DSP called digital signal processing is basically nothing but modified form of analog signals which is going to under operation through quantizer, processors etc. Here three steps are involves in digital processing of analog signals : a) In first step analog signals is digitized and after that sampled and each sample quantized changed into finite number of bits and it is called analog-digital conversion. b) In second step each signals which digitized samples are done by the digital signal processors. c) Output signals can be converted back into the analog signal by the device digital-analog converter.
the whole process is basically called mathematical signal representation in digital domain. Here some basic needs of digital signal processing such as, Signals are sensitive to environmental changes, Ageing, In production unit performance are uncertain, variations are shown in performance unit, system is very expensive, scalability.