Basic UMTS UnderstandingSymbol Explanation Ec Average energy per Chip Not considered individually, but used or Ec!"o #ilot Ec is $easured by the UE %or &'( or the #ilot scanner, in the or$ o )eceived Signal Code #o*er %)SC#( +or C#"C& Ec, -epends on po*er and path loss. Constant or a given po*er and path loss. Ec is not dependent on load +or -#C& Ec, -epends on po*er and path lossSy$bol E/planationEbAverage energy per inor$ation bit or the #CC#C&, SCC#C&, and -#C&, at the UE antenna connector.Typically not considered individually, but used or Eb!Nt -epends on channel po*er %can be variable(, path loss, and spreading gain %0p( Constantor a given bit rate, channel po*er, and path lossCan be esti$ated or$ Ec and processing gain Speech 12.23bps e/a$ple Ec 4 567 dB$ 12.23bps data rate 48 #rocessing gain 4 29.:6 dB Eb; 567 < 29.:6 4 5==.72 dB$Sy$bol E/planation"o The total received po*er spectral density, including signal and intererence, as $easured at the UE antenna connector. Si$ilar to UT)A carrier )eceive Strength Signal "ndicator %)SS"(, at least or practical consideration %SC scanner( )SS" in > or dB$ "o in >!&? or dB$!&? Measured by the UE %or &'( or #ilot scanner in the or$ o )SS" -epends on All channel po*er, All cells, and path loss -epends on sa$e5cell and other cell loading -epends on e/ternal intererencesSy$bol E/planationNoco$$on )+ deinitionTher$al noise densityTypically not considered individually, but used or Eb!NoCan be calculated No 4 @T @ is the Bol?$an constant, 1.A6B17C52A T is the te$perature, 2:7 @ No 4 1D9 dB$!&? under typical conditionsTypically the band*idth noise and the receiver noise igure are also considered No 4 @TBN+, *here N+ is noise igureTo avoid conusion, N+ should be used *hen reerring to ther$al noiseSy$bol E/planationNoor >C-MA syste$Total one5sided noise po*er spectral density due to all noise sourcesTypically not considered individually, but used or Eb!No-eined this *ay, No and "o are substituted or one another,'n the uplin3 the substitution is valid'n the do*nlin3, dierentiating bet*een Noise and "ntererence is $ore challengingSy$bol E/planation)T>#)eceived Total >ide Band*idth po*erTo describe uplin3 intererence level>hen uplin3 load increase =7E, )T># value *ill increase AdB)SS")eceived Signal Strength "ndicatorTo describe do*nlin3 intererence level at UE sideSy$bol E/planation)SC#)evived Signal Code #o*er %Ec(Ec!"o 4 )SC#!)SS", to describe do*nlin3 C#"C& Fuality"SC#"ntererence Signal Code #o*erG can be esti$ated by,"SC# 4 )SS" )SC#Concept o #ilot #ollution Concept o pilot pollution #ilot pollution $eans that there are too $any strong pilots *ithin the coverage, but none o the pilots is do$inantCriteria o pilot pollution There are $ore than A pilots *ith Ec 8 5:= dB$The level dierence bet*een the strongest pilot and the ourth strongest pilot is H = dBEect o #ilot #ollution #ilot pollution is speciic to the C-MA syste$ C-MA and greatly aects the net*or3 peror$anceEect o pilot pollution &igh BIE)Io* syste$ capacity&igh call drop rate due to reFuent handoverIo* access success rate due to no do$inant cell Causes o #ilot #ollution The causes o the pilot pollution includes, Unreasonable cell layout Too high site or antenna Unreasonable a?i$uth or tilt angle o an antenna Eect o the bac3 lobe o an antenna Eect o the a$bient environ$ent o the coverageUnreasonable cell layout The distances a$ong the Site A, B and C are not balanced, and the location relation bet*een the Sites is distinctly dierent ro$ an eFuilateral triangleSite ASite CSite BToo high site or antenna The antennas o A and C are too high, so it is hard to control overshooting Pilot pollution Pilot pollutionUnreasonable a?i$uth o an antenna The antenna a?i$uth o the sector *ith scra$ble o 177 is unreasonable Unreasonable tilt angle o an antennaThe too s$all antenna tilt angle results in overshootingEect o the bac3 lobe o an antenna +ront5to5bac3 ratio o the antenna does not $eet the reFuire$ent, so the signal o the bac3 lobe lea3sThe >ays to )educe #ilot #ollution An area *ith pilot #ollution can be predicted in the planning si$ulation'pti$i?e the planned sche$e to avoid the pilot #ollution'pti$al solution e/cellent syste$ design #roper site#roper a?i$uth and tilt angle o antennas#roper trans$it po*er and po*er ratio o sites