简介:摘要随着时代的发展,我国通讯技术也在不断的进步,通信网络一直处于完善发展状态中,业务水平也在不断提升。因此为了满足大量用户和业务工作的需求,需要进行无线网络的规划和优化,在频谱资源一定的情况下,如何提高网络覆盖率、增加网络容量、如何满足网络未来发展的需求都需要网络规划和优化来解决,通过网络规划和优化实现各方面的良好平衡。为了在激烈的市场竞争中占据先机,必须以优质的网络为前提,提高企业核心竞争力。及时准确的优化工作不但可以有效提高网络效益,而且能够提升企业的公众形象力,为进一步的市场扩展打下坚实的基础。本文将基于CDMA的内容和特点分析CDMA网络关键技术对于网络规划和优化的影响,并给出CDMA无线网络优化的流程和方法。
简介:摘要在LTE覆盖不完善的情况下,采用LTE与3G数据业务互操作解决方案,可保证用户在4G与3G网络之间的平滑切换。在此对C/L互操作原理进行了研究,探索C/L互操作的实现原理、交互流程以及分类。
简介:Inthispaper,weproposeatheoreticalmethodinordertoestimatetheforwardlinkoutageprobabilityandusercapacityofacellularsystemwhicharebasedonIS-95CDMAstandard,especialyimpactofpowercontrolstrategyandwiceactivitymonitoringinthesystemunderlong-termfadingeffects,inwhichthelightandheavyfadingsareconsidered.Accordingtothenumericalresultsobtainedinthispaper,thepowercontrolstrategyleadstoapproximatelythethreefoldusercapacityincontrasttothesituationwithoutpowercontrolstrategy,ThereultsarecomparedwithInterference-to-SignalRatio(ISR)drivenpowercontrolscheme^[6][9]whichcanbeusedonlyforsimulationofthesystem.Thepowercontrolstrategynotonlyimprovesthedesiredsignaltotheinterferencerationinthereferenceuser'sreceiver,butalsooffersuniformservicetotheuserwhereveritislocatedinthecell.
简介:针对往返时延时变的CDMA系统功率控制,在传统的Smith预估器的基础上,提出了一种多模Smith预估功率控制方法。这种多模Smith预估功率控制是由多个传统的Smith预估器构成,每个Smith预估器对应不同的时延项,通过设计似然函数来计算各自概率进而确定权重,最终达到最优的补偿效果。仿真结果表明,该方法能使输出信号与干扰加噪声比(SINR)渐进无偏地跟踪目标SINR,能有效补偿未知的、时变的往返时延,对CDMA系统中时变的往返时延具有一定的鲁棒性。
简介:Theparallelinterferencecancellationformulti-carrierDS-CDMA(whichistermedFDC-PIC)isproposedbyintegratingfrequencydiversitycombination.ThesimulationsaremadeoverFDC-PICwithrespecttodifferentdecisionways-hard,softandlineardecisions,respectively,andweconcludethatFDC-PICacquiressuperiorperformanceimprovementovercorrelationreceptionofmulti-carrierDSCDMA.Withanincreaseininterferencecancellationstages,thesystemperformanceisimprovedfurther.Theinitial2stagesbringaboutthemostdominantperformanceimprovement,butuptothe3rdstagethesystemperformanceisimprovedlittle.ItisalsoshownbythesimulationresultsthatFDC-PICwithsoftdecisionwouldexhibitthebestperformancewithahighimplementationcomplexity,whileFDC-PICwithlineardecisionacquiresperformancecomparabletothatofFDC-PICwithsoftdecisionwithareduced-complexityifthenumberoftheinterferencecancellationstagesisthesame,whichindicatesthatFDC-PICwithlineardecisionhasoptimalperformance/complexitytradeoffandthereforewillbesuitableforpracticalapplicationinfuture.