Embed Size (px)
Citation preview
TD-SCDMA (China)
802.16e (Mobile WiMAX)
WiBRO (Korea)
802.16d (Fixed WiMAX)
802.11n
Wireless evolution 1990 - 2014
GSM (Europe)
IS-136 (US TDMA)
PDC (Japan)
IS-95A (US CDMA)
HSCSD GPRS iMODE IS-95B (US CDMA)
W-CDMA (FDD & TDD)
E-GPRS (EDGE)
HSDPA HSUPA
EDGE Evolution
1x EV-DO 0 A B
HSPA+ / E-HSPA
LTE (R8/9 FDD & TDD)
LTE-Advanced (Release 10, 11, 12)
802.16m / WiMAX2 WirelessMAN-Advanced
802.11h
802.11ac 802.11ad
cdma2000 (1x RTT)
802.11a/g
802.11b 2G
W-LAN
2.5G
3G
3.5G
3.9G/ 4G
4G / IMT-Advanced
Market evolution
Technology evolution
Increasin
g efficien
cy, ban
dw
idth
and
data rates
© 2012 Agilent Technologies
2
Agilent N5106A PXB
SSD/Wireless Business Unit
September 2008
Page 3
Technologies Evolution
QAM, FSK,
QPSK
Vector Signals
AM, FM
Scalar Signals
TDMA,
FDMA, SDMA
Signals
OFDMA,
MIMO
Beamforming
DSSS, FHSS,
CDMA Signal
Power Time
Frequency TDMA
Power
Time
Frequency CDMA
Page 4
The Digital Revolution
Systems Developers
Market
Demands Physics & Regulatory
Restrictions
Limited By:
Available Bandwidth
Permissible Power
Inherent Noise Level.
Demand For:
More Information Capacity
Digital Data Compatibility
Higher Signal Quality
Greater Information Security
Increased System Availability
Page 5
Multiple Access Modes I FDMA/TDMA
FDMA
Frequency
Division
Multiple
Access
Time
1 2 3 4 5 6
1 2 3 4 5 6
Frequency Frequency
Time
TDMA
Time
Division
Multiple
Access
Page 6
Multiple Access Modes II CDMA/OFDMA
Frequency
Time
Code
No. CDMA
Code
Division
Multiple
Access 1 2 3 4 5 6
ô genki desu ka ?
Encoding/Decoding
Subcarriers
Sym
bols
(Tim
e)
OFDMA
OFDMA
Orthogonal
Frequency
Division
Multiple
Access
Page 7
Duplex Transmission Modes
Time
Frequency
Rx
Tx
FDD
Frequency
Division
Duplex
Different
frequency
for Tx and Rx
Time
Tx Rx Tx Rx Tx Rx
TDD
Time
Division
Duplex
Tx and Rx are
separated by
different time
slots
Frequency
Page 8
Receiver
Transmitter
Speech
Speech
Speech
Codec Error
Coding
Inter-
leaver
FIR and
Transmit
Receive
Demod
De-Inter-
leave
Viterbi
Decode
Speech
Codec
Radio System Overview
Page 9
Wireless digital communications systems
Page 10
Binary Phase Shift Keying Quadrature Phase Shift Keying
1
00
10 11
2 states
4 states
symbols 01
0
Two bits per symbol
One bits per symbol
Q
I
0
1
Modulation Formats
The purpose of having different modulation formats is to provide different
efficiency when using the frequency spectrum resource.
The more complicated modulation format uses less (narrower) spectrum to
transmit the same amount of information.
Page 11
Interference
Capacity
f f
System Capacity & Interference Limited Spectrum
Page 12
Pt – Lt + Gt – Lp – LF + Gr – NFr – kT – BW – C/Nrequired = M ≥ 0
Reception Range
... ...
?
To Minimize These... Optimize These...
(Minimizing Bandwidth!)
The Link Budget & Margin
Page 13
BPSK 16QAM
Q
Modulation
2QAM
4QAM
16QAM
32QAM
64QAM
128QAM
Max. Error
90.0º
45.0º
16.9º
10.9º
7.7º
5.1º
I
90º
1 0
Q
I 16.9º
0000 0100 0110 0111
0100 1100 1110 1111
0010 0101 1010 1101
0001 0011 1000 1001
Spectrally Efficient is Difficult
Page 14
...
Harmonics
PA Noise Removal ...
Pt
f
Transmitter
Regulatory Mask
Spurious
Thermal Noise Floor
Tx
Rx
Tx
Rx
Local
Transmitter
Local
Receiver
PA Output Noise Floor
Transmit Filter Functions
Page 15
RF Filter IF Filter BB Filter
C/N+
Vic
tim
Inte
rfe
ren
ce
Filtering Interference
Threshold
Adjacent Channel Filtering for RX
Page 16
Measuring instrument
Signal analyzers: • spectrum analyzers: swept architecture, large frequency span, high dynamic range,
no phase information.
• Vector signal analyzers (VSA): FFT-based analyzers, signal processing capabilities, high flexibility, amplitude and phase available.
• One box testers: standard-specific measurements, both RF and basic protocol verification (call setup).
• Network analyzers: used to characterize single component behavior under sinewave stimulus (“linear behavior”)
Signal generators: • CW generators: used on component testing or for jamming/blocking signal in
receiver testing
• digitally modulated signals generators: standard-compliant digital signals.
Power meters: with special capabilities (peak detection, time gating)
BER Tester: for receiver BER testing
Page 17
Receiver block diagram
Page 18
Common Components of the digital radio receiver
Pre-selecting filter:
• attenuates out-of-band signals received by the antenna
• Reduce the receiver’s response to the image frequency ( twice the IF
from the desired frequency)
LNA:
• boosts the desired signal while minimally adding to the noise of the
radio signal
IF filter:
• attenuates unwanted frequency components generated by the mixer
and signals from adjacent channels
I/Q demodulator
Page 19
Measurement model
RF/IF signal power
Shoulder attenuation
Out-of-band Emissions (SEM)
Adjacent Channel Power (ACP)
Peak-to-average power ratio (CCDF)
Coherent interferer, unwanted emissions
(Spurious)
Phase noise
EVM/MER, SNR
BER results at different stages
Channel frequency response
Channel impulse response
RF COMPONENT/SUB-SYSTEM TEST MEASUREMENTS
X-Series Signal Generator
Tx/Rx
Component
DUT Amplifier, Tuner,
Repeater/Gap-filler etc
Analog I/Q
Digital I/Q
X-Series Signal Analyzer
Analog BBIQ/ IF/RF
IF/RF
MXG Pure & Precise RF
9 kHz to 6 GHz Vector &
Analog
N9310A Basic Bench
9 kHz to 3 GHz
EXG Cost Effective RF & uW
9 kHz to 6 GHz Vector & Analog
MXG N5183A
100 kHz to 40 GHz Analog
Signal Studio Most trusted Signal
Creation Software
PSG World’s Highest Performance
100 kHz to 44 GHz uW Vector
100 kHz to 70 GHz uW Analog
(>500 GHz external)
100 kHz to 9 GHz RF Analog
PXB Multi-Channel baseband
Fading & MIMO
Perf
orm
ance
Price
AGILENT SIGNAL GENERATION PORTFOLIO (EXCLUDES PXI)
Vector simulation
EXG/MXG/PSG
X-SERIES CUSTOM MODULATION EMBEDDED REAL TIME AND ARB MODULATION
Single/multicarrier custom modulation:
PSK: BPSK, QPSK, OQPSK, π/4DQPSK, 8PSK, D8PSK, 16PSK,
Gray Coded & Unbalance QPSK
MSK
QAM: 4, 16, 32, 64, 128, 256, 1024
FSK: Selectable: 2, 4, 8, 16 level symmetrical or custom map of up
to 16 deviation levels
ASK: 0 to 100% ASK depth
User defined: Up to 1024 custom constellation points
Data Types (real-time mode):
User file, PN9, PN11, PN15, PN20, PN23, Fixed 4, Direct-Pattern
RAM, External serial Input stream
Data Size: up to 1024 MBytes (Option 023 MXG)
Max Symbol rate: up to 100 Msymbols/sec
Filter types: Nyquist, Root Nyquist, Gaussian, Rectangular, APCO
25 C4FM, IS-95, custom FIR
Quick Setup modes:
GSM, EDGE, NADC, PDC, APCO 25 w/C4FM, APCO25 w/CQPSK,
TETRA, DECT, PHS, BLUETOOTH, CDPD, PWT
Agilent Arbitrary Waveform Generator Portfolio Expansion
Step 3
High Resolution and Wide Bandwidth
Step 1
High Resolution
More
to
Come!
M9330A / N8241A
15 bit, 1.2 Gsa/s
Perceived leader
in signal
performance
Step 2
Economic Version
81180A
12 Bit, 4.2 GSa/s AWG
Released April 2010
Be on the market as soon
as possible
M8190A
14 bit 8 GSa/s / 12 bit 12 Gsa/s
71.9
dB
64
dB
69.4
dB
Enhance Your Reality!
High Resolution
Wide Bandwidth
Measurement done with breadboard
1/26/2011
Page 23
Application Software for Waveform Generation
Signal Studio Waveform Creator
24
SystemVue
Application Software for Waveform Generation
Signal Studio Waveform Creator
25
SystemVue
AGILENT SIGNAL STUDIO & EMBEDDED SOFTWARE MOST COMPREHENSIVE & SOPHISTICATED APPLICATIONS
LTE/LTE-Advanced FDD
+ MIMO
LTE/LTE-Advanced TDD
+ MIMO
W-CDMA/HSPA+
GSM/EDGE/Evo
cdma2000/1xEV-DO
TD-SCDMA/HSDPA
WLAN 802.11a/b/g/n/ac
+MIMO
Mobile WiMAX +MIMO
Bluetooth
- V1.1, V2.1+EDR
- Low Energy
Digital Video
- DVB-T/H/T2/C/S/S2
- J.83 Annex A/B/C
- DOCSIS DS
- ISDB-T/TB/TSB/Tmm
- DTMB(CTTB)
- CMMB
- ATSC, ATSC-M/H
Broadcast Radio:
- FM Stereo/RDS
- DAB/DMB/ETI
GNSS - GPS - GLONASS
Toolkit
Multitone
Phase Noise Impairment
Calibrated Noise (AWGN)
Custom Modulation
MATLAB
ADS / SystemVue Signal Studio software
Embedded software
Partner products
Legend
Cellular
communications Wireless
connectivity
Audio/video
broadcasting
General
RF & MW Detection, positioning,
tracking & navigation
Application Software for Waveform Generation
Signal Studio Waveform Creator
27
SystemVue
Waveform Plugins
M9099A Waveform Creator
Waveform Creator Core Framework and User Interface M9099T-LIC Waveform Creator “Core”
Output / Downloader Plugin
M9381A VSG (Included in M9099T
“Core”)
File Write (Opt DFW)
Mixer
File Import (Included in M9099T
“Core”)
Multitone (Included in M9099T
“Core”)
GP Digital (Opt AYA)
SystemVue
Model Plugin (Opt SVM)
impairments Switch
Waveform Creator
Utility (Included in M9099T
“Core”)
Application Software for Waveform Generation
Signal Studio Waveform Creator
29
SystemVue
Validate before HW commitments Transition naturally from EDA to Test
IP Reference Libraries 4G/3.9G LTE-Advanced, LTE
3G HSPA+, WCDMA, etc
WLAN 802.11ac/n/a/
WPAN 802.11ad, 802.15.3c
RF / Analog
Channel Modeling MIMO Channel (OTA)
Digital Pre-Distortion (DPD)
RF System Design
RF EDA platforms
BB Algorithm
Modeling MATLAB .m
FixedPoint, HDL/FPGA
Embedded C++
Filtering, EQ, Modem
Test Equipment RF Sources & Analyzers
AWG & Digitizers
Scopes, Logic, Modular
Test Software I/O Lib, ComExpert
89600 VSA
Signal Studio
3rd Party
Start verifying designs against
emerging standards while both
are still evolving
Virtualize Simulation & HW
to allow earlier co-verification
Maximize ROI on Test Assets
Early Design & Validation with Evolving Standards
30
Page 31
Error Vector Magnitude for RX signal
The most widely used modulation quality metric in digital RF
communications systems is the EVM.
An alternative to BER testing to examine the quality of a
demodulated signal,because BER can indicate a problem
exists, but it may not help identify the source of the problem.
EVM provides a way to quantify the errors in digital
demodulation and is sensitive to any signal impairment that
affects the magnitude and phase trajectory of a demodulated
signal.
Troubleshoot baseband signal problem
Page 32
Modulation quality The Error Vector Concept
I-Q Magnitude Error
I
Q Error Vector Time
Reference Vector
I-Q Phase Error
Measured
Vector
Reference
Decision Point
=( Error Vector / Reference Vector) * 100%
)(Q)(I
)](Q)(Q[)](I)([IEVT
ref22
ref
2
mearef
2
mearef
tt
tttt
)(Q)(I
)(Q)(I)(Q)(IError Mag Q-I
ref22
ref
2
ref
2
ref
2
mea
2
mea
tt
tttt
(t) )II(
)Q(Q
refmeas
refmeas1
Tan
)(θ)(θ)θ( refmeas ttt
Reference to Decision Point
I-Q Phase Error =
Page 33
Modulation Impairments: examples Q
I
Phase Imbalance
I
Q
Gain Imbalance
Interference Added Noise
How small of an error can you see?
I
Q
I-Q Offsets
Phase Noise
Page 34
Receiver Performance Verification Measurements Bit Error Rate (BER)
BER
• Best measurement to verify receiver performance, especially
for sensitivity and selectivity
• Percentage of erroneous bits received compared to the total
number of bits received during an observation period
• Pseudo-Random Binary Sequence(PRBS,PNx) as the test
signal,PRBS eliminates the need to synchronize the received
and transmitted bits( reconstructed from any sequence of “x”
bits)
Baseband BER test
Loopback BER test
Page 35
Measuring Bit Error Rate (BER) Baseband BERT
RF Signal
Source
BERT
I/Q Modulator
0011011011000101.....
Base Band I/Q
Generator
RF Signal
Base Band
Signal
•Simple system config. •Fast
Page 36
RF Signal
Source
BERT
I/Q Modulator
RF Signal
Receiver
Base Band I/Q
Generator
RF Signal RF Signal
Demodulator
Measuring Bit Error Rate (BER) Loopback BERT
•Complex system •Slow
BIT ERROR RATE ANALYZER (OPTION UN7)
Data
BER
Results
Rx A
Optional signal using Real-time custom modulation for continuous PN sequence or large arb waveform with a continuous PN9 sequence in payload of carrier.
RF
DUT
Raw demodulated and decoded PN sequences + clock + gate (if required) output from DUT. MXG/EXG support 5 V, 3 V or 3.3 V CMOS or TTL signals
Clock
Gate (if required)
BIT ERROR RATE ANALYZER (OPTION UN7)
Self test data output (Aux IO) PN9 out = Pin #15
PN9 Clock out = Pin #17 (fixed 20 MHz)
BER Error out = Pin #18
Input data (BNC connectors) Clock input = BB TRIG 1
Gate input = BB TRIG 2
Data input = EVENT 1
Page 39
In-Channel testing
Measuring Sensitivity and maximum input level at a specified BER • Sensitivity is the minimum received signal level that produces a specified BER
when the signal is modulated with a bit sequence of data.
Verifying co-channel rejection • A measure of the ability of the Rx to remain sensitive to the desired signal
while subjected to the interfering signal
• Example
- The desired signal(931.4375MHz),power level of –102 dBm. At this power level the BER is less than 3%.
- The channel width for the pager is 25 kHz. The interfering signal is set to 931.4380 MHz. The power level of the interfering signal is first set to –105 dBm and gradually increased until the BER is again 3%.
- If a level of –97 dBm is required to return the BER to 3%, then the co-channel rejection is 5 dB.
Page 40
Adjacent and alternate channel selectivity test setup
Page 41
Out-of-Channel testing
Verifying spurious immunity • Spurious responses (spurs)
- Generated internally by the receiver
- Result from the interaction of the receiver with external signals
• The ability of Rx to prevent single, unwanted signals from causing an undesired response at the output of the Rx.
• Identify the spurs generated internally by the Rx. • Identify the spurs resulted from the interaction of the Rx with external signals.
• Spurious Immunity(SI)=Pint-Ptest (dB)
Verifying intermodulation immunity • Tests for distortion products that are generated when more than one tone is
present at the input of Rx.
• The frequencies of the interfering signals are set such that one of the third-order intermodulation products lies within the passband of the receiver
Measuring adjacent and alternate channel selectivity • The ability of the Rx to process the desired signal with a strong signal in the
adjacent channel or two channels away.
Page 42
Verifying intermodulation immunity
Questions?
Thanks for listening!
