Sökning: "power spectral analysis"

Visar resultat 1 - 5 av 117 avhandlingar innehållade orden power spectral analysis.

1. 1. Variability of blood pressure and heart rate in borderline and mild hypertension : With special reference to spectral analysis

   Författare :Reijo Takalo; Uppsala universitet; []
   Nyckelord :Medical sciences; hypertension; blood pressure; ambulatory monitoring; power spectrum analysis; pulsecontour method; systemic hemodynamics; MEDICIN OCH VÅRD; MEDICINE; MEDICIN; Clinical Physiology; klinisk fysiologi;

   Sammanfattning : The aim of this thesis was to study whether blood pressure (BP) or heart rate (HR) variability in borderline (BHT) and hypertensive (HT) subjects differs from that in normotensive (NT) subjects, and whether indices for BP and HR variability can be used in risk stratification for future hypertension. The study groups consisted of 35 NT, 29 BHT, and 34 HT middle-aged men. LÄS MER

3. 2. Mobile Satellite Broadcast and Multichannel Communications : analysis and design

   Författare :Cristoff Martin; Björn Ottersten; Jack Winters; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; communications; satellite broadcast; mobile; MIMO; asymptotic analysis; spatial multiplexing; Signalbehandling; Signal processing; Signalbehandling;

   Sammanfattning : In this thesis, analytical analysis and design techniques for wireless communications with diversity are studied. The impact of impairments such as correlated fading is analyzed using statistical models. Countermeasures designed to overcome, or even exploit, such effects are proposed and examined. LÄS MER

4. 3. Statistical Analysis of Hardware Impairments in Communication Systems

   Författare :Mohammad Hossein Moghaddam; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hardware impairments; distortion analysis; PA nonlinearity; phase noise; spectral analysis; pulse shaping and matched filter; IQI;

   Sammanfattning : This thesis delves into the study of hardware impairments, the inevitable limiting factors in radio frequency (RF) communication systems, and their substantial influence on system performance. It addresses the incongruity between the often stringent requirements imposed by standards and the innate imperfections of analog circuits present in real-world RF electronics. LÄS MER

5. 4. ROBUST DETECTION AND SPECTRAL ANALYSIS OF SIGNALS WITH APPLICATIONS IN SPECTROSCOPY

   Författare :Naveed Butt; Matematisk statistik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Detection; NQR; NMR; Raman Spectroscopy; Spectral Analysis.;

   Sammanfattning : Modern spectroscopic techniques, such as nuclear quadrupole resonance (NQR), nuclear magnetic resonance (NMR), and Raman spectroscopy, rely heavily on statistical signal processing systems for decision making and information extraction. The first part of this thesis introduces novel robust algorithms for detection, estimation, and classification of signals obtained through these spectroscopic techniques. LÄS MER

7. 5. CALLUM Linear Transmitter - Architecture and Circuit Analysis

   Författare :Roland Strandberg; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Telekommunikationsteknik; Telecommunication engineering; loop time delay; modulation negative feedback; spectral emissions; baseband model; CALLUM; Linear transmitter architecture; power amplifier linearization;

   Sammanfattning : This doctoral dissertation presents a study of linear radio transmitters based on the combined analog locked loop universal modulator (CALLUM) approach. Linear architectures such as CALLUM are very attractive for power-efficient operations, since they have no fundamental limitations prohibiting a 100% efficiency for all envelope levels, without sacrificing the potential of a linear transmission. LÄS MER