Question

Discuss the role digital filters in the modern communication technology

Answer 1

Answer)

-> A filter is used to pass the specific frequency of signal and reject undesired frquency.

-> A filter is a digital filter when it does processing of  discrete signal available at input. A discrete signal is obtained from an analog signal using analog to digital converter (ADC).

  x(nT)=x(t)

-> The response of digital filter is given in terms of difference equations like

a_ky(n-k) =    b_kx(n-k)

Where y[n] is discrete output and x[n] is discrete input.

Main example of digital filters are

1. Infinite Impulse Response (IIR) filter 2. Finite Impulse Response (FIR) filter

-> Now a days with the advancement of technology the importance of digital filter is increasing day by day because with the advancement of technology in communication the device size also getting smaller and smaller where analog filter are not suitable for the choice.

-> Digital filter can be  designed in VHDL and implemented on FPFA easily which requires very small area as compare to conventional analog filter.

-> Main benefits of digital filter in communications are

1. Easily designed and implemenation

2. Accuracy is high for low frequency signal

3. Digital filter behavior is adaptive i.e accoding to input signal the response of filter changes.

4.Harware requirement is simple and compact as compare to conventional analog filter.

5. These filter are more stable in term of temperature and time as conventional analog filter component has aging effect.