标签: 相邻

WCDMA相邻信道功率比(ACPR)和交替信道功率比(AltCPR)以及噪音的测量ApplicationNote99May2005LT5528WCDMAACPR,AltCPRandNoiseMeasurementsDougStuetzleINTRODUCTIONACPR(adjacentchannelpowerratio),AltCPR(alternatechannelpowerratio),andnoiseareimportantperformancemetricsfordigitalcommunicationsystemsthatuse,forexample,WCDMA(widebandcodedivisionmultipleaccess)modulation.ACPRandAltCPRarebothmeasuresofspectralregrowth.ThepowerintheWCDMAcarrierismeasuredusinga5MHzmeasurementbandwidth;seeFigure1.InthecaseofACPR,thetotalpowerina3.84MHzbandwidthcenteredat5MHz(thecarrierspacing)awayfromthecenteroftheoutermostcarrierismeasuredandcomparedtothecarrierpower.TheresultisexpressedindBc.ForAltCPR,theprocedureisthesame,exceptwecenterthemeasurement10MHzawayfr……