Search for dissertations about: "narrow-band interference"

Showing result 1 - 5 of 7 swedish dissertations containing the words narrow-band interference.

2. 1. Interference Rejection in Wireless Communication Systems

   Author : Anders Ranheim; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; direct-sequence spread spectrum; parameter estimation; multi-user detection; antenna array processing; iterative minimization; interference rejection; finite alphabet; order detection; signal structure; narrow-band interference;

   Abstract : This thesis is concerned with the problem of interference rejection in wireless communication systems. Different solutions are proposed, depending on the type of system under study and the amount of knowledge available about the signal and the propagation environment. READ MORE

4. 2. Towards dynamic array processing for GNSS software receivers

   Author : Staffan Backén; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Industriell elektronik; Industrial Electronics;

   Abstract : Since the very first Global Positioning System satellite was launched in 1978, Global Navigation Satellite Systems (GNSS) have developed into a world wide utility, providing everyone with an affordable method for determining accurate position and time. However, the system is susceptible to multipath (when the signal is reflected off a surface), interference (other signals in the same frequency band) and attenuation (for example canopies blocking some of the signal energy). READ MORE

5. 3. Subspace-Based Parameter Estimation Problems in Signal Processing

   Author : Joakim Sorelius; Torsten Söderström; Peter Stoica; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sensor array processing; parameter estimation; spread spectrum communication; direct sequence CDMA; order estimation; subspace fitting; blind identification; system identification; Signal Processing; Signalbehandling;

   Abstract : The effects of multipath-induced angular spread and non-zero band-width on narrow-band direction-of-arrival (DOA) estimation are investigated. In both cases expressions for the resulting estimation error are developed for the MUSIC, ESPRIT and WSF DOA estimators. READ MORE

6. 4. The Auroral Large Imaging System : design, operation and scientific results

   Author : Urban Brändström; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; Aurora; Artificial airglow; HF-pump enhanced airglow; Multistation measurements; Polar Stratospheric clouds; Radio-Induced optical emissions; Spectroscopic imaging observations; Tomography; Rymd- och plasmafysik; Space physics; Rymdfysik; rymdfysik; Space Physics;

   Abstract : The Auroral Large Imaging System (ALIS) was proposed in 1989 by Åke Steen as a joint Scandinavian ground-based nework of automated auroral imaging stations. The primary scientic objective was in the field of auroral physics, but it was soon realised that ALIS could be used in other fields, for example, studies of Polar Stratospheric Clouds (PSC), meteors, as well as other atmospheric phenomena. READ MORE

7. 5. Subband Beamforming for Speech Enhancement in Hands-Free Communication

   Author : Zohra Yermeche; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Beamforming; Speech enhancement; Subband filtering;

   Abstract : Speech enhancement by means of microphone array signal processing has a major role in voice communication applications such as audio-conferencing, hands-free telephony, voice recognition and hearing aids. In these communication scenarios, the speaker is positioned at a remote distance from the microphones, which causes problems of environment noise and interfering sound corrupting the received speech. READ MORE