MIMO Antenna

8/7/2019 MIMO Antenna

1/23

08BEC024 Jaydip Fadadu08BEC030 Kuldip Gor

Nirma University


2/23

` Introduction

` Motivation for design

` Basics

` Diversity and Spatial Multiplexing` Applications

` Conclusion


3/23

` MIMO Multiple Input Multiple Output

Array of antennas at transmitter and receiver at input

Diversity Gain improves BER Spatial Multiplexing improves data rates


4/23

` To achieve high data rate that still offer good Quality of

Service (QoS) ( i.e. improves BER)

` But using Less complex system

Minimum power transmission

Minimum bandwidth


5/23

` In SISO system to achieve high data rate more signal

power and more bandwidth is required.

` A combination a smart modulation, coding and

multiplexing techniques have yielded good results but

not sufficient for 1GBPS!!!

channel

User data stream

User data stream


6/23

` se multiple antenna at Tx and Rx

` Now that supports higher data rates but

How!!!??? Lets see

User data streamUser data stream

.

.

1

2

MT

.

.

.

1

2

MR

.

.

.

.

.

channel


7/23


8/23

` Transmitter uses a weighting vector

u = [u1, u2] while receiver uses a weighting vector

v = [v1, v2]

` Channel coefficient matrix H (??)` s(t) = transmitting signal, r(t) = received signal

` r1(t) = (u1H v1) * s1(t) + (u2H v1) * s2(t)

` r2(t) = (u1H v2) * s1(t) + (u2H v2) * s2(t)

` We can decide value of u and v according to our

need.


9/23


10/23

` Diversity Gain Minimize BER

Reliable QoS

`

Spatial Multiplexing Gain` Maximize transmission rate

` Uses rich scattering/fading to your advantage

` System designs are based on trying to achieve

either goal or a little of both


11/23

` Each pair of transmit-receive antennas provides a signalpath from transmitter to receiver. By sending the SAME

information through different paths, multiple independently-

faded replicas of the data symbol can be obtained at the

receiver end. Hence, more reliable reception is achieved

` The maximal diversity gain dmax is the total number ofindependent signal paths that exist between the transmitter

and receiver

` For an (MR,MT) system, the total number of signal paths is

MRM

T1 d dmax= MRMT

` The higher my diversity gain, the lower my Pe


12/23

1

2

MT

Channel coding Symbol

mapping

Space-Time

Coding.

.

R bits/symbol

Spectral efficiency = (R*Rc info bits/symbol)(rs)(Rs symbols/sec)/w

= R*Rc*rs bits/s/Hz assuming Rs = w

rs is the parameter that we are concerned about: 0 rs MT

If rs = MT, we are in spatial multiplexing mode (max transmission rate)

If rs 1, we are in diversity mode


13/23

Scheme Spectral

Efficiency

Pe Implementation

Complexity

V-BLAST HIGH HIGH LOW

D-BLAST MODERATE MODERATE HIGH

ALAMOUTI LOW LOW LOW


14/23

the data is divided among large number of closely spaced carriers


15/23


16/23


17/23

` WLAN WiFi 802.11n

` Mesh Networks (e.g., MuniWireless)

` WMAN WiMAX 802.16e

` 4G` Digital Home


18/23

` Target applications include: large files backup, HD

streams,online interactive gaming, home

entertainment, etc.

` Channel bandwidth of 20 MHz and 40 MHz` Current product offerings (pre-N) use only 2

spatial streams with 3Tx/3Rx in the AP and

2Tx/3Rx in the mobile supporting up to 300 Mbps

` Spatial diversity, spatial multiplexing


19/23

High capacity (MIMO) cross-links

WiFi access


20/23


21/23

` Non line of site, up to 4-6 mbps per user for a fewkm

` 2.5 GHz (US) and 3.5 GHz licensed bands

` Channel bandwidth from 1.25 to 20 MHz

` QPSK, 16 QAM and 64 QAM modulation

` OFDMA access (orthogonal uplink)

` TDD for asymmetric traffic and flexible BWallocation

` Advanced Antenna Systems (AAS):spatialdiversity, spatial multiplexing using MIMO (2x2)


22/23


23/23

` MIMO delivers whole home coverage with thespeed and reliability to stream multimediaapplications

` MIMO can reliably connect cabled video devices,

computer networking devices, broadbandconnections, phone lines, music, storage devices,etc.

` MIMO is interoperable and can leverage the

installed based of 802.11 wireless that is alreadydeployed: computers, handheld gaming devices,cameras, VoIP Phones, etc.

MIMO Antenna

Documents

Transcript of MIMO Antenna