I am fairly new to DSP and RF receivers in general, and I was recommended to read Gardner's original paper for symbol timing error recovery for QPSK signals.
I have a question regarding an equation for early-late gates; in the following picture, why is
L(r-1) equal to
x^2((r-5/4)*T)? It seems to me that it should be
x^2((r-3/4)*T). Am I missing something?
Also, intuitively, if the spacing for the Early and Late is 1/4 each, then the spacing between Early and Late should be
2 * 1/4 T = 1/2 T, not
1 * T.