Frequency resolution improvement by sub-bins and an inverse matrix in discrete Fourier transform.

We proposed a method to use sub-bins (SBs) and the inverse matrix to reduce the spectral leakage in discrete Fourier transform (DFT) over the conventional spectral resolution. SBs were assigned between two conventional bins. Utilizing the real signal, the process reproducing complex amplitudes at each SB was described and confirmed through simulations with the pseudo-inverse matrix.