tdd lte training material (agilent)

For internal use only1 © Nokia Siemens Networks

Concepts of 3GPP LTELong Term Evolution


Orthogonal Frequency Division Multiplexing

…

Sub-carriersFFT

Time

Symbols

5 MHz Bandwidth

Guard Intervals

…

Frequency

25.892 Figure 1: Frequency-Time Representation of an OFDM Signal

OFDM is a digital multi-carrier modulation scheme, which uses a large number of closely-spaced orthogonal sub-carriers. Each sub-carrier is modulated with a conventional modulation scheme (such as QPSK, 16QAM, 64QAM) at a low symbol rate similar to conventional single-carrier modulation schemes in the same bandwidth.


Why OFDM for the downlink?

OFDM already widely used in non-cellular technologies and was considered by ETSI for UMTS in 1998

CDMA was favoured since OFDM requires large amounts of baseband processing which was not commercially viable ten years ago

OFDM advantages

• Wide channels are more resistant to fading and OFDM equalizers are much simpler to implement than CDMA

• Almost completely resistant to multi-path due to very long symbols

• Ideally suited to MIMO due to easy matching of transmit signals to the uncorrelated RF channels

OFDM disadvantages

• Sensitive to frequency errors and phase noise due to close subcarrier spacing

• Sensitive to Doppler shift which creates interference between subcarriers

• Pure OFDM creates high PAR which is why SC-FDMA is used on UL

• More complex than CDMA for handling inter-cell interference at cell edge


CDMA vs. OFDM

CDMA

• All transmissions at full system bandwidth

• Symbol period is short – inverse of system bandwidth

• Users separated by orthogonal spreading codes

OFDM

• Transmission variable up to system bandwidth

• Symbol period is long – defined by subcarrier spacing and independent of system bandwidth

• Users separated by FDMA & TDMA on the subcarriers


OFDM vs. OFDMALTE uses OFDMA – a variation of basic OFDM

OFDM = Orthogonal Frequency Division Multiplexing

OFDMA = Orthogonal Frequency Division Multiple Access

OFDMA = OFDM + TDMA

User 1

User 2

User 3

Subcarriers

Sym

bols (Tim

e)

OFDM

Subcarriers

Sym

bols (Tim

e)

OFDMAOFDMA’s dynamic allocation enables better use of the channel for multiple low-rate users and for the avoidance of narrowband fading & interference.


LTE uses SC-FDMA in the uplinkWhy SC-FDMA?

SC-FDMA is a new hybrid modulation technique combining the low PAR single carrier methods of current systems with the frequency allocation flexibility and long symbol time of OFDM

SC-FDMA is sometimes referred to as Discrete Fourier Transform Spread OFDM = DFT-SOFDM

TR 25.814 Figure 9.1.1-1 Transmitter structure for SC-FDMA.

DFT Sub-carrier

Mapping

CP insertion

Size-NTX Size-NFFT

Coded symbol rate= R

NTX symbols

IFFT

Frequency domain Time domainTime domain


Comparing OFDM and SC-FDMAQPSK example using N=4 subcarriers

The following graphs show how this sequence of QPSK symbols is represented in frequency and time

1, 1 -1,-1 -1, 1 1, -1 1, 1 -1,-1 -1, 1 1, -1

15 kHzFrequency

fc

V

Time

OFDMA

sym

bol

OFDMA

sym

bol

CP

OFDMAData symbols occupy 15 kHz for

one OFDMA symbol period

SC-FDMAData symbols occupy N*15 kHz for

1/N SC-FDMA symbol periods

60 kHz Frequencyfc

V

Time

SC-FDM

A

sym

bol

SC-FDM

A

sym

bol

CP


OFDM modulationQPSK example using N=4 subcarriers

1,1 +45°

-1,-1 +225°

-1,1 +135°

1,-1 +315°

f0

(F cycles)

f0 + 15 kHz(F+1 cycles)



One OFDMA symbol period

…

…

…

…

Each of N subcarriers is encoded with one QPSK symbol

N subcarriers can transmit N QPSK symbols in parallel

One symbol period

The amplitude of the combined four carrier signal varies widely depending on the symbol data being transmitted

With many subcarriers the waveform becomes Gaussian not sinusoidal

Null created by transmitting 1,1 -1,-1 -1,1 1,-1

1,1-1,1

1,-1-1,-1

I

Q


SC-FDMA modulationQPSK example using N=4 subcarriers

To transmit the sequence:

1, 1 -1,-1 -1, 1 1,-1

using SC-FDMA first create a time domain representation of the IQ baseband sequence

+1

-1

V(Q)

One SC-FDMA symbol period

+1

-1

V(I)

One SC-FDMA symbol period

Perform a DFT of length N and sample rate N/(symbol period) to create N FFT bins spaced by 15 kHz

V,Φ

Frequency

Shift the N subcarriers to the desired allocation within the system bandwidth

V,Φ

Frequency

Perform IFFT to create time domain signal of the frequency shifted original

1,1-1,1

1,-1-1,-1

Insert cyclic prefix between SC-FDMA symbols and transmit

Important Note: PAR is same as the original QPSK modulation

1,1-1,1

1,-1-1,-1

I

Q


What is MIMO

Multi-Input Multi-Output

Space-Time Processing ( 2D processing )


SISO

Single-Input Single-Output

SIMO

Single-Input Multi-Output

MISO

Multi-Input Single-Out


Why MIMO

• Increasing channel capacity

• Increasing robustness

• Increasing coverageMIMO Classification

• Spatial Multiplexing

• Spatial Diversity


Spatial Multiplexing(2 Tx BS, 2 Rx MS)

• Matrix B with vertical encoding takes one set of data (“layer”) and maps it to 2 transmit streams, with half the data on each antenna: doubles the transmitted data rate (rate 2)

• Transmitted signals pass through 4 channels hxx. Signals at receive antennas are a combination of signals from both Tx antennas.

• Signal recovery requires knowledge of channels, which are estimated from pilots

[ ][ ] =[ ] s0

s1

r0

r1

h00 h01

h10 h11

R=HS or

S=H-1R

Bits to

Symbol

Mapping

e.g. QPSK

TxSymbol

toAntenna

Mapping

b0 ,b1 ,b2 ,b3... s0, s1, S2, S3, ...

1,1,1,0... -1-j1, 1-j1...

s0, s2...

s1 ,s3...

I

11

01 00

t1, t2 (time)

10

Q

Antenna 0

Antenna 1

r0, r2 ...

Rxr1, r3 ...

h00

h01

h10

h11

Antenna 0

Antenna 1


0 0 0 1 1 0 0 10 0 0

1 01 1 11 1 0 0 1 1

r h s h s n h hr s n

h hr s nr h s h s n ∗ ∗∗ ∗∗ ∗ ∗ ∗

= + + ⇒ = + ⇒ = + −= − + r Hs n

s0, -s1*

s1 ,s0*

TX

h0

h1

r0, r1 ...RX

Solution: 0 01 0 1

2 211 00 1

1

1s rh h

rh hh hs

∧∗∧

−∗∗∧

= = = −+ s H r

t1, t2

Transmission Diversity using Alamouti STBC


Single user MIMO

SU-MIMO

eNB 1 UE 1

Σ Σ

= data stream 1

= data stream 2


Multiple user MIMO

UE 2

UE 1

eNB 1

MU-MIMO

Σ

= data stream 1

= data stream 2


The LTE air interface

Consists of two main components – signals and channels

Physical signals

• These are generated in Layer 1 and are used for system synchronization, cell identification and radio channel estimation

Physical channels

• These carry data from higher layers including control, scheduling and user payload

The following is a simplified high-level description of the essential signals and channels.

eMBMS, MIMO and some of the alternative frame and CP configurations are not covered here for reasons of time


Signal definitions

DL Signals Full name Purpose

P-SCH Primary Synchronization Channel Used for cell search and identification by the UE. Carries part of the cell ID (one of 3 orthogonal sequences).

S-SCH Secondary Synchronization Channel

Used for cell search and identification by the UE. Carries the remainder of the cell ID (one of 170 binary sequences).

RS Reference Signal (Pilot) Used for DL channel estimation. Exact sequence derived from cell ID, (one of 3 * 170 = 510).

UL Signals Full name Purpose

RS (Demodulation) Reference Signal Used for synchronization to the UE and UL channel estimation


Channel definitions

DL Channels Full name Purpose

PBCH Physical Broadcast Channel Carries cell-specific information

PDCCH Physical Downlink Control Channel Scheduling, ACK/NACK

PDSCH Physical Downlink Shared Channel Payload

UL Channels Full name Purpose

PRACH Physical Random Access Channel Call setup

PUCCH Physical Uplink Control Channel Scheduling, ACK/NACK

PUSCH Physical Uplink Shared Channel Payload


Signal modulation and mapping

DL Signals Modulation Sequence Physical Mapping Power

Primary Synchronization Signal (P-SCH)

One of 3 Zadoff-Chu sequences

72 subcarriers centred around DC at OFDMA symbol #6 of slot #0

[+3.0 dB]

Secondary Synchronization Signal (S-SCH)

Two 31-bit M-sequences (binary) – one of 170 Cell IDs plus other info

72 subcarriers centred around DC at OFDMA symbol #5 of slot #0

Reference Signal (RS) OS*PRS defined by Cell ID (P-SCH & S-SCH)

Every 6th subcarrier of OFDMA symbols #0 & #4 of every slot

[+2.5 dB]

UL Signals Modulation Sequence Physical Mapping Power

Reference Signal (RS) uth root Zadoff-Chu SC-FDMA symbol #3 of every slot


Channel modulation and mapping

DL Channels Modulation Scheme Physical Mapping

Physical Broadcast Channel(PBCH) QPSK

72 subcarriers centred around DC at OFDMA symbol #3 & 4 of slot #0 and symbol #0 & 1 of slot #1. Excludes RS subcarriers.

Physical Downlink Control Channel (PDCCH) QPSK

OFDMA symbol #0, #1 & #2 of the first slot of the subframe. Excludes RS subcarriers.

Physical Downlink Shared Channel (PDSCH)

QPSK, 16QAM, 64QAM Any assigned RB

UL Channels Modulation Scheme Physical Mapping

Physical Random Access Channel (PRACH) QPSK Not yet defined

Physical Uplink Control Channel (PUCCH) BPSK & QPSK Any assigned RB but not

simultaneous with PUSCH

Physical Uplink Shared Channel (PUSCH)

QPSK, 16QAM, 64QAM

Any assigned RB but not simultaneous with PUCCH


OFDM (DL) – Physical Layer

Tim

eFrequency

1 ra

dio fr

ame

= 10

mse

c (3

0720

0 x

Ts)

#0#1

#2#3

#4#5

#19#18

#17#16

Sub-fram

e

NBWDL subcarriers

NBWRB subcarriers (=12)

Po

wer

1 sl

ot =

0.

5 m

sec


Physical Layer definitions – TS36.211Frame Structure

Ts = 1 / (15000x2048)=32.552nsec Ts: Time clock unit for definitions

Frame Structure type 1 (FDD/TDD)

FDD: Uplink and downlink are transmitted separatelyTDD: Subframe 0 and 5 for downlink, others are either downlink or uplink

#0 #2 #3 #18#1 ………. #19

One subframe

One slot, Tslot = 15360 x Ts = 0.5 ms

One radio frame, Tf = 307200 x Ts = 10 ms

Subframe 0 Subframe 1 Subframe 9


Agilent Confidential

Slot Structure ( Time Domain )

7 OFDM symbols @ Normal CP

Cyclic Prefix

160 2048 144 2048 144 2048 144 2048 144 2048 144 2048 144 2048

1slot = 15360 Ts

13 Aug 2007

0 1 2 3 4 5 6

6 OFDM symbols @ Extended CP

Cyclic Prefix

512 2048

1slot = 15360 Ts

4 5 54

512 2048 512 2048 512 2048 512 2048 512 2048

53210 4

( )2048150001s ×=T

3 OFDM symbols @Extended CP downlink only

Cyclic Prefix

1024 4096

1slot = 15360 Ts

0 1 21 2

1024 4096 1024 4096


Slot structure and physical resource elementDownlink – OFDM

NDLsymb OFDM symbols

One downlink slot, Tslot

:

:

NDLRB x NRB

sc subcarriers

Resource blockNDL

symb x NRBsc

Resource element(k, l)

l=0 l=NDLsymb – 1

NRBsc subcarriers

Condition NRBsc

NDLsymb

Frame Structure

type 1

Frame Structure type 2

Normalcyclic prefix ∆f=15kHz 12 7 9

Extendedcyclic prefix

∆f=15kHz 12 6 8

∆f=7.5kHz 12 3 4

Resource Block0.5 ms x 180 kHz


Slot structure and physical resource elementUplink – SC-FDMA

NULsymb SC-FDMA symbols

One uplink slot, Tslot

:

:

NULRB x NRB

sc subcarriers

Resource blockNUL

symb x NRBsc

Resource element(k, l)

l=0 l=NULsymb – 1

NRBsc subcarriers

Condition NRBsc

NULsymb

Frame Structure

type 1

Frame Structure

type 2

Normalcyclic prefix 12 7 9

Extendedcyclic prefix 12 6 8

Resource Block0.5 ms x 180 kHz


Physical Layer definitions – TS36.211Frame Structure (DL) – Slot/Frame

NsymbDL OFDM symbols (=7 OFDM symbols @ Normal CP)

Cyclic Prefix

160 2048 144 2048 144 2048 144 2048 144 2048 144 2048 144 2048 (x Ts)

1slot = 15360

10 2 3 4 5 6 10 2 3 4 5 6

0 1 2 3 4 5 6

P-SCH

S-SCH

PBCH

PDCCH

Reference Signal

1 frame1 sub-frame

1 slot

#0 #1 #8#2 #3 #4 #5 #6 #7 #9 #10 #11 #12 #19#13 #14 #15 #16 #17 #18

Ts = 1 / (15000x2048)=32.552nsec

ConfigurationCP length Guard interval

FS type1 FS type2

Normal CP ∆f=15kHz160 (#0) 512 (#8 slot#0)

224 otherwise0 (slot#)

288 otherwise144 (#1..#6)

Extended CP∆f=15kHz 512 (#0 .. 5) 768 (#7 slot#0)

512 otherwise0 (slot#)

288 otherwise

∆f=7.5kHz 1024 (#0..#2) 1280 (#3 slot#0)1024 otherwise -----


Ts = 1 / (15000x2048)=32.552nsec Ts: Time clock unit for definitions

Frame Structure type 2 (TDD)

DwPTS, T(variable)

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

Guard period, T(variable)

UpPTS, Ｔ (variable) One slot, Tslot =15360 x Ts = 0.5 ms

#7 #8 #9

For 5ms switch-point periodicity

For 10ms switch-point periodicity


TDD Downlink and Uplink Allocation

Configuration Switch-point

periodicity

Subframe number

0 1 2 3 4 5 6 7 8 9

0 5 ms D S U U U D S U U U

1 5 ms D S U U D D S U U D2 5 ms D S U D D D S U D D

3 10 ms D S U U U D D D D D

4 10 ms D S U U D D D D D D

5 10 ms D S U D D D D D D D

6 10 ms D S U U U D S U U D

•5ms switch-point periodicity: Subframe 0, 5 and DwPTS for downlink, Subframe 2, 7 and UpPTS for uplink•10ms switch-point periodicity: Subframe 0, 5,7-9 and DwPTS for downlink, Subframe 2 and UpPTS for Uplink


#0 #1 #8#2 #3 #4 #5 #6 #7 #9

10 2 3 4 5 6 10 2 3 4 5 6 10 2 3 4 5 6 10 2 3 4 5 610 2 3 4 5 61 0 2 3 4 5 6


Cyclic Prefix

160 2048 144 2048 144 2048 144 2048 144 2048 144 2048 144 2048 (x Ts)

1slot = 15360

0 1 2 3 4 5 6

Ts = 1 / (15000x2048)=32.552nsec1 slot

Subframe 0

Downlink

P-SCH

S-SCH

PBCH

PDCCH

PDSCH

Reference Signal

Uplink

Reference Signal(Demodulation)

PUSCH

UpPTS

Downlink TDD Resource Mapping ( Single Antenna Port )

10 2 3 4 5 6 10 2 3 4 5 6

Subframe 1(Special Field)

Subframe 2 Subframe 3


Frame Structure Type 1 (DL) - Physical Mapping

P-SCH - Primary Synchronization Channel

S-SCH - Secondary Synchronization Channel

PBCH - Physical Broadcast Channel

PDCCH - Physical Downlink Control Channel

PDSCH – Physical Downlink Shared Channel

Reference Signal – (Pilot)64QAM16QAM QPSK

Frequency

Time


Downlink – Let’s verify this with the 89600 VSA






Reference Signal – (Pilot)

10 2 3 4 5 6 10 2 3 4 5 6

Slot#0 Symbol#0RS onlyRS + PDCCH









10 2 3 4 5 6 10 2 3 4 5 6

Slot#0 Symbol#1PDCCH









10 2 3 4 5 6 10 2 3 4 5 6

Slot#0 Symbol#3PBCHPBCH + PDSCH









10 2 3 4 5 6 10 2 3 4 5 6

Slot#0 Symbol#4RS onlyRS + PBCHRS + PBCH + PDSCH









10 2 3 4 5 6 10 2 3 4 5 6

Slot#0 Symbol#5S-SCHS-SCH + PDSCH


P-SCHP-SCH + PDSCH








10 2 3 4 5 6 10 2 3 4 5 6

Slot#0 Symbol#6


RS onlyRS + PBCH








10 2 3 4 5 6 10 2 3 4 5 6

Slot#1 Symbol#0RS + PBCH + PDSCH


Downlink – Let’s verify this with the 89600 VSA (Mixed)







10 2 3 4 5 6 10 2 3 4 5 6

Slot#0 Symbol#4RS onlyRS + PBCHRS + PBCH + PDSCH(QPSK)RS + PBCH + PDSCH(QPSK+16QAM)RS + PBCH + PDSCH(QPSK+16QAM+64QAM)


Physical Layer definitions – TS36.211Frame Structure (UL) – Slot/Frame


Cyclic Prefix

160 2048 144 2048 144 2048 144 2048 144 2048 144 2048 144 2048 (x Ts)

1slot = 15360

10 2 3 4 5 6

0 1 2 3 4 5 6

Reference Signal(Demodulation)

1 slot

#0 #1 #8#2 #3 #4 #5 #6 #7 #9 #10 #11 #12 #19#13 #14 #15 #16 #17 #18

1 frame

10 2 3 4 5 6

1 sub-frameConfiguration

CP length Guard interval

FS type1 FS type2

Normal CP160 (#0)

224 (#0..#8) 288144 (#1..#6)

Extended CP 512 (#0..#5) 512 (#0 ..#7) 256


Frame Structure Type 1 (UL) - Physical Mapping

64QAM16QAM QPSK

PUSCH - Primary Uplink shared Channel

Reference Signal – (Demodulation)

Frequency

Time


PUSCH

Uplink – Let’s verify this with the 89600 VSA (Sample#1)



10 2 3 4 5 6 10 2 3 4 5 6

Slot#0 Symbol#0


PUSCH



10 2 3 4 5 6 10 2 3 4 5 6

Slot#0 Symbol#3



PUSCH



10 2 3 4 5 6 10 2 3 4 5 6

Slot#0 Symbol#0



PUSCH



10 2 3 4 5 6 10 2 3 4 5 6

Slot#0 Symbol#3

Uplink – Let’s check it by VSA (Sample#2)


Agenda

LTE Context and Timeline

LTE major features

Overview of the LTE air interface

Agilent LTE design and test solutions

• Test items

• Simulation

• Baseband

• Sources

• Analysis

• Integrated mobile test platform


LTE development challenges

Shortened time-plan for development and deployment

• Development in parallel with standards refinements

Early requirement for full functional testing

• Interoperability testing likely to show up different interpretations of standards

• Mix of FDD and TDD based testing

• System test for MIMO architecture

Channel bandwidth up to 20MHz / 172.8 Mbps

• Component and device capabilities will be greater than network capability

• Huge strain on mobile platform design


Transmitter Characteristics – eNB

6.2 Base Station Output Power

6.3 Output Power Dynamics

6.4 Transmit ON/OFF Power

6.5 Transmit Signal Quality

• 6.5.1 Frequency Error

• 6.5.2 Error Vector Magnitude

• 6.5.3 Time alignment between transmitter branches

6.6 Unwanted Emissions

• 6.6.1 Occupied bandwidth

• 6.6.2 Adjacent Channel Leakage Power Ratio (ACLR)

• 6.6.3 Operating band unwanted emissions ( same as SEM)

• 6.6.4 Transmitter spurious emission6.7 Transmit Intermodulation

These transmitter tests are work in progress and the definitions and requirements covered in this presentation are working assumptions per TR36.804 v1.2.0 & TS 36.104 V8.1.0


Transmitter Characteristics – UE6.2 Transmit Power


6.4 Control and Monitoring Functions


• 6.5.1 Frequency error

• 6.5.2 Transmit modulation6.6 Output RF Spectrum Emissions


• 6.6.2 Out of band emission– 6.6.2.1 Spectrum emission mask (SEM)

– 6.6.2.3 Adjacent channel leakage power ratio (ACLR)

• 6.6.3 Spurious emissions6.7 Transmit Intermodulation

These transmitter tests are work in progress and the definitions and requirements covered in this presentation are working assumptions per TR36.803 v1.1.0 & TS 36.101 v8.1.0


Output Power Dynamics – eNB

Power control dynamic range The RE power control dynamic range is the difference between the power of a RE and the average RE power for a BS at maximum output power for a specified reference condition.

Total power dynamic range The upper limit of the dynamic range is the OFDM symbol power for a BS at maximum output power. The lower limit of the dynamic range is the OFDM symbol power for a BS when one resource block is transmitted. The OFDM symbol shall carry PDSCH and not contain RS.

Modulation scheme used on the RE

RE power control dynamic range (dB)

(down) (up)

QPSK (PDCCH) [-6] [TBD]

QPSK (PDSCH) [-6] [+3 …4]

16QAM [-4] [+3]

64QAM [-0] [+0]

E-UTRAchannel bandwidth (MHz)

Total power dynamic range (dB)

1.4 [8]

3 [12]

5 [14]

10 [17]

15 [19]

20 [20]


Frequency Error Test

A quick test is use the Occupied BW measurement (Agilent 89601A VSA SW shown)

An accurate measurement can then be made using the demodulation process

If the frequency error is larger than a few sub-carriers, the receiver demod may not operate, and could cause network interference

The same source shall be used for RF frequency and data clock generation.

Minimum Requirement:–UE: ±0.1 ppm –Wide Area BS: ±0.05 ppm –Medium Range and Local Area BS: TBD


Error Vector Magnitude MeasurementeNB – Downlink (OFDM)

Measurement Block: EVM is measured after the FFT and a zero-forcing (ZF) equalizer in the receiver

BS TX Remove CP

FFT Per-subcarrier Amplitude/phase correction

Symbol detection /decoding

Reference point for EVM measurement

Pre-/post FFT time / frequency synchronization

Current working assumptions for downlink EVM limits are:

Parameter Unit Level

QPSK % [17.5]

16QAM % [12.5]

64QAM % [7 to 8]

Signal BW 89650S(typ)

MXA (typ)

5 MHz 0.28 % 0.5 %

10 MHz 0.32 % 0.5 %

20 MHz 0.35 % 0.56 %

Agilent Signal Analyzer EVM Performance – Both Uplink and Downlink

The basic unit of EVM measurement is defined over one subframe (1ms) in the time domain and 12 subcarriers (180kHz) in the frequency domain


Occupied bandwidth- eNB

Channel bandwidth BWChannel [MHz] 1.4 3 5 10 15 20

Transmission bandwidth configuration NRB 6 15 25 50 75 100


ACLR Requirements – eNB case

Adjacent Channel Leakage power Ratio (ACLR) is the ratio of the filtered mean power centred on the assigned channel frequency to the filtered mean power centred on an adjacent channel frequency

ACLR defined for two cases

• E-UTRA (LTE) ACLR 1 and ACLR 2 with rectangular measurement filter

• UTRA (W-CDMA) ACLR 1 and ACLR 2 with 3.84 MHz RRC measurement filter with roll-off factor α =0.22.

ACLR limits defined for adjacent LTE carriers

ACLR limits defined for adjacent UTRA carriers


ACLR Limits – eNB case

TR 36.804 v1.0.0 Table 6.6.2.3-1: Working assumption for BS ACLR for adjacent E-UTRA carriers (paired spectrum)

E-UTRAChannel BW (MHz)2

ACLR limit for 1st and 2nd Adjacent channel relative to assigned channel frequency [dB]

UTRA1

5.0 MHzE-UTRA2

1.4 MHzE-UTRA2

3.0 MHzE-UTRA2

5.0 MHzE-UTRA2

10 MHzE-UTRA2

15 MHz E-UTRA2

20 MHz

1.4ACLR 1 [45] [45] - - - - -

ACLR 2 [45] [45] - - - - -

3.0ACLR 1 [45] - [45] - - - -

ACLR 2 [45] - [45] - - - -

5ACLR 1 [45] - - [45] - - -

ACLR 2 [45] - - [45] - - -

10ACLR 1 [45] - - - [45] - -

ACLR 2 [45] - - - [45] - -

15ACLR 1 [45] - - - - [45] -

ACLR 2 [45] - - - - [45] -

20ACLR 1 [45] - - - - - [45]

ACLR 2 [45] - - - - - [45]

NOTES: 1 Measured with a 3.84 MHz bandwidth RRC filter with roll-off factor α =0.22 centered on the adjacent channel.2 Measured with a rectangular filter with a bandwidth equal to the transmission bandwidth configuration NRB ∙ 180 kHz centered on the 1st or 2nd adjacent channel


Spectrum Emission Mask (SEM)

Spectrum emissions mask is also known as “Operating Band Unwanted emissions”

These unwanted emissions are resulting from the modulation process and non-linearity in the transmitter but excluding spurious emissions

TR 36.804 v1.0.0 figure 6.6.2.2-1 Defined frequency range for Operating band unwanted emissions with an example RF carrier and related mask shape (actual limits are TBD).

eNB example:Base station SEM limits are defined from 10 MHz below the lowest frequency of the BS transmitter operating band up to 10 MHz above the highest frequency of the BS transmitter operating band.


Spurious Emission Requirements

Spurious emissions are emissions caused by unwanted transmitter effects such as harmonics emission & intermodulation products but exclude out of band emissions

Example of spurious emissions limit for a BS

TS 36.104 v8.1.0 Table 6.6.4.1-1: BS Spurious emission limits, Category A

Band Maximum level Measurement Bandwidth

Note

9kHz 150kHz‑

-13 dBm

1 kHz Note 1

150kHz 30MHz‑ 10 kHz Note 1

30MHz 1GHz‑ 100 kHz Note 1

1GHz 12.75 GHz‑ 1 MHz Note 2

NOTE 1: Bandwidth as in ITU-R SM.329 [2] , s4.1NOTE 2: Bandwidth as in ITU-R SM.329 [2] , s4.1. Upper frequency as in ITU-R SM.329 [2] , s2.5 table 1


Measuring system Set-up

For base station output power, output power dynamics, transmitted signal quality, Frequency error, EVM, DL RS power, Unwanted emissions

Measurement equipment (Global in-Channel TX tester)

BS under test


Transmitter Characteristics – UE

6.2 Transmit Power


6.4 Control and Monitoring Functions


• 6.5.1 Frequency error

• 6.5.2 Transmit modulation6.6 Output RF Spectrum Emissions


• 6.6.2 Out of band emission– 6.6.2.1 Spectrum emission mask (SEM)

– 6.6.2.3 Adjacent channel leakage power ratio (ACLR)

• 6.6.3 Spurious emissions6.7 Transmit Intermodulation

These transmitter tests are work in progress and the definitions and requirements covered in this presentation are working assumptions per TR36.803 v 1.0.0 & TS 36.101 v8.1.0


Transmit Signal Quality UE – Uplink

Currently there are four requirements under the transmit modulation category for a UE:1. EVM for allocated resource blocks 2. In-Band Emission for non-allocated resource

blocks 3. I/Q Component (also known as carrier leakage power

or I/Q origin offset) for non-allocated resource blocks4. Spectrum flatness (relative power variation across

the subcarrier of all RB of the allocated UL block ) for allocated resource blocks

Let’s look at each one of these transmit modulation requirements…


Error Vector Magnitude MeasurementUE – Uplink (SC-FDMA)

DFT

IFFT TX

Front-end Channel RF

correction FFT

Tx-Rx chain equalizer

In-band emissions

meas.

EVM meas.

0

0

…

……

IDFT

DUT Tx

Test equipment Rx

…

……

…

……

…

……

Modulated symbols

Measurement Block

( ) ( )

0

2'

PT

vivz

EVMm

Tv m

⋅

−=

∑∈

for allocated Resource Block

( )vz'( )vi

is modified signal under test

is the ideal signal reconstructed by the measurement equipment


Error Vector Magnitude RequirementsUE – Uplink

EVM – For allocated resource blocks• EVM is a measure of the difference between the reference waveform and the measured waveform

Minimum requirement For signals above -40 dBm, the RMS EVM for the different modulations must not exceed the value in the table below

Parameter Unit Level

QPSK % 17.5

16QAM % 12.5

64QAM % [tbd]

•It is not expected that 64QAM will be allocated at the edge of the signal

TS 36.101 v8.1.0 Table 6.5.2.1.1-1: Minimum requirements for Error Vector Magnitude


Occupied Bandwidth Requirement

Occupied bandwidthOccupied bandwidth is a measure of the bandwidth containing 99 % of the total integrated mean power of the transmitted spectrum on the assigned channel.

Occupied channel bandwidth / channel bandwidth

Channel bandwidth [MHz] 1.4 3.0 5 10 15 20

Nominal Transmission bandwidth configuration for FDD

6 RB(1.08 MHz)

15 RB(2.7 MHz)

25 RB(4.5 MHz)

50 RB(9 MHz)

75 RB(13.5 MHz)

100 RB(18 MHz)

Minimum Requirement: The occupied bandwidth shall be less than the channel bandwidth specified in the table below


ACLR Requirements – UE case

ACLR defined for two cases:

•E –UTRA (LTE) ACLR1 with rectangular measurement filter

•UTRA (W-CDMA) ACLR1 and ACLR 2 with 3.84 MHz RRC measurement filter with

roll-off factor α =0.22.

E-UTRAACLR1 UTRA ACLR2 UTRAACLR1

RB

E-UTRA channel

Channel

ΔfOOB

TR 36.803 v1.0.0 Figure 6.6.2.2 -1: Adjacent Channel Leakage requirements

The data presented in this slide is still 3GPP working assumptions


Spurious Emission Requirements

Frequency Range Maximum Level Measurement Bandwidth

9 kHz ≤ f < 150 kHz -36 dBm 1 kHz

150 kHz ≤ f < 30 MHz -36 dBm 10 kHz

30 MHz ≤ f < 1000 MHz -36 dBm 100 kHz

1 GHz ≤ f < 12.75 GHz -30 dBm 1 MHz

Spurious emissions are emissions caused by unwanted transmitter effects such as harmonics emission & intermodulation products but exclude out of band emissions

Example of spurious emissions limit for a UE

TS 36.101 v8.1.0 table 6.6.3.1-2: Spurious emissions limits


Amplifier Performance - ACLR

LTE QPSK-5MHz 4 carrierseNB spec -45 dBcamplifier expectation -55 dBcdesired sig gen -65 dBcactual sig gen -68 dBc

Mixed LTE QPSK-5MHz / W-CDMA test model 1-64DPCHeNB spec -45 dBcamplifier expectation -55 dBcdesired sig gen -65 dBcactual sig gen -68 dBc adjacent to LTE -70 dBc adjacent to W-CDMA

LTE 64QAM-20MHz 1 carriereNB spec -45 dBcamplifier expectation -55 dBcdesired sig gen -65 dBcactual sig gen -71 dBc


Crossing the Analogue-Digital divide


Tools & Using Them Together


Agilent’s Current Measurement Solutions and Plans for LTE - Commitment

Agilent will provide design and test tools across the R&D lifecycle

Support for early R&D in components, base station equipment and mobile devices with design automation tools and flexible instrumentation, based on current measurement platforms

Refine test solutions and introduce tools for product integration as development progresses to initial functional prototypes

Be ready with manufacturing test capability for early ramp-up


Integrated Mobile Test platform

New Platform for multiple serial lanes

LTE Products2006 2007 2008 2009 2010

3GPP LTE UL/DL Signals

3GPP LTE UL/DL Analysis and Demodulation

MIMO capability

ADS simulation SW

Demod Analysis SW

Signal Generation

Signal Analysis

Logic Analysis

MIPI D_Phy

Commercial ReleasePrototype Versions

MXG

MXA

Basic Coded RT

DigRF

89601A VSAProto VSA


ADS Wireless Library for LTEExplore and verify your designs

Current Status• Library of simulation components for the Agilent EESof

Advanced Design System (ADS) to facilitate the generation and analysis of 3GPP LTE compliant downlink (DL) and uplink (UL) signals.

• First release Oct 2006. Major updates in Feb 07, May 07, Sept 07.

• Based on latest physical layer specifications V8.0.0 *Sept 07).

• Generated signals are spectrally correct and encoded, and can be multi-channel, fixed-length, real-time etc. as required.

• Signals can be exchanged with alternative simulation platforms, and can be downloaded to, or uploaded from hardware for real-world signal generation and analysis.

• Received signals can be demodulated and analyzed.

Next Steps• Continue to follow developments in 3GPP specifications.

Add/evolve signal coding and further develop both DL and UL transmitter measurements (such as EVM, Constellation etc.).

• Further commercial releases at regular intervals.

• Working on TDD support


Advanced Design System Simulation environment

An LTE downlink model in ADS


Example here is from IEEE 802.11a/g

ADS “Connected Solutions”

Develop library elements for 3GPP LTE in order to build physical layer models for both transmitter and receiver in software

Links to test equipment for prototype verification

Implement and deliver a design tool while standard evolves phased implementation in close cooperation with customer

Download

Analyze

RF Component

or DUT


Demodulator

RF IF

BasebandDe-Coding

RF/RF BER

A/DConverter

I

Q

Where can R&D BER Measurements be Performed?

Simulated Portion of System Design

MXG, ESGMXA*, PSA

ADS, VSA SW

*Note: Different Analyzer(s) may be used, dependent on required capture depth

Simulated


Demodulator

RF IF

BasebandDe-Coding

RF/IF BER

A/DConverter

I

Q

MXG, ESGMXA*, PSA

ADS, VSA SW



*Note: Different Analyzer(s) may be used, dependent on required capture depth

Simulated


Demodulator

RF IF

BasebandDe-Coding

A/DConverter

I

Q



MXG, ESG

ADS, VSA SW

RF/Digital IF BER

Logic Analyzer

SimulatedI

Q

I Q


BasebandDe-Coding

BasebandEncoding


SimulatedSimulated

Digital/Digital BER

ESG + N5102, or Logic Analyzer withPattern Generator Board

Logic Analyzers

ADS, VSA SW


Digital Serial Stimulus / Analysis

• Current Status Introduced DigRF v3 products and solutions Bridge gaps between simulation, IC evaluation & handset integration. The N4850A & N4860A digital probes designed for 1Gbps For LTE digital interfaces that > 1Gbps leverage existing multi GHz

serial technology to support higher speed interfaces. Agilent is a MIPI member at Adopter level.

• 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.

N4850A 312Mbps DigRF v3 Digital Serial Acquisition ProbeN4860A 312Mbps DigRF v3 Digital Serial Stimulus Probe


BB/RF Interface Stimulus / Analysis OverviewTwo modes of operation

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.

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).

BB ASIC

TEST EQPT(emulation)

RF ASIC

BB ASIC

TEST EQPT(spying)

RF ASIC


RF-IC Validation (DigRF example)

89601A Vector Signal Analyzer software

RF-IC

Signal Studio Signal Creation Software

N4850AAcquisition Probe

N4860AStimulus Probe

Tx

Rx

16900Logic Analyzer

MXA Spectrum Analyzer

MXG Signal Generator


89601A VSA SoftwareDigRF v3 Protocol/Packet Viewer

The N4850A outputs 34 channels RX and 34 Channels TX , Signal Ended to the Logic Analyzer.

N4850A Graphical Part Two: Analysis Probe to LA Interface

Split analyzer-Tx and Rx can be running at completely different speeds.


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

DSPDigRFv3.xx

89601A Vector Signal Analyzer

RF

Logic Analyzer Oscilloscope Spectrum Analyzer

RF

BB-IC RF-IC

MXG Signal Generator

Signal StudioSignal Creation Software

DigRF

uCDigRFv3.xx

Vis Port

Digital

For internal use only83 © Nokia Siemens NetworksSC-FDMA – the new LTE uplink explained Moray Rumney

Page 83Page 83

Signal Studio for LTE

Signal Studio Signal Generator LTE Signal


LTE Signal Analysis

Features/Capabilities Summary

89601A LTE Modulation Analysis: Option BHD


LTE Signal AnalysisDownlink 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<=3.

• User can configure PDCCH symbol allocations on a subframe-by-subframe resolution.

• Demod. user specified Slot# and OFDM symbol#

• User definition of up to 6 PDSCH 2D Data Bursts for EVM analysis (format QPSK, QAM16, QAM64)

• Downlink frequency lock range approximately +/- 22.5kHz


Analyzing OFDM impairments using 89601A

This downlink signals shows a common OFDM impairment where the allocated subcarriers have an image

The distortion that create this image was 0.1dB IQ gain imbalance

The lower trace shows the increased EVM at the image

Requirements will be developed to limit the image

Allocation Image

EVM by subcarrier


LTE Signal AnalysisUplink Capabilities (based on 36.211 V8.0.0)

• Synchronisation to ADS 2006U1(or U2).407 Dev1 generated LTE Uplink signals

• Multiple resource block allocations restricted to sub carrier DFT sizes which are multiples of 2, 3 and 5 as per current 3GPP working assumption.

• The DM RS Pilot symbol is located in 4th symbol (i.e. sym=3) of allocated slots.

• Demodulation of user specified SC-FDMA symbol# within a Slot of Radio Frame

• Assumes DM RS Pilot symbol contains Zadoff-Chu Sequence mapped to every subcarrier within allocated contiguous RB size.

• User definition of PUSCH two-dimensional Data Bursts for EVM analysis (format QPSK, 16QAM, 64QAM)

• Supports Half-Subcarrier-Shift = On/Off

• Uplink frequency lock range approx. +/- 7.5kHz


LTE Signal Analysis - Measurements

• Sync Correlation

• Freq Error (Hz)

• IQ Offset (dB)

• EVM (%RMS and dB), EVM Peak(%pk and sub carrier location)

• Data EVM (%rms and dB), EVM Peak (%pk and sub carrier location)

• Pilot EVM (%rms and dB), EVM Peak (%pk and sub carrier location)

• Common Pilot Error (%rms)

• Symbol Clock Error (ppm)

• CP Length

• Slot #, Symbol #

• Channel EVM table metrics – Downlink supports P-SCH, S-SCH,

RS Pilot, PBCH, PDCCH, PDSCH 01 thru 06 (dB, %rms, %pk, Peak Loc'n)

– Uplink supports DM Pilot, PUSCH (dB, %rms, %pk, Peak Loc'n)

• Channel Power table metrics – Downlink supports P-SCH, S-SCH,

RS Pilot, PBCH, PDCCH, PDSCH 01 thru 06 (dB relative to un-boosted reference)

– Uplink supports DM Pilot, PUSCH (dB relative to un-boosted reference)


LTE Signal Analysis – Trace views

• Channel Freq Response (Adj. Diff Mag Spectral Flatness,Magnitude, Phase, Group Delay)

• Common Pilot Error (Magnitude, Phase)

• Differential Pilot Error (Timing)

• EVM Spectrum (composite EVM displayed per Sub-Carrier, or per Resource Block)

• EVM Time (composite EVM displayed per OFDMA/SC-FDMA symbol)

• Power Spectrum (composite Power displayed per Sub-Carrier, or per Resource Block)

• Power Time (composite Power displayed per OFDMA/SC-FDMA symbol)

• Symbol Demod IQ Constellation/Vector

• Symbol Demod Spectrum Magnitude

• Symbol Demod Time Magnitude

• Symbol Data (Demodulated symbol bits represented as two hexadecimal characters per sub carrier)


Spectrum Analyzer HW platforms

PSA with 40MHz or 80MHz analysis BW• Can be used as RF front end to external PC

where 89601A VSA based LTE application is running

MXA with 25MHz analysis BW• Can be used as RF front end to external PC

where 89601A VSA based LTE application is running

• Since MXA is a windows product, the 89601A software can run inside the instrument


Agilent N5106A PXBMIMO Receiver Tester

Value PropositionFor R&D engineers developing and integrating MIMO receivers for LTE, WiMAX, and emerging wireless standards, the N5106A PXB MIMO Receiver Tester simulates real-world conditions to test beyond standards requirements more quickly and validate design robustness earlier in the development cycle to minimize design uncertainties and rework.

Designed For Engineers Who Are Doing…BTS and mobile BB ASIC design validation

RF and BB integration design validation

Co-existence test with multi-format generation

0


Agilent N5106A PXBMIMO Receiver Tester

Industry Leading Baseband Performance

Up to 4 baseband generators (with up to 8 faders)

125 MHz BW & 512 MSa of memory per BBG

Real-time signal creation for receiver test

Support analog and digital IQ outputs

Signal Creation Software

Supports multiple signal creation apps

• LTE, WiMAX, W-CDMA, GSM/EDGE

Fading

Up to 8 real-time faders (with RF in or up to 4 BBGs)

Up to 125 MHz real-time fading BW

Up to 24 paths per fader

Stress devices beyond standard requirements with custom fading setups to ensure design robustness

MIMO

Up to 4x2 MIMO in one box

Supports MIMO channel models + diversity

Power management and noise calibration

Upgrade to higher order configurations in one hour

Leverage existing Agilent RF equipment for RF->RF fading up to 6 GHz

Flexible digital I/Q outputs with N5102A


Page 93

N5106A PXB

Transforming MIMO TestReal-Time Generation

Digital or Analog I/Q outputs

RF outputs

1 Output

1 Output

2 Outputs

2 Outputs


Page 94

N5106A PXB

Transforming MIMO TestMIMO RF Fading

RF in & Digital or Analog I/Q out

RF in & RF out

2x2 MIMO

2x2 MIMO

4x2 MIMO

4x2 MIMO

2x4 MIMO

2x4 MIMO


LTE UE Design Flow Solutions

E6620AE6620A



E6620AE6620A

E6620A


E6620A

E6620A



Design Validation: Radio and Protocol Radio Conformance Test


LTE_001 HIT 2008Agilent Restricted

11/19/14

FPGABB L1/PHY

RF Proto

ASIC DevelopmentBB L1/PHY

RF Chip Dev Design Validation

Pre-Conformance

Protocol Development L2/L3 MAC/RLC

BB ASIC

RFIC Digital Interface

Design Integration

Conformance

DesignSimulation

Manufacturing

LTE Network Deployment

Network Signaling AnalysisNetwork Signaling Analysis Just introduced for LTE & SAE Enables passive probing & analysis of LTE network

interfaces Total visibility for all layers from L1 to L7 Complete decoding of all protocol messages

J7880A Signaling Analyzer with J6860A distributed performance manager


Agilent 3GPP LTE Portfolio


Agilent LTE Resources:


E6620A Integrated Mobile Test Platform: Specifications

L1 PHY

DSP Engine

PDCPRLCMAC

Protocol Processor

UP/DOWN CONV.

20MHz B/W RF

RF I/O

digital I/O

A

P

I

RF I/O

RF I/O*

SISO

MIMO(2x2 DL)

*Optional 2nd Source/Receiver for 2x2 MIMO

Scalable single box Solution• 2G/3G/3.9G (LTE) capable• LTE L1-L2 signalling stack + scripting API• 20MHz BW• Data rates up to 100 Mbps DL / 50 Mbps UL• 2x2 MIMO• 2 cells• Digital Baseband Fading• RF Parametric Measurements

Scripted testcases


Coming Soon!

Software Solutions

• ADS LTE Design Libraries

• N7624B Signal Studio

• 89601A VSA Software

Distributed Network

Analyzers

Conformance Network

Digital VSA

VSA, PSA, ESG, Scope, Logic

R&D

Network Analyzers, Power supplies, and More!

MXA/MXG R&D

Agilent 3GPP LTE Portfolio

Signalling

Agilent/Anite SAT LTE – Protocol Development Toolset

Agilent/Anite SAT LTE – UE Protocol Conformance Development Toolset

E6620A Wireless Communications Platform

Drive Test Introduced

at MWC NEW!

Introduced at MWC

Coming Soon!


Any Questions?


Chipset Interfaces: Analog IQSpectrum Analyzers, Scopes, Analog VSAs


Modern Design has the ADCs placed in the RFIC, -making the Chip interface Digital.

Chipset Interfaces: Digital IQDigital VSA/N4850A/N4860A

This was made possible by technology changes in substrates and electronics.

It makes it much easier to turn around a BBIC-which

can take months.


The Test & Measurement Challenge

Cross Domain Solutions

RF-IC / BB-IC IntegrationRF-IC ValidationBB-IC Turn-on

RF

A/D

A/D

D/A

D/A

IF

Ba

seb

an

dD

igita

l

RF

A/D

A/D

D/A

D/A

IF

Ba

seb

an

dD

igita

l

DESER

SERDESER

SER

Digital Serial IQ + ControlAnalog IQ

Evolving To:DigitalSerial

Was: Analog

Measurement


LTE Integrated Mobile Test Platform

RLC/MAC interface for protocol test

Full LTE signalling stack

Protocol conformance test

GSM/GPRS, W-CDMA/HSPA

2x2 MIMO

Scalable single box solution• 2G/3G/3.9G capable• 20MHz BW• 2x2 MIMO• 2 cells• RF parametric measurements• Signalling Conformance Test• RF Conformance Test

initial introduction: Mid-2008

Planned

enhan

cem

ents

RF conformance test

RF parametric measurements


Agilent LTE Brochure5989-6331ENwww.agilent.com/find/lte

http://www.agilent.com/find/lte

tdd lte training material (agilent)

Mobile

ofdm tdmauser

ofdm signalofdm

spread ofdm

ofdm equalizers

better use

frequency errors

frequencytime representation

system bandwidth symbol