的基本原理PPT学习教案

1、会计学1的基本原理的基本原理Gray mapping: 3 bits per symboland only one bit changes between adjacent symbolsdifferentialencoding-1, +1Gaussianprefilteringfor frequencypulsesfrequencymodulatorlocal oscillatorrotation byk3pi/8LinearizedGaussianFilterfor DiracpulsesGray mappingto 8PSKconstellation3 bits persymbol I

2、& Q(0,0,1)(1,0,1)(d3i, d3i+1, d3i+2)=(0,0,0)(0,1,0)(0,1,1)(1,1,1)(1,1,0)(1,0,0)IQ第1页/共17页-2-1.5-1-0.500.511.5200.10.20.30.40.50.60.70.80.91h(t)Time Symbol periodsImpulse response h(t) for linearised Gaussian filter1234567-3-2-101234Angle radiansTime Symbol periods8-PSK symbols represented by Dir

3、ac pulses第2页/共17页第3页/共17页02040608010012014016000.511.5Magnitude VoltageTime Symbol periodsEnvelope of 8-PSK modulated Normal Burst第4页/共17页第5页/共17页indicates input level where gain is dropped 1dB from maximum value. nThe term back-off is also used to define output power decrease e.g. back-off is defin

4、ed from output compression. (back-off = power decrease +1 dB) 第6页/共17页0100200300400500600700800-80-70-60-50-40-30-20-1008-PSK Spectrum (3 dB back-off for linear class-AB amplifier)Frequency (kHz)dBc0100200300400500600700800-80-70-60-50-40-30-20-1008-PSK Spectrum (3 dB back-off for typical class-AB a

5、mplifier)Frequency (kHz)dBc第7页/共17页to be studied with normal receiver filter.Adjacent channel powers(measured at 200kHz rectangular window)ItemACP-1200kHzACP-2400kHzACP-3600kHzGMSK(reference)-16dB-61dB-80dBclass AB(3dB back-off)-16dB-45dB-62dBlinear class AB(3dB back-off)-16dB-51dB-71dB第8页/共17页05001

6、00015002000250015161718192021222324第9页/共17页 10% EVM -1.5-1-0.500.511.5-1.5-1-0.500.511.5bit sourcetransmitterreferenceRX filterreferenceRX filtercompensations and measurementssamplingbit detectoridealmodulator第10页/共17页20/ 10).()(dBoffbackoffbackowdBoffback00.511.522.533.5411.522.533.54Compression po

7、int and power consumption vs back-off for 1W outputCompression Point, Power Consumption WBack-off dBCompression PointPower Consumption00.511.522.533.5425303540Power efficiency versus back-off for class-AB amplifierEfficiency %Back-off dB第11页/共17页第12页/共17页第13页/共17页1E-31E-21E-11E+01015202530idealRX PN-1RX PN-2RX PN-3RX PN-4RX PN-5第14页/共17页services: (TU-3, iFH)ServiceBER Es/N0 Level - -Speech8%6 dB -104dBm9.610-514 dB -96dBm 14.410-516 dB -94dBm 32(8-PSK)10-518 dB -92dB