AN-1434

Crest Factor Invariant RF Power Detector Crest Factor Invariant RF Power Detector Introduction Over the past few years cellular phone system have made a major transition from power efficient digital modulation schemes to bandwidth efficient digital modulation techniques. This is because new cellular phone systems need to provide a high transmission rate capability to satisfy the needed broadband applications. Power efficiency modulation schemes provides reliable transmission of information in a communications system at the lowest practical power level. One of the very successful examples is the GSM/GPRS network. The binary signaling GMSK modulation is used in the GSM/GPRS network. A bandwidth efficient modulation scheme delivers a higher data rate within a limited spectrum bandwidth. All the initial phases of 3G networks take advantage of this kind of modulation. A Sixteenth-ary Quadrature Amplitude Modulation (16QAM) scheme is even used in the latest High Speed Downlink Packet Access (HSDPA) of W-CDMA air interface. The 16QAM is used in the downlink to provide mobile users with the capability to download information much quicker. The move to bandwidth efficient modulation provides more information capacity with varieties of 3G cellular phone services, higher data security, better quality of services (QoS), and quicker system availability. The high level M-ary modulation schemes, like 8PSK, 16QAM, etc, have a greater capacity to convey large amounts of information than low l...