What is DSP?

DSP, or Digital Signal Processing, as the term suggests, is the processing of signals by digital means. A signal in this context can mean a number of different things. Historically the origins of signal processing are in electrical engineering, and a signal here means an electrical signal carried by a wire or telephone line, or perhaps by a radio wave. More generally, however, a signal is a stream of information representing anything from stock prices to data from a remote-sensing satellite. The term "digital" comes from "digit", meaning a number (you count with your fingers - your digits), so "digital" literally means numerical; the French word for digital is numerique. A digital signal consists of a stream of numbers, usually (but not necessarily) in binary form. The processing of a digital signal is done by performing numerical calculations.

DIGITAL SIGNAL PROCESSING

Digital Signal Processing illuminates and explores the path of creativity in the field of signal processing. The journal publishes a diverse content of original research articles and reviews, covering new technologies, significant new programs, and breakthroughs in the field. Each article is critically peer-reviewed, ensuring top-quality research and information.

The journal is a time-saving aid to electronic engineers and to researchers, scientists, and corporate managers who want to keep abreast of vital research and information that is typically scattered among a number of separate publications.

Digital signal processing, a discipline that spans electrical engineering, computing, mathematics and the physical sciences, includes applications such as:


• Image processing
• Neural networks
• Pattern recognition
• Digital communications
• Biomedical applications
• Speech processing
• Underwater acoustics
• Radar signal processing
• Astronomy
• Geophysical data analysis

Papers published are categorized in the following disciplines:


• General methods (filters, filtering, etc.)
• Data Analysis
• Multichannel & multidimensional signal processing
• Speech and audio processing
• Image and multimedia processing
• Communications
• Implementation, design, and hardware
• Statistical signal processing
• Pattern recognition
• Information fusion
• Emerging techniques
• Education

ANALOG AND DIGITAL SIGNALS

In many cases, the signal of interest is initially in the form of an analog electrical voltage or current, produced for example by a microphone or some other type of transducer.
In some situations, such as the output from the readout system of a CD (compact disc) player, the data is already in digital form. An analog signal must be converted into digital form before DSP techniques can be applied. An analog electrical voltage signal, for example, can be digitised using an electronic circuit called an analog-to-digital converter or ADC.
This generates a digital output as a stream of binary numbers whose values represent the electrical voltage input to the device at each sampling instant.

SIGNAL PROCESSING

Signals commonly need to be processed in a variety of ways. For example, the output signal from a transducer may well be contaminated with unwanted electrical "noise". The electrodes attached to a patient's chest when an ECG is taken measure tiny electrical voltage changes due to the activity of the heart and other muscles. The signal is often strongly affected by "mains pickup" due to electrical interference from the mains supply. Processing the signal using a filter circuit can remove or at least reduce the unwanted part of the signal. Increasingly nowadays, the filtering of signals to improve signal quality or to extract important information is done by DSP techniques rather than by analog electronics.