This thesis is concerned with the processing of time domain signals received by a single sensor. An example of such signals is the radar return, which is used in one way or another to estimate the power spectral density a frequency representation of the power of the signal in order that we can pick up and track the moving targets. since the POWER SPECTRAL DENSITY ESTIMATION is a fundamental tool in digital signal processing, the theory of the different approaches to PSDE is given in the Literature review chapter. The aim of this research is to develop a technique for the Power Spectral Density Estimation (PSDE) of multiple signals in white noise, which has high resolution capability and less frequency estimation errors. Hence, the various techniques mentioned above are tested for their detection, resolution capabilities and performance. Finally the different parameters affecting the resolution and detection capabilities of the Eigen Vector Decomposition Techniques (EVDT) for PSDE are studied in some depth.

No description available.

This thesis describes the design and implementation of a positional-control scheme for a limited angle torque motor, using a digital signal processor (DSP).

No description available.

No description available.

This thesis proposes an implementation of a DSP-Based single-phase small-scale photovoltaic energy conversion system. The conversion system converts dc power generated by photovoltaic cells into ac power. A digital signal processor and a combined circuit with push-pull and full-bridge architectures are used in this study to reduce the complexity of the circuit design. Several operation and protection functions, such as maximum power point tracking, over/under voltage protection, over current protection, over/under frequency protection and detection of islanding operation are considered in the design. The operation performance of the conversion system at different stages is analyzed. The proposed conversion system can supply the local loads and feed excess power to the utility network with unit power factor (grid-connection mode), or it can supply loads exclusively (stand-alone mode). The simulation and experimentation results are presented and discussed to show the performance of the photovoltaic system and verify the feasibility of the proposed energy conversion system.

Thesis (M. Phil.)--University of Hong Kong, 1989.

The dissertation presents the design and development of a systematic signal analysis and representation framework beyond short-time Fourier power spectrum for sounds, in particular environmental sounds. This framework is consistent with the underlying assumptions of the analysis method and its elements are correlated with human perception. The sound signal has to conform to certain conditions for its power spectrum to have a physical and perceptual meaning. We contend that very few environmental sounds readily meet these criteria and argue that the quantities that are traditionally used to describe sounds need to be repurposed and, if necessary, redefined to represent sounds by non-Fourier means. We propose a perceptuo-analytic organization of sounds so that any environmental sound can be analyzed based on its signal characteristics and perception. We present environmental sound acquisition in the context of collection and annotation of a database for the footstep sounds, a common environmental sound, and show that it can be represented by these unconventional means and further analyzed to produce descriptions which are obscured with the traditional analysis. We present a novel application of extracting gait characteristics from the footstep sounds which is enabled by the proposed framework.

No description available.

Digital Signal Processors (DSPs) have evolved to a level where it is feasible for digital modems with relatively low data rates to be implemented entirely with software algorithms. With current technology it is still necessary for analogue processing between the RF input and a low frequency IF but, as DSP technology advances, it will become possible to shift the interface between analogue and digital domains ever closer towards the RF input. The software radio concept is a long-term goal which aims to realise software-based digital modems which are completely flexible in terms of operating frequency, bandwidth, modulation format and source coding. The ideal software radio cannot be realised until DSP, Analogue to Digital (A/D) and Digital to Analogue (D/A) technology has advanced sufficiently. Until these advances have been made, it is often necessary to sacrifice optimum performance in order to achieve real-time operation. This Thesis investigates practical real-time algorithms for carrier frequency synchronisation, symbol timing synchronisation, modulation, demodulation and FEC. Included in this work are novel software-based transceivers for continuous-mode transmission, burst-mode transmission, frequency modulation, phase modulation and orthogonal frequency division multiplexing (OFDM). Ideal applications for this work combine the requirement for flexible baseband signal processing and a relatively low data rate. Suitable applications for this work were identified in low-cost satellite return links, and specifically in asymmetric satellite Internet delivery systems. These systems employ a high-speed (>>2Mbps) DVB channel from service provider to customer and a low-cost, low-speed (32-128 kbps) return channel. This Thesis also discusses asymmetric satellite Internet delivery systems, practical considerations for their implementation and the techniques that are required to map TCP/IP traffic to low-cost satellite return links.