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Concepts of LTE&RF Parametric Receiver Tests on PHY layer
David BarnerAgilent Technologies
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Agenda
• Brief review of LTE physical layer
• LTE physical layer Receiver tests
• Measurement solutions
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LTE PHY Layer Characteristics
Service Goals
• Data transfer rate ( max) DL: 173Mbps, UL: 86Mbps
• Users/cell (max) 200 active
• Mobility 0-15 km/h best performance
15-120 km/h high performance
Physical Layer Details
• Duplex Modes FDD, TDD
• Frequency assignments 700 MHz Public Safety
840, 940, 1750, 1930, 2150, 2570 MHz
• Channel bandwidths FDD: 1.4, 3, 5, 10, 15, 20 MHz
• DL transmission OFDM using QPSK, 16QAM, 64QAM
• UL transmission SC-FDMA using QPSK, 16QAM ,64QAM
• Number of carriers 72 to 1200
• Carrier spacing Fixed 15 kHz (7.5 kHz extended CP)
• Additional mod types Zadaoff-Chu, BPSK (CMD)
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Physical Layer Definitions: Frame Structure
Frame Structure type 1 (FDD) FDD: Uplink and downlink are transmitted separately
#0 #2 #3 #18#1 ………. #19One subframe = 1ms
One slot = 0.5 ms
One radio frame = 10 ms
Subframe 0 Subframe 1 Subframe 9
Frame Structure type 2 (TDD)One radio frame, Tf = 307200 x Ts = 10 ms
One half-frame, 153600 x Ts = 5 ms
#0 #2 #3 #4 #5
One subframe, 30720 x Ts = 1 ms
DwPTS
Guard period
UpPTS
One slot, Tslot =15360 x Ts = 0.5 ms
#7 #8 #9
DwPTS
Guard period
UpPTS
PTS = Pilot Time Slot
TDD: Uplink and downlink are transmitted at the same time
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Condition (DL) NRBsc NDL
symb
Normal
cyclic prefix∆f=15kHz 12 7
Extended
cyclic prefix
∆f=15kHz 12 6
∆f=7.5kHz 24 3
RB
scN
RB
scN
OFDM symbols
One slot, Tslot
:
:
x subcarriers
Resource block
x
Resource
element
(k, l)
l=0 l= – 1
subcarriers
RB
scN
DLsymbN
DLsymbN
DLsymbN
RB
scN
Condition (UL) NRBsc NUL
symb
Normal
cyclic prefix12 7
Extended
cyclic prefix12 6
Slot Structure & Physical Resource Elements
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LTE Physical Layer Signals & Channels
LTE air interface consists of two main components:
1. Physical channels
• These carry data from higher layers including control,
scheduling and user payload
2. Physical signals
• These are generated in Layer 1 and are used for
system synchronization, cell identification and radio
channel estimation
The following is a simplified high-level description of the
essential signals and channels.
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LTE Air Interface:
Downlink Physical Channels (1 of 2)
BaseStation
(eNB)
UserEquipment
(UE)
PBCH – Physical Broadcast Channel
Broadcast Channel
PBCH: - Carries cell specific information such as system bandwidth, number of Tx
antennas etc…
- Transmitted in the centre 72 subcarriers (6 RB) around DC at OFDMA symbol #0 to
#3 of Slot #1 of sub-frame #0
- Modulation scheme = QPSK
PCFICH:
- Carries information on the number of OFDM symbols used for transmission of
PDCCH’s in a sub-frame
- Transmitted on symbol #0 of slot 0 in a sub-frame
- Modulation scheme = QPSK
PHICH:- Carries the hybrid-ARQ ACK/NACK feedback to the UE for the blocks received
- Transmitted on symbol #0 of every sub-frame (Normal duration) and symbols #0, 1
& 2 of every sub-frame (Extended duration) if the number of PDCCH symbols = 3
- Modulation scheme = BPSK (CDM)
PCFICH – Physical Control Format Indicator Channel
PHICH –Physical Hybrid-ARQ Indicator Channel
Indicator Channels
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LTE Air Interface:
Downlink Physical Channels (2 of 2)
BaseStation
(eNB)
UserEquipment
(UE)
PDCCH – Physical Downlink Control Channel
Control Channel
PDCCH
- Carries uplink and downlink scheduling assignments and other
control information depending on format type (there are 4 formats)
- Transmitted on the first 1, 2 or 3 symbols of every subframe
- Modulation scheme = QPSK
PDSCH
- Carries downlink user data
- Transmitted on sub-carriers and symbols not occupied by
the rest of downlink channels and signals
- Modulation scheme = QPSK, 16QAM, 64 QAM
PDSCH - Physical Downlink Shared Channel
Shared (Payload) Channel
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LTE Air Interface:
Downlink Physical Signals
BaseStation
(eNB)
UserEquipment
(UE)
P-SS - Primary Synchronization Signal
RS – Reference Signal (Pilot)
P-SS:
- Used in cell search and initial synchronization procedures
- Carries part of the cell ID (one of 3 sequences) and identifies 5 ms timing
- Transmitted on 62 out of the reserved 72 subcarriers (6 RBs) around DC at
OFDMA symbol #6 of slot #0 & #10
- Modulation sequence = One of 3 Zadoff-Chu sequences; CAZAC
S-SS:
- Used to identify cell-identity groups. Also identifies frame timing (10 ms)
- Carries remainder of cell ID (one of 168 binary sequences)
- Transmitted on 62 out of the reserved 72 subcarriers (6 RBs) around DC at
OFDMA symbol #5 of slot #0 & #10
- Modulation sequence = Two 31-bit binary sequences; BPSK
RS:
- Used for DL channel estimation and coherent demodulation
- Transmitted on every 6th subcarrier of OFDMA symbols #0 & #4 of every slot
- Modulation sequence = Pseudo Random Sequence (PRS). Exact sequence
derived from cell ID, (one of 3 * 168 = 504). QPSK
S-SS - Secondary Synchronization Signal
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LTE Air Interface:
Uplink Physical Channels
BaseStation
(eNB)
UserEquipment
(UE)
PRACH - Physical Random Access Channel
Random Access Channel
PRACH:- Used for call setup
- Modulation scheme = uth root Zadoff-Chu
PUCCH:- Carries ACK/NACK for downlink packets, CQI information and scheduling
requests
- Never transmitted at same time as PUSCH from the same UE
- Two RBs per sub-frame, the outer RB regions, are reserved for PUCCH
- Modulation scheme = OOK, BPSK and QPSK
PUSCH:- Carries uplink user data
- Modulation scheme = QPSK, 16QAM, 64QAM
PUCCH – Physical Uplink Control Channel
Control Channel
PUSCH - Physical Uplink Shared Channel
Shared (Payload) Channel
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LTE Air Interface:
Uplink Physical Signals
BaseStation
(eNB)
UserEquipment
(UE)
DM-RS - (Demodulation) Reference Signal
S-RS - (Sounding) Reference Signal
DM-RS: There are two types of DM-RS. PUCCH-DMRS and PUSCH-DMRS
PUSCH-DMRS:
- Used for uplink channel estimation
- Transmitted on SC-FDMA symbol #3 of every PUSCH slot
- Modulation sequence = nth root Zadoff-Chu
PUCCH-DMRS:
- Transmitted on different symbols depending on PUCCH format and cyclic
prefix. For normal cyclic prefix and PUCCH format 1, it is transmitted on
SC-FDMA symbols #2, #3 and # 4 of every PUCCH slot. For PUCCH format
1, it is transmitted on SC-FDMA symbols #1 and 5
- Modulation sequence = Zadoff-Chu
S-RS:
- Used for uplink channel quality estimation when no PUCCH or PUSCH
is scheduled.
- Modulation sequence = Based on Zadoff-Chu
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OFDM symbols (= 7 OFDM symbols @ Normal CP)
The Cyclic Prefix is created by prepending each
symbol with a copy of the end of the symbol
160 2048 144 2048 144 2048 144 2048 144 2048 144 2048 144 2048 (x Ts)
1 sub-frame= 2 slots
= 1 ms
1 slot= 15360 Ts
= 0.5 ms
0 1 2 3 4 5 6
etc.
CP CP CP CPCPCP
DL
symbN
Downlink Frame Structure Type 1
RS - Reference Signal (Pilot)
P-SS - Primary Synchronization Signal
S-SS - Secondary Synchronization Signal
PBCH - Physical Broadcast Channel
PCFICH – Physical Control Channel Format Indicator Channel
PHICH (Normal)– Physical Hybrid ARQ Indicator Channel
PDCCH (L=3) - Physical Downlink Control Channel
PDSCH - Physical Downlink Shared Channel
#0 #1 #8#2 #3 #4 #5 #6 #7 #9 #10 #11 #12 #19#13 #14 #15 #16 #17 #18
10 2 3 4 5 610 3 4 5 62
Su
b-C
arr
ier
(RB
)
Time (Symbol)
1 Frame
= 10 sub-frames
= 20 slots
= 10 ms
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Page 13
#0 #1 #8#2 #3 #4 #5 #6 #7 #9 #10 #11 #12 #19#13 #14 #15 #16 #17 #18
10 2 3 4 5 6 10 2 3 4 5 6
PUSCH - Physical Uplink Shared Channel
Reference Signal – (Demodulation) [Sym 3 | Every Slot]
OFDM symbols (= 7 OFDM symbols @ Normal CP)
The Cyclic Prefix is created by prepending each
symbol with a copy of the end of the symbol
160 2048 144 2048 144 2048 144 2048 144 2048 144 2048 144 2048 (x Ts)
1 slot= 15360 Ts
= 0.5 ms
0 1 2 3 4 5 6
etc.
CP CP CP CP CPCPCP
UL
symbN
1 sub-frame= 2 slots
= 1 ms
1 frame= 10 sub-frames
= 10 ms
Ts = 1/(15000 x 2048) = 32.6 ns
Uplink Frame Structure Type 1PUSCH Mapping
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Uplink Frame Structure Type 1PUCCH Mapping (Formats 1, 1a, 1b )
[Syms 2-4 | Every Slot]
[Syms 0,1,5,6 | Every Slot]
1
UL
symbN
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15 kHzFrequency
fc
V
CP
OFDMAData symbols occupy 15 kHz for
one OFDMA symbol period
SC-FDMAData symbols occupy M*15 kHz for
1/M SC-FDMA symbol periods
1,1-1,1
1,-1-1,-1
I
Q 1, 1 -1,-1 -1, 1 1, -1 1, -1 -1, 1
Sequence of QPSK data symbols to be transmitted
QPSK modulating
data symbols
60 kHz Frequency
V
CP
-1,-1 1, 1
Comparing DL (OFDMA) and UL (SC-FDMA):QPSK example using M=4 subcarriers
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Agenda
• Brief review of LTE physical layer
• LTE physical layer Receiver tests
• Measurement solutions
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LTE eNB Design Challenges
Increased capacity & throughput
• MIMO radios
• Requires more RF hardware
• Requires more complex baseband processing
• Requires extensive validation with channel emulation
• Robust error correction techniques
• Requires more complex baseband processing
• Wider modulation bandwidth
• Higher order modulation schemes
• More sophisticated power control
Interference & Interoperability
• Must integrate with existing cellular & wireless connectivity formats
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LTE eNB Receiver Test Challenges
LTE Conformance Tests Require Sophisticated Signals
• Various modulation bandwidths (1.4 MHz to 20 MHz)
• Various modulation types (QSPK, 16QAM, 64QAM)
• Transport channel coding with specific configurations, i.e. Fixed Reference Channels (FRC)
• Interfering Signals
• AWGN
• Emulation of channel propagation conditions
New Conformance Tests Require Special Test Configuration
• Three performance requirements tests require dynamic changes in signal characteristics
• Closed loop control of RV index based on HARQ feedback
• Closed loop control of RF frame timing based on TA feedback
• Interference and Rx diversity tests require MU-MIMO test configurations
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LTE eNB Receiver Test ChallengeseNB Rx Conformance Test Details
S7. Rx Characteristics Tests
• Reference sensitivity level
• Dynamic range
• Adjacent Channel Selectivity (ACS)
• Blocking characteristics
• Intermodulation characteristics
• In-channel selectivity
• Spurious emissions
S8. Rx Performance Requirements Tests
• Performance requirements for PUSCH• Multipath fading propagation conditions
• UL timing adjustment
• HARQ-ACK multiplexed on PUSCH
• High speed train conditions (high mobility)
• Performance requirements for PUCCH• ACK missed detection using user PUCCH format 1a
• CQI missed detection for PUCCH format 2
• ACK missed detection for multi user PUCCH format 1a
• Performance Requirements for PRACH
Summary of Test Requirements
• Tests are performed open loop
• Tests require interfering signals
• Performance metric = BLER
Summary of Test Requirements
• Some tests require closed loop feedback
• Tests require fading
• Performance metric = Throughput
(or missed detection)
3GPP LTE eNB Rx Conformance Tests (36.141)
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Receiver Characteristics Wanted Signal Interfering Signal Dynamic Range(wanted interferer)
Agilent Solution
7.2 Reference Sensitivity LevelFRC A1-1, 1-2, 1-3
QPSK ModNone required for this test -- Signal Studio +MXG
7.3 Dynamic RangeFRC A2-1, 2-2, 2-3
16QAM ModAWGN 12.4 dB Signal Studio + MXG
7.4 In-Channel SelectivityFRC 1-2, 1-3, 1-4, 1-5
QPSK ModE-UTRA with all BW 21.5 dB Signal Studio + MXG
7.5 Adjacent Channel SelectivityFRC A1-1, 1-2, 1-3
QPSK Mod
E-UTRA
Offsets up to 2.5 MHz*48.1 dB Signal Studio + MXG
7.5 Narrowband BlockingFRC A1-1, 1-2, 1-3
QPSK Mod
E-UTRA
Offsets up to 4.66 MHz*51.1 dB Signal Studio + MXG
7.6 Blocking
(in-band)
FRC A1-1, 1-2, 1-3
QPSK Mod
CW or E-UTRA
Offsets up to 7.5 MHz*57.1 dB Signal Studio + MXG + PXB
7.6 Blocking
(out-of-band)
FRC A1-1, 1-2, 1-3
QPSK Mod
CW
Offsets up to 12.75 GHz85.1 dB Signal Studio + MXG + PSG
7.6 Blocking
(Co-location with other base stations)
FRC A1-1, 1-2, 1-3
QPSK Mod
CW
Freq from 728 MHz to 2690 MHz116.1 dB Signal Studio + MXG + MXG
7.7 Receiver Spurious Emissions NA NA NA MXA Spectrum Analyzer
7.8 Receiver IntermodulationFRC A1-1, 1-2, 1-3
QPSK Mod
CW offset up to 7.5 MHz* &
E-UTRA offset up to 18.2 MHz*48.1 dB Signal Studio + MXG + PXB
7.8 Receiver Intermodulation
(Narrow Band Intermodulation)
FRC A1-1, 1-2, 1-3
QPSK Mod
CW offset up to 415 kHz* &
E-UTRA offset up to 1780 kHz*48.1 dB Signal Studio + MXG + PXB
LTE eNB Receiver Test ChallengeseNB Conformance Tests – Receiver Characteristics
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LTE eNB Receiver Test ChallengeseNB Conformance Tests – Performance Requirements
Performance Requirements Wanted Signal Channel ModelChannel
ConfigurationFeedback
Agilent
Solution
8.2.1 PUSCH in Multipath Fading
Propagation Conditions
FRC A3, A4, A5
QPSK, 16QAM, 64QAM
EPA 5 Hz
EVA 5, 70 Hz
ETU 70, 300 Hz
1x2 (2x RX diversity)
1x4 (4x RX diversity)HARQ Real-time
8.2.2 UL Timing Adjustment
FRC A7, A8
QPSK & 16QAM
(SRS is optional)
Moving Propagation Model
a. ETU 200 Hz
b. AWGN
2x2 (2x RX diversity)
2x4 (2x RX diversity)
(Stationary & moving UE)
HARQ &
timing adjustment
Real-time +
Waveform Playback
8.2.3 HARQ-ACK Multiplexed on
PUSCH
FRC A3-1, A4-3 to A4-8
QPSK, 16QAMETU 70 Hz 1x2 (2x RX diversity) -- Waveform Playback
8.2.4 High Speed Train Conditions
FRC A3-2 to A3-7
QPSK
(PUCCH is optional)
High Speed Train with:
a. Open Space
b. Tunnel for multi-antenna
1x2 (2x RX diversity)
1x4 (4x RX diversity)HARQ Real-time
8.3.1 ACK Missed Detection
for Single User PUCCH Format 1aPUCCH ACK
EPA 5 Hz
EVA 5, 70 Hz
ETU 70, 300 Hz
1x2 (2x RX diversity)
1x4 (4x RX diversity)--
Real-time or
Waveform Playback
8.3.2 CQI Missed Detection
for PUCCH Format 2PUCCH CQI ETU 70 Hz
1x2 (2x RX diversity)
1x4 (4x RX diversity)--
Real-time or
Waveform Playback
8.3.3 ACK Missed Detection
for Multi User PUCCH Format 1aPUCCH ACK ETU 70 Hz
4x2 (2x RX diversity)
(Requires 3 interferers)-- Waveform Playback
8.4.1 PRACH False Alarm
Probability and Missed DetectionPRACH Preamble
ETU 70 Hz
AWGN (no fading)
1x2 (2x RX diversity)
1x4 (4x RX diversity)-- Waveform Playback
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LTE eNB Receiver Test Challenges
R&D Lifecycle RX Test Considerations Test Solution Implications
RF Front End Verification Linearity, EVM, Noise Figure, LO phase noise →Simple signals (i.e., CW or statically correct)
for initial RX testing
Baseband Chipset Development BER/BLER measurements → Transport channel coding
Baseband Chipset Development Functional verification → Advanced feature set for testing HARQ, etc
Baseband Chipset Development Verify performance in real-world conditions →Real-time channel emulation (fading)
Calibrated AWGN
Baseband Chipset Development Rx Diversity → Multiple synchronized baseband generators
RF & Baseband Integration Verify performance in real-world conditions →Real-time channel emulation (fading)
Calibrated AWGN
System Design Validation Interference tests → Simulation of modulated or CW signals
System Design Validation Interoperability tests → Simulation of multiple cellular formats
Pre-Conformance TestAWGN, Channel Emulation, HARQ, Timing
Adjustments, transport channel coding →Complex signaling with closed loop feedback
from the eNB
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Agenda
• Brief review of LTE physical layer
• LTE physical layer Receiver tests
• Measurement solutions
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Agilent 3GPP LTE Test Solutions Rx RF Front End Verification
Generate simple test signals
• Create CW signals
• Create multi-tone signals
Generate simple LTE signals
• Ultimate physical layer flexibility
• Supports December 2009 version of LTE standard
• Selectable BW from 1.4 MHz to 20 MHz
• Select PUSCH modulation: QSPK, 16QAM, 64QAM
• Configurable data payloads
• Allocate resource blocks in frequency & time
Measure basic RF parameters
• Analyze amplitude flatness
• Measure gain at each stage
• Analyze phase linearity
• Determine noise figure
• Measure EVM of components & subsystems
Signal Studio- Uplink FDD LTE
- ARB basic capability
MXG Vector Signal Generator Receiver Front End
MXA Signal Analyzer
Analog I/Q,
Digital I/Q,
DigRF
RF
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Agilent 3GPP LTE Test Solutions Rx Baseband Verification
Generate sophisticated LTE signals
• Supports December 2009 version of LTE standard
• Transport channel coded PUSCH with frequency
hopping (inter and intra & inter subframe hopping)
• Uplink control multiplexing with PUSCH
• Process based frame configuration
• Test incremental redundancy with retransmitted
processes (HARQ)
• Sounding Reference Signal with frequency hoppingMXG Vector Signal Generator
Baseband Filter
Demodulator
I
Q
I
QSymbol
Decoder
Transport
Channel
Decoding
Output to
Higher
Layers
Signal StudioUplink FDD LTE
ARB advanced capability
Baseband Subsection
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Agilent 3GPP LTE Test Solutions Rx BB/RF Integration & System Test
First To Market Track Record
• Keeping pace with evolving LTE standard
• Supports both FDD & TDD frame structures
• Supports December 09 version of LTE standard
• Beta program for latest changes to standard
Scalable Test Solutions
• Tailor capability & performance from SISO to MIMO
• Easily upgrade as your test needs evolve
• Multi-format application support
for interoperability / interference testing
- LTE, W-CDMA/HSPA, GSM/EDGE, cdma2000,
1xEV-DO, WiMAX, WLAN …
High Performance
• Real-time uplink LTE signal creation
• Real-time MIMO channel emulation
• Simplified power calibration
• Wide bandwidth – ready for LTE Advanced (Rel 10)
Signal Studio
MXG Vector Signal Generators
PXB BBG & Channel Emulator
00h
01h
Tx0 Rx0
Rx1
RX Diversity
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Agilent 3GPP LTE Test Solutions Interference and Interoperability Test
Configuration flexibility
• Create (SS): LTE, W-CDMA/HSPA, GSM/EDGE,
cdma2000, 1xEV-DO, WiMAX, WLAN …
• Up to four internal baseband generators
• Sum CW carriers with wanted signal
• Sum modulated carriers with wanted signal
• Sum custom Matlab waveforms with wanted signal
• Add calibrated AWGN for accurate C/N ratios
Scalable Test Solutions
• Tailor capability & performance from SISO to MIMO
• Easily upgrade as your test needs evolve
• Connect to ESG, MXG, & DSIM for signal creation
• Connect to MXA for RF fading applications
• Field upgradable with calibrated DSP blocks
High Performance
• Real-time uplink LTE signal creation
• Real-time MIMO channel emulation
• Simplified power calibration
• Wide bandwidth – ready for LTE Advanced (Rel 10)
PXB BBG & Channel Emulator Interoperability testing
∑
Signal StudioMXG Vector Signal Generator
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Agilent 3GPP LTE Test Solutions Rx Conformance Test
Real-time LTE Signal Generation
• PXB accepts closed loop feedback
• HARQ ACK/NACK signals
• Timing adjustment feedback
• LTE signal continuously adjusted based on feedback
• Predefined Fixed Reference Channel definitions
Real-time Channel Emulation
• Standards based channel models
• Custom defined channel models
• 24 paths of fading
• 120 MHz modulation bandwidth
• Simplified power calibration
Interfering Signals
• Add CW blocking signals
• Add modulated signals for blocking &interoperability test
• Calibrated AWGN for accurate C/N ratios
RF
Digital I/Q
Feedback
Signal StudioUplink FDD LTE
Real-time capability
eNBPXB BBG & Channel Emulator
MXG Vector Signal Generator
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HARQ / Incremental RedundancyConcepts
Coding
Original data
NACK
1st TX
IR Buffer in Receiver
2nd TX
NACK
RV Index=1
3rd TX
ACK
RV Index=2
Rate Matching
RV Index=0
Effects of Propagation
i.e., 1/3 CC and then RM to make Block Size
Match Radio Frame
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HARQRV Index Test Assignments
Process # HARQ
Response
RV Index
0 ACK 0
1 ACK 0
2 ACK 0
3 ACK 0
7 NACK 1
0 NACK 1
0 NACK 2
0 NACK 3
0 ACK 0
RV Index is
incremented for
each process for
each NACK
response using
defined sequence
shown at left of
slide
RV Index
Sequence
0
1
2
3
3
Maximum RV
Index sequence
length is 15 in
software
The RV Index
sequence is
user definable.
RV Index value
can range from
0 to 3
1
2
3
15
RV Index reset to
“0” after receiving
n NACKs to reach
end of RV Index
Sequence or when
ACK is received
RV Index “0” is
used for each ACK
response
HARQ feedback can be from external
CMOS 3.3 V or RS-232 input into PXB,
or from a predefined programmable
ACK/NACK sequence.
Example of how RV Index works
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Timing AdjustmentConformance Test Concept
Moving UE simulates changing propagation path lengths
In this example, the mobile UE is assigned blue Resource Blocks
Stationary UE
eNB Frame Timing
1 symbol (2048·Ts)
Normal Cyclic Prefix
Res
ou
rce
Blo
ck
s
Moving UE signal can arrive at wrong eNB frame timing as path length changes
UE transmission interferes with next symbol without timing adjustment
Details
• Stationary UE and moving UE transmit in same
subframe, but with different subcarriers
• Moving UE simulates changing propagation path
lengths & therefore different arrival times at eNB
• eNB must command moving UE to advance or delay
timing of transmission such that the signal arrives at
eNB with proper frame timing, i.e. does not overlap into
adjacent symbols
• Timing adjustment test is performed with even
subfames occupied
• Sounding Reference Signal (SRS) is optional for this
test
• This test is performed with real-time HARQ feedback
eNB
Timing Adjustment transmitted back to
UE, to align UE with eNB frame timing
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PXB Closed Loop Test ConceptHARQ & Timing Adjustment Tests
10MHz
HARQ ACK/NACK
Digital I/Q
Baseband w/ Fading
10MHzLAN
GPIB
Frame Pulse
Signal Studio
N7624B 3GPP LTE FDD
eNB
RF
Throughput Testing Equipment Configuration
N5182A MXG
N5106A PXB
Timing Adjustment
CMOS 3.3 V inputs from eNB
•HARQ – Level triggered or serial data
•Timing Adjustment – serial data
•Feedback can be multiplexed into one line
Dynamically Changing RF
•Frame Timing based on TA
•RV Index based on ACK/NACK
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Digital IQ
Timing Adjustment
Digital IQ
HARQ ACK/NACKSignal StudioReal-time LTE
(Moving UE)
PXB
eNBSignal StudioARB LTE
(Stationary UE)
MXG
CMOS 3.3V Signals
Typical Conformance Test ConfigurationsUL Timing Adjustment Configuration
RF
RF
Digital IQ
Signal StudioReal-time LTE
(Moving UE)
PXB
eNBSignal StudioARB LTE
(Stationary UE)
CMOS 3.3V Signals
RF
HARQ ACK/NACK & Timing Adjustment
RF
RF
RF
2x4 MIMO case
2x2 MIMO case
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Digital IQ
Digital IQ RF
RF
PXBeNBSignal Studio
ARB LTE
(Wanted UE)
MXG
Typical Conformance Test ConfigurationsMulti-User PUCCH Test - 4x2 MIMO Case
Agilent Configuration
Note: Closed loop feedback not required for this test
Signal StudioARB LTE
(Interfering UE’s)
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Agilent N5106A PXBBaseband Generator & Channel Emulator
Page 35
RF
Analog I/Q
- Direct from PXB
- Connect to any DUT or RF
vector signal generator with
analog I/Q inputs
RF
Digital I/Q
Signal OutputsSignal Inputs
Performance & Scalability to Meet Future Testing Needs
Signal Creation Tools
ESG or MXGPXB
MXA
N5102A
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Agilent SolutionsAddressing eNB LTE Test Challenges Today
N7624B/25B Signal Studio for 3GPP LTE FDD/TDD
• Real-time LTE signal creation options
• Creates all required wanted signals for Receiver Characteristics
• Creates all required wanted signals for Performance Requirements
(including closed loop requirements)
• Waveform playback LTE options
• Ultra flexible parameter adjustment for R&D troubleshooting
• Perform conformance tests without closed loop control
N5106A PXB Baseband Generator and Channel Emulator
• Adds real-time channel emulation (fading)
• Creates interfering LTE and CW signals (and other formats)
• Adds calibrated AWGN to signal
• Creates MIMO-like configurations (fading + summing, etc)
• Adds real-time baseband generator for LTE software
N5182A MXG vector signal generator
• Upconverts LTE baseband signal with interferers and channel emulation from PXB to RF
• Used stand-alone (without PXB) with Signal Studio waveform playback options
PXB BBG & Channel Emulator
MXG Vector Signal Generator
Signal StudioUplink LTE
Real-time capability
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Agilent SolutionsKey Benefits
Most Cost Effective eNB Rx Testing
• Leverage existing ESG/MXG investments
• Easily scale to higher order MIMO configurations
• Prepare for evolving LTE standard including IMT Advanced
The Fastest Time to Market
• Perform all eNB Rx conformance tests now including closed loop requirements
• Supports December 2009 version of LTE standard
• Predefined setups for required Fixed Reference Channels (FRC) and fading models
• Flexible parameter adjustments for troubleshooting problems
• Dedicated LTE application engineer support available
Best Way to Minimize LTE Design Uncertainties and Rework
• More robust design validation early in the R&D lifecycle
• Consistent test signals from BB to RF
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Thank You!
Questions?