1、April 2013 IEC/TR 61282-10 (First edition 2013) Fibre optic communication system design guides Part 10: Characterization of the quality of optical vector-modulated signals with the error vector magnitude CORRIGENDUM 1 4.2 Normalization of the measured data Replace the existing text of the second par
2、agraph by the following new text: The normalization factor is chosen to match the measured vectors to the reference by first finding the value of a scaling factor for the reference vectors that minimizes the corresponding unnormalized EVM rmswithout changing the distribution of the measured vectors.
3、 Then the inverse of is used as to scale the measured vectors to the normalized reference. For this purpose, the unnormalized EVM rmsis expressed as ( ) ( ) ( ) ( ) = = = n Q n I n n N U N n r(n) meas meas meas 1 2 meas refwhere 1 S S S (6) The value of that gives minimum U is determined by solving 0 = U(7) leading to ( ) ( ) ( ) = = + + = = N n n r ref n r N n n r n r n Q Q n I I Q I 1 meas ) ( meas ) ( ref 1 2 ) ( ref 2 ) ( ref 1 (8)
