WLAN技术及其测试

Slide1WLAN技术及其测试Slide2什么是WLAN?(WirelessLocalAreanetwork)WLAN:无线局域网，即没有线缆的局域网，实际上就是用无线电波代替以太网中的cable，进行信号的传输和宽带的接入Slide3WLANapplicationSlide4IEEE802.11规范Whatisit?a4.8to6GHz,54MbpsWLANstandardb2.4GHz,11MbpsWLANstandardcBridgesconnectionsbetweenaccesspointsdHarmonisationof802.11afreqplaneQoSspecforsteamedvideoandVoIPfRoamingbetweenaccesspointsfromdifferingnetworksg2.4GHz,54MbpsWLANstandardhPowercontrolforEuropeanmarketiAdditionalsecurityfeaturesjJapaneseversionof802.11a(freqplan,andadditionalNationalregulatoryrequirements)kRadioandnetworkinformationforlocationbasedapplicationslNotusedmMaintenanceofstandardnHigherdataratestandard–notyetratified（更高速率的规范－还未发布）Slide5WLAN规范发布1997IEEE802.11–1997年无线局域网标准发布只支持1Mbit/s和2Mbit/s1999IEEE802.11b-1999年扩展了物理层规范增加了5.5Mbit/s和11Mbit/sIEEE802.11a–1999年增加5GHz的规范增加了6,9,12,18,24,36,48,54Mbit/s速率2003IEEE802.11g–2003年发布54Mbit/sin2.4GHzbandSlide6IEEE802.11a/b/g标准802.11b802.11g802.11a频率2.4GHz2.4GHz4.9–5.85GHz速率1to11Mbpsto54Mbpsto54Mbps净速率4Mbps30Mbps30Mbps调制方式DSSS(直接序列扩频)1MbpsBarkerDBPSK2MbpsBarkerDQPSK5.5&11MbpsCCKDQPSK1/2/5.5/11Mbps调制方式同802.11b(1)OFDM（正交频分复用）6/9MbpsBPSK12/18MbpsQPSK24/36Mbps16QAM48/54Mbps64QAM信道数14实际信道数受限于各国的相应规定13实际信道数受限于各国的相应规定30实际信道数受限于各国的相应规定颁布时间199920031999覆盖范围30to300m30to300m20to50m（1）802.11g兼容802.11b的1/2/5.5/11Mbps,并增加了6/9/12/18/24/36/48/54Mbps速率等级Slide7AnalogmodulationSlide8Digitalmodulation01010Slide9IEEE802.11b射频测试IEEE编号测试项目要求测试用途MT8860C是否支持？18.4.7.1Transmitpowerlevels（发射功率）Followsnationalregulatoryrequirementsfor2.4GHzISMbandProductionYes18.4.7.2Transmitpowerlevelcontrol（功率控制）Requiredforradios100mWProductionYes18.4.7.3.Transmitspectrummask（频谱模板）DefinedlimitmaskProductionYes18.4.7.4Transmitcenterfrequencytolerance（中心频率容限）±25ppmProductionYes18.4.7.5Chipclockfrequencytolerance（码片时钟频率容限）±25ppmR&DYes18.4.7.6Transmitpower-onandpower-downramp（上升时间/下降时间）2µsR&DYes18.4.7.7RFcarriersuppression（载波抑制）15dBforunscrambled10payloadR&DYes18.4.7.8Transmitmodulationaccuracy（调制精度）0.35EVMpeakforhighestdatarateR&D/ProductionYes18.4.8.1Receiverminimuminputsensitivity（接收机灵敏度）FER8%for–76dBminput,11Mbit/sProductionYes18.4.8.2Receivermaximuminputlevel（接收机最大输入电平）FER8%for–10dBminput,11Mbit/sR&DYes18.4.8.3Receiveradjacentchannelrejection（接收机临道功率抑制）ACR35dBwithFER8%,25MHzseparationR&DYes(withsecondsource)18.4.8.4ClearChannelAssessment(CCA)（信道估计）AbilitytofindclearchannelR&DYes(witho’scope)Slide10IEEE802.11a/g射频测试IEEE编号测试项目要求测试用途MT8860C是否支持?19.4.7.1Transmitterpowerlevels（发射功率）Followsnationalregulatoryrequirementsfor2.4GHzISMbandProductionYes19.5.4(17.3.9.2)Transmitterspectrummask（频谱模板）DefinedlimitmaskProductionYes17.3.9.3Transmissionspurious（杂散发射）SetbyNationalregulationsR&DNo19.4.7.2Transmitcenterfrequencytolerance（中心频率容限）±25ppmProductionYes19.4.7.3Symbolclockfrequencytolerance（符号时钟频率容限）±25ppmR&DYes17.3.9.6.1Transmittercenterfrequencyleakage（发射机中心频率泄漏）-15dBrelativetooveralloutputpowerR&DYes17.3.9.6.2Transmitterspectralflatness（频谱平坦度）±2dBmaximumdeviationforsubcarrier1to16,(+2to–4dBforsubcarrier17to26)R&DYes17.3.9.6.3Transmitterconstellationerror（星座误差）-25dBRMSEVMfor54Mbit/sProductionYes19.5.1(17.3.10.1)Receiverminimuminputsensitivity（接收灵敏度）PER10%for–65dBminput,54Mbit/sProductionYes19.5.2Adjacentchannelrejection（临道功率抑制）PER10%,3dBinterfererR&DYes(withsecondsource)17.3.10.3Non-adjacentchannelrejection（非临道功率抑制）PER10%,3dBinterfererR&DYes(withsecondsource)19.5.3Receivermaximuminputlevel（接收机最大输入电平）PER10%for–30dBminputR&DYes19.4.6ClearChannelAssessment(CCA)（信道估计）AbilitytofindclearchannelR&DYes(witho’scope)Slide11802.11b测量Slide1218.4.7.1–发射功率调制方式DSSS(DBPSK/DQPSK/CCK)Gates之间的平均功率典型的发射功率在＋14dBm左右Slide1318.4.7.2–功率控制被测件功率20dBm时才需要测试允许4各功率等级Gate内的平均功率Slide1418.4.7.7–载波抑制要求抑制达15dB以上被测件发出的调制信号必须内有加扰，且为10101010payloadSlide1518.4.8.1–接收灵敏度FER8%for–80dBminputat2Mbit/sFER8%for–76dBminputat11Mbit/sMT8860B计算从DUT反馈回来的Acknowledge数据包来计算FERSlide1618.4.8.2–接收机最大输入电平FER8%for–10dBminputat11Mbit/sSlide1718.4.8.1–邻道抑制25MHzchannelseparationOn-channelsignalat–70dBm35dBleveloffsetbetweenwantedandadjacentsignalsFER8%for11Mbit/srateWantedsignalInterfererFcFc+25MHzSlide18802.11a/g测量Slide1919.4.7.1–发射功率调制方式OFDM(BPSK/QPSK/16-QAM/64-QAM)Crestfactoris~8dBGate内的平均功率典型的发射功率为+14dBm左右Slide2019.5.1(17.3.10.1)接收灵敏度对于54Mbps速率，当输入功率为-65dBm时PER10%DataRate(Mbits/s)Sensitivity(dBm)6-829-8112-7918-7724-7436-7048-6654-65