In the RAKE receiver illustrated in Figure each correlator is

In the RAKE receiver illustrated in Figure each correlator is synchronized by inserting the right delay into the received signal.
(a) Show that, in theory, the same result is obtained by inserting the right delay into the reference signal (i.e., pseudo-noise sequence).
(b) In practice, the preferred method is to use the procedure described in Figure what reason can you suggest for this preference?