Radwin 2000 C PLUS

RADWIN2000CPlusUserManual Release3.5.70 E‐1
AppendixE:
SettingAntennaParameters
AntennaIssues
ThechoiceofTxPower,antennagainandcableloss(betweentheradioandtheantenna)
determinestheEIRPandisaffectedbysuchconsiderationsasradiolimitationsandregulatory
restrictions.
Beforeproceedingtoantennainstallationdetails,thefollowingbackgroundinfo rmation
shouldbeconsidered:
AboutSingleandDualAntennas
EachRADWIN2000CPlusODUismadeoftworadiotransceivers(radios).Theradiosmake
useofalgorithmsthatutilizebothSpatialMultiplexingandDiversityresultinginenhanced
capacity,rangeandlinkavailability.Thenumberofantennas(i.e.radios)usedisdetermined
byuserconfigurationandbyautomaticsystemdecisions,
explainedbelow.
DualAntennasattheHBSandanHSU
Whenusingdualantennasatbothsites(singlebipolarantennaortwomo‐unipolarantennas)
youcanchoosebetweenSpatialMultiplexingModeandDive rsityMode.
SpatialMultiplexingMode
Underthismode,thesystemdoublesthelinkcapacity.Atthesametime,itkeepsthesame
rateandmodulationperradioaswasusedwithsingleantenna,thusincreasingcapacity,
rangeandavailability.
ForexamplewithadualantennaRADWIN2000CPluscantransmitatmodulationof64QAM
andFECof5/6 andgetanairrateof130Mbps,comparedto65Mbpswithsingleantenna.
Toworkinthismode,eachantennaportmustbeconnectedtoanantenna,theRSSlevelin
bothreceiversshouldbebalancedandaminimalseparationbetweentheantennasmustbe
maintained.(Forexample,byusingdualpolarizationantennasacrosspolarizationseparation
isattained).