Signal Processing- An Introduction

Signal Processing is a field of applied mathematics and Engineering, it deals in analysing signals in both discreet and continuous time. Whereas Digital Signal Processing is concerned with analyzing discrete time signals by a sequence of numbers or symbols. The DSP aims at measuring, filtering and compressing the analog signals.

The signal processing is divided under various sub heads, such as:

Analog Signal Processing: It is for signals that have not been digitized , it involves both linear electronic circuits and non linear circuits.

Discrete Time Signal Processing: It is for sampled signals that are considered definite at discrete time intervals, and can only be quantized in time and not magnitude.

Digital Signal Processing: It involves processing of digitized discrete time signals. A continuously changing wave form is converted into a series of different levels.

Converting Analog Signals into Digital Signals

Analog to Digital Converter

The device used for converting Analog to Digital signals is called Analog to Digital Converter (ADC). The simplest ADC uses resistance ladder to switch in the appropriate number of resistors in series to create the desired voltage that is compared to the input voltage. The output of the resistance ladder is compared to the analog voltage in a comparator when there is a match, the digital equivalent is captured.

An important application of Analog to Digital conversion is Binary search, which depends upon:

• The clock speed of ADC
• The BIT Resolution

Typical DSP operations include:

• Filtering
• Energy of Signals
• Frequency Transformation

Currently DSP is used in a wide variety of everyday application like:

• Speech Coding
• Image/Video Synthesis
• Adaptive Filtering
• Image Analysis
• RADAR/SONAR
• Data Transmission and Reception     

Digital Signal processing is usually implemented with the help of microprocessors, which process the data using fixed point arithmetic. Nowadays a growing number of DSP applications are being implemented on Embedded systems using powerful PCs with multi core processors.