Understanding Unde rstanding the Intricac Intricacies ies of
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Keysight LTE Design & Test Portfolio LTE Major
Features
FDD Frame Structures
TDD Frame Structures
FDD Downlink Frame Structure
DL, UL, and Special Subframe
Feature
Capabilit y
Access Acc ess mod modes es
FDD and TDD – with with a commo commonn 10 10 ms fra frame me timi i ming n g but but diffe ifferen rentt frame frame str struct ucture uress
Variable channel bandwidth
1.4, 3, 5, 10, 15, and 20 MHz All bandwidths apply forFDD and TDD
160
2048
144
2048
Baseline i ne UE UE capabili capability ty
20 MHz MHz UL and DL, DL, two two Rx anten antennas, nas, one Tx antenna e nna
CP
0
CP
1
User data rates
DL: 172.8 Mbps (2x2 single user MIMO, 64QAM); UL: 86.4 Mbps (single link 64QAM)
Downli Dow nlink n k transmis a nsmissio sionn
OFDMA OFD MA using using QPSK, QPSK, 16QA 16QAM, M, 64QAM 64QAM
Uplink i nk tran transmi smissi s sion on
CP
2048
144
2048
CP
2
144
2048
CP
3
144
2048
CP
4
5
144
2048
CP
One radio frame, T f = 307200 x Ts = 10 ms
(x Ts)
One half-frame, 153600 x Ts = 5 ms
6
etc. The cyclic prefix is created by prepending each symbol with a copy of the end of the symbol
One subframe (1 ms)
1 slot = 15360 x Ts Ts = 0.5 ms
0 1 2 3 4 5 6 0 1 2 3 45 6
Single Sin gle carri carrier e r FDMA FDMA (SC-FD (SC-FDMA) MA) usin usingg QPSK, QPSK, 16QAM, 16QAM, 64QAM 64QAM
DL spati spatial a l diversit v ersityy
144
#0
#1
#2
One slot (0.5 ms)
#3
#4
#5
#6
DwPTS
GP
#5
#6
#7
Optional Optio nal open open loop loop Tx diver diversity, sity, 2x2 multi-user t i-user MIMO, MIMO, option optional al 2x2 single user MIMO
Trans Tr ansmis missio sionn time time interv interval al
1 ms
H-ARQ retr retransmi ansmission s sion time
8 ms
Frequency hopping
Intra-TTI: UL once per 0.5 ms slot, DL once per 66 μs symbol Inter-TTI across retransmissions
Bearer services
Packet only – no circuit switched voice or data services are supported
DwPTS
1 frame = 10 sub-frames = 10 ms #0
voice must use VoIP
→
#1
#2
#3
#4
#5
#6
#7
#8
#9
#10
#11
#12
#13
#14
#15
#16
#17
#18
GP
Special subframe (1 ms)
UpPTS
#0
#1
DwPTS
Enhanced multimedia broadcast/multicast service (eMBMS) supporting multicast/broadcast over single frequency network (MBSFN) – Release 9
#2
GP
#3
UpPTS
#4
#7
#9
Special subframe (1 ms)
TDD 5 ms Switch Periodicity Mapping 16QAM
64QAM
N DL symb OFDM symbols (= 7 OFDM symbols at normal CP)
Q PS K 160
2048
CP
0
LTE-Advanced Features
144 CP
2048 1
144
2048
144
2048
144
2048
CP
2
CP
3
CP
4
etc. The cyclic prefix is created by prepending each symbol with a copy of the end of the symbol
1. Carrier Aggregation
3. Relayi Relaying ng
Carrier Aggregation is the creation of wider bandwidths through the aggregation of 20 MHz contiguous and non-contiguous component carriers to achieve up to 100 MHz of spectrum.
The relay method is the use of a repeater, which receives, amplifies, and then retransmits the d ownlink and uplink signals to overcome areas of poor coverage.
DwPTS (3-12symbols)
144
2048 5
CP
P-SS Frequency P-SS – Primary synchronization signal is transmitted on symbol 6 of slots 0 and 10 of each radio frame S-SS – Secondary synchronization signal is transmitted on symbol 5 of slots 0 and 10 of each radio frame PBCH – Physical broadcast channel is located in 4 symbols of sub-frame 0 only on symbols 0 to 3 of slot 1
Relay node
Band A
PDCCH – Physical downlink control channel exists on all sub-carriers at the start of the first slot PDSCH – Physical downlink shared channel – carries the payload data for multiple users Reference signal – (Pilot) – Reference signals are located at symbol 0 and symbol 4 of every slot
GP (1-10symbols)
144
2048
CP
(x Ts)
6
1 slot = 15360 x Ts Ts = 0.5 ms Ts = 1/(15000 x 2048) = 32.6 ns
UpPTS (1-2symbols)
0123456 0123456 0123456 0123456 0123456 0123456
e i m T
Component Carrier (CC) Up to 20 MHz BW
f
#8
UpPTS
For 10 ms switch-point periodicity
#19
FDD Downlink Physical Mapping
Unicast scheduling schemes Frequency selective (partial band); Frequency equency diversity by frequency requency hopping
Band A
#9
1 sub-frame = 2 slots = 1ms
Openn loop Ope loop Tx diversit v ersity Sin Single gle-us -user er MIMO M O up to to 4x4 supp support ortabl a ble
f
#8
Ts = 1/(15000 x 2048) = 32.6 ns
UL spatial spatial diver diversity sity
Multicasting
Ts = 1/(15000 x 2048) = 32.552 nsec Ts = Time clock unit for definitions
For 5 ms switch-point periodicity
DL Nsymb OFDM symbols (= 7 OFDM symbols at normal CP)
S-SS
Reference signal (Demodulation)
PBCH
PUCCH
PDCCH
UpPTS – Uplink pilot time slot
PDSCH
DL/UL subframe
FDD Uplink Physical Mapping
Relay node
Relay node
Band B
2. Clust Clustered ered SC-FDMA with simultaneous PUSCH/PUCCH PUSCH/PUCCH For the uplink, clustered SC-FDMA is similar to SC-FDMA but has the advantage that it allows non-contiguous (clustered) groups of subcarriers to be allocated for transmission by a single UE, enabling uplink frequency-selective scheduling. In addition, there can be simultaneous transmission of control and data channels by allowing the PUSCH (Physical Uplink Shared Channel) and the PUCCH (Physical Uplink Control Channel) to be transmitted simultaneously. Different scenarios
Comparing OFDMA and SC-FDMA
4. Enha Enhanced nced multiple antenna transmission 16QAM
Downlink: 8 antennas, 8 streams Uplink: 4 antennas, 4 streams
64QAM
QPSK
Zadoff-Ch u PUSCH ≥ 3RB
BP SK (1a)
QPSK (1b)
–1, 1
QPSK PUSCH < 3RB orPUCCH
–1,–1
e m i T
fc
Signal Creation — UL/DL
A M o l D F b O m s y
–1, 1
1, –1
–1,–1
1, 1
1, –1
–1, 1
A M o l D F b O m s y
Frequency
15 kHz
t e r M A t a n o w - D n s r p F d C o a r r i e h S C e r i o c c a l p b s u i n g e m b o r y d u s e m i T
fc
A M l F - D b o S C s y m A M l F - D b o S C s y m
CP
Frequency
60 kHz SC-FDMA
LTE downlink: Uses OFDMA multi-carrier modulation scheme with closely-spaced orthogonalsub-carriers.
Frequency
Baseband Analysis
V
CP
OFDMA
Physicaluplin k sharedchannel(PUSCH)
Physicaluplink controlch annel(PUCCH)
Demodulation referencesignal forPUSCH
Demodulation referencesignal for PUCCH format1a/1b
Keysight Covers the Simulation
–1,–1
Sequence of QPSK data symbols to be transmitted
1, –1
e m i T
The network includes a mixture of different base station classes such as local area BS (picocell), home BS (femtocell) and relay node, all occupying the same frequency. This scenario has been termed “het-net” for short.
PUCCH PUC CH
1, 1
QPSK modulating data symbols V
Coordinated multipoint (CoMP) is an advanced variant of MIMO. The difference between the two systems is that with coordinated multipoint, the transmitters do not have to be physically co-located, although they are linked by some type of high speed data connection and can share payload data.
support
PUSCH
1, 1
I
5. Coordinated multipoint
6. Heterog Heterogeneous eneous network
Frequency
Q
The graph shows an example sequence of eight QPSK symbols with four sub-carriers. For OFDMA, four symbols are taken in parallel, each modulating its own sub-carrier at the appropriate QPSK phase. After one OFDMA symbol period, a guard period called the cyclic prefix (CP) is inserted before the next OFDMA symbol period. For SC-FDMA each symbol is transmitted sequentially and the four data symbols are transmitted in one SC-FDMA symbol period. The higher rate data symbols require four times the spectrum bandwidth. Note the OFDMA and SC-FDMA symbol periods are the same.
LTE uplink: Uses single carrier frequency division multiple access (SC-FDMA) to reduce peak to average ratio and power consumption.
LTE and LTE-Advanced Lifecycle
Signal Analysis — UL/DL
UE Integration and Verification
Conformance Test
Manufacturing Manufacturin g
Install/Maintenance
N6070A Series Signaling Conformance Test System PXB Baseband Generator and Channel Emulator
SystemVue
M9381A PXIe Vector Signal Generator
89600 VSA for FDD and TDD with MIMO
Infiniium 90000 X-Series Oscilloscope
6607B EXT Wireless Communications Test Set and E6617A Multi-port Adapter
E6621A PXT Wireless Communications Test Set
16800 Series Portable Logic Analyzer
LTE Measurement MeasurementApplication Application
FieldFox RF Handheld Analyzer
Handheld Spectrum Analyzer
N7109A Multi-Channel Signal Signal Studio Software
89600 WLA Wireless Link Analysis Software
Wireless Design Library MXG Signal Generator
RDX DigRF Test Environment
X-Series Signal Analyzers
Interactive Functional Test (IFT) Software N6781A 2-Quadrant Battery Drain Analysis
HARDWARE + SOFTWARE + PEOPLE = LTE-A INSIGHTS
T4010S LTE RF Conformance Test System MXA Signal Analyzer with MXG Signal Generator
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Handheld RF Cable and Antenna Tester
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