Undersampled Polyphase Filter Bank

1. What is a polyphase filter bank?
2. Why polyphase filter is used?
3. How many types of filter banks are there?
4. What is polyphase decomposition in DSP?

What is a polyphase filter bank?

A polyphase quadrature filter, or PQF, is a filter bank which splits an input signal into a given number N (mostly a power of 2) of equidistant sub-bands. These sub-bands are subsampled by a factor of N, so they are critically sampled.

Why polyphase filter is used?

The polyphase FIR filter realization can provide advantages in computational efficiency when used for decimation or interpolation of discrete time signals.

How many types of filter banks are there?

There are two main types of filter banks. An analysis filter bank and a synthesis filter bank.

What is polyphase decomposition in DSP?

Polyphase Decomposition. The multirate operations of decimation and interpolation that were introduced. in the previous section will now be used to decompose any system function. H(z) into its polyphase representation. Consider a discrete–time LTI system.