2 Contents What is LTE ? How does LTE interfere with DTT ? How to filter out LTE interference ?Soontai LTE filter
3 What is LTE ?LTE (Long Term Evolution) is a 4th generation (4G) standard for mobile communication.Currently 17 communication companies worldwide have adopted LTE, more than 100 more are about to follow.LTE uses- FDD (Frequency Division Duplexing) and- TDD (Time Division Duplexing) protocolsFDD : LTE base stations and handheld devices use different bandsTDD : LTE base stations and handheld devices use the same bands
5 FDD LTE 800MHz Spectrum Digital TV Frequency LTE Downlink Band LTE Uplink Band
6 LTE-800 Transmission Interferance into DTT How does LTE interfere with DTT ?LTE Base StationLTE-800 Transmission Interferance into DTT當DVB-T的信號在最低準位-72dBm(35dBuV)時, LTE的信號如果高於DVB-T信號27dB時, 則DVB-T信號就會被干擾, 所以如果直接以基地台的最高發射功率167dBuV計算時那麼要衰減105dB才能免除對DVB-T的干擾, 或是相距5公里
7 LTE User Equipment再來是當手機或其它LTE裝置發射時, 當DVB-T信號在最低準位-72dBm(35dBuV)時, 其發射信號強度不可高於31dBc, 所以以實際LTE裝置的25dBm(132dBuV)發射功率計算, 則必需衰減66dB
8 LTE Interference to DTT When LTE uses the 800 MHz “digital dividend” (Europe MHz) or the 700 MHz “white space” band (USA MHz) there will be interference with digital video broadcast signals (DVB-T/ATSC).DTV picture noise: How to solve this problem?
9 LTE Interferes with DTT LTE signalDVB-T signalTVAntennaLTE Base StationDVB-TsignalLTEsignalLTE FilterDVB-Tset-top boxLTEUser EquipememtDVB-TsignalLTEsignal
10 Teletronik LTE FilterLTE is the 4th generation mobile communication standard. This standard uses the frequency band next to the DVB-T band ( MHz in Europe, MHz in the Americas), which will lead to interferences with DVB TV or set-top-boxes. According to tests from Ofcom this interference can be eliminated with the help of a high rejection low pass filter.Our LTE Filters pass all requirements to eliminate interferences by LTE signals on digital broadcast reception. As a professional filter designer, teletronik can offer the LTE filter in a variety of packages and frequencies for various markets. Your inquiries are welcome.