A project report sUbmitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering. Sandtoh, 1995. / Amplitude modulation, is the oldest modulation technique used for voice communication.It is the simplest and cheapest way to modulate and demodulate voice, and as a result, it did not lose much popularity in spits of the development of other, more efficient modulation technique. This project offers a new approach for AM demodulation. The two sidebands are separated and divided into many su-bands. The signals with the lowest noise level are solected and thier levels are individually adjusted according to signal conditions. The result is reduction of over 35 dB in continuous interference and about 15 dB in whit noise level. The new detector and about out-performs the conventional detectors in all aspects and can be used in applications where top performance is required and where mone is no object.

No description available.

Thesis (M.S.)--Brigham Young University. Dept. of Audiology and Speech-Language Pathology, 2006. / Includes bibliographical references (p. 79-84).

Thesis (M.S.)--Oregon State University, 2004. / Typescript (photocopy). Includes bibliographical references (leaves 43-44). Also available on the World Wide Web.

Thesis (Ph. D.)--Brigham Young University. Dept. of Electrical and Computer Engineering, 2005. / Includes bibliographical references (p. 137-141).

The majority of fundamental research on wave-driven sediment transport has been based on regular waves and regular oscillatory flows. Systematic research into isolating the effect of irregularity on oscillatory boundary layer hydrodynamics and sand transport are not presently available. This research reports on large-scale oscillatory flow tunnel experiments designed to isolate the effect of flow irregularity (specifically amplitude-modulated flows) on oscillatory flow boundary layer hydrodynamics and net sand transport rates. Two main series of experiments - one focussing on the hydrodynamics of amplitude-modulated flows over a fixed (immobile) bed and a second focussing on the sediment transport over mobile sand beds – were conducted. Detailed boundary layer velocity measurements are presented for regular and amplitude-modulated oscillatory flows over two fixed rough beds, coarse sand and gravel. The results show that amplitude-modulation of the flow has a variable effect on the hydrodynamic behaviour of the oscillatory boundary layer: the broad conclusion is that time-history effects are not significant near the bed but become more significant higher in the flow. Net transport rate measurements are presented for regular and amplitudemodulated flows for two mobile sand beds, medium and fine sand. The mobile bed experiments show that: for medium sand, net transport rates are similar for the amplitude-modulated and equivalent regular; for fine sand, net transport rates are very different for the amplitude-modulated and equivalent regular flows. The SANTOSS model-predicted sand transport rates shows that the model correctly predicts the net transport for the present experimental conditions, indicating that the major unsteady transport processes are captured in the model. The SANTOSS model is used to compare net transport rates for equivalent regular and amplitude-modulated flows across a wide range of flow conditions and two sand sizes. The results show good agreement in net transport rate between equivalent regular and amplitude-modulated flows, for conditions in which phase lag effects are weak and poor agreement when phase lags effects are strong.

To Kin Fai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 99-104). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Multi-carrier Communication Systems --- p.1 / Chapter 1.2 --- Objective of the Thesis --- p.4 / Chapter 1.3 --- Thesis Outline --- p.5 / Chapter 2 --- Wavelet Packet Division Multiplexing (WPDM) --- p.7 / Chapter 2.1 --- "Wavelets, Wavelet Packets and Multiresolution Analysis (MRA)" --- p.8 / Chapter 2.2 --- Application of Wavelet Packets in Multiple Signal Transmission --- p.14 / Chapter 2.3 --- Summary --- p.20 / Chapter 3 --- Nonlinear System Theories --- p.22 / Chapter 3.1 --- Characteristics of Memoryless Nonlinearities --- p.23 / Chapter 3.1.1 --- Memoryless Baseband Nonlinearities --- p.23 / Chapter 3.1.2 --- Memoryless Bandpass Nonlinearities --- p.24 / Chapter 3.2 --- Volt err a Series for Nonlinearities with Memory --- p.26 / Chapter 3.2.1 --- Baseband Nonlinearities with Memory --- p.26 / Chapter 3.2.2 --- Bandpass Nonlinearities with Memory --- p.27 / Chapter 3.3 --- High Power Amplifier (HPA) Models --- p.28 / Chapter 3.3.1 --- Traveling Wave Tube Amplifier (TWTA) --- p.28 / Chapter 3.3.2 --- Solid State Power Amplifier (SSPA) --- p.28 / Chapter 3.3.3 --- Input and Output Backoff Ratios --- p.29 / Chapter 3.4 --- Summary --- p.29 / Chapter 4 --- WPDM in the Presence of Amplifier Nonlinearities --- p.30 / Chapter 4.1 --- System Model --- p.31 / Chapter 4.2 --- Derivation of Channel Models --- p.32 / Chapter 4.2.1 --- Single-carrier WPDM --- p.32 / Chapter 4.2.2 --- Multi-carrier WPDM --- p.34 / Chapter 4.3 --- Performance Analysis --- p.35 / Chapter 4.3.1 --- Conditional Mean --- p.36 / Chapter 4.3.2 --- Conditional Variance --- p.41 / Chapter 4.3.3 --- Power Spectral Density (PSD) --- p.44 / Chapter 4.4 --- Probability of Symbol Error --- p.48 / Chapter 4.5 --- Simulation Results --- p.52 / Chapter 4.6 --- Summary --- p.56 / Chapter 5 --- Nonlinear Compensation (The pth-Order Inverse) --- p.57 / Chapter 5.1 --- Data Predistortion --- p.58 / Chapter 5.2 --- Predistorter Structure --- p.62 / Chapter 5.3 --- Complexity --- p.63 / Chapter 5.4 --- Simulation Results --- p.66 / Chapter 5.5 --- Summary --- p.78 / Chapter 6 --- Conclusions and Suggestions for Future Research --- p.79 / Chapter 6.1 --- Conclusions --- p.79 / Chapter 6.2 --- Suggestions for Future Research --- p.82 / Appendices --- p.83 / Chapter A --- Derivation of (4.14) --- p.83 / Chapter B --- Derivation of (4.16) --- p.85 / Chapter C --- Evaluation of higher order expectations --- p.86 / Chapter D --- Derivation of φ ss(T) in (4.32) --- p.90 / Chapter E --- Derivation of φsi(T) in(4.32) --- p.93 / Chapter F --- Derivation of φ is(T) in (4.32) --- p.95 / Chapter G --- Derivation of φii(T) in (4.32) --- p.97 / Bibliography --- p.99

No description available.

Researchers previously have found a correlation between the strength of the auditory steady-state response (ASSR) and corresponding auditory behavioral measurements such as speech recognition scores, thus concluding that the ASSR can be used as an objective measurement of auditory supra-threshold properties. In the present study, it was hypothesized that the increase in the strength of the ASSR at different modulation depths would be reflected in corresponding psychophysical measures, specifically, auditory modulation discrimination. These relationships were investigated in normally-hearing listeners at modulation rates of 40 and 80 Hz for both amplitude (AM) and mixed modulation (MM), at several modulation depths. Analyses were completed for two sets of measurements derived from the physiological and behavioral responses. For the first analysis, derived measures of iso-neurometric thresholds were compared to isometric modulation discrimination thresholds. For the second analysis, derived estimates of physiological neurometric slope were compared to estimated psychometric function slopes. Mixed-model analyses for both of these measures revealed significant or near-significant relationships between physiological and psychophysical measures at 40 Hz for AM and at 80 Hz for MM. Bootstrap resampling analyses were completed to estimate the distribution of the resultant statistics. Implications regarding the location of neural encoding for amplitude and frequency modulation were discussed. / text

published_or_final_version / Chemistry / Master / Master of Philosophy