Tektronix OM4006D, User Manual

Page: 119 / 205

Core Processing function reference
pHyb – 2x4 array (4 column vectors) containing characteristic Jones vectors
of optical hybrid ports, usually obtained by separate calibration
Clock – structure having fi elds (and may have more fi elds) de fi ning the output
time grid:
.t0 – time of fi rst symbol
.dt – symbol duration BoundValsIn – structure of boundary values from
previous block
AlertsIn – structure of alerts accumulated before executing function
p – dual polarization representation of optical signal constructed from scope
records V, retimed to align with Clock
.t0 – time of fi rst symbol
.dt – symbol duration
.Values – 2xN array (row of Jones vectors) of symbol center signal values
BoundValsOut – structure of boundary values to be passed to next block
AlertsOut – structure of alerts including any alerts raised during execution of
function
ClockRetime forms an output parameter p, representing a dual-polarization signal
vs. time, from four oscilloscope waveforms V. The output p is retimed to be
aligned with the timing grid speci
fi ed by Clock. The function is executed in two
steps:
1. The scope waveforms are adjusted for the known relative delays ChDelay
between the four scope channels and retimed to be aligned with Clock.
2. The dual polarization signal (a Jones vector vs. time) is computed, given the
known relative phase and polarizations of the optical hybrid pHyb.
DiffDetection
[v,BoundValsOut,AlertsOut] =
DiffDetection(p,SigType,Delay,CentFreq,BalancedDiffDetection,BoundValsIn,
AlertsIn)
p – single or dual polarization parameter vs. time:
.t0 – time of fi rst symbol
.dt – symbol duration
.Values – 1xN or 2xN array of complex values
SigType – integer value indicating signal modulation format
Delay – positive real value, interferometer delay
OM4000D Series Coherent Lightwave Signal Analyzer 95