keysight test solutions for 802 · keysight test solutions for 802.11ad philip chang dec 08, 2015 1...
Post on 29-Sep-2018
218 Views
Preview:
TRANSCRIPT
2
Use Model Example
Wireless Display/Audio/
Docking
Uncompressed transfer to computers, portable
devices to one or more monitors/projectors,
Distribution of HDTV
Upload/Download | Mobile
Applications
Kiosk Download, Movies to computer for editing,
library sharing, Cordless Computing
Networking/Access Points Wireless Gigabit Ethernet
Small Cells & Backhaul
Mesh networks, Peer-to-Peer, Tri-band (2.4/5/60
GHz) Access Points.
LTE and WiFi CA
802.11ad/WiGig format : Applications targeted High Data Throughput over short range using 60GHz RF, 2GHz channels with Beamsteering technology
MOBILE UE APPLICATIONS WIRELESS DISPLAY NETWORKING / APs
BACKHAUL
802.11ad Overview
Current chipsets being rolled out
support only MCS -12
WW Channel allocations
3
Modulation & Coding Schemes
Current chipsets being rolled out
support Channels 2 & 4 at least; few
cover all 4 as standard
• 2.4G, 5G bands are congested and lack the capability of delivering multi-gigabit data
• The 60 GHz band is ‘green field’ and can meet the demand for short range multi-gigabit links
IEEE802.11ad Test items
EVM
Transmitter test
21.3.2 Transmit mask
21.3.3.3 Center frequency tolerance
21.3.3.4 Symbol clock tolerance
21.3.3.5 Transmit center frequency
leakage
21.3.3.6 Transmit ramp-up and ramp-
down
21.4.4.1.2 Transmit EVM (Control PHY)
21.4.5.1.2 Transmit EVM (OFDM)
21.5.4.1.3 Tx flatness
21.6.4.1.1 Transmit EVM (SC PHY)
Receiver test
21.3.3.8 Maximum input requirement
21.3.3.9 Receive sensitivity
SEM
4
11ac Transmit Spectrum Mask for 160 and 80+80 MHz 160 MHz spectral mask is an extension of 40 and 80 MHz masks
For 80+80 MHz, mask is linear sum of the separate 80 MHz masks for
values from -20 dBr to -40 dBr. For values from 0 to -20 dBr, use higher
value.
5
80+80 MHz signals, with center frequencies separated
by 160 MHz
160 MHz Channel
11ac Transmitter Error Vector Magnitude (EVM)
Test method same as 802.11n:
• Channel estimation (equalizer training) based on preamble only
• Pilots used for phase tracking
• Minimum 16 data symbols in frame, RMS average over at least 20 frames
Modulation Coding
Rate
802.11n
EVM (dB)
802.11ac
EVM (dB)
BPSK 1/2 -5 -5
QPSK 1/2 -10 -10
QPSK 3/4 -13 -13
16QAM 1/2 -16 -16
16QAM 3/4 -19 -19
64QAM 2/3 -22 -22
64QAM 3/4 -25 -25
64QAM 5/6 -28 -27
256QAM 3/4 N/A -30
256QAM 5/6 N/A -32
7
802.11ad Reference Solution Signal creation and demodulation
DUT
Keysight SW (Signal Studio, SystemVue, VSA)
Acq'd Signal
81199A Wideband
Waveform Center (WWC)
89601B VSA SW
WARNING: Exit 89600 VSA Software before changing instrument setup
Dem
od
M8190A Wideband AWG (I/Q Generation)
Differential IQ
Waveform
N1999A 60GHz/5GHz
Down-converter N5183A MXG (Rx LO)
N5152A 5GHz/60GHz
Up-converter E8267D PSG
N5183A MXG (Tx LO)
Infiniium Scope
Could use VDI
for V/E/W-Bands
M1971E Smart Mixer
VDI UDC
63GHz Scope New
VDI UDC
VDI Configuration
I+ I- Q+ Q-
9 GHz, 2 dBm
11.58 GHz, 2 dBm
(69.48 GHz / 6)
Notes:
• Connect all 10 MHz references together. Use PSG as Ref Source.
• Connect Scope, SA, M8190A to LAN
CH1
Insert 60.48 GHz filter with 2 GHz
BW for SEM measurements
11.395 GHz, 2 dBm
(68.37 GHz / 6)
SA with External Mixer useful to check for spurs,
harmonics, and power levels at RF & mmW.
IF output at 7.89 GHz
NOTE: For lab on Left side of room, set Freq to 67.37
GHz since S-Scope only has BW up to 8 GHz
On left side of room
your IF=6.89 GHz
VDI Configuration
Up Converter w/ High LO Input
Up Converter w/ Low LO Input Down Converter w/ Low LO Input
Down Converter w/ High LO Input
= Not used in this configuration
Recommended Configurations
mmW Performance VDI Up Converter Maximum Output Power
VDI Up Converter /w Amp & filter: ~-3 dBm VDI Up Converter w/ filter, no amp: ~-25 dBm
Input Signal Configuration
• +12 dBm, about maximum where distortion starts to get worse
• 2 GHz BW
• 802.11ad 16QAM signal, MCS12
M1971E Configuration
I+ I- Q+ Q-
Aux RF In LO/IF
10 MHz USB 9 GHz, 2 dBm
11.58 GHz, 2 dBm
(69.48 GHz / 6)
Notes:
• Connect all 10 MHz references together. Use PSG as Ref Source.
• Connect Scope, SA, M8190A to LAN
CH1
USB 10 MHz Ext Mixing Port
Insert 60.48 GHz filter with 2 GHz
BW for SEM measurements
mmW Performance SEM: Spectral Emission Mask Measurements
• SEM mask will be available as preset in XA18 FW (Summer 2016 timeframe)
• Note: Mask is available as state file along with presets for ACPR (currently not defined)
• Contact Randy/Moto/S800 archives for copy of state file, Note: also requires proto FW.
802.11ad Transmit Mask Requirements
Note: Not clear how far beyond 3.06 GHz offset
customers want to make measurements
mmW Performance SEM: Spectral Emission Mask Measurements
Conclusions:
• M1971E can meet requirements of 802.11ad mask
• Only tested at 60.48 GHz since we only have 1 filter available today
• Requires VDI with filters at other frequencies to validate; but likely works
• N5152A introduces spur, so cannot validate
N5183B - MXG Test Configuration
VDI Up Converter Baseband M8190A
IF E8267D PSG
LO PSG/MXG/EXG
9 GHz 60.48 GHz
69.48 GHz x6 x6
SA X-Series Analyzer VDI Amp
Notes:
• Must remove filter for testing real DUT
• Amp and filter may be required to get signal level
into optimal range of M1971E
mmW Performance SEM: Spectral Emission Mask Measurements
M1971E Mask Measurement
Source: N5182A w/ filter
Result: Spur just beyond 3.06 GHz offset
M1971E Mask Measurement
Source: VDI Up Converter w/amp & filter
Result: Spur just beyond 3.06 GHz offset
No filter, mask fails No filter, spectrum similar to above (N5152A includes filter)
mmW Performance Down Converters – Source is VDI up converter
1
7
Conclusions
• Choice of down converter dependent on application
• N1999A has great low level performance
• VDI has impressive EVM over wide range of input levels, not much higher than direct scope meas.
• Smart Mixer requires high drive level, great for optimizing mmW system
• Results may be limited by ‘test source’ performance which is ~2% EVM for this test case
M1971E
Smart Mixer N1999A
Down-converter
63GHz Scope VDI UDC
1
8
mmW Performance Up Converters: 5182A vs VDI
Conclusions
• N5152A and VDI have similar EVM performance. VDI has small edge & requires healthy
input level to get performance.
N5152A
Up-converter VDI UDC
mmW Performance Calculating EVM limits (assuming noise limited)
An example with the M1971E: • Noise floor: -134 dBm/Hz
• BW: For a 2 GHz wide system, this equates to:
• -134 dBc/Hz + 10log (2 GHz) = -41 dBm (over 2 GHz of BW)
• This sets our noise floor.
• 1 dB compression point = ~0 dBm
• Crest factor of ~10 dB for communication signals
• Power level: So average input power level into mixer is ~-10 dBm
• This sets our upper limit on dynamic range
• Dynamic Range = -41 dBm – (-10 dBm) = ~31 dB =10−3120 =2.8%
• This limits the best EVM that can be measured.
M1971E
Smart Mixer
12/8/201
5 2
0
Keysight
Confidenti
al
LO Selection Which source is the best LO? Phase Noise Comparison at 10 GHz
N5173B - EXG E8257D - PSG
N5183B - MXG
*All Sources have the best phase noise option (UNY) (applies to PSG & MXG)
**Scale is 15 dB / div
12/8/201
5 2
1
Keysight
Confidenti
al
LO Selection Which source is the best LO? Phase Noise Comparison at 10 GHz
N5173B - EXG E8257D - PSG
N5183B - MXG
*All Sources have the best phase noise option (UNY) (applies to PSG & MXG)
**Scale is 15 dB / div
This is area is important
1 MHz Offset
LO Selection Which source is the best LO?
N5183B - MXG
PSG is LO MXG is LO EXG is LO
EVM = ~1.8% EVM = ~2.1% EVM = ~2.1%
x6
Up Converter
WARNING: Exit 89600 VSA Software
before changing instrument setup
Baseband M8190A
IF E8267D PSG
Scope Infiniium
LO PSG/MXG/EXG
5 GHz 60 GHz
10 GHz
Test Configuration
Test Signal QPSK
12/8/201
5 2
3
Keysight
Confidenti
al
LO Selection Using a YIG filter on the output of the LO
Phase Noise Comparison at 10 GHz between PSG and MXG
*All Sources have the best phase noise option available (applies to PSG & MXG)
N5183B MXG – with YIG Filter
E8257D PSG
E8257D PSG with YIG Filter
LO Selection Sample demodulation results with YIG filter on output of LO
N5183B - MXG
PSG is LO EXG is LO
EVM ~ 1.7% EVM ~ 1.7%
x6
Up Converter
WARNING: Exit 89600 VSA Software
before changing instrument setup
Baseband M8190A
IF E8267D PSG
Scope Infiniium
LO PSG/MXG/EXG
5 GHz 60 GHz
10 GHz
Test Configuration
Test Signal QPSK
YIG
Filter
802.11ad Design Challenges
• Performance taken for granted at lower frequencies, not so easy to acheive at mm frequencies
• Mismatch, skew, cable lengths matter
mm WaveTechnology
• ~2 GHz Modulation BW
• Data rates up to 6.75 Gbps
• 100x wider modulation bandwidth than 802.11n. 11x wider than 802.11ac
• Complex frequency response (flatness) difficult
Wide Bandwidth
• Built-in multi-element anntenas lack test connection
• Path losses significant
• Over-the-air (OTA) testing required jeapodizes measurement plane
• Multi-path intrinsic in performance and in measurement environment
No Connectors at 60 GHz
25
mmW Accessories V-Band VDI Amplifier Specs
• Frequency Range: 57-66 GHz
• ~20 dB gain, +10 dBm input damage level
• 10 dB NF
Other VDI Amplifiers Specs
• E-Band, Frequency Range: 71-86 GHz
• D-Band, Frequency Range: 152-162 GHz
• Specs similar to V-Band
VDI Waveguide Filters
• Models currently available
• 57.32-65.8 GHz Use case: Covers all four 802.11ad channels
• 57.32-59.32 GHz Use case: 802.11ad channel 1
• 59.48-61.48 GHz Use case: 802.11ad channel 2
• 61.64-63.64 GHz Use case: 802.11ad channel 3
• 63.8-65.8 GHz Use case: 802.11ad channel 4
• 71-76 GHz Use case: 5G/Backhaul in ‘lightly licensed band’
• 81-86 GHz Use case: 5G/Backhaul in ‘lightly licensed band’
• 152-162 GHz Other mmW
• Insertion loss ~1 dB
Can be purchased directly through VDI. Working on setting up as Keysight orderable parts, but
requires customer order to trigger.
top related