Studentarbeten // Student Theses

Använd denna länk för att länka till samlingen:

https://odr.chalmers.se/handle/20.500.12380/1

Browse

Visar 1 - 20 av 145

A Channel Estimation Between a Base Station, Intelligent Reflecting Surface, and a User Equipment
(2023) Saltykova, Ekaterina; Chalmers tekniska högskola / Institutionen för elektroteknik; Monti, Paolo
A fusion-based multiclass AdaBoost for classifying object poses using visual and IR images
(2011) Changrampadi, Mohamed Hashim; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
A rapid acquisition GPS receiver based on ultra tightly coupled IMU and GPS
(2010) Garcia, Gabriel E.; Chalmers tekniska högskola / Institutionen för rymd- och geovetenskap; Chalmers University of Technology / Department of Earth and Space Sciences
Nowadays, the importance to obtain position in weak signal environments, such as indoors, has increased in order to take a step forward in the greater use of GPS. However, the weak signal environment may include several negative factors such as low signal to noise ratio, signal jamming and interference among others that shall be studied. The present thesis work proposes an open loop approach to deal with the signal dynamics. A Doppler model is proposed in order to remove the dynamics of the incoming GPS signal with the aid of an Inertial Measurement Unit (IMU). The model is broken down into calculating the satellite dynamics, the receiver dynamics and the receiver's oscillator dynamics. An error budget is created in order to see the unpredictable errors and their influence. A bandwidth analysis is also performed in order to analyze the effects of the dynamics in the receiver's phase locked loop (PLL), more specifically in the loop bandwidth. Available measurements from a high tech IMU and a GPS receiver oscillator are analyzed to quantify the time dependant errors. An algorithm to account for the satellite dynamics is proposed with an accuracy Doppler error of ±:0005 Hz. It is shown that the errors from the IMU are dominant in the error budget. However, the receiver dynamics errors are reduced: For a scenario where a vehicle enters a tunnel at 100 km/h and 50 seconds later exits the tunnel with a speed of 28 km/h it is shown that the dynamics of the signal can be reduced from 100 Hz to 6 Hz after implementing the open loop approach. The errors introduced by the oscillator are also shown to be significant with up to 2.58 Hz for L1 GPS signal. These conclusions give arise to the use of lower bandwidth usage in the PLL. Higher signal to noise ratio can be deduced and rapid acquisition and reacquisition of the signal is possible, meaning the GPS signal can be tracked immediately after blockage situations.
A study of MIMO precoding algorithm in WCDMA uplink
(2015) Huang, Sheng; Tao, Mengbai; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
A study of poisson multi-Bernoulli mixture conjugate prior in multiple target estimation
(2017) Xia, Yuxuan; Chalmers tekniska högskola / Institutionen för elektroteknik; Chalmers University of Technology / Department of Electrical Engineering
A survey of information geometry in iterative receiver design, and its application to cooperative positioning
(2012) Liu, Dapeng; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
Adaptive interference suppression algorithm for analog beamforming
(2020) Asaad, Abdullah Yousif; Chalmers tekniska högskola / Institutionen för elektroteknik; Svensson, Tommy
Alternative technologies for providing voice services onboard trains
(2019) Mikkelsen Ylander, Herman; Chalmers tekniska högskola / Institutionen för elektroteknik; Ström, Erik
An empirical study of cellular-IoT
(2020) Ekman, Tim; Jönsson, Samuel; Chalmers tekniska högskola / Institutionen för elektroteknik; Agrell, Erik
Analysis, simulations and improvement proposals of IEEE 802.15.4g-2012
(2016) Xue, Liang; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
Anomaly detection in communication system using machine learning
(2019) Eklund, Erik; Sjögren, Bengt; Chalmers tekniska högskola / Institutionen för elektroteknik; Chalmers University of Technology / Department of Electrical Engineering
Automatic detection of 3D breast lesions in dynamic contrast-enhanced MR images
(2011) Arvidsson, Jonathan; Johansson, Fredrik; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
Automatic identification and localization of EEG electrodes using photogrammetry
(2014) Zhao, Lin; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
Automatic View Compensation
(2018) Dahl, Rickard; Chalmers tekniska högskola / Institutionen för elektroteknik; Chalmers University of Technology / Department of Electrical Engineering
Controlling the luminance in the tunnel threshold zone is a challenging task. On one hand the luminance in the threshold zone needs to be high enough for a driver experiencing significant glare to be able to detect a possible obstacle located in the relatively dark threshold zone and stop in time to avoid an accident. On the other hand there are demands to keep the luminance as low as possible to reduce the energy consumption. In order to control the luminance in the threshold zone, the glare experienced by the driver needs to be estimated. This is done by measuring the equivalent veiling luminance Lseq. Ideally Lseq would be measured at the stopping distance, 1.5m above the road surface and in the middle of the road with the camera centered on the tunnel opening. In practice however, the camera often needs to be mounted on a height of 5 − 7m to avoid staining and vandalism and it sometimes also needs to be placed on the side of the road. This camera positioning leads to a significant Lseq error. In this thesis a view transformation method aimed at automatically reducing the Lseq error is presented. The method is based on Depth Image Based Rendering, which requires a camera pose for a virtual view as well as the depth map for the original view. Depth maps of a scene are rarely available however and for this reason a monocular depth map estimation method is proposed. The depth estimation method is based on detecting Maximally Stable Extremal Regions and classifying the regions according to detected line segments. The proposed view transformation method has been evaluated on a small number of scenes and the error reduction is as high as 40 − 85%. There are however several issues that require future improvements, including: a long computation time, high occurrence of errors in the estimated depth maps and errors in the centering of the diagram used for the Lseq computation. Nevertheless, the proposed approach can with a few minor adjustments be implemented in the luminance measurement system and be used in practice.
Backward Gaussian particle message passing with applications to fiber optic communications
(2015) Sackey, Isaac Alex; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
Bandlimited power-efficient signaling and pulse design for intensity modulation
(2013) Czegledi, Cristian Bogdan; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
Bayesian tracking of multiple point targets using expectation maximization
(2015) Selvan, Raghavendra; Chalmers tekniska högskola / Institutionen för signaler och system; Chalmers University of Technology / Department of Signals and Systems
Beamforming in Wireless Coded Caching systems
(2022) Madhusudan, Sneha; Chalmers tekniska högskola / Institutionen för elektroteknik; Svensson, Tommy
Benefits of adaptivity in time slotted channel hopping systems
(2023) Kumar, Vaidyanathan; Chalmers tekniska högskola / Institutionen för elektroteknik; Svensson, Tommy
Calibration of array antennas
(2020) Wu, Han; Chalmers tekniska högskola / Institutionen för elektroteknik; McKelvey, Tomas

Browse

Browsar Studentarbeten // Student Theses efter Program "Communication Engineering (MPCOM), MSc"

Sökresultat per sida

Sortera efter