Specifications

Maxiva UAX
October 17, 2013
3‐93
888‐2693‐004 WARNING:Disconnectprimarypower priortoservicing.
Copyright©2013,HarrisBroadcast
Figure 3-88 LPU CTTB Modulator Status Screen 3
Table3‐84XmtrHome>ExciterHome>Status>CTTBModulator>Next(screen2)
Field Explanation
OutputBan
dwidth DisplaysRFOutputbandwidth.Presentlyfixedat8MHz.Futureoptionsare7MHz,6MHzor5MHz.
Carriers
Displaysthenu
mberofRFcarriersintheoutputsignal.Pre sentvaluesareMulti,Single,orTwoPilot.
Multi=COFDMtypemodulation,Single=singlecarriermodulationsystem,TwoPilot=singlecarrier
modulationmodewithtwopilots
GuardInt
erval
Displaysthegu
ardintervaltime.PresentlyfixedatPN595(1/6).OptionsarePN945(1/4),PN595
(slightlylessthan1/6),orPN420(1/9).Thisisthelengthoftheguardintervalinsymbols.Thetotal
framelengthis3780symbols.Guardintervalistheguardintervalsymbollengthdividedbythetotal
sym
bollength.Example:945/3780=1/4.
GuardIntervalPN
Displaysoptions,whi
charevariableorconstant.ConstantonlyusedwithPN595,Variableisusedwith
PN945andPN420
Constellation Displaychoice
sare4QAM,16QAM,32QAM,or64QAM.
LDPCRa
te
Displayvaluesare0.4(2/5),0.6,(3/5)or0.8(4/5).TheLDPCRateprovidesthreeratesofforwarderror
correction.Thedecimal,orfraction,givestherelativeefficiencyoftheforwarderrorcorrectionby
dividingtheinformationbitsbythetotalblocklength.Forexample,blocklength=7488bits,
informationbit
s=3008,therefore:3008/7488=0.4or2/5.Thisindicatesthattherearetwo
informationbitsforeveryfiveoutputbits.
TimeInterleaver
Displayva
luesare240or720symbols.Thisisadataconvolutionalinterleaver.Thedataisinterleaved
toadepthof240or720symbols.
Table3‐85XmtrHome>ExciterHome>Status>CTTBModulator>Nextx2(screen3)
Field Explanation
Time
OutputProcessTime
Thisisadisplayofthethroughputdelay,measuredafteritleavestheex citernetworkdelaycircuit
andtravelstotheoutputofthetransmitter.Thisdelayisimportantifthenetworkconsistsof
transmittersfromdifferentmanufactures,wheretheoutputprocesstimewillchangefromone
manufacturertoan
other.
LocalDelayAdjust
Thisisadisplayoftheoffsettime,whichisused,alongwithotherdelays,tocalculatetheexciter
datastoragetime.Itisneededtosynchronizethedataarrivalatthesinglefrequencynetwork
overlapzonewhenitisnotlocatedatthegeographiccenteroftwoormoretransmitt
ers.