資源描述:
《無線通信(Wireless Communication by A.Goldsmith) .pdf》由會員上傳分享,免費(fèi)在線閱讀,更多相關(guān)內(nèi)容在學(xué)術(shù)論文-天天文庫。
1、RDJUNIOFORNUANTSIVEDRANSSTANFORDUNIVERSITYLTIEYLOR91GANIZED18EE359WIRELESSCOMMUNICATIONSProfessorAndreaGoldsmithWirelesscommunicationsisarapidlygrowingsegmentofthecommunicationsindustry.Thenumberofcell-phoneusersaloneisexpectedtopass1billionworldwidewithinthenextfewyears,
2、andwirelessLANsarealsopoisedtoexperienceexponentialgrowth.Wirelesstechnologynotonlysupportsvoice,data,andvideocommunicationbetweenportabledeviceslocatedanywhereintheworld,butalsoprovidesthebackbonetechnologyforsensornetworks,smarthomes,telemedicineandremotelearning,andaut
3、omatedfactoriesandvehicles.Thiscoursewillcoverthefundamentalwirelesscommunicationtechniquesthatsupportthesevariousapplications,withaprimaryfocusonthecommunicationsystemdesign.Webeginwithabriefoverviewofcurrentwirelesssystemsandstandards,including2ndand3rdgenerationcellula
4、rsystems,wirelessLANs,wideareawirelessdatasystems,satellitenetworks,andBluetooth.Wethencharacterizethewirelesschannel,includingpathlossfordi?erentenvironments,randomlog-normalshadowingduetosignalattenuation,andthe?atandfrequency-selectivepropertiesofmultipathfading.Nextwe
5、examinethefundamentalcapacitylimitsofwirelesschannelsandsomecharacteristicsofthetransmissionstrategiesthatachievetheselimits.Thisgivesusaperformanceboundagainstwhichwecancomparepracticalschemesaswellasinsightintooptimaltransmitterandreceiverdesigns.Infact,thecapacityresul
6、tsindicatethatfor?at-fadingchannels,adaptivemodulationordiversitycanprovidesigni?cantcapacityimprovements.Thenextpartofthecourseisspentinvestigatingtechniquesforcommunicatingoverwirelesschan-nels.We?rstreviewdigitalmodulationtechniquesandthenstudytheirperformanceunderwire
7、lesschan-nelimpairments,including?atandfrequencyselectivefading.We?ndthatmultipathfadingseverelydegradestheperformanceofcommunicationsystems,andwethereforeneedmethodstoovercometheinherentimpairmentsofthewirelesschannel,inparticular?atandfrequencyselectivefading.Wenextinve
8、stigatethedesignandperformanceoftwotechniquestomitigatethee?ectsof?atfading:adaptivemodulationan