AgilentLTE

Concepts of 3GPP LTE

Sonali Sarpotdar 16 Jan 2008

Agenda

• LTE Context and Timeline • LTE major features • Overview of the LTE air interface • Agilent LTE design and test solutions • • • • •

Simulation Baseband Sources Analysis Integrated mobile test platform

Concepts of 3GPP LTE Page 2

Agenda

• LTE Context and Timeline • LTE major features • Overview of the LTE air interface • Agilent LTE design and test solutions

Concepts of 3GPP LTE Page 3

3GPP standards evolution (RAN & GERAN) Release Commercial Main feature of Release introduction

1999

2010 Concepts of 3GPP LTE Page 4

Rel-99

2003

Basic 3.84 Mcps W-CDMA (FDD & TDD)

Rel-4

Trials

1.28 Mcps TDD (aka TD-SCDMA)

Rel-5

2006

HSDPA

Rel-6

2007

HSUPA

Rel-7

2008+

HSPA+ (64QAM DL, MIMO 16QAM UL). Many smaller features plus LTE & SAE Study items

Rel-8

2009-10?

LTE Work item – OFDMA air interface SAE Work item New IP core network Edge Evolution, more HSPA+

LTE context and timeline The many faces of LTE • LTE is the 3GPP project name for the evolution of UMTS • LTE is now linked with the development of a new air interface but the evolution of UMTS via HSDPA and HSUPA is still happening • The official terminology for the new LTE radio system is: • Evolved UTRA / Evolved UTRAN • Evolved UMTS Terrestrial Radio Access • Evolved UMTS Terrestrial Radio Access Network

• Earlier names for this included: • 3.9G • HSOPA - Evolution of HSDPA/HSUPA with OFDM • Super 3G

• This naming is not standard and may fade out but 3.9G is likely to stick • For this paper LTE is assumed to be E-UTRA & E-UTRAN • SAE – System Architecture Evolution refers to the evolved core network

Concepts of 3GPP LTE Page 5

Wireless evolution – five competing 3.9G systems 2G

IS-95A cdma

IS-136 TDMA

GSM

PDC

802.11b

802.11a 2.5G

3G

IS-95B cdma

HSCSD

GPRS

iMode 802.11g

E-GPRS EDGE

IS-95C cdma2000

W-CDMA FDD

W-CDMA TDD

TD-SCDMA LCR-TDD

802.11h

802.11n 3.5G

3.9G

1xEV-DO Release 0

UMB cf 802.20

Concepts of 3GPP LTE Page 6

1xEV-DO Release A

LTE E-UTRA

HSDPA FDD & TDD

1xEV-DO Release B

EDGE Evolution

HSPA+

HSUPA FDD & TDD

802.16e Mobile WiMAXTM

802.16d Fixed WiMAXTM WiBRO

LTE in context • LTE is just one of five major new wireless technology developments • • • • •

3GPP LTE 3GPP HSPA+ 3GPP Edge Evolution 3GPP2 UMB (similar to 802.20) IEEE WiMAX – (802.16e / WiBRO)

• All five systems share very similar goals in terms of spectral efficiency, with the wider systems providing the highest single user data rates • Spectral efficiency is primarily achieved through use of less robust higher order modulation schemes and multi-antenna technology ranging from basic Tx and Rx diversity through to full MIMO • HSPA+ and Edge Evolution are natural extensions to existing technologies • LTE, UMB and WiMAX are new OFDM systems with no technical precedent other than the early implementation of WiBRO which is now a WiMAX profile. Concepts of 3GPP LTE Page 7

LTE standards development timing Rel-7 Study Phase Rel-8 Work Phase Test Specs

Core specs drafted

First UE certification?

Commercial release?

First Test Specs drafted

2005

2006

2007

2008

2009

2010

• 3GPP plan @ Aug 2007; Final specs - Feb 08, Initial Conformance tests - Sept 08 • Timeline has slipped about 6 months but still considered a stretch goal by many • Historically, test specs have been much more than 3 months after core specs but the gap between core specs and conformance is consistently dropping • UE certification not possible until after test implementation and validation • Commercial release is hard to predict but is very unlikely before 2010 Concepts of 3GPP LTE Page 8

Agenda

• LTE Context and Timeline • LTE major features • Overview of the LTE air interface • Agilent LTE design and test solutions

Concepts of 3GPP LTE Page 9

LTE major features Feature

Capability

Access modes

FDD & TDD – each with their own frame structure

Variable channel BW

1.4, 3 , 5, 10, 15, 20 MHz All bandwidths supported by FDD and TDD

Concepts of 3GPP LTE Page 10

Baseline UE capability

20 MHz UL/DL, 2 Rx, one Tx antenna

User Data rates

DL 172.8 Mbps / UL 86.4 Mbps @ 20 MHz BW (2x2 DL SU-MIMO & non-MIMO 64QAM on UL)

Downlink transmission

OFDM using QPSK, 16QAM, 64QAM

Uplink transmission

SC-FDMA using QPSK,16QAM, 64QAM

DL Spatial diversity

Open loop TX diversity Single-User MIMO up to 4x4 supportable

UL Spatial diversity

Optional open loop TX diversity, 2x2 MU-MIMO, Optional 2x2 SU-MIMO

LTE major features Feature

Capability

Transmission Time Interval 1 ms

Concepts of 3GPP LTE Page 11

H-ARQ Retransmission Time

7 or 8ms* (This is tight and one of the hardest specs to meet in baseband) *under negotiation

Frequency reuse

Static & semi-static (reuse per UE)

Frequency hopping

Intra-TTI:

Bearer services

Packet only – no circuit switched voice or data services are supported
voice must use VoIP

Unicast Scheduling schemes

Frequency selective (partial band) Frequency diversity by frequency hopping

Multicasting

Enhanced MBMS with SFN and cell-specific content

Uplink once per .5ms slot Downlink once per 66μs symbol Inter-TTI Across retransmissions

Why did 3GPP want LTE? • Much untapped potential in HSDPA + HSUPA (HSPA+) • But some LTE requirements can’t be met by HSPA+ • LTE goal is to provide further benefits • • • •

Spectrum Flexibility Higher Peak Data Rates with wider 20 MHz channel bandwidth OFDM Access better suited for Broadcast Services OFDM enables less complex implementation of Advanced Antennas/MIMO Technology • Reduced terminal complexity

• LTE itself has some less complex aspects • But terminals will have to carry the legacy of GSM, GPRS, W-CDMA and HSPA which increases overall complexity Concepts of 3GPP LTE Page 12

LTE vs. HSPA+ Attribute

HSPA+ (Rel-8)

LTE targets

Peak Data Rate / 5 MHz sector in ideal radio conditions

DL – 42 Mbps UL – 10 Mbps

DL – 43.2 Mbps UL – 21.6 Mbps

Peak Data Rate / 20 MHz sector in ideal radio conditions

Not possible without multi-carrier

DL – 172.8 Mbps UL – 86.4 Mbps

Cell Edge improvement compared to HSPA Release 6 Spectral Efficiency (real world)

Evolved HSPA & LTE - DL – 3x to 4x; UL – 2x to 3x All solutions will benefit from ongoing improvements to the radio interface such as UE RX diversity, equalization, interference cancellation; MIMO, higher order modulation etc.

Latency: End to End Ping Delay

40 ms

Latency: Idle to Active

Currently around 600ms Goal to reduce to 100 ms

1Gbps leverage existing multi GHz serial technology to support higher speed interfaces. • Agilent is a MIPI member at Adopter level. N4850A N4860A

• Next Steps • Support digital serial stimulus and analysis for other RF-IC to BB-IC interfaces, integrated with RF stimulus/analysis, to provide comprehensive cross domain solutions. • Review the physical layer specifications for other (public and vendor-specific) interfaces between the RF-IC and the BB-IC to guide LTE specific implementation decisions. • Agilent is committed to providing test tools for DigRF v4.0. Concepts of 3GPP LTE Page 49

312Mbps DigRF v3 Digital Serial Acquisition Probe 312Mbps DigRF v3 Digital Serial Stimulus Probe

BB/RF Interface Stimulus / Analysis Overview Two modes of operation TEST EQPT

• Emulation: The stimulus and analysis pods actively drive and terminate the BB/RF bus, thus emulating the BB ASIC's interface. The test equipment provides support for RF ASIC configuration / control, and drives it with signal payload data.

(emulation)

BB ASIC

RF ASIC

TEST EQPT

• Spying: The analysis pod passively monitors the bus to collect data for further analysis. The test equipment parses the traffic and presents the transactions (XML-based protocol viewer) and payload (89601A Vector Signal Analyzer).

Concepts of 3GPP LTE Page 50

(spying)

BB ASIC

RF ASIC

RF-IC Validation (DigRF example) Signal Studio Signal Creation Software

MXG Signal Generator

N4860A Stimulus Probe

Tx

RF-IC

Rx

16900 Logic Analyzer

N4850A Acquisition Probe

MXA Spectrum Analyzer

89601A Vector Signal Analyzer software Concepts of 3GPP LTE Page 51

RF-IC / BB-IC Integration (DigRF example)

Signal Studio Signal Creation Software

MXG Signal Generator

DigRF RF DSP

BB-IC

uC

DigRF v3.xx

RF-IC DigRF v3.xx

Vis Port

89601A Vector Signal Analyzer Digital

Logic Analyzer

Concepts of 3GPP LTE Page 52

RF

Oscilloscope

Spectrum Analyzer

LTE Signal Generation Signal Studio Software User-friendly, parameterized and reconfigurable 3GPP LTE signal generation software for use in conjunction with Agilent ESG-C or MXG RF Signal Generators.

• Current Status • Spectrally correct version available since April 07 • Fully coded version released recently • Now based on TS 36.211 V8.0.0 – DL Physical channel framing – Reference signal, Synchronization signal – PDSCH, PDSCH, PDCCH, PBCH – UL Physical channel framing – Reference signal (Demodulation and Sounding) – PUSCH, PUCCH, PRACH E4438C (ESG(ESG-C) N5182A (MXG)

Concepts of 3GPP LTE Page 53

LTE Signal Generation N7624B Signal Studio V3.0.0.0 September 2007 Just released Signal Studio V3.0.0.0. Build your own custom LTE signals Based on the latest V8.0.0 (Sept 07) LTE physical layer specifications RF playback requires instrument license (free 14-day trial license available)

Download now at: www.agilent.com/find/signalstudio Concepts of 3GPP LTE Page 54

LTE Parametric Signal Analysis • Analyzes all LTE modulation types: BPSK, QPSK, 16QAM, 64QAM, CAZAC, and • • • • • •

OSxPRS Covers all bandwidths: 1.4MHz (6RB) to 20MHz (96/100 RB) Handles UL and DL, normal and extended Cyclic Prefix Advanced analysis of radio frame, subframe, resource blocks, and channels Auto detection and demodulation of DL user bursts P-SCH, S-SCH, PBCH, PDCCH, RS, PDSCH and PUSCH analysis EVM = -50dB (measurement platform dependent)

Concepts of 3GPP LTE Page 55

Agilent Confidential 13 Aug 2007

LTE Signal Analysis Downlink Capabilities (based on 36.211 V8.0.0) • Synchronisation to ADS 2006U1(or U2).407 Dev 1 generated LTE Downlink signals • Supports Antenna Port 0..3 RS pilot subcarrier/symbol mappings per TS36.211 OS and PN9 PRS • Supports latest PSCH using ZC root indices 25, 29, 34 for cell ID Groups 0, 1, 2 respectively. • Auto detect / report RS Orthogonal Sequence • Auto detection of RS PRS • Latest RS subcarrier antenna mappings • PDCCH can occupy the first L OFDM symbols in first slot of subframe, where L