Yi.= y Sir Xie + » Gigs AOpeP 3 00 9 y Sika Xk-t-r, 
T=-@ T=-@ T=-O 
lee) 
Se he > Bik Xki-z> i=1to/. (2.177) 
T=-—0 
or in vector form, 
Y,= ay &: Xp - (2.178) 
T=-0 
[1 x 1] [1 x k] [k x 1] 
Fig. 2.30. Multiple inputs multiple outputs system. 
If the output is expressed by spectral representation, then 
aw 
Yi,= | et gw) i= 1 tol, (2.179) 
1 
where 
dZ°”(w) = G,. (@)dZP(w) +... . +G;_(@)dZP(w) i=1 tol. (2.180) 
2.6.5 Multiple Inputs Single Output Case, Multiple and Partial Coherencies 
A multiple inputs, single output case, as in Fig. 2.31, is a special case of Eq. 2.177. 
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