The Constant Tone Extension (CTE) function introduced since Bluetooth Low Energy 5.1 greatly improves indoor Bluetooth Low Energy localization. These small, low-energy beacons transmit signals that Bluetooth-enabled devices can use to calculate proximity and positioning. This technology enables continuous navigation, location-based services, indoor wayfinding, and so on. The new feature, used together with an appropriate antenna array, can calculate the Angle of Arrival (AoA) and Angle of Departure (AoD). This study is solely concerned with AoA mode analysis.

Estimating AoA is challenging, especially indoors. Multipath signals, which greatly corrupt results in such a complex environment, cannot be ignored. The low-energy equipment used in BLE frequently results in a substantial frequency offset, which cannot be overlooked. Several elements are thoroughly examined in order to comprehend the positioning algorithm.

The processing of I/Q data is the first step in the prokect. Then we look at how frequency offset is created and how it affects estimation. We use maximum likelihood to calculate frequency offset after modeling the data structure. Following that, numerous AoA estimation and multipath-solving methods are discussed. We discuss the operation of a 4x4 URA and the advantages and disadvantages of having multiple antennas. A virtual antenna (VA) solution addresses hardware limitations, but it fails when it comes to multipath. Finally, we model AOA estimation and use the estimated angles to localize. The Matlab algorithm, as well as the LS and TLS methods, are introduced.

In this paper, we propose an end-to-end indoor BLE positioning solution. The algorithm is tested using a Matlab simulation. The multipath scenario is created by simulating an empty room with raytracing and focusing on first-order reflection routes. The simulation demonstrates that Toeplitz Reconstruction (TR) works best with the appropriate settings. Over 90% of the results in a 4-by-4 uniform rectangular array (URA) have position errors of less than 0.14 meters. In about 60% of cases, increasing the size of the 8-by-8 Uniform Rectangular Array (URA) results in a position accuracy of less than 0.1 meters.

Following the simulation, a real-world experiment is conducted to assess the solutions' practicability and efficacy. To reduce uncontrolled multipath interference, the experiment was carried out outside. The TR method has a distance inaccuracy of 0.4 m, whereas conventional methods have a distance inaccuracy of 0.1-0.2 m. The most difficult challenge is estimating elevation angles, which necessitates additional research. The results of azimuth angle estimation studies match those of 1-D AoA estimation studies. Even with a high prediction error for elevation angle, the distance error is lower than in previous positioning research.

Finally, we make recommendations for future research. This could include optimizing algorithm parameters, taking antenna-related factors into account, changing CTE configurations, and so on.

The work presented in this thesis investigates the creation of virtual sound sources in a room equipped with a limited number of loudspeakers. This limited number of loudspeakers is typical for consumer loudspeaker systems. Ideally, these systems can provide a listening experience in which localisation cues are completely present. However, in current systems, this is not the case. The limited number of loudspeakers make it impractical to produce a physically accurate sound field. A possible solution is to create a perceptually accurate sound field instead. In this work, a step towards an algorithm which can do so is presented. The developed algorithm requires knowledge of the listener placement, the room, and the loudspeaker placement. Spatial weighting is used to construct a region in which the acoustic en-ergy should be large and a region in which the acoustic energy should be limited. The loudspeaker playback signals are obtained by maximising the energy ratio between these regions, while at the same time ensuring that the perceptual difference between the received audio and reference audio remains limited. The algorithm employs a convex optimisation problem to facilitate efficiently solving for the playback signals. Concretely, six convex optimisation problems are proposed with somewhat increasing complexity and different weighting matrices. For each of the optimisation problems, the proposed algorithm is compared against a simple amplitude panning algorithm and a nearest neighbour algorithm. It is found that none of the considered algorithms is clearly preferred over the others in terms of the considered evaluation metrics. A major limitation of the presented work is that the evaluation metrics do not explicitly test for localisation accuracy. In future work, this should be investigated by including subjective tests.