presenter: iqbal singh josan, p.e., pmp director ......interactive question #3 which technique will...

Copyright © USPurtek LLC, 2012 All Rights Reserved. No part of this publication may be reproduced without the prior written permission of USPurtek LLC, uspurtek.com

MIMO in 4G Wireless Presenter: Iqbal Singh Josan, P.E., PMP Director & Consulting Engineer USPurtek LLC About the presenter: Iqbal is the founder of training and consulting firm USPurtek LLC, which specializes in providing Professional Engineering Services to telecom operators and network equipment vendors in the domain of Wireless Broadband and Enterprise Networks. Iqbal is a Senior Member of IEEE and a Licensed Professional Engineer, and has 26 years of experience in the industry, having held engineering and project lead positions with multinational companies in the US as well as India. Iqbal can be reached at [email protected]


MIMO Introduction Realizing Benefits from MIMO Antenna Diversity, Beamforming and SDM Applications of MIMO in WiFi, WiMax and LTE Future of MIMO

MIMO in 4G Wireless


Introduction Multiple Input Multiple Output

o Multiple Tx & Rx Antennas Multiple radio channels

Tx Rx

1 1

2 2

M N


Introduction Multiple Input Multiple Output

o Multiple Tx & Rx Antennas Multiple radio channels


What came before MIMO? SISO

o Single Input Single Output

Tx Rx

1 1


What came before MIMO? SISO

o Single Input Single Output


What came before MIMO? SIMO o Single Input Multiple Output

Tx Rx

1 1

2

N


What came before MIMO? SIMO o Single Input Multiple Output

Tx Rx


What came before MIMO? MISO o Multiple Input Single Output

Tx Rx

1 1

2

M


What came before MIMO? MISO o Multiple Input Single Output


Finally MIMO! MIMO

o Multiple Input Multiple Output


Interactive Question #1 Which Antenna configuration is depicted by the following figure?

1. SISO 2. SIMO 3. MISO 4. MIMO

Tx Rx

Rx

Rx

Rx


Promises of MIMO Robust Radio Channel

o Effects of fading and multipath interference mitigated o No breaks in voice calls or data

Higher Throughput o Faster downloads o More Mbps with existing spectrum and power

Enables 4G Wireless Broadband applications o WLAN (IEEE 802.11n/ad) o WiMAX (IEEE 802.16m) o LTEA (3GPP Rel 10)

I Is this handset in your future?


Realizing MIMO Promises

Antenna Diversity o Receive Diversity o Transmit Diversity

Beamforming Space Division Multiplexing (SDM)


Multipath Propagation

I 20 30 dB Fading

+ = no signal

Tx Rx

Path 3

Path 2

Path 1

+ =


Multipath Propagation

I Inter Symbol Interference (ISI)

time

Path 1

Path 2

Path 3

+ +

s1 s2

s1, s2 s2

s1 s2

Tx Rx

Path 3

Path 2

Path 1


Receive Diversity Mitigates Effects of Multipath Propagation Enhances Signal to Noise Ratio (SNR) SIMO Configuration

Tx Rx

λ/2 λ/2

I Signals combined from multiple antennas

Tx Rx

λ/2 λ/2


I Selection Combining


Tx Rx

λ/2 λ/2


I Equal Gain Combining

Mitigates Effects of Multipath Propagation Enhances Signal to Noise Ratio (SNR) SIMO Configuration

Receive Diversity


Tx Rx

I Maximal Ratio Combining

λ/2 λ/2



Transmit Diversity Redundant copies of signal transmitted across space and time Space Time Block Codes (STBC) used

o 50 – 200 ns time delay inserted in transmission paths Mitigates Effects of Multipath Propagation Enhances Signal to Noise Ratio (SNR) MISO Configuration

time

Ant 1

Ant 2

Ant 3


Interactive Question #2 What is not a benefit of Antenna Diversity?

1. Diversity Gain 2. Enhanced Signal to Noise Ratio 3. Increased Bandwidth 4. Redundant Copies of Signal


Beamforming Controls shape and direction of radio signals Used on Transmit or Receive Antenna Arrays Extends range of radio signals in a direction

o Signals from multiple antennas add up constructively to maximize receiver gain

Mitigates Effects of Multipath Propagation


Space Division Multiplexing (SDM) Different signals transmitted and received simultaneously over same RF bandwidth Exploits spatial separation provided by MIMO Configuration Achieves Higher Throughput Ideal for RF channels with High Signal to Noise Ratio (SNR)

Tx Rx

1 1

2 2

M N

M X N MIMO λ/2

λ/2


Space Division Multiplexing (SDM) Signal Path Coefficients (h11….hMN) represent amplitude and phase response for each signal path

o Determined during training sequence – Tx generates known training signal – Rx processes training signal to estimate path responses

Tx Rx

1 1

2 2

M N

M X N MIMO

h11

h1N h21

h22

hM2

hMN

λ/2

λ/2


Space Division Multiplexing (SDM) MIMO channel represented as matrix of signal path coefficients, H Receivers use H1 to spatially demultiplex the original transmitted signals

o T = H1 R

I Received Signals

I MIMO Channel I Transmitted

Signals

Rx1

Rx2

RxN

• •

•

₌ h11 h21 • • hM1

h21 h22 • • hM2

• • • • •

• • • • •

hM1 hM2 • • hMN

Tx1

Tx2

TxM

• •

•

R H T


Interactive Question #3 Which technique will you recommend when the radio channel is very noisy (SNR is low)?

1. Space Division Multiplexing (SDM) 2. Transmit Antenna Diversity 3. Space Time Block Codes (STBC) 4. Time Division Multiplexing (TDM)


Multiplexing Rate in MIMO

Base Station

1 1

2 2

3

Single User

3 X 2 MIMO Multiplexing Rate = 2

Multiplexing Rate o Number of distinctive data streams that can be received correctly and simultaneously

– For MxN MIMO, it is the min (M,N)


Multiplexing Rate in MIMO Multiplexing Rate

o Number of distinctive data streams that can be received correctly and simultaneously


Base Station

1 1

2 2

3


Single User



Base Station

1 1

2 2

3

Single User






Base Station

1 1

2 2

3


Single User




Diversity Gain in MIMO For narrow band system with slow fading

o Product of M & N

Base Station

1 1

2 2

3

Single User

3 X 2 MIMO Diversity Gain = 6


Trade Off is Possible For 5x4 MIMO oCase 1: Reliable Mode

– Multiplexing Rate = 2 – Diversity Gain = 3x2 = 6

Multiplexing & Diversity Combo


Multiplexing & Diversity Combo

Trade Off is Possible For 5x4 MIMO oCase 2: High Rate Mode

– Multiplexing Rate = 3 – Diversity Gain = 2x1 = 2


MIMO in WiFi

IEEE 802.11n standard has adopted MIMO o Antenna Diversity upto 4 x 4 o Tx Beamforming o Space Division Multiplexing (SDM)

2.4/5 GHz ISM band o 20/40 MHz Bandwidth

PHY Data rates upto 600 Mbps o Throughput > 200 Mbps

Extended Range o Indoor 70 m o Outdoor 250 m


MIMO in WiFi Antennas for Access Point o Narrowband Monopole

λ/2 λ/2

λ / 4


MIMO in WiFi Antennas for Access Point o Multiband Compact

Top View

2.4 GHz 5 GHz

RF Cable

Ground

Multiband Antenna Element

Antenna Element


MIMO in WiFi Antennas for Portable Devices

o Tradeoffs between design, performance and placement

Antenna Feed Point

Ground Plane

Antenna Configuration: Case1


MIMO in WiFi Antennas for Portable Devices

o Tradeoffs between design, performance and placement

Antenna Feed Point

Ground Plane

Antenna Configuration: Case2


Interactive Question #4 What is the recommended physical separation between Antenna elements of a MIMO system?

1. λ/4 2. Depends on the wireless standard 3. Minimum λ/2 4. Does not matter


MIMO in WiMax IEEE 802.16m has full featured MIMO o Antenna Diversity o Beamforming o Space Division Multiplexing (SDM)

2.32.4, 3.33.4 GHz (country specific) o 510 MHz Bandwidth

Enhanced Throughput o 1 Gbps for fixed stations o 100 Mbps for mobile stations

Single or Multi User MIMO o SUMIMO o MUMIMO


MIMO in LTEA 3GPP Rel 10 (LTEA) has full featured MIMO o Antenna Diversity o Beamforming o Space Division Multiplexing (SDM)

22 Freq. bands covering 6983600 MHz o Scalable Bandwidth (20100 MHz)

Enhanced Throughput o 1 Gbps Downlink o 500 Mbps Uplink

Single or Multi User MIMO o SUMIMO o MUMIMO


SUMIMO Single User gets the benefit of full

Throughput

Base Station

1 1

2 2

3

3 X 2 MIMO

Single User


SUMIMO

1

1

2

2

3

3 X 2 MIMO

Base Station

Single User

Single User gets the benefit of full Throughput


MUMIMO Multiple Users share full Throughput

1 1

2 2

3

Base Station Multiple

Users

3


A Glimpse of the Future Massive MIMO & WiGig (IEEE 802.11ad)

o 60 GHz unlicensed band – 4 channels of 2 GHz each

o Upto 7 Gbps data rates o mm Wave MIMO Antenna Arrays

– small λ ( 5 mm) means very small antenna

λ /2 = 2.5 mm Distance between elements

1 cm


A Glimpse of the Future

256 elements

16 elements

Massive MIMO & WiGig (IEEE 802.11ad) o 60 GHz unlicensed band

– 4 channels of 2 GHz each o Upto 7 Gbps data rates o mm Wave MIMO Antenna Arrays

– small λ ( 5 mm) means very small antenna


Bibliography

“An Introduction to MUMIMO Downlink” IEEE Communications Magazine, October 2004 “MIMOOFDM based air interface” IEEE Communications Magazine, January 2005 “Downlink MIMO in LTEA” IEEE Communications Magazine, February 2012 “Understanding IEEE 802.11n amendment” IEEE Circuits and Systems Magazine 1Q 2008 “Advancement of MIMO in WiMax” IEEE Communications Magazine June 2009 “MIMO in WiMax and LTE” IEEE Communications Magazine May 2010 “MIMOOFDM Wireless Systems” IEEE Wireless Communications August 2006 “Antennas for WiFi Connectivity” Proceedings of the IEEE July 2012 “Overview of Mobile WiMax – Technology and Evolution” IEEE Communications Magazine October 2008 The ARRL Handbook for Radio Communications, 2010


Questions And Answers

A copy of the slides from this seminar will be made available to you Information to claim 1 PDH and Certificate of Completion

o Visit http://bit.ly/mimoforum where you will be required to

– complete a feedback form – respond to a problem statement from this seminar

and your Certificate of Completion will be emailed to you within 2 business days

Presenter: Iqbal Singh Josan, P.E., PMP, USPurtek LLC

o [email protected] o LinkedIn: http://www.linkedin.com/in/iqbalsinghjosan o Twitter: @uspurtek

Visit us at http://uspurtek.com to learn more about our upcoming webinars and onsite training services

http://bit.ly/mimoforum

mailto:[email protected]

http://www.linkedin.com/in/iqbalsinghjosan

http://uspurtek.com/


Upcoming Free Webinars

Antenna Engineering: Part 1 of 2 o Saturday, Nov 3, 2012 12:00 PM Eastern Time, Duration: 60 min

Learn the basics of Antennas Understand practical Antenna Design Parameters, such as Directivity, Gain, Beamwidth, Aperture, Polarization, EIRP, Field and Power Patterns, Return Loss, Axial Ratio Design considerations for cellular Base Station and Handset Antennas Learn about different Antenna types and their characteristics Understand Phased Array Antennas and Multiple Independent Beamforming Learn about Smart Antennas and their applications

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Upcoming Free Webinars

Antenna Engineering: Part 2 of 2 o Saturday, Nov 10, 2012 12:00 PM Eastern Time, Duration: 60 min

Learn about the Antenna Design Process and Measurements of Impedance, Gain and Field Patterns in the Near and Far Field Understand RF Site Surveys for Wireless LAN and Cellular Networks Learn about different Antenna Diversity techniques and Diversity Combiners Learn about techniques to expand Wireless System Capacity, such as Frequency Reuse, Cell Splitting and Cell Sectoring Understand Flexible Frequency Reuse in 4G LTE networks Learn about overlay macrocell networks and Femto Cells in 4G LTE Understand MIMO techniques with diversity, beamforming and Space Division Multiplexing Understand applications of MIMO in WiFi, WiMax and LTE

Visit http://bit.ly/Pwq6Zp to register

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presenter: iqbal singh josan, p.e., pmp director ......interactive question #3 which technique will...

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