83080 Receiver Architectures and Synchronization in Digital CommunicationsPractical RF Architectures for GSMand WCDMA Mobile Terminals1 NOKIATTKK00.PPT/18.10.2000 / Mikko PesolaNOKIAMain Drivers for RF Architecture DesignMobile Generations1st generation systems, analog NMT, AMPS, TACS2nd generation systems, digital GSM, IS-136 TDMA, IS-95 CDMA, PDC3rd generation systems, digital wide band WCDMA standards have been prepared by ETSI (Europe), ARIB (Japan), TIA (USA), 3GPP1 is a joint project that combines all proposals into one standard Harmonized standard includes three modes Direct sequence mode based on 3GPP (UTRA 3GPP = 3rd Generation Partnership Project UTRA = Universal Terrestrial Radio Access/FDD) Multi carrier mode based on CDMA2000 (USA proposal)2 NOKIATTKKOO.PPT/18.10.2000 / Mikko PesolaNOKIA TDD mode based on 3GPP (UTRA/TDD)Cost, Size, Power consumptionSystem complexity, time to market3 NOKIAComponent count in GSM RFTTKKOO.PPT/18.10.2000 / Mikko PesolaNOKIADesign Process - time to marketReq Specfs| System DesMeeh. DesignCritical Interface:A/AS IC Desk sPrMCtrsw 二 _desi9n_ /ASIC DesignConceptsApplicationsfrom system design iodetailed design4 NOKIATTKKOO.PPT/18.10.2000 / Mikko PesolaIntegration | Mfg ramp-upCritical Interface: from detailed desig to integrationNOKIAGSM Specifications for Receiver Bad frame indication performance Sensitivity Usable receiver input level range Co - channel rejection Adjacent channel rejection (selectivity) Intermodulation rejection Blocking and spurious response AM suppression5 NOKIATTKKOO.PPT/18.10.2000 / Mikko PesolaNOKIAExample of sensitivity specificationTable 1: Reference sensitivity performanceGSM 900Type of channelstaticPropagation conditionsHTI00TU50TU50RA250FACCH/H(FER)0.1 %(no FH) 6.9%(ideal FH)6.9%(no FH) 5.7%(no FH) 10.0%FACCH/F(FER)0.1 %8.0%3.8%3.4%6.3%SDCCH(FER)0.1 %13%8%8%12%RACH(FER)0.5%13%13%12%13%SCH(FER)1 %16%16%15%16%TCH/F9.6 & H4.8(BER)IO-50.5%0.4%0.1 %0.7%TCH/F4.8(BER)-IO4io-410-4io-4TCH/F2.4(BER)一2 IO-410-5io-5io-5TCH/H2.4(BER)-IO4io-4io-4io-4TCH/FS(FER)0.1a%6a%3a%2a %7a%class lb (RBER)0.4/a%0.4/a%0.3/a%0.2/a %0.5/a %class 11 (RBER)2%8%8%7%9%TCH/HS(FER)0.025 %4.1 %4.1 %4.1 %4.5%class lb (RBER. BF1=O)0.001 %0.36 %0.36 %0.28%0.56%class II (RBER. BF1=O)0.72%6.9%6.9%6.8%7.6%(U1R0.048 %5.6%5.6%5.0%7.5%class lb (RBER.(BFI or UFl)=0)0.001 %0.24%0.24%0.21 %032%(EVS1DR)0.06%6.8%6.8%6.0%9.2%(RBER. S1D=2 and (BFI or UFI)=0)0.001 %0.01 %0.01 %0.01 %0.02%(ES1DR)0.01 %3.0%3.0%3.2%3.4%(RBER.SID=1 or S1D=2)0.003%0.3%0.3%0.21 %0.42%6 NOKIATTKKOO.PPT/18.10.2000 / Mikko PesolaNOKIAHow to convert system specificationsto RF design parameters ? From the bit error rate (BER) requirement of the whole phone we can derive secondary specifications for the radio section (Gain, Signal to Noise ratio, Linearity) System specification and detector implementation define the required S/N ratio GSM needs 8.9 dB S/N (number includes some implementation margin 2.3dB)-15 dBm7 NOKIA-102 dBmTTKK00.PPT/18.10.2000 / Mikko PesolaNOKIASensitivitySignal must be 9 dB above noise floor, so requirement for receiver noise figure (NF) isNF = Ps+ 174 dBm -10 log B - S/N八PowerwhereB is equivalent noise bandwidth of the receiverPs is reference sensitivity levelFor GSM 900 MHz Ps = -102 dBm - NF = 10dB8 NOKIAtoTTKK00.PPT/18.10.2000 / Mikko PesolaNOKIASensitivity and SelectivityCascaded noise figure NF = 10 log F, where NF is noise figure and F is noise factor F = F1 + (F2-1 )/G1 + (F3-1 )/G-|G2 + . + (Fn-1)/ G1G2.Gn_1RF section must have enough gain to provide adequate signal level for A/D converterMinimum input level is -102 dBm - 1.8 uV 50 ohm. If we need for example 100 mV at A/D converter input, voltage gain needs to be 20 log(100mV/1.8uV) = 95dB二FiF2G1G29 NOKIATTKK00.PPT/18.10.2000 / Mikko PesolaNOKIASelectivityBefore detector interfering signals need to be filtered so that S/N is adequateThis attenuation is split between IF filter, analog BB filter and digital filter after A/DDigital filtering at baseband would be cost effective but then A/D coverter must be able to handle wider dynamic range (typical A/D resolution 10.12 bits)Distribution of gain and selectivity affects also linearity requirement of the analog partIf interfering signal is