Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 31 for “"adaptive beamforming"”.
-
A real-time adaptive-beamforming hearing aid
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1989.
-
Analysis and Development of Blind Adaptive Beamforming Algorithms
… for the development and analysis of blind adaptive algorithms. An adaptive algorithm is said to be 'blind' if it does not require a known training sequence. The main focus is on application of these algorithms to adaptive antenna arrays in mobile radio communications. Adaptive antenna …
-
Adaptive beamforming of steerable array monopole antenna for WLAN application
… by using CST Microwave Studio software. The adaptive beamforming is proposed by using downhill simplex algorithm. The results show that the optimum reactance values are suggested after 0.074 second with 94 iterations to achieve a direction of arrival of 180° and 0°. The simulated radiation is …
-
Broadband adaptive beamforming with low complexity and frequency invariant response
… as well as increasing the adaptation rate of adaptive broadband beamformers. This is performed exemplarily for the generalised sidelobe canceller (GSC) structure. The GSC is an alternative implementation of the linearly constrained minimum variance beamformer, which can utilise well-known …
-
Adaptive Beamforming Using a Microphone Array for Hands-Free Telephony
… of a 4-channel microphone array that is an adaptive beamformer used for hands-free telephony in a noisy environment. The microphone signals are amplified, then sent to an A/D converter. The microprocessor board takes the data from the 4 channels and utilizes digital signal processing to …
-
Adaptive Beamforming using ICA for Target Identification in Noisy Environments
The blind source separation problem has received a great deal of attention in previous years. The aim of this problem is to estimate a set of original source signals from a set of linearly mixed signals through any number of signal processing techniques. While many methods exist that attempt to …
-
Comparison of Machine Learning-Based Methods for Narrowband Blind Adaptive Beamforming
There are many different approaches to beamforming and interferer cancellation. The earliest methods of beamforming assumed prior knowledge of the receive array geometry and of the incoming signal directions. This information is normally found via array calibration. Blind source separation methods …
-
Four Branch Diversity Combining and Adaptive Beamforming Measurements Using Mobile Arrays at 2.05 GHz
Mobile arrays employing diversity combining and adaptive beamforming techniques overcome multipath fading, improve coverage, and increase capacity in wireless communications systems. In this thesis, diversity combining and adaptive beamforming performance of different four element arrays for mobile …
-
Array Signal Processing for Communications from High Altitude Platforms and Other Applications
Digital beamforming (DBF) technology using antenna array has reached a sufficient level of maturity that it can be applied to communications to improve system capacity. In this thesis, the applications to digital beamforming in the communications from high altitude platforms (HAPs) and the high …
-
Randomly Spaced Smart Antennas
The goal of this thesis is to develop adaptive array' features out of randomly spaced antenna elements. Most optimization techniques that have been presented so far for non-equidistant antenna arrays have been restricted to the analysis of symmetric or linear geometries. Several direction of …
-
Radar Space-Time Processing for Range-Folded Spread-Doppler Clutter Mitigation
… and Doppler shift produced by ionospheric winds. Adaptive beamforming is known to provide asymptotically optimal array gain if sufficient training data is available. In highly nonstationary environments however, obtaining this asymptotic performance is difficult as neither knowledge of the target …
-
Demonstration of passive acoustic detection and tracking of unmanned underwater vehicles
… and river tracking a UUV using conventional and adaptive beamforming. The spectral filters resulted in a probability of detection of 96% and false alarms of 18% at a distance of 100 m, with boat traffic in a river environment. Tracking the vehicle with adaptive beamforming resulted in a 6.2±5.7 ∘ …
-
Demonstration of passive acoustic detection and tracking of unmanned underwater vehicles
… and river tracking a UUV using conventional and adaptive beamforming. The spectral filters resulted in a probability of detection of 96 % and false alarms of 18 % at a distance of 100 m, with boat traffic in a river environment. Tracking the vehicle with adaptive beamforming resulted in a 6.2 ± …
-
Adaptive Arrays and Diversity Antenna Configurations for Handheld Wireless Communication Terminals
… of an investigation into the performance of adaptive beamforming and diversity combining using antenna arrays that can be mounted on handheld radios. Handheld arrays show great promise for improving the coverage, capacity, and power efficiency of wireless communication systems. Diversity …
-
High-resolution source imaging with bio-inspired sensing systems
… line system similar to the one of fish. An adaptive beamforming algorithm is used to provide high-resolution images of source locations. The other system is built based on the principle of weakly electric fish. As it is an active sensing system, signals from multiple sources are coherent, …
-
The development and application of random matrix theory in adaptive signal processing in the sample deficient regime
This thesis studies the problems associated with adaptive signal processing in the sample deficient regime using random matrix theory. The scenarios in which the sample deficient regime arises include, among others, the cases where the number of observations available in a period over which the …
-
The development and application of random matrix theory in adaptive signal processing in the sample deficient regime
This thesis studies the problems associated with adaptive signal processing in the sample deficient regime using random matrix theory. The scenarios in which the sample deficient regime arises include, among others, the cases where the number of observations available in a period over which the …
-
Horizontal directional spectrum estimation of the Heard Island transmissions
… estimation and demodulation required before beamforming is described. Conventional and adaptive beamforming methods are examined with synthetic data to demonstrate the limitations on the directional spectrum results. The principle result of this work is that no stable horizontal multipath is …
-
Novel decoupling networks for small antenna arrays
… like diversity reception, MIMO technique, adaptive beamforming or nulling, and direction finding. In the case of size-limited platforms, multiport antenna arrays have element spacing significantly smaller than half wavelength. A small element spacing introduces strong mutual coupling …
-
Improved broadband adaptive beamformer performance
… of active interference suppression. Broadband adaptive beamforming is one such technique which may be used to suppress interference by spatial and spectral filtering of the signals received by an array antenna. The hardware requirements of adaptive Beamforming systems are high in comparison to …
Page 1 of 2