Polyphase filter tutorial

1. How does a polyphase filter work?
2. Why use polyphase filter?
3. What is polyphase in DSP?
4. What is polyphase interpolation filter?

How does a polyphase filter work?

A polyphase filterbank uses the DFT (discrete fourier transform) to modulate (move in frequency) a prototype filter and perform summation, effectively returning multiple bands of decimated and filtered time-domain data from the DFT stage. The DFT operation is typically performed using the FFT (fast fourier transform).

Why use polyphase filter?

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

What is polyphase in DSP?

Polyphase is a way of doing sampling-rate conversion that leads to very efficient implementations. But more than that, it leads to very general viewpoints that are useful in building filter banks.

What is polyphase interpolation filter?

With the modified implementation, the input samples to the filter is clocked at the original sampling rate of . However, we need to have additional circuitry to dynamically load the coefficients and latch the output at the upsampled frequency . These filtersets are called polyphase filters.