I need to resample my signal from 44100 hZ to 8000 hZ with similar method that Matlab does. As Matlab's help description says that resample method uses polyphase implementation:
resample Change the sampling rate of a signal.
Y = resample(X,P,Q) resamples the sequence in vector X at P/Q times
the original sample rate using a polyphase implementation. Y is P/Q
times the length of X (or the ceiling of this if P/Q is not an integer).
P and Q must be positive integers.