q
H
2
Problem:
find a stabilizing controller K that minimizes
||
T
zw
||
2
q
Let
X
2
and
Y
2
be stabilizing solutions to
q
q
q
q
q
•
There exists a unique optimal controller
•
•
Moreover,
•
min ||
T
zw
||
2
2
=
||
G
c
B
1
||
2
2
+||
F
2
G
f
||
2
2
=
||
G
c
L
2
||
2
2
+||
C
1
G
f
||
2
2