1© 2014 The MathWorks, Inc.

From Bits to Antenna to RF: Wireless System Design with MATLAB

Houman Zarrinkoub, PhD.Signal Processing & CommunicationsMathWorkshoumanz@mathworks.com

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Agenda

Landscape of wireless design

Antenna-to-Bit simulation

Case study: 802.11n/ac/ad Systems

Smart RF design

Case study: ADI Agile Transceiver Modeling

LTE and LTE-Advanced

Case study: MU-MIMO

Summary

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Mobile Communications: LTE, 5G and Beyond

5G standardization

100-1000 times faster speeds

Reliable service everywhere

Greater complexity

New architectures

New frequency bands (mmWave)

More antennas (massive MIMO)

Advanced RF and DSP co-design

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Connected Smart Devices, Internet of Things

Internet of Things

Embedded sensors

Digital health

Industrial instruments

Pervasive computing

Connected wirelessly to internet

Low power

Generate lots of data

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Wireless System Design: MATLAB and Simulink

Who are our users?

R&D algorithm designer

Digital baseband engineer

RF system engineer

Test or validation engineer

What do they need?

End-to-end simulation

Design verification

Real-world over-the-air testing

Simulate& Analyze

ImplementPrototype & Test

Wireless SystemDesign

Multi-domainsystem

Single domainsystem

Algorithm

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1 Antenna to Bits simulation

2Smart RF design

3LTE & LTE-Advanced

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Antenna-to-Bits Simulation

Design modern wireless systems with components such as MIMO, OFDM, and adaptive beam-forming

Analyze signals and make measurements such as EVM, ACLR, BLER, Throughput

Generate waveforms and create verification references for downstream implementation

New Antenna Toolbox 1.0 released in R2015a

MATLAB & Simulink

Simulate a complete wireless link

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Step-by-step MATLAB demo – OFDM as the air interface technology of 802.11n– Beamforming as a MIMO technique

Easy-to-follow end-to-end simulation Graphical test bench Adjustment of channel characteristics on

the fly

Demo: 802.11n/ac/ad modelinga MIMO-OFDM system

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How does a MIMO-OFDM System work?

Input bits

ModulationChannelcoding

MIMO ....

Transmitter

Channel

Large-scale fading

(path-loss …)

Small-scale fading

(Multipath, Doppler effects)

Interference

NoiseReceiver

Channeldecoding

De-modulation

MIMOReceiver

(Equalizer)

Channel estimation

OFDMreceiver

OFDMreceiver

……

……

Output bits

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Baseband demo workflow

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Version 1: Baseline - Modulation and Coding

Start with a SISO transceiver with modulation, coding, scrambling Channel modeling (Interferer + path loss) No multipath fading yet Isotropic (non-directional) antennas (1x1)

Signal Source (S)

InterferenceSource (I)

𝜃𝜃𝑆𝑆𝜃𝜃𝐼𝐼

𝑑𝑑𝑆𝑆𝑑𝑑𝐼𝐼

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MATLAB tools for modeling of adaptive modulation and coding

• Use algorithms in Communications System Toolbox

• Quickly build and run fast & reliable simulations

• Simulate dynamic changes of systems (such as modulation scheme)

• Perform measurements and examine performance metrics during simulation

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Version 2: Baseline + OFDM

Introduce OFDM transmission Transceiver with modulation, coding, scrambling & OFDM

transmitter & receiver Channel (Interferer + path loss) modeling No multipath fading yet

Signal Source (S)

InterferenceSource (I)

𝑑𝑑𝑆𝑆𝑑𝑑𝐼𝐼

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MATLAB tools for modeling OFDM multi-carrier transmission systems

• OFDM modulator and demodulator from Communications System Toolbox

• Gold or PN Sequence generators to generate pilots (reference signals)

• System objects make exploring with system parameters easier

• Explore a wide range of center frequencies and bandwidths

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Version 3: Baseline + OFDM +Transmit-side beamforming Introduce Receive-side beamforming Transceiver with modulation, coding, scrambling, OFDM transmitter

& SIMO receiver Channel with Interferer + path loss + fading Receiver has multiple Antennas (1 to 8)

Signal Source (S)

InterferenceSource (I)

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MATLAB tools for modeling multi-antenna systems and beamforming• Antenna arrays and beam-

formers from Phased-Array System Toolbox

• 2-D and 3-D spatial array responses and directional gains

• Implement null-steering and interference cancelation algorithms with a few lines of MATLAB code

• Easily quantify interference mitigation gains provided by beam-forming

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Version 4: Baseline + OFDM +Transmit-side beamforming + Multipath fading Introduce Transmit-side beamforming with Multipath fading Transceiver with modulation, coding, scrambling, MIMO-OFDM

transmitter & receiver Channel with Interferer + path loss + fading Transmitter has multiple Antennas (1 to 8)

Signal Source (S)

InterferenceSource (I)

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MATLAB tools for modeling fading channels and channel estimation-equalization

• MIMO fading channels from Communications System Toolbox

• Channel estimation and equalization with received values of time-frequency grid

• Combine OFDM and MIMO to approach a prototype of 802.11n/ac

• Experiment with ideal and pilot-based channel estimation algorithms

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What We Learned in This Demo

Easily setup MIMO-OFDM system components

Modulation, coding, OFDM

MIMO fading channels

Beamforming, beam steering & interference cancelation

Dynamic & interactive MATLAB test benches

On-the-fly tunable parameters

Spectral analysis

Visualizations and measurements

Qualitative and quantitative metrics

Live feeds of telemetry data as transmitted bit stream

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Antenna Toolbox Easy design

– Library of 22 parameterized antenna elements– Functionality for the design of linear and

rectangular antenna arrays – No need for full CAD design

Rapid simulation setup– Method of Moments field solver for port, field,

and surface analysis – No need to be an EM expert

Seamless integration– Model the antenna together with signal

processing algorithms– Rapid iteration of different antenna scenarios

for radar and communication systems design

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Antenna Toolbox DemoBuild your first antenna array

>> a = linearArray

>> a.Element = p;

>> a.ElementSpacing = 0.1;

>> a.NumElements = 4;

>> layout(a);

>> pattern(a, 1.66e9);

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Integration Demo: Phased Array System Toolboxatx_array_modeling_with_embedded_element_pattern

...

% Import antenna element in Phased Array

myURA1 = phased.URA;myURA1.Element = mydipole;...

% Import the embedded element pattern

EmbAnt = Phased.CustomAntennaElement(...

'FrequencyVector',freqVector,... 'AzimuthAngles',az,... 'ElevationAngles',el,... 'RadiationPattern',embpattern);

myURA2 = phased.URA;

myURA2.Element = EmbAnt;

...

Antenna element

Pattern of the embedded element computed with Antenna Toolbox

Phased Array

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Learn more about measurement, analysis, visualization

Constellation Scope Visualizes the effects of channel

degradations on modulated symbols Shows rotations and attenuations

caused by various fading mechanism Measurements included:

– EVM – MER

Spectrum Analyzer Visualizes flat or frequency-selective

nature of channel Measurements included:

– Complimentary Cumulative Distribution Function (CCDF) measurement and visualization

– Adjacent Channel Power Ratio (ACPR) measurements

– Harmonic & Intermodulation distortions

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Learn more about Speeding up simulations Use Best Practices in

Programming – Vectorization – Pre-allocation

Parallel Computing– High level parallel constructs

(e.g. parfor)– Utilize cluster, clouds, and

grids

MATLAB to C GPUs

Webinar: Accelerating Communications System Simulations in MATLAB

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Summary

We have modern algorithms (OFDM and MIMO) & analysis tools and even modern standard-based products (LTE) for modern systems

We have incorporated features and tools like C code generation, parallel computing etc. into our tool that “substantially” accelerate simulation

We now have very high end communications measurements and analysis tools like Spectrum Analyzers, etc. They work directly in MATLAB and come at the low toolbox price

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1 Antenna to Bits simulation

2Smart RF design

3LTE & LTE-Advanced

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Smart RF Design

Model and simulate RF transceiver together with baseband algorithms

Develop calibration and control algorithms such as DPD or AGC to mitigate impairments and interferers

Add measured RF component characteristics

Use circuit envelope techniques to accelerate simulation of RF transceivers

Fast behavioral RF modeling & simulation MATLAB & Simulink

Analog Devices AD9361RF Agile Transceiver™

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AGC RSSI

Example: Simulation of Analog Devices® RF Transceivers with MATLAB and SimRF

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CW test signal

LTE-like or custom test signal

Multi-rate finite-precision programmable decimation filters

Analog continuous-time programmable filters

Tunable RF receiver

RF Receiver

Third order Delta-Sigma ADC

RSSI

AGCManual and slow attack mode

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Simulation Results: MGC, 2 TonesFundamentalDC Offset IP2 IP3In-band noise Images

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Which Tools? MATLAB, Simulink and …

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Learn More About: RF Modeling

SimRF: fast simulation of RF front-ends Design the architecture and specs of the RF front-end

Integrate RF with adaptive algorithms such as DPD, AGC

Test and debug the implementation before going in the lab

Provide a model to your colleagues and customers

Webinar: Design and Verify RF Transceivers for Wireless Communication Systems

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Trade Off Simulation Speed and Modeling FidelityHow do your signals look like?

Modeling fidelity

Sim

ulat

ion

spee

d

True Pass-Band

Circuit Envelope

Equivalent Baseband

Carrier

Signal bandwidth

freq

Spe

ctru

m

Carrier 1 freq

Spe

ctru

m

Carrier 2DC

freq

Spe

ctru

m

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Summary

Executable specifications of real-life communication systems across multiple disciplines Develop smarter algorithms faster Improve the communication between different teams Understand, debug, test your system before going in the lab Provide (IP protected) models to the end users

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1 Antenna to Bits simulation

2Smart RF design

3LTE & LTE-Advanced

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LTE & LTE-Advanced

Specify your LTE and LTE-A PHY systems covering all transmission modes, channels, and signals

Combine your LTE baseband models with RF modeling for a combined digital-RF design

New features in R2015a LTE Rel. 11 support UMTS/HSPA+ Waveform Generation Coordinated Multipoint (CoMP)

Qualifying question• Are you working on LTE Physical layer?

Design, simulate, and test LTE and LTE-Advanced systems

MATLAB & Simulink

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What’s the LTE System Toolbox?

Release 8,9, 10 &11 (LTE-A) Scope

– TDD/FDD, – Uplink/Downlink– Transmitter/Receiver

~200 functions for physical layer (PHY) modeling

Link-level simulation Conformance Tests

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Signal Generation and Analysis Reference Measurement Channels

>> lteRMCDLTool

Standard-compliant signal available in the MATLAB workspace

TS 36.101

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Typical Use Cases

Golden reference to verify in-house PHY models

Complete end-to-end link-level simulation

Signal generation and analysis

Signal information recovery

RF Signal GeneratorTransmitter

Test Waveform Generation

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Demo: Equalizing the Downlink Grid

ReceiverTransmitter Channel

Test Waveform Generation

Synchronisation & OFDM Demodulation

Channel Estimation&

EqualisationFading Channel

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Summary

Comprehensive– Comprehensive set of PHY models– Numerous preset, extensible examples

Open environment– MATLAB-based– Link to test and measurement instruments

Standard-compliance– Ability to generate and transmit signals using hardware signal generators– Trusted by numerous customers