Question

General Introduction of IIR & FIR filters and their applications in telecommunication industry.

Answer 1

IIR Filters:

Infinite imulse response filters are filters that use current and past input sample values along with past output sample values to obtain the current output sample value. The transfer fuction of IIR filters have Both zero and Poles . The IIR filters as the name suuggest have infinte imulse response and so are not stable due to their recursive nature . Since they involve both poles and zeroes , they have more coefficents to be designed and hence consmes more power. But they are More efficient as they have less delay and also have higher sesnsitivity.

FIR Filters:

Finite impulse response filters uses only the current and past input digital samples to get the current output sample value . Their transfer fuction have only zeroes and need more memory for implementation . Due to their finite impulse response , they are stable and have non recursive nature . Also their Design Coefficients are less than IIR and so they consume less power . They are preferrred due to their LINEAR PHASE RESPONSE . They are less efficient  and more delay with much lower sensitivity.

APPLICATION IN TELECOMMUNICATION:

They are used in the Transmitter and Reciever unit of the communication devices for removing the noise , acheiving the signal required frequency response so that it can suitably modulated and demodulated during the process of communication.

They are often employed in the digital communcation systems to preocees out the digital signals . They are integral part of the sampling and decimation systems used in communication modules for communicating the signal . They can also be used to select out specifc output Signal from ADC unit of communcation transmitter or reciever for user requied operation.