upsample This function upsamples the signal, inserting n-1 zeros between every element. y = upsample (x, n) y = upsample (x, n, phase) x: scalar, vector or matrix of real or complex numbers n: real number or vector phase: integer value, 0 <= phase <= (n - 1 ), default value 0, or logical This is an Octave function. This function upsamples the signal, inserting n-1 zeros between every element. If x is a matrix, every column is upsampled. The phase determines the position of the inserted sample in the block of zeros. The default value is 0.