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Transceiver Performance Generic Transceiver Architecture •Transceiver Overview •Transmitter Performance Spec

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Transceiver Performance Generic Transceiver Architecture •Transceiver Overview •Transmitter Performance Spec Slide from before: Performance Concerns •DC offset •Image rejection Communication system •Quadraturerequirements performance •Noise and noise figure •Phase noise and Jitter revisited •Distortion –Compression –Desensitization –Cross modulation –Intermodulation –IP2, IP3 –Harmonic distortion (THD, SFDR,…) •Bit error rate •Data rate (bandwidth) 1 2 System level concerns Mobility vs. Bit Rate •Data rate (voice, text, image, video,…) Where is Military? •Cost (CMOS, SiGe, …) Where is UWB? •Mobility (fixed, indoor, outdoor, ground Vehicle r o vehicle, airborne, …) o d Walk t u •Battery life (power consumption) O y WLAN t i l Stationary W-CDMA/ i •Weight (discrete, multi-chip, single chip, ) b EDGE (IEEE o M r Walk 802.11a/b/g) •Multi-standard support (hardware sharing) o o d Bluetooth n Stationary/ I Zigbee (IEEE 802.15) LAN •Security (baseband DSP) Desktop •Quality of service (protocol, transceiver) 0.1 1 10 100 Mb/s Bit Rate 3 4 Motorola 3G Smart Phone Architecture Cost vs. Bit Rate $ High t i b / t Medium W-CDMA/ s W-CDMA/ o EDGE C EDGE r e HIPERLAN/2 s Low WLAN U Bluetooth (IEEE Very Low Zigbee (IEEE 802.15) 802.11a/b/g) LLANAN 0,1 1 10 100 Mb/s Bit Rate 5 6 1 Transceiver performance Generic Transceiver Architecture •Transceiver Overview •Transmitter Performance Spec. •Transmitter Architecture •Receiver Performance Spec. •Receiver Architecture •Receiver Link Budget 7 8 Transceiver Role of a Receiver Role of a Transmitter Information Information HPMX-2007 4. discard carrier and The lkhefwwlkhq The lkhefwwlkhq The lkhefwwlkhq wilehrejklhwajkhrqwilu wilehrejklhwajkhrqwilu wilehrejklhwajkhrqwilu wesaejlkhq. whwlhlihewrwwesaejlkhq. whwlhlihewrw wesaejlkhq. whwlhlihewrw wklhjrqlihqilhq q3wih wklhjrqlihqilhq q3wih wklhjrqlihqilhq q3wih HPMX-2007 wejklhwajkhrqwilu wejklhwajkhrqwilu wejklhwajkhrqwilu q q q wae. wesaejlkhq. whwlhlihewrw wesaejlkhq. whwlhlihewrw esjlkhqwhwlhlihewrwwklhjrqlihqilhq q3wih wklhjrqlihqilhq q3wih wklhjrqlihqilhq q3wih wejklhwajkhrqwilu wejklhwajkhrqwilu q q qwejklhwajkhrqwilu wesaejlkhq. whwlhlihewrw wesaejlkhq. whwlhlihewrw wesaejlkhq. whwlhlihewrwwklhjrqlihqilhq q3wih wklhjrqlihqilhq q3wih wklhjrqlihqilhq q3wih wejklhwajkhrqwilu q q qwejklhwajkhrqwilu wesaejlkhq. whwlhlihewrw wklhjrqlihqilhq q3wih wesaejlkhq. whwlhlihewrwwklhjrqlihqilhq q3wih qwejklhwajkhrqwilu wklhjrqlihqilhq q3wih esjlkhqwhwlhlihewrw q wae. 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Modulator (cost and/or performance) De-Modulator frequency A A D D Baseband Mixer Mixer Processor I Data I Data 0 0 9 uP/ 9 uP/ 0 Antenna DSP Antenna 0 DSP Power Amplifier Baseband Low Noise Amplifier A Q Data Processor A Q Data 4. amplify to D D broadcast 1. amplify received signal with min. added noise Oscillator Oscillator bias bias bias bias bias 1. create carrier 3. LO for down conversion Power Supply Power Supply 9 10 Transmitter Performance Spec. Digital Communication System: •Output Power •Spurious Emission Information per bit increases Bandwidth efficiency increases •Adjacent Channel Power Ratio; ACPR •Frequency Stability •Data rate noise immunity increases •Bandwidth efficiency Transmitter •Noise immunity Receiver 11 12 2 Increasing Information Increasing Noise Immunity •Information in a source –Mathematical Models of Sources Error correction –Information Measures coding •Compressing information Block coding –Huffman encoding Channel coding –Lempel-Ziv-Welch Algorithm Adaptive feedback –Optimal Compression? coding •Quantization of analog data … –Scalar Quantization Diversity –Vector Quantization Space time –Model Based Coding diversity • m-law encoding •Delta Modulation •Linear Predictor Coding (LPC) 13 14 Increasing bandwidth Efficiency Output Power Gt•Pt •Modulation of digital data into l P analog waveforms r –Impact of d Modulation on 2 Bandwidth æ λ ö 1 LoLossss f afactcortor n noot t efficiency Pr = Pt Gt Gr ç ÷ related to propagation è 4πd ø L related to propagation 2 æ P ö æ æ λ ö 1 ö PL = -10logç r ÷ = -10logçG G ÷ ç ÷ ç t r ç ÷ ÷ è Pt ø è è 4πd ø L ø f (GHz) D (m)Prop Loss (dB)Pt (dBm)Pr (dBm)L (dB) 2.45 10 60.23 20 -70.23 30 15 16 Adjacent Channel Power Ratio Spurious Emission •Definition depends on specification P ACPR = adjacent Main P Channel main Adjacent Channel Pmain Padj 17 18 3 Adjacent channel reject Transmit Specifications •Transmit spectrum mask 19 20 Transmitter Architecture RF/BB Interface •RF/BB Interface •Direct Conversion Transmitter •Two-step Conversion Transmitter •Offset PLL Transmitter 21 22 BPSK Transmitter QPSK transmitter Bit 1: A S (t) Bit 0: -Ax BPSK in Pulse shaping cos(2pf t+q ) a cos(2pf t+f) c c n c s(t) bit 2 bits to Map to Local + 2 E stream 4 levels constellation Oscillator s (t ) = b cos( 2pf t + q ) (bit 1) 90o BPSK T c c b b n -sin(2pfct+f) Pulse 2 E b shaping s BPSK (t ) = - cos( 2p f c t + q c ) (bit 0 ) T b 23 24 4 •Direct-conversion transmitter •Direct-conversion transmitter with offset LO I I 0 9 0 0 9 0 wLO Q w1 wLO Q w2 Pros: less spurious synthesized Pros: less LO pulling Cons: more LO pulling Cons: more spurious synthesized 25 26 •Two-Step Transmitters •Two-step transmitter I 0 9 0 w +w cosw1t 1 2 t Q cosw2 Pros: less LO pulling superior IQ matching Cons: required high-Q bandpassfilter 27 28 Transmitter Performance Check •Offset PLL transmitter 1.Sensitivity and Dynamic Range 2.Unwanted Emission I 0 9 0 PD/LPF VCO cosw1t Q 1/N 29 30 5 Receiver Performance Spec. •Sensitivity Sensitivity •Selectivity •Adjacent Channel •Co-Channel •Spurious Response Rejection Interference Interference •IntermodulationRejection Adjacent Adjacent 890.4 890.4 Channel Channel •Receiver Self-quieting Desired •Dynamic Range Channel 890.4 890.4 890.4 890.4 890.4 890.2 890.4 890.6 MHz 31 32 Receiver Specifications Sensitivity alternate adjacent channel Noise Floor = Pnf (dBm) = kTB(dBm) + Freceiver (dB) Adjacent channel Sensitvity = Pin,min (dBm) = kTB(dBm) + Freceiver (dB) + SNRmin (dB) = Pnf (dBm) + SNRmin (dB) Desired Signal (must be higher than sensitivity) SNRmin Receiver Added Noise 200 200 Receiver Thermal Noise 400 400 33 34 Sensitivity Example Calculate Receiver Noise Figure Power to Antenna: +45 dBm Transmitter: TX. Antenna Gain: +10 dB ETP + 55 dBm Frequency: 10 GHz Path Losses -200 dB Bandwidth: 100MHz Rcvr. Ant. Gain 60 dB •Stage Thermal Noise Rcvr. Antenna Gain: +60 dB Power to Receiver -75 dBm •Image Noise Receiver: Noise Floor @ 290K -174 dBm/Hz Margin: 4 dB Noise in 100 MHz BW + 80 dB •LO Wideband Phase Noise ETP = +55 dBm Receiver N.F. +10 dB SNR min +5 dB Path Losses: 200 dB Receiver Sensitivity -79 dBm F1 -1 F2 -1 F3 -1 F4 -1 Ftot = 1+ + + + +L 1 G1 G1G2 G1G2G3 How to increase Margin by 3dB ? 35 36 6 Selectivity •IF filter rejection at the adjacent channel •LO spurious in IF bandwidth •Phase noise of LO RF Filter IF Filter Receiver Added Noise Receiver Thermal Noise 37 38 Selectivity Spurious Response RF Filter IF Filter Ch Ch Ch Ch Ch Ch Ch Ch 1 2 3 n 1 2 3 n f f RF n × f RF IF fIF freq fRF freq f LO m × f LO f freq LO 39 40 Spurious Reponses Spurious Response Chart IF = n × RF + m × LO IF LO = m × + n RF RF IF LO y = , x = RF RF y = m × x + n m + n = order of spurious response 41 42 7 IntermodulationRejection •Nonlinearity and Spurious respone 1 IP3 output = (mW ) å 1 i IP 3i Gi+1Gi + 2 L Gn 43 44 Receiver Self-quieting Dynamic Range P DR1dB = P1dB ,in - Pin,min out 1dB n × f LO 2 = P1dB ,in - Pnf - SNR min f IF1 f IF 2 Psf,out DR sf = Psf ,in - Pin,min f RF 2P + P = IIP 3 IM ,in - P SNR 3 in,min f LO1 f LO 2 P 2PIIP 3 + Pnf IM,out DP DP DP = - Pin,min n × f LO 2 Pin PI 3 Pnf DR IP3 sf Psf,in
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