEEE Transactions on Wireless Communications, 2000

Abstract—Delay estimation in direct-sequence code-division multiple-access (DS-CDMA) systems is n... more Abstract—Delay estimation in direct-sequence code-division multiple-access (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 ...

Research paper thumbnail of Feedforward Delay Estimators in Adverse Multipath Propagation for Galileo and Modernized GPS Signals

EURASIP Journal on Advances in Signal Processing, 2006

The estimation with high accuracy of the line-of-sight delay is a prerequisite for all global nav... 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 proposals specify higher code-epoch lengths compared to the traditional GPS signal and the use of a new modulation, the binary offset carrier (BOC) modulation, which triggers new challenges in the delay tracking stage. We propose and analyze here the use of feedforward delay estimation techniques in order to improve the accuracy of the delay estimation in severe multipath scenarios. First, we give an extensive review of feedforward delay estimation techniques for CDMA signals in fading channels, by taking into account the impact of BOC modulation. Second, we extend the techniques previously proposed by the authors in the context of wideband CDMA delay estimation (e.g., Teager-Kaiser and the projection onto convex sets) to the BOC-modulated signals. These techniques are presented as possible alternatives to the feedback tracking loops. A particular attention is on the scenarios with closely spaced paths. We also discuss how these feedforward techniques can be implemented via DSPs.

Research paper thumbnail of Extended Kalman Filter Channel Estimation for Line-of-Sight Detection in WCDMA Mobile Positioning

EURASIP Journal on Advances in Signal Processing, 2003

... abdelmonaem.lakhzouri@tut.fi Elena Simona Lohan Institute of Communications Engineering, Tamp... more ... abdelmonaem.lakhzouri@tut.fi Elena Simona Lohan Institute of Communications Engineering, Tampere University of Technology, PO Box 553, 33101 Tampere, Finland Email: elena-simona.lohan@tut.fi Ridha Hamila Etisalat ...

Research paper thumbnail of A Highly Efficient Generalized Teager-Kaiser-Based Technique for LOS Estimation in WCDMA Mobile Positioning

EURASIP Journal on Advances in Signal Processing, 2005

... abdelmonaem.lakhzouri@tut.fi Elena Simona Lohan Institute of Communications Engineering, Tamp... more ... abdelmonaem.lakhzouri@tut.fi Elena Simona Lohan Institute of Communications Engineering, Tampere University of Technology, PO Box 553, 33101 Tampere, Finland Email: elena-simona.lohan@tut.fi Markku Renfors Institute ...

Research paper thumbnail of An improved simulation model for Nakagami-m fading channels for satellite positioning applications

- This paper presents a simple and efficient simulation model for Nakagami-m fading channels. We ... more - This paper presents a simple and efficient simulation model for Nakagami-m fading channels. We first show, via measurement data, that the Nakagami-m distribution provides the best fit for the fading amplitudes of the satellite-to-indoor and satellite-to-outdoor ...

Research paper thumbnail of Hybrid search single and double-dwell acquisition architectures for Galileo signal

CDROM Proc. of IEEE IST Mobile & …, 2004

GPS and Galileo receivers must perform two dimensional searches, in time and in frequency, in ord... more GPS and Galileo receivers must perform two dimensional searches, in time and in frequency, in order to acquire the correct code phase and correct Doppler frequency. Accurate and fast acquisition plays an important role in achieving reli-able satellite-based ...

Research paper thumbnail of Spectral shaping of Galileo signals in the presence of frequency offsets and multipath channels

Abstract—Recently, the authors have proposed a new class of Binary-Offset-Carrier (BOC) modulatio... more Abstract—Recently, the authors have proposed a new class of Binary-Offset-Carrier (BOC) modulation, namely the Double-BOC (DBOC) mod-ulation which generalizes the main modulation types used in GPS and Galileo under a single, unified formula, and allows extra-flexibility ...

Research paper thumbnail of Indoor fading distributions for GPS-based pseudolite signals

2007 International Workshop on Satellite and Space Communications, 2007

During the past few years, accurate positioning of terminals has received much attention in wirel... more During the past few years, accurate positioning of terminals has received much attention in wireless communication. One reason is that of the requirement for emergency call positioning imposed by the authorities. The positioning algorithms based on the Navstar satellites have limitations in the indoor environment because the signal experiences severe attenuation in the indoor environment. The characteristics of the indoor propagation is still not well understood. In many cases, it is assumed that with the deployment of pseudolites, indoor navigation can show better performance. In this paper we analyze the indoor channel propagation using pseudolites, based on the measurement data collected in different scenarios.