# Former Master semester projects

#### Online Tutorial for Polar Codes (LTHC)

The aim of this project is to develop an online tutorial thought for a broad audience to illustrate the advantages and applications, but also the disadvantages and open questions in the field of polar coding. The tutorial should be interactive in the sense that it should contain demos to allow trade-offs between parameters and performance comparisons…

#### Polar Codes for the Binary Coded Side-Information Problem (LTHC)

Polar codes, introduced by Arikan in [1], have been demonstrated to achieve the capacity of any binary-input memory less output-symmetric channel with encoding and decoding complexity $\Theta(N\ log\,N)$ and error probability decaying roughly as $2^{-\sqrt{N}}$, where $N$ is the block length of the code. Since then, the original point-to-point communication scheme has been extended to several multi-terminal scenarios, in order to provide low-complexity coding schemes capable of matching the information theoretic bounds. A practical solution for the problem of binary source coding with coded side-information which employs LDPC codes and a trellis quantizer has been developed…

#### Wireless Keyboard & Mouse/Trackpad App for iOS (LCM)

The goal of this project is to develop an iOS app (for iPad/iPhone) which acts as a remote keyboard and track-pad for a laptop. For connecting to the laptop, the app can use either Bluetooth or WiFi. The app should use the default touch keyboard of an iPad/iPhone and add to this keyboard custom features as needed. Custom features can include for example gestures, special keys (CTRL, Command, Shift), interactions with the mouse, etc…

#### UAVs using Bayesian Optimization to Locate WiFi Devices (LCM)

We address the problem of localizing non­-collaborative WiFi devices in a large region. Our main motivation is to localize humans by localizing their WiFi devices, e.g., in search and rescue operations. We use an active sensing approach that relies on Unmanned Aerial Vehicles (UAVs) to collect signal­-strength measurements at informative locations. The problem is challenging since the WiFi signals are transmitted at random times, they are very noisy and they are received only when the UAV is in close proximity to the device. For these reasons, it is extremely important to use a technique which can make robust and efficient estimates with sparse and noisy data. Bayesian Optimization based on Gaussian process (GP) regression is well suited for such problems…

#### Wireless communication system using Software Defined Radio platforms (LCM)

The goal of this project is to implement an over-the-air communication system using two bladeRF modules, one at each end of the wireless link. Some of the basic blocks are already implemented in Matlab (data source, modulator, pulse shaper, matched filter, demodulator, error correction mechanism).
In order to have a fully operational wireless link, there are several modules that are still missing. The purpose of this project is to implement them. First, one needs to perform the clock synchronization between the transmitter and the receiver. Next, one has to synchronize the received data and detect the start/end of the transmitted blocks/frames. Finally, one has to estimate the channel parameters, using some training data. Once these blocks are implemented, a fully operational transmission chain should be demonstrated…

#### Community Detection in Directed Graphs (LTHI)

The problem of clustering or “community detection” in large random graphs has received a lot of attention recently. One thoroughly studied model is the so called “stochastic block model” (SBM), which models random undirected graphs with multiple communities. In the present project, we aim at studying the community detection problem in directed random graphs. Interesting questions arise from the fact that the graph is directed…

#### Analyzing the Structure of Wikipedia (LTHI)

The aim of this project is to analyze the structure of a large existing web graph such as Wikipedia with roughly $N = 6$ million nodes and $E = 200$ million edges. Spectral algorithms exist for such tasks, but their runtime $O(N^3)$ is prohibitive for the above application. Various methods have been developed for tackling this issue. We aim at studying and implementing some of these…