€; + Ci €44 + Cr2r€12 0 0 6 5R Cle 1 =€;, (6.4) 
€, being a pure random process. 
From Eq. 6.2 
lee) 
€; =Y, - yy Su Gens, (6.2’) 
u=0 
€n =Ypi- »y Ln Gein. (6.5) 
u=0 
Inserting these values into Eq. 6.4 gives, where 1] — 
Mig y, Bu Xrup + C149 Yr — » Su X1-u ¢ + C24 Yi-2 — y Bu X21 
u=0 u=0 u=0 
+...4+C) Gn SS ay ey shay rie = €;, (6.6) 
u=0 
or 
Y,+ CY) + C2Y;_2 tec: + Ci 1-1 Sy ten 
- > {au Xiu st Ci 8u Xiu + G3 8u X-2-u WP 610 6 
u=0 
+ C 8u Xiu + ne .} = €;, (6.7) 
Or 
YS Gp 4S > bu > Cr Xr + € 
1=0 u=0 =—«1=0 
= y Dena G; Xp + €;. (6.8) 
u=0 I=0 
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