Introduction to Circular Convolution and Filtering with the DFT

Multiplication of DFT coefficients for two signals corresponds to

Multiply the $N$ DFT coefficients for two signals of length $N$ and take an inverse $N$ point DFT. The result is length

The linear convolution of a length 100 signal with a length 50 signal is a signal of length

Which of the following DFT lengths can be used to compute the linear convolution of two signals of length 128? Select all that apply.