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Self-Guided Demonstration Option BHD 3GPP LTE Modulation Analysis 89600 Vector Signal Analysis Software The 89600 VSA software shown in this document has been replaced by the new 89600B VSA software, which enables more simultaneous views of virtually every aspect of complex wireless signals. The instructions provided herein can be used with the 89600B; however, some of the menu selections have changed. For more information, please reference the 89600B software help: Help > Getting Started (book) > Using the 89600B VSA User Interface (book) > VSA Application Window Illustration

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Page 1: Option BHD 3GPP LTE Modulation Analysis 89600 Vector Signal

Self-Guided Demonstration

Option BHD 3GPP LTE Modulation Analysis89600 Vector Signal Analysis Software

The 89600 VSA software shown in this document has been replaced by the new 89600B VSA software, which enables more simultaneous views of virtually every aspect of complex wireless signals. The instructions provided herein can be used with the 89600B; however, some of the menu selections have changed. For more information, please reference the 89600B software help:

Help > Getting Started (book) > Using the 89600B VSA User Interface (book) > VSA Application Window Illustration

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Table of Contents Technology OverviewLTE Overview ........................................................................................................................... 3 Transmission bandwidth .................................................................................................. 3 Transmission schemes ..................................................................................................... 3 Modulation and coding ..................................................................................................... 3Physical Layer Channels ....................................................................................................... 4 Downlink physical layer channels and signals ............................................................ 4 Uplink physical layer channels and signals ................................................................. 5 Uplink and downlink physical resource ........................................................................ 5Duplexing Techniques ........................................................................................................... 7 Type 1 (FDD) mode ............................................................................................................. 7 FDD Downlink frame structure ................................................................................... 7 FDD Uplink frame structure ......................................................................................... 8 Type 2 (TDD) mode ............................................................................................................ 9 TDD frame structure: switch-point periodicity ...................................................... 9 TDD special subframe................................................................................................. 10 TDD detailed frame structure ...................................................................................11Conclusion ...............................................................................................................................11 Self-Guided Demonstration Measurement and Troubleshooting Sequence ............................................................. 12 Setting up the demonstration ....................................................................................... 13Spectrum and Time Domain Measurements ................................................................. 15 Using the spectrogram display .................................................................................... 15 Measuring occupied bandwidth and power .............................................................. 17Basic Digital Demodulation................................................................................................ 19 LTE FDD downlink analysis ............................................................................................ 19 Navigating around the display ...................................................................................... 20 Frame Summary ................................................................................................................ 21 Constellation ..................................................................................................................... 22 Detected allocations........................................................................................................ 22 Error Vector Magnitude (EVM) ..................................................................................... 23 Error Summary table ........................................................................................................ 23 Selective channel analysis ............................................................................................. 24 Resource block data traces ........................................................................................... 25 LTE TDD analysis ............................................................................................................. 26Advanced Digital Demodulation ....................................................................................... 27 Troubleshooting PBCH and PDDCH impairments .................................................... 28 Measured versus reference power levels .................................................................. 29 MIMO measurements and displays ............................................................................. 30 MIMO Info table ............................................................................................................... 31 MIMO Common Tracking Error trace ......................................................................... 31 MIMO channel frequency response ............................................................................ 32 MIMO channel frequency response, adjacent difference ...................................... 32 MIMO condition number ................................................................................................ 33 Symbol table ...................................................................................................................... 33 LTE TDD MIMO .................................................................................................................34Conclusion ..............................................................................................................................34

Glossary .................................................................................................................................. 35Related Literature ................................................................................................................. 36Web Resources ..................................................................................................................... 36

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Third-generation (3G) wireless systems, based on W-CDMA, are now being deployed all over the world. W-CDMA maintains a mid-term competitive edge by providing high speed packet access (HSPA) in both downlink and uplink modes. To ensure the competitiveness of the 3G systems into the future, a long term evolution (LTE) of the 3rd Generation Partnership Project (3GPP) access technol-ogy is being specified in Release 8 of the 3GPP standard. The LTE specification provides a framework for increasing capacity, improving spectrum efficiency, improving coverage, and reducing latency compared with current HSPA imple-mentations. In addition, transmission with multiple input and multiple output (MIMO) antennas is supported for greater throughput, as well as enhanced capacity or range. To support transmission in both the paired and unpaired spec-trum, the LTE air interface supports both frequency division duplex (FDD) and time division duplex (TDD) modes. The following section provides a high-level description of the LTE physical layer.

LTE Overview

Transmission bandwidthIn order to address the international wireless market and regional spectrum regu-lations, LTE includes varying channel bandwidths selectable from 1.4 to 20 MHz, with sub-carrier spacing of 15 kHz. In the case of multimedia broadcast multicast service (MBMS), a sub-carrier spacing of 7.5 kHz is also possible. Sub-carrier spacing is constant regardless of channel bandwidth. To allow for operation in different sized spectrum allocations, the transmission bandwidth is altered by varying the number of OFDM sub-carriers:

Table 1. Transmission bandwidth at varied numbers of OFDM subcarriers

Transmission schemesThe LTE downlink transmission scheme is based on orthogonal frequency divi-sion multiplexing (OFDM). For the LTE uplink, single carrier frequency division multiple access (SC-FDMA), also referred to as DFT-spread OFDM (DFTS-OFDM), is used. The DL OFDM supports high data rates. The UL SC-FDMA has a lower peak to average power ratio (PAPR) than OFDM which helps extend the battery life of mobile LTE user equipment.

Modulation and codingJust like high speed data packet access (HSDPA), LTE also uses adaptive modu-lation and coding (AMC) to improve data throughput. This technique varies the downlink modulation coding scheme based on the channel conditions for each user. When the link quality is good, the LTE system can use a higher order modu-lation scheme (more bits per symbol), which will result in more system capacity. On the other hand, when link conditions are poor due to problems such as signal fading, the LTE system can change to a lower modulation scheme to maintain an acceptable radio link margin. The modulation schemes supported for payload in the downlink and uplink are QPSK, 16QAM and 64QAM.

For channel coding, both turbo coding and convolutional coding schemes are used. Turbo coding with a coding rate of 1:3 is used for uplink and downlink transport channels (TrCH). Convolutional coding is used for the uplink and downlink control channels.

Transmission Bandwidth [MHz] 1.4 3 5 10 15 20

Number of sub-carriers 72 180 300 600 900 1200

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The LTE DL and UL are composed of two sets of physical layer channels: physi-cal channels and physical signals. Physical channels carry information from higher layers and are used to carry user data, as well as user control information. Physical signals are used for system synchronization, cell identification and radio channel estimation, but do not carry information originating from higher layers.

Downlink physical layer channels and signalsThe DL physical channels are physical downlink shared channel (PDSCH), physi-cal downlink control channel (PDCCH), and Physical Broadcast Channel (PBCH). The DL physical signals are reference signal (RS) and synchronization signals. Table 2, below, contains information on the modulation format and purpose for each of the downlink channels and signals.

Table 2. LTE downlink channels and signals

DL channels Full name Modulation

format Purpose

PBCH Physical Broadcast Channel QPSK Carries cell-specific information

PDCCH Physical Downlink Control Channel QPSK Scheduling, ACK/NACK

PDSCH Physical Downlink Shared

Channel

QPSK16QAM64QAM

Payload

PMCH Physical Multicast Channel

QPSK16QAM64QAM

Payload for Multimedia Broadcast

Multicast Service (MBMS)

PCFICH Physical Control Format Indicator

ChannelQPSK

Carries information about the number

of OFDM symbols (1, 2, 3, or 4) used

for transmission of PDCCHs in a

sub-frame.

PHICH Physical Hybrid ARQ Indicator

Channel

BPSK modulated on I and Q with the spreading factor 2 or4 Walsh codes

Carries the hybrid-ARQ ACK/NAK

DL signals Full name Modulation

sequence Purpose

P-SS Primary Synchronization SignalOne of 3 Zadoff-Chu sequences

Used for cell search and identifi ca-

tion by the UE. Carries part of

the cell ID (one of 3 orthogonal

sequences).

S-SS Secondary Synchronization SignalTwo 31-bit BPSK M-sequence

Used for cell search and identi-

fi cation by the UE. Carries the

remainder of the cell ID (one of

168 binary sequences).

RS Reference Signal (Pilot)

Complex I+jQ pseudo random sequence (length-31 Goldsequence) derived from cell ID

Used for DL channel estimation.

Exact sequence derived from

cell ID, (one of 504).

Physical Layer Channels

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Uplink physical layer channels and signals Uplink (UL) physical channels are Physical Uplink Shared Channel (PUSCH), Physical Uplink Control Channel (PUCCH) and Physical Random Access Channel (PRACH). Two types of uplink reference signals are supported: demodulation refer-ence signal (DM-RS) which is associated with transmission of PUSCH or PUCCH and sounding reference signal (S-RS) which is not associated with transmission of PUSCH or PUCCH. Table 3, below, has information on the modulation format and purpose for each of the uplink channels and signals.

Uplink and downlink physical resourceThe smallest time-frequency unit for uplink and downlink transmission is called a resource element. A resource element corresponds to one OFDM subcarrier dur-ing one OFDM symbol interval. A group of contiguous sub-carriers and symbols form a resource block (RB), as shown in Figure 1. Data is allocated to each user in terms of RB.

Table 3. LTE uplink channels and signals

UL channels Full name Modulation

format Purpose

PRACH Physical Random Access Channeluth root Zadoff-Chu Call setup

PUCCH Physical Uplink Control Channel BPSK, QPSK Scheduling, ACK/NACK

PUSCH Physical Uplink Shared Channel

QPSK16QAM64QAM

Payload

UL signals Full name Modulation

sequence Purpose

DM-RS Demodulation Reference SignalBased on Zadoff-Chu

Used for synchronization to the UE

and UL channel estimation

S-RS Sounding Reference SignalBased on Zadoff-Chu

Used to monitor propagation

conditions with UE

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6

Figure 1. Downlink resource grid (Ref 3GPP TS 36.211 ).

For example, for an FDD frame structure using normal cyclic prefi x (CP), an RB spans 12 consecutive sub-carriers at a sub-carrier spacing of 15 kHz, and 7 consecutive symbols over a slot duration of 0.5 ms. Thus, an RB has 84 resource elements (12 sub-carriers x 7 symbols) corresponding to one slot in time domain and 180 kHz (12 sub-carriers x 15 kHz spacing) in the frequency domain. Even though an RB is defi ned as 12 subcarriers during one 0.5 ms slot, scheduling is carried out on a subframe, (1 ms) basis. Using normal CP, the minimum allocation the base station uses for UE scheduling is 1 sub-frame (14 symbols) by 12 sub-carriers. The size of an RB is the same for all bandwidths; therefore, the number of available physical RBs depends on the transmission bandwidth, as shown by Table 4, below.

Channel bandwidth [MHz] 1.4 3 5 10 15 20

Number of resource blocks 6 15 25 50 75 100

Number of sub-carriers 72 180 300 600 900 1200

Table 4. Number of resource blocks (RB) and subcarriers for the different uplink and downlink transmission bandwidths

One downlink slot Tslot

Resource block

N x N resource elementsDLsymb

RBSC

Resource elementN

x N

s

ubca

rrier

sDL SC

RB SC

N

su

bcar

riers

RB SC

N OFDM symbolsDLsymb

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Duplexing Techniques Two radio frame structures are defi ned in LTE: Type 1 frame structure, which uses FDD duplexing, and a Type 2 frame structure, which uses TDD duplexing. Although the two modes differ, the 3GPP committees exercised care to minimize operational differences.

Type 1 (FDD) modeThe Type 1 (FDD) mode employs a different frame structure depending on whether the transmission is downlink or uplink. For either link direction, however, a radio frame has a duration of 10 ms and consists of 20 slots, with a slot duration of 0.5 ms. Two slots comprise a sub-frame. A sub-frame, also known as the transmission time interval (TTI), has a duration of 1 ms.

Type 1 (FDD) downlink frame structure

Figure 2 shows a DL Type 1 FDD frame structure. As shown in the fi gure, the physical mapping of the DL physical signals and channels for a Type 1 FDD frame structure are:

• The reference signal (pilot) is transmitted at every 6th subcarrier of OFDMA symbols 0 & 4 of every slot• PDCCH can be allocated to the fi rst three symbols (four symbols when the number of RB is equal to or less than 10)• P-SS is transmitted on 62 out of the 72 reserved sub-carriers centered around the DC sub-carrier at OFDM symbol 6 of slots 0 and 10 of each radio frame• S-SS is transmitted on 62 out of the 72 reserved sub-carriers centered around the DC sub-carrier at OFDM symbol 5 of slots 0 and 10 of each radio frame • PBCH is mapped to the fi rst four symbols in slot #1 in the central 6 RB (72 subcarriers). Excludes reference signal subcarriers.• PDSCH is transmitted on any assigned OFDMA subcarriers not occupied by any of the above channels and signals

Figure 2. DL Type 1 FDD frame structure. For simplicity, the PHICH and PCFICH channels are not shown.

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Type 1 (FDD) uplink frame structureThe uplink (UL) FDD frame structure is similar to downlink (DL) FDD frame structure in terms of frame, sub-frame and slot length. An FDD UL slot structure is shown in Figure 3, below.

The FDD UL demodulation reference signals, which are used for channel estimation for coherent demodulation, are transmitted in the fourth symbol (ie. symbol number 3) of every slot.

A mapping for PUCCH format 1a/1b is shown in Figure 4 below. Other PUCCH formats exist that use the inner RB.

Figure 3. Mapping of PUSCH and demodulation reference signal for the PUSCH.

Figure 4. Example of PUCCH mapping and demodulation reference signal for PUCCH.

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Type 2 (TDD) modeThe LTE frame structure 2 (FS2) is defi ned as a TDD mode. While there are signifi cant differences between the TDD and FDD, care was taken so that there are no operational differences between the two modes at higher layer or in the system architecture. At the physical layer, the fundamental design goal was to achieve as much commonality between the two modes as possible.

TDD frame structure: switch-point periodicityUnlike the FDD mode, there is no separate UL/DL frame structure. Instead, there are two supported switch-point periodicities where the transmission switches between DL and UL, 5 ms and 10 ms, each with an overall length of 10 ms and divided into 10 subframes. The TDD frame structure is shown in Figure 5.

Figure 5. Type 2 TDD frame structure for 5 ms switch-point periodicity (top) and 10 ms periodicity (bottom). Note the difference in subframe 6.

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TDD special subframeFor the 5 ms switch-point periodicity radio frame, subframe 6 is a special subframe, identical to subframe 1. For the 10 ms switch-point periodicity radio frame, subframe 6 is a regular downlink subframe. Table 5 illustrates the possible UL/DL allocations which have been specifi ed in the 3GPP standard for Type 2 TDD mode for both 5 ms and 10 ms periodicities.

As shown in Figure 5, the special subframe consists of the following fi elds: Downlink Pilot Timeslot ( DwPTS),Guard Period (GP), and Uplink Pilot Timeslot (UpPTS). The total length of these fi elds is 1 ms. However, within the special subframe the length of each fi eld may vary depending on co-existence requirements with legacy TDD systems and supported cell size. Table 6 provides the supported special confi gurations which are also specifi ed in 3GPP.

Table 5. Uplink-downlink configurations (36.211 Table 4.2.2)

Table 6. Configuration of special subframe length (by Ts unit)

Uplink-downlinkconfiguration

Downlink-to-uplinkswitch-point periodicity

Subframe number0 1 2 3 4 5 6 7 8 9

0 5 ms D S U U U D S U U U1 5 ms D S U U D D S U U D2 5 ms D S U D D D S U D D3 10 ms D S U U U D D D D D4 10 ms D S U U D D D D D D5 10 ms D S U D D D D D D D6 5 ms D S U U U D S U U D

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TDD detailed frame structureFigure 6 shows a detailed physical layer defi nition of a TDD frame for 5 ms downlink-to-uplink switch-point periodicity. Unlike the FDD frame structure, where the primary and secondary synchronization signals are contiguously placed within one subframe, for TDD the two signals are placed in different subframes and separated by two OFDM symbols.

Again, this frame structure is designed for maximum commonality with the FDD mode at the physical layer.

The 3GPP LTE standard provides exciting new capability for wireless users, with an accompanying complexity of signal structure. The 89600 VSA software will allow you to examine that complexity with powerful troubleshooting tools. The examples to follow will use both TDD and FDD signals for different parts of the demonstration guide. However, thanks to their similarity at the PHY layer, you will be able to apply almost all of the same measurement techniques to either mode.

Figure 6. FS2 (TDD) frame structure with 5 ms switch-point periodicity. Note the location of the primary synchronization (P-SS) and secondary synchronization (S-SS) signals.

Conclusion

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Measurement andTroubleshootingSequence

When measuring and troubleshooting digitally modulated systems, it isusually best to follow a measurement sequence: one that begins with basicspectrum measurements and continues with vector (combined frequency andtime) measurements, then switch to basic digital modulation analysis, and,fi nally, to advanced and/or standard-specifi c analysis. This is the sequence wewill use in this demo guide. This sequence of measurements is especially usefulbecause it reduces the chance that important signal problems will be missed.

Step 1: Spectrum and time domain measurementsThese measurements give the basic parameters of the signal in the frequencyand time domain so that correct demodulation can take place in step 2.Parameters such as center frequency, bandwidth, symbol timing, power,and spectral characteristics are investigated.

Step 2: Basic digital demodulationThese measurements evaluate the quality of the constellation. Along with a display of the constellation, they include static parameters such as EVM, I/Q offset, frequency error, and symbol clock error.

Step 3: Advanced digital demodulationThese measurements are used to investigate the causes of errors uncovered in the basic modulation parameters, particularly EVM errors. These include dynamic parameters such as error vector frequency, error vector time, and selective error analysis.

The 89600 VSA software has the advantage that you can recall saved time capture recordings and analyze the signal as though you were acquiring data from hardware. In the following pages, we will recall and analyze LTE signals supplied with the 89600 VSA software.

Spectrum and time domain measurementsGet basics right, fi nd major problems

Basic digital demodulationSignal quality numbers, constellation, basic error vector measurement

Advanced digital demodulationFind specifi c problems and causes

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Setting up the demonstration

Table 7 describes the minimum hardware required to run the 89600 VSA software.

Table 8 describes the 89600 VSA software required to use this demonstration guide. If you do not already have a copy of the software, you can download a free trial version at www.agilent.com/find/89600.

Table 7. System requirements

CharacteristicMicrosoft® Windows®

XP Professional

Microsoft® Windows® Vista Business,

Enterprise, or Ultimate

CPU600 MHz Pentium® or AMD-K6

> 600 MHz (> 2 GHz recommended)

1 GHz 32-bit (x86)

(> 2 GHz recommended)

RAM 512 MB (1 GB recommended) 1 GB (2 GB recommended)

Video RAM 4 MB (16 MB recommended) 128 MB (512 MB recommended)

Hard disk 1 GB available 1 GB available

Additionaldrives

CD-ROM to load the software;

license transfer requires a 3.5 inch floppy

disk drive, network access,

or USB memory stick

CD-ROM to load the software;

license transfer requires network access,

or a USB memory stick

Interfacesupport2

LAN, GPIB, USB, or FireWire1 interface

(VXI HW only)

LAN, GPIB, USB, or FireWire1 interface

(VXI HW only)

Table 8. Software requirements

Version 89600 version 11.00 or higher (89601A, 89601AN, 89601N12)

Options -200 -300 -BHD -BHE

(89601A, 89601AN only)

Basic vector signal analysis

Hardware connectivity (required only if using measurement hardware)

LTE FDD modulation analysis

LTE TDD modulation analysis

1. For a list of supported IEEE-1394 (FireWire) interfaces, visit www.agilent.com/fi nd/89600 and search the FAQ's for

information on "What type of IEEE-1394 interface can I use in my computer to connect to the 89600S VXI hardware?"

2. No interfaces or hardware required to follow the demonstration steps listed in this guide.

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This is a 60 msec recording of a downlink TDD signal. You can use the controls of the player just as you would other players. Your display should look similar to Figure 7.

Figure 7. Time and frequency display of 5 MHz TDD downlink signal.

Note: This fi rst fi gure includes the menu toolbar and status bar on the top and bottom of the window, respectively. In the interest of displaying as much information as possible, the remaining fi gures will not display them. You can toggle them on/off by clicking Display > Appearance > Window

Table 9. Recall the demonstration signal

Instructions: 89600 VSA software Toolbar menus

Preset the software

File > Preset > Preset AllNote: Using Preset All will cause all saved user state

information to be lost. If this is a concern, save the current

state before using Preset All.

Click File > Save > SetupNote: The Menu/Toolbars, Display Appearance, and

User Color Map may also be saved in a similar way.

Recall the demonstration signal. This is a 10 ms

switch point periodicity LTE TDD downlink signal

with 5 MHz bandwidth.

File > Recall > Recall Recording > LTE > LTE_TDD_DL_5MHz_v860.sdf (Default directory is C:\Program Files\Agilent\89600 VSA\Help\Signals)

Click Open

Start playback of the recording Press (toolbar, left)

Auto scale both traces. Note that you need to

make sure to do this when the signal is turned on.

Right click in Trace A. Then select Y Auto Scale.

Right click in Trace B. Then select Y Auto Scale.

Turn on the signal player Control > Player…

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The first step in the troubleshooting process is to set up the signal measurement parameters, such as range and scaling, and verify its spectral and time domain behavior before demodulation takes place.

Using the spectrogram displayFirst, let’s take a look at the overall characteristics. We’ll use the spectrogram capability to see how the signal changes over time and frequency. In addition, you will get a chance to see how overlap processing works.

The spectrogram is a three-dimensional display that shows the changes in signal spectrum over time. It is particularly useful when analyzing time-varying signals. Features of signal transients, OFDM signal structure, and spectral splatter can all be identifi ed with this display.

Using overlap processing improves its usefulness further. Overlap processing causes the analyzer to adjust the amount of new data it uses for each time record, and has the effect of causing the signal to replay in "slow motion." It is particularly useful for locating and examining transients.

You can fi nd out more about overlap processing by pressing Help > Contents … > and then typing overlap processing in the search block. Since this is a 60 msec recording, we should be able to analyze multiple frames. However, overlap processing extends the length of time a signal takes to display in a spectrogram. So, in the steps that follow, we’ll have to turn off overlap processing in order to see the full 2-frame, 20 msec behavior.

Spectrum and time domain measurmentsGet basics right, fi nd major problems

Basic digital demodulationSignal quality numbers, constellation, basic error vector measurement

Advanced digital demodulationFind specifi c problems and causes

Spectrum and TimeDomain Measurements

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Figure 8. Spectrogram trace showing 10 msec switch point periodicity and 4.55 MHz of occupied bandwidth. Note frequency “ears” to each side, indicating frequency splatter.

Table 10. Using spectrogram and spectrogram markers

Instructions: 89600 VSA software Toolbar menus

Change to single grid display Click in Trace A to activate it. Then choose Display > Layout > Single.

Turn on spectrogram Right-click in Trace A and select Show Spectrogram.

Adjust color for greatest contrast.

Note that as you vary the colors,

different aspects of the signal

environment become more visible.

Left click on the vertical rainbow-colored scale located to the left of

the display. Use your mouse’s scroll button to adjust the color display.

Pause the signal by pressing the Pause/Restart key

(toolbar, left).

If you note the timing annotation

to the lower left of the display, you

will see something like xx msec. This

refers to the amount of time being

shown in the full display.

Since we’d like to ensure that the

signals are of the proper duration,

we want to see at least 20+msec,

which represents 2 full frames. To

do this, we’ll need to turn overlap

processing off, as it is extending the

detail of the signal, which is good,

but it also reduces the time over

which it is shown, which does not

meet our current needs.

MeasSetup > Time…In the Max Overlap (Avg Off) box, type 0%

Click OK

Press Start (toolbar, lower left)

Note that the signal frames to pass by much more quickly.

Turn on spectrogram markers and

measure delta between sections

of signal.

Using the offset markers, you can

measure the y-delta (time) and

x-delta (frequency) simultane-

ously. Thus, you can read the time

between the start of one burst and

the start of the next, as well as the

rough frequency bandwidth the

signal is occupying.

Figure 8 shows roughly 9.9 msec

between bursts, and about 4.55 MHz

of occupied bandwidth.

Pause the signal by pressing the Pause/Restart key

Right click in the display and select Show Marker.

Click on the Y axis and drag the vertical marker to the right edge of

the signal. Click on the X axis and drag the horizontal marker to the

bottom of a signal burst.

Right click in the display and select Show Offset.Right click in the display and select Move Offset to Marker.

Click the horizontal marker and move it to the bottom of the next

burst down. Click on the vertical marker and move it to the left edge

of the signal.

Your display should look similar to Figure 8.

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While we were able to measure the approximate occupied bandwidth using the spectrogram markers, you can make more precise measurements using the 89600 VSA’s OBW markers and band power markers.

Measuring occupied bandwidth and band power

Table 11. Using OBW markers

Instructions: 89600 VSA software Toolbar menus

Change to 2-grid display Display > Layout > Stacked 2

Turn off spectrogram markers Right click in Trace A and de-select Show Marker

Turn off the spectrogram display format Right click in Trace A and de-select Show Spectrogram

Turn on OBW marker Right click in Trace A and Select Show OBW

Turn on OBW marker table

(Note: you may want to start and then

pause the recording to get valid data)

Your display should look similar to Figure 9.

Double click on Trace B title (B: Ch1 Main Time).

From the drop down menu which appears, select

Marker (left column) > Obw Summary TrcA

(right column)

Figure 9. Turning on the OBW trace provides basic information in the trace status bar at the bottom of the display. By activating the Marker OBW summary trace in Trace B, more detailed information is available.

Table 12. Clear OBW measurement

Instructions: 89600 VSA software Toolbar menus

Clear OBW display

Double click the Trace B title (B: TrcA OBW Summary Data)

Select Channel 1 from the Type menu on the left-hand column

of the drop down menu.

Select Main Time from the Data menu on the right-hand column of the

menu.

Click OKRight-click Trace ADe-select Show OBW

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The band power marker feature measures the power of the modulated signal, or “channel power”, by integrating over a specifi ed bandwidth in the frequency domain.

Table 13. Setting up band power marker

Instructions: 89600 VSA software Toolbar menus

Select the band power marker tool

Click Markers > Tools > Band Power(Or, alternatively, you can click the band power marker button

on the menu toolbar)

Drop the band power marker on

Trace A

On Trace A, move the mouse to the center frequency of the band

to be measured.

Click to drop the marker.

Expand the band power marker

Place the mouse pointer on the vertical band power marker and

left click to drag/expand the marker so it includes the entire

bandwidth.

Note: You may need to adjust the center of the band power

marker by dragging it with the mouse.

The band power should be displayed at the bottom of the window. This is the total power inside the bandwidth of the band power marker. You can expand or shrink the width of the marker to measure the power over specifi c frequencies. You can control the band power marker more precisely by opening the Markers Properties window. Click Markers > Calculation to access user-settable text boxes for setting the center and width of the band power marker.

Figure 10. Band power display.

Note that the “band power” markers will do more than just band power. They are, in essence, integrating band markers. So, for instance, they will integrate EVM between 2 points, if they are used on an EVM spectrum error trace, or calculate total EVM for a range of RB, if used on an RB EVM error trace.

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Basic Digital Demodulation

Spectrum and time domain measurmentsGet basics right, fi nd major problems

Basic digital demodulationSignal quality numbers, constellation, basic error vector measurement

Advanced digital demodulationFind specifi c problems and causes

Once you have examined your signal and verified that there are no major spectral or time problems, the next step is to demodulate it. We'll set up a constellation display and measure basic I/Q parameters using the LTE demodulator as shown in Table 14. This time we will recall a recording of an LTE FDD format signal. Remember, though, that the measurements and displays you will see will apply to LTE TDD signals as well.

LTE FDD downlink analysis

Your display should look similar to Figure 11.

Table 14. Recall demo signal package

Instructions: 89600 VSA software Toolbar menus

Preset the software. In general, this is

a good thing to do prior to beginning

measurements with a new modulation

format.

File > Preset > Preset AllNote: Using Preset All will cause all saved user state information

to be lost. If this is a concern, save the current state before using

Preset All.

Click File > Save > Setup

Note: The Menu/Toolbars, Display Appearance, and User Color Map may also be saved in a similar way.

Recall demo signal package for LTE

FDD downlink signal. Using this feature

will recall the selected signal, with its

pre-defined setup file. In addition it will

open your browser to display an html

format file which will have additional

information on the signal. You can

read this information or just close the

browser window.

File > Recall > Recall Demo > LTE > LTE_FDD_DL_5MHz_v860.htm (Default directory is C:\Program Files\Agilent\89600 VSA\Help\Signals)

Click Open

Start the signal. Once it has populated

the display, pause the signal. LTE

demodulation is a resource-intensive

measurement, and pausing it will let us

make changes to the display faster.

Press Start (toolbar, left)

Once all displays are painted, pause the analysis by pressing the

pause/restart key (toolbar, left)

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Figure 11. Initial display of FDD DL recording. Note consistent color-coding used throughout all traces.

Navigating around the displayThe fi rst thing you will notice is that there are 6 individual displays. You can control the content of any display. To see the wide range of data traces available to you, simply double click on the trace title, located at the top left of each trace. Or, go to the menu toolbar and select Trace>Data >… Either way, when you do so, you will see an entire list of available trace data. See Figure 12.

Figure 12. Trace data available for each display. To see more available trace data, click on another “Type:” selection, e.g., Channel 1, Demod, or MIMO. Additional data choices will appear in the right hand “Data:” column.

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Figure 13. Control the display layout of your measurements using the menu toolbar or the quick-select button located just below the toolbar.

To change the layout of the displays, go to the menu toolbar and click on Display > Layout >… You can choose to display 1, 2, 3, 4, or 6 traces, in either stacked or grid format. Alternatively, you can click on the display layout quick-select button, located just below the menu toolbar. See Figure 13 for an example of both methods.

Frame SummaryLet’s take a look at each display. First, let’s start with Trace F, the Frame Summary (see Figure 14). This trace is a table of all detected signals and chan-nels. Important overall information is provided: error (EVM), power, modulation format, and number of resource blocks detected. Note that each channel and signal has a unique color. This same color will be used throughout the other displays, whenever channel or signal type is available or important. Thus, the Frame Summary serves as a fi rst-level troubleshooting tool, as well as a legend for the other traces.

Figure 14. The Frame Summary display provides a quick overview of the entire frame structure. It also serves as the color-code legend for the other traces.

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Figure 15. Detail in the constellation display can be seen when you use the Select Area marker to scale and expand the X and Y axis.

ConstellationTrace A shows a constellation. The colors in this constellation match the colors in the Frame Summary. You can see that some dots in the constellation appear to have multiple colors. You can use the 89600 VSA’s Select Area marker to expand the X and Y axis to gain further resolution. See Figure 15 as an example. The Select Area marker is highlighted with a red box.

Figure 16. The Detected Allocation Time trace provides detailed visual information about your signal structure.

Detected allocationsTrace B is the Detected Allocations Time trace for Layer 0. See Figure 16. This signal is not MIMO, so only results for Layer 0 are available. This trace is also a good way to get an overall view of your signal. It shows the subcarriers versus symbols, color-coded to show what signals and channels are occupying the symbols and subcarriers. Again, if you want greater detail, use the Select Area marker to expand the X and Y axis scaling. Use this trace to confi rm your signal structure.

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Error Vector Magnitude (EVM)Traces C and E plot the EVM versus frequency (sub-carrier) or time (symbol). The average error value for a given sub-carrier or symbol is shown in white. The 89600 VSA provides you with some useful tools for tracking errors, including marker-coupling. Marker coupling allows you to look at an error or item of interest, and see what it looks like in the other domains. To see how marker coupling works, follow the steps in Table 15.

Your display should look similar to Figure 17.

Figure 17. Marker coupling allows you to track errors between traces. Note that the marker readout area (bottom of display) verifies that the marker is indicating the same point in all traces.

Error Summary tableTrace D shows the Error Summary table. See Figure 18. This table provides parametric data for the signal, including EVM, frequency errors, power, and IQ errors. This table also shows the cyclic prefi x length mode, the cell ID, and whether the VSA is set up for the resource signal pseudo random sequence to be custom or standard (3GPP).

Table 15. Marker coupling

Instructions: 89600 VSA software Toolbar menus

Turn markers ON in Traces A, B, C, E Right-click in Trace A and select Show Marker. Do the same for Traces B, C, and E.

Couple markers. As you activate a marker

in one trace, you’ll be able to see where

that data point is in another trace.

Click in any trace (A, B, C, or E). This activates the trace.

On the menu toolbar, click Markers > Couple Markers.

In the EVM Time Trace E, place a

marker on a peak. This will put the mark-

er to the symbol with the highest EVM.

Right click on Trace E and select Peak.

Note: the location of the marker in Traces A, B, C. (It may be

at the extreme beginning of the EVM spectrum and Detected Allocations Trace.)

Choose another peak. Note how

the marker location in all the other

traces moved as well. Often you can see

similarities with other error peaks, which

might indicate a problem. In this case,

for example, most of the higher peaks

appear to be associated with the first or

last carriers. The higher EVM here could

be associated with filter cut-off problems.

On the display, choose another high peak. Or, you can use the

marker search function.

Click Markers > Search > Peak Right (or Peak Left)

Figure 18. The Error Summary Table provides important information about the overall signal quality. Note that the peak EVM value was detected at subcarrier 150, as discovered in the previous section.

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Table 16. Selective channel analysis

Instructions: 89600 VSA software Toolbar menus

Turn markers OFF in Traces A, B, C, E Right-click in Trace A and de-select Show Marker. Do the same

for Traces B, C, and E.

Exclude control channels and signals

from the analysis results

Your results should look similar to Figure 19.

By selecting and de-selecting channels,

you can focus your analysis and trou-

bleshooting on one area at a time.

Click MeasSetup > Demod Properties > Profile (tab) Un-check P-SS, S-SS, PBCH, PCFICH, PHICH, PDCCH, and RSClick Close

Re-select all the channels and signals

before continuing

Click MeasSetup > Demod Properties > Profile (tab) Select Incl. AllClick Close

Selective channel analysisThe analysis software allows users to make EVM measurement on selected channels only. Let's set up the analyzer to measure EVM for the data channels, but not for control channels and signals.

Figure 19. Using the VSA’s channel select capability, you can investigate the behavior of each class of channel and signal, independently.

It’s important to note that, although we may have de-selected certain channels or signals, the Frame Summary Table will continue to display information for all available channels and signals.

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Resource block data tracesThe information shown in the previous section reflects the default trace data selec-tions. But for LTE, there is another important view of your signal: by resource block (RB). The 89600 VSA has four views of RB performance: EVM by RB, EVM by slot, power per RB, and power per slot. Let’s take a look at these, as well as the Symbol Table, by following the instructions in Table 17.

Table 17. Display RB traces plus Symbol Table

Instructions: 89600 VSA software Toolbar menus

Change Trace A to display EVM by RB

for each time slot

The EVM for each time slot is shown,

along with an average line (shown in

orange on this display)

Select Trace A by clicking anywhere in it.

Double click on the Trace A title (currently A: Layer 0 OFDM Meas).

From the left hand column, select Layer 0. From the right hand

column select RB Error Mag Spectrum.

Right click in the trace then select Y Auto Scale.

Change Trace B to display power in each RB

for all time slots. The power for each time slot

is shown, along with average power.

Double click on the Trace B title. From the left hand column, select

Layer 0. From the right hand column select RB Power Spectrum.

Right click in the trace then select Y Auto Scale.

Change Trace C to display EVM per time

slot, for all RB. The average EVM value

across all RB is also shown.

Double click on the Trace C title. From the left hand column, select

Layer 0. From the right hand column select RB Error Mag Time.

Right click in the trace then select Y Auto Scale.

Change Trace D to display power in

each RB, across all time slots

Double click on the Trace D title. From the left hand column, select

Layer 0. From the right hand column select RB Power Time.

Right click in the trace then select Y Auto Scale.

Change Trace E to display the Symbol TableDouble click on the Trace E title. From the left hand column, select

Layer 0. From the right hand column select Symbol Table.

Your display should look similar to Figure 20.

Figure 20. Error and power data by RB or slot. Note that an RB may contain channel and signal data, so no color coding is used. In contrast, the Symbols Table uses the same color-coding given in the Frame Summary.

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LTE TDD analysisAlthough this section used an LTE FDD signal, you can make the same measurements using an LTE TDD signal. Table 18 shows you how to recall an LTE TDD recording. With that, you can perform all of the measurement steps shown in this section.

When you are fi nished, your display should look similar to Figure 21.

Figure 21. The LTE TDD demo signal shows obvious differences from the LTE FDD demo signal used in the previous section. However, all the same tools are available here as well.

Table 18. Recalling an LTE TDD recording

Instructions: 89600 VSA software Toolbar menus

Preset the software. In general, this is

a good thing to do prior to beginning

measurements with a new modulation

format.

File > Preset > Preset AllNote: Using Preset All will cause all saved user state information

to be lost. If this is a concern, save the current state before using

Preset All.

Click File > Save > Setup

Note: The Menu/Toolbars, Display Appearance, and User Color Map may also be saved in a similar way.

Recall demo signal package for LTE

TDD downlink signal. Using this feature

will recall the selected signal, with its

pre-defined setup file. In addition it will

open your browser to display an html

format file which will have additional

information on the signal. You can

read this information or just close the

browser window.

File > Recall > Recall Demo > LTE > LTE_TDD_DL_5MHz_v860.htm (Default directory is C:\Program Files\Agilent\89600 VSA\Help\Signals)

Click Open

Start the signal. Once it has populated

the display, pause the signal. This is

because the LTE demodulation is a

resource-intensive measurement, and

pausing it will let us make changes to

the display faster.

Start (toolbar, left)

Once all displays are painted, pause the analysis by pressing the

pause/restart key (toolbar, left)

Page 27: Option BHD 3GPP LTE Modulation Analysis 89600 Vector Signal

27

Advanced Digital Demodulation

Spectrum and time domain measurmentsGet basics right, fi nd major problems

Basic digital demodulationSignal quality numbers, constellation, basic error vector measurement

Advanced digital demodulationFind specifi c problems and causes

Advanced demodulation techniques allow you to focus in on signal errors, or set up the analyzer so that more detailed troubleshooting is possible. Next, we’ll begin analyzing a 5 MHz LTE FDD DL 4x4 MIMO signal with impairments. It is centered at 1 GHz. In the signal the PBCH power is 2 dB high and the PDCCH channel power is 1 dB high. This signal includes direct MIMO paths only; there are no cross-channel paths.

Table 19. Recall impaired LTE FDD DL 4x4 MIMO signal

Instructions: 89600 VSA software Toolbar menus

Preset the software. In general, this is a

good thing to do prior to beginning mea-

surements with a new modulation format.

File > Preset > Preset All

Note: Using Preset All will cause all saved user state information to be

lost. If this is a concern, save the current state before using Preset All.

Click File > Save > Setup

Note: The Menu/Toolbars, Display Appearance, and User Color Map may also be saved in a similar way.

Before starting the measurement, we

must enable 4x4 analysis. To do this, we

must set up the hardware to simulate an

Agilent 4-channel Infiniium scope.

In the toolbar: Utilities > Hardware > ADC1(tab) > scroll down and

check SIM::Infiniium. Select any tab with a red check and uncheck all

checked boxes.

Press OKIn the toolbar press: Input > Channels > 4 Channels

Recall the demo signal package for the

LTE FDD 4x4 MIMO downlink signal.

File > Recall > Recall Demo > LTE> LTE_FDD_DL_5MHz_4x4_v860.htm (Default directory is C:\Program Files\Agilent\89600 VSA\Help\Signals)

Click Open

Start the signal playback. Once it has

populated the display, pause the signal.

Press Start (toolbar, left)

Once all displays are painted, pause the analysis by pressing the

pause/restart key (toolbar, left)

The measurement set-up file sets all of

the parameters for measuring the modu-

lation on the signal. You can change

most parameters. Adjustment of some

parameters is limited by the length of

the recording or the capabilities of the

platform use to record the signal. To see

what these modulation parameters are,

check the Demod Properties tab.

MeasSetup > Demod Properties > Format (tab)

Note: Click the Help button (lower right of the menu) for an

explanation of the controls.

Auto scale Traces C and E Right click on Trace C and select Y Auto Scale. Repeat for Trace E.

The display should look similar to Figure 22.Figure 22. LTE FDD DL 4x4 MIMO with impairments.

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28

Troubleshooting PBCH and PDDCH impairmentsIn examining Traces C and E, it is obvious that something is wrong with the PBCH and PDDCH channels. We can tell this by noticing that two colors, yellow and bright green are in the EVM traces, elevated and if we put a marker on those colors we can read their titles and values. The channel's EVM and power can be seen in Trace F, Frame Summary.

To begin the troubleshooting process, we will isolate the problem channels in order to analyze them in detail.

The reference IQ trace is developed by the VSA software based on the modulation format, control channel parameters, LTE allocations, and other parameters set by the user or read in from an Agilent Signal Studio setup file. For more information, see Help > Contents…>Index (tab). Type IQ Ref in the search window, and select IQ Ref (LTE) as your desired topic.

Your display should look similar to Figure 23. Note that in Trace A, both the PDCCH (yellow) and PBCH channels (green) are outside the reference target, the PBCH more so than the PDCCH. This indicates that both channels are higher in amplitude than expected.

Figure 23. The reference Trace (B, lower), indicates what the constellation would be like if the data were perfect. The measured Trace (A, upper), indicates what was actually measured and clearly shows a problem.

Table 20. Troubleshooting PBCH and PDDCH channels step 1: isolate channels

Instructions: 89600 VSA software Toolbar menus

Isolate the PBCH and PDDCH channels

for further analysis.

MeasSetup> Demod Properties > Profile(tab) > Excl. All

Check PBCH and PDCCH in the window

Change Trace B to display the reference sig-

nal. This signal represents the ideal locations

of the signal.

Double-click on the Trace B title, and select Layer 0 from the left

hand column, and IQ Ref from the right hand column

Change display format to stacked two Display > Layout > Stacked 2

Page 29: Option BHD 3GPP LTE Modulation Analysis 89600 Vector Signal

29

Measured versus reference power levelsNow that we have isolated the channels with problems, let’s check out the power levels of the signals, both what should exist (reference IQ power), and what was actually measured (measured IQ power).

Table 21. Troubleshooting PBCH and PDDCH channels step 2: measured power vs. reference power

Instructions: 89600 VSA software Toolbar menus

Change Trace A to show the measured

power versus time

Double click on Trace A Y-axis title (Const)

Choose Log Mag (db)

Right click in the trace and press Y auto scale

Change Trace B to show the reference

power versus time

Double click on Trace B Y-axis title (Const)

Choose Log Mag (db)

Right click in the trace and press Y auto scale

To simplify the display, turn off the average

line in both traces

Click in Trace A to select it

In the toolbar, press Trace > Digital Demod…

In the menu, de-select Show 2D Avg Line (bottom right corner

of dialog box)

Click in Trace B to select it, then repeat above step to remove

the average line

You may need to auto scale the traces again

Display the expected reference power

level and the measured power level, in

order to compare them

When you are done, your display

should look similar to Figure 24.

Click in Trace A to select it

Click on the marker pointer in the toolbar

Place the cursor on a PBCH (green) channel. The information on

the selected point is displayed in the marker status bar at the bot-

tom of the screen.

Repeat for Trace B

Figure 24. Power per carrier for PBCH. Both the measured (Trace A) and expected reference power (Trace B) are shown. Marker values are shown in the marker annotation area at the bottom of the window.

The reference power level for PBCH is 0 dB, as shown by the Trace B marker at the bottom of the display. The actual power level is 2 dB, as noted by the Trace A marker. You can repeat the steps, beginning with the last step in Table 20 but this time placing the markers on a PDCCH channel (yellow). If you do this, you will note that actual power is 1 dB high.

Page 30: Option BHD 3GPP LTE Modulation Analysis 89600 Vector Signal

30

MIMO measurements and displaysThe 89600 VSA software lets you make a wide range of measurements to help you understand the behavior of your MIMO system. Let’s take a look at some of them.

Table 22. Display MIMO-specific traces and tables

Instructions: 89600 VSA software Toolbar menus

We have made alot of changes to the

measurement set-up, so let’s recall the

signal as we did in the beginning, so that

we are at known starting place

File > Recall > Recall Demo > LTE> LTE_FDD_DL_5MHz_4x4_Impair_v860.htm (Default directory is C:\Program Files\Agilent\89600 VSA\Help\Signals)

Click Open

Start the signal. Once it has populated the

display, pause the signal.

Press (toolbar, upper left)

Once all displays are painted, pause the analysis by pressing

the pause/restart key (toolbar, upper left)

Change Trace A to display MIMO info table

Click anywhere in Trace A to activate it

Double-click on the Trace A title

Select MIMO from the left hand column, and Info Table from

the right hand column

Change Trace B to display MIMO common

tracking error

Click anywhere in Trace B to activate it

Double-click on the Trace B title

Select MIMO from the left hand column, and Common Tracking Error from the right hand column

Right-click in the trace and select Y auto scale

Change Trace C to display MIMO channel

frequency response

Click anywhere in Trace C to activate it

Double-click on the Trace C title

Select MIMO from the left hand column, and Eq Chan Freq Resp from the right hand column

Right-click in the trace and select Y auto scale

Change Trace D to display MIMO channel

frequency response adjacent difference trace

Click anywhere in Trace D to activate it

Double-click on the Trace D title

Select MIMO from the left hand column, and Eq Chan Freq Resp Adj Diff from the right hand column

Right-click in the trace and select Y auto scale

Change Trace E to display MIMO condition

number

Click anywhere in Trace E to activate it

Double-click on the Trace E title

Select MIMO from the left hand column, and Eq Cond Number from the right hand column

Right-click in the trace and select Y auto scale

Change Trace F to display Layer 1

Symbol Table

Click anywhere in Trace F to activate it

Double-click on the Trace F title

Select Layer 1 from the left hand column, and Symbol Table

from the right hand column

Let’s take a look at each trace individually. For complete information, see the Help text.

Page 31: Option BHD 3GPP LTE Modulation Analysis 89600 Vector Signal

31

MIMO Info tableThe MIMO Info table shows the performance metrics for each transmission path. The color coding here signifies the the MIMO path and coordinates with the MIMO traces. This MIMO signal was collected by direct connection to the transmitters so it contains only the direct Tx/Rx paths. No data is shown for the cross paths because there is no signal there. The Antenna Detection Threshold specified on the Format tab of the LTE Demod Properties dialog box detects this and blanks all of the results for those paths except resource signal power. Were data available on the other pairs, metrics would be shown.

Figure 25. MIMO Info table. Note the color coding by transmission path.

MIMO Common Tracking Error TraceThe MIMO Common Tracking Error Trace displays the common tracking error data for all Tx/Rx antenna paths. See Figure 31. Traces for missing paths are not shown. The color-coding maps to the same color-coding used in the MIMO Info table of Trace A. Placing a marker on any trace will also display the transmission path.

Figure 26. MIMO Common Tracking Error. There is 1 trace per Tx/Rx pair. This trace uses the same color-coding as the MIMO Info Table.

Page 32: Option BHD 3GPP LTE Modulation Analysis 89600 Vector Signal

32

MIMO channel frequency responseTrace C, Figure 27, shows the frequency response for all Tx/Rx paths simultaneously. Each individual trace is computed using the reference signal of the selected Tx Antenna port. The color-coding maps to the same color-coding used in the MIMO Info table of Trace A.

Figure 27. Equalizer frequency response traces for all active transmission paths.

MIMO channel frequency response, adjacent differenceThe MIMO Eq Chan Freq Resp Diff Trace, Figure 28, shows the channel response's rate of change with respect to frequency, for each transmission path, and is computed by subtracting the channel frequency response from a shifted version of itself (by one subcarrier).

This trace can be used to fi nd the source of a spur or other problem in a signal that causes high EVM. See the Help text for more information. The color-coding is again the same as the MIMO Info table.

Figure 28. This trace shows the rate of change for the equalizer frequency response. It can help distinguish between channel-caused and signal-caused errors.

Page 33: Option BHD 3GPP LTE Modulation Analysis 89600 Vector Signal

33

MIMO condition numberTrace E shows the MIMO condition number by subcarrier. See Figure 29. Condition number is a standard measure of how ill-conditioned the MIMO matrix is.If the condition number is larger than the SNR of the signal, it is likely that separation of the multiple MIMO transmission paths will not work correctly and so proper de-coding will not occur.

Figure 29. The equalizer condition number can provide a value of the overall quality of the MIMO signal.

Symbol tableThe Symbol table shows the data transmitted in the MIMO layer selected by the user. To change the layer data displayed, double-click the trace title and select a different layer. The color-coding used here matches the Frame Summary table.

Figure 30. Symbol Table for Layer 1. Symbols for the other layers are available as well. The color-coding matches that of the Frame Summary Table.

Page 34: Option BHD 3GPP LTE Modulation Analysis 89600 Vector Signal

34

LTE TDD MIMOJust as a reminder, although the demo signal shown here is FDD, you can also make the same measurements on an LTE TDD MIMO signal. Included in the LTE demo signal directory is a 4x2 MIMO example. Press File > Recall Demo > LTE > LTE_TDD_DL_5MHz_4x2_WithChannel_v860.htm to access it.

The 3GPP LTE standard is a powerful standard which has undergone major development to provide extensive capabilities to end users. The 89600 VSA software is designed to provide fl exible displays and powerful control of the measurement parameters in order to dig deep into the signal to troubleshoot it. Option BHD provides LTE FDD modulation analysis, while Option BHE provides LTE TDD analysis. Both options are capable of analyzing uplink, downlink, and 2x2, 4x2, and 4x4 MIMO systems. With a careful understanding of how LTE signals work, you can use the 89600 VSA to uncover virtually all aspects of your physical layer signal and any problems therein.

Conclusion

Page 35: Option BHD 3GPP LTE Modulation Analysis 89600 Vector Signal

35

Glossary 3GPP 3rd Generation Partnership Project3G 3rd GenerationAMC Adaptive Modulation and CodingACK AcknowledgementCAZAC Constant Amplitude Zero Auto CorrelationCCDF Complementary Cumulative Distribution FunctionCP Cyclic PrefixDL Downlink (base station to subscriber transmission)DM RS Demodulation Reference SignalDFTS-OFDM Discrete Fourier Transform Spread - Orthogonal Frequency Division MultiplexingDwPTS Downlink Pilot TimeslotEVM Error Vector MagnitudeFDD Frequency Division DuplexGP Guard PeriodHSDPA High Speed Downlink Packet AccessHSPA High Speed Packet AccessLTE Long Term EvolutionMBMS Multimedia Broadcast Multicast ServiceMIMO Multiple Input Multiple OutputNACK Negative AcknowledgementOFDM Orthogonal Frequency Division MultiplexingOFDMA Orthogonal Frequency Division Multiple AccessOS Orthogonal SequencePAPR Peak-to-Average Power RatioPBCH Physical Broadcast ChannelPCFICH Physical Control Format Indicator ChannelPDCCH Physical Downlink Control ChannelPDSCH Physical Downlink Shared ChannelPHICH Physical Hybrid ARQ Indicator ChannelPMCH Physical Multicast ChannelPRACH Physical Random Access ChannelPRS Pseudo Random SequenceP-SS Primary - Synchronization SignalPUCCH Physical Uplink Control ChannelPUSCH Physical Uplink Shared ChannelQAM Quadrature Amplitude ModulationQPSK Quadrature Phase Shift KeyingRB Resource BlockRS Reference Signal (pilot)SC-FDMA Single Carrier - Frequency Division Multiple AccessS-RS Sounding Reference SignalS-SS Secondary - Synchronization SignalTDD Time Division DuplexTrCH Transport ChannelTTI Transmission Time IntervalUpPTS Uplink Pilot TimeslotUL Uplink (Subscriber to base station transmission)W-CDMA Wideband - Code Division Multiple Access

Page 36: Option BHD 3GPP LTE Modulation Analysis 89600 Vector Signal

36

Related Literature

Web Resourses

89600 Series Vector Signal Analysis Software,Technical Overview, 5989-1679EN

89600 Series Vector Signal Analysis 89601A/89601AN/89601N12 Software,Data Sheet, 5989-1786EN

89600 Vector Signal Analysis demo software,CD, 5980-1989E

Understanding the Intricacies of LTE, LTE poster, 5989-7646EN

Move Forward to What's Possible in LTE,Agilent's LTE Solutions Guide, 5989-7817EN

Hardware Measurement Platforms for the Agilent 89600 Series Vector Signal Analysis Software, Data Sheet, 5989-1753EN

89600S Series VXI-based Vector Signal Analyzers,Configuration Guide, 5968-9350E

3GPP Long Term Evolution: System Overview, Product Development, and Test Challenges, 5989-8139EN

Agilent Infiniium Oscilloscopes Performance Guide Using 89600 Vector Signal Analyzer Software, 5988-4096EN

For additional information, visit:

www.agilent.com/find/89600www.agilent.com/find/LTE

Page 37: Option BHD 3GPP LTE Modulation Analysis 89600 Vector Signal

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