“…The filter parameters A f , B f , C f , D f in [6,24,26,36,41,43,50] are chosen to estimate x m ðtÞ, x p ðtÞ, which are cannot be used to estimate the signal z m ðtÞ, z p ðtÞ. The filter discussed in this paper of the form (9) and (10) is the same as that in [13,47,52].…”