Radwin 2000 C PLUS - Diversity Mode

RADWIN2000CPlusUserManual Release3.5.70 E‐2
SingleAntennasatBothSites ChapterE
UponselectingAntennaTypeasDual,RADWIN2000CPlusautomaticallyselectsthismode
anddoublestheairrates.
RADWINManagerindicatesacaseofunbalancedRSSbetweenthetwoantennasintheHBS
panels.
DiversityMode
Divers ityModeusestwoantennastoimprove thequalityandreliabilityofthelink.Often,
thereisnotaclearline‐of‐sight(LOS)betweentransmitterandreceiver.Insteadthesignalis
reflectedalongmultiplepathsbeforefinallybeingreceived.
Eachsuch“bounce”canintroducephaseshifts,timedelays,attenuations,andeven
distortionsthatcandestructivelyinterferewithoneanotherattheapertureofthereceiving
antenna.Antennadiversityisespeciallyeff ectiveatmitigatingthesemulti‐pathsituations.
Thisisbecausemultipleantennasaffordareceiverseveralrecordingsofthesamesignal.Each
antennawillbeexposedtoadifferentinterferenceenvironment.Thus,ifoneantennais
undergoingadeepfade,itislikelythatanotherhasasufficientsignal.Collectivelysucha
systemcanprovidearobustlink.
Antennadiversityrequiresantennaseparationwhichispossiblebyusingadual‐polarization
antennaorbytwospatiallyseparatedantennas.
UseDiversityinsteadofSpatialMultiplexinginthefollowingsituations:
• WhenthesystemcannotoperateinSpatialMultiplexingMode
• Whenoneofthereceivershashighinterferencecomparedtothesecondreceiver(i.e.
thesystemis“unbalanced”)
• WhenyouachievehighercapacityinDiversityModethaninSpatialMultiplexingMode
• WhenhighrobustnessisofimportanceandthecapacityofDiversityModeissufficient
(upto25Mbpsfullduplex)
SingleAntennasatBothSites
ByselectingasingleantennaattheHBSandHSU,theODUsoperatewithasingleradiothatis
connectedtotheANT1connector.Thesecondradioisautomaticallyshutdown.
SingleatOneSite,DualAntennasattheOther
InthismodeoneofthesitesusestheODUwithasingleantennawhiletheothersiteusesthe
ODUwithadualantenna.
Theadvantagesinthismodeincomparisontousingasingleantennainbothsitesare
doubledtotalTxPowerandadditionalpolarizationand/orspacediversity(dependingonthe
polarizationofinstalled antennas).
Theairratesusedinthismodearesameaswhenusingsingleantennasinbothsites.