Introduction to Digital Signal Processing 1.1 What is DSP DSP is a technique of performing the mathematical operations on the signals in digital domain. As real time signals are analog in nature we need first convert the analog signal to digital, then we have to process the signal in digital domain and again converting back to analog domain. Thus ADC is required at the input side whereas a DAC is required at the output end. A typical DSP system is as shown in figure 1.1.
Digital Signal Processor
DAC Output Signal
Fig 1.1 A Typical DSP System 1.2 Need for DSP Analog signal Processing has the following drawbacks They are sensitive to environmental changes Aging Uncertain performance in production units Variation in performance of units Cost of the system will be high Scalability If Digital Signal Processing would have been used we can overcome the above shortcomings of ASP. 1.3 A Digital Signal Processing System A computer or a processor is used for digital signal processing. Antialiasing filter is a LPF which passes signal with frequency less than or equal to half the sampling frequency in order to avoid Aliasing effect. Similarly at the other end, reconstruction filter is used to reconstruct the samples from the staircase output of the DAC Figure 1.2 .
Fig 1.2 The Block Diagram of a DSP System Signals that occur in a typical DSP are as shown in figure 1.3.