Utility functions

convolve(inp, ker[, padding, axis, precision])	Filters an input inp of length N by convolving it with a kernel ker of length K.
fft(tensor[, axis, precision])	Computes the normalized DFT along a specified axis.
ifft(tensor[, axis, precision])	Computes the normalized IDFT along a specified axis.
empirical_psd(x[, show, oversampling, ylim, ...])	Computes the empirical power spectral density.
empirical_aclr(x[, oversampling, f_min, ...])	Computes the empirical ACLR.
Upsampling(samples_per_symbol[, axis, ...])	Upsamples a tensor along a specified axis by inserting zeros between samples.
Downsampling(samples_per_symbol[, offset, ...])	Downsamples a tensor along a specified axis by retaining one out of samples_per_symbol elements.