Exfo PSO-200 Optical Modulation Analyzer Manual do Utilizador Página 263

  • Descarregar
  • Adicionar aos meus manuais
  • Imprimir
Vista de página 262
Measurement Definitions
Optical Modulation Analyzer 255
Measurements for Constellation Charts
Quadrature-Phase Error
The quadrature-phase error (EQ) is the rms deviation of the Q component
of the error vector, denoted Q in the graph. It is calculated according to:
given in percent to the magnitude of the longest reference vector.
IQ Offset
The IQ offset measures the signal constellation DC offset from origin of the
constellation chart. Its value is given in dB units according to:
The following diagram illustrates a signal with IQ offset and the
corresponding ideal reference vectors.
EQ
rms
1
N
----
Q
meas
n() Q
ref
rn()

2
n 1=
N
100 %rms=
IQ
offset
20
1
N
----
I
meas
n()
2
n 1=
N
1
N
----
Q
meas
n()
2
n 1=
N
+log dB=
Vista de página 262
1 2 ... 258 259 260 261 262 263 264 265 266 267 268 ... 284 285

Comentários a estes Manuais

Sem comentários