Radwin 2000+ SERIES User Manual - Diversity

RADWIN

2000+

Series

User

Manual

Release

4.2.40

C

‐

2

Single

Antennas

at

Both

Sites

Upon

selecting

Antenna

Type

as

Dual,

a

RADWIN

2000+

Series

radio

automatically

selects

this

mode

and

doubles

the

air

rates.

The

RADWIN

Manager

indicates

a

case

of

unbalanced

RSS

between

the

two

antennas

in

the

center

panel.

Diversity

Mode

Diversity

Mode

uses

two

antennas

to

improve

the

quality

and

reliability

of

the

link.

Often,

there

is

not

a

clear

line

‐

of

‐

sight

(LOS)

between

transmitter

and

receiver.

Instead

the

signal

is

reflected

along

multiple

paths

before

finally

being

received.

Each

such

“bounce”

can

introduce

phase

shifts,

time

delays,

attenuations,

and

even

distortions

that

can

destructively

interfere

with

one

another

at

the

aperture

of

the

receiving

antenna.

Antenna

diversity

is

especially

effective

at

mitigating

these

multi

‐

path

situations.

This

is

because

multiple

antennas

afford

a

receiver

several

recordings

of

the

same

signal.

Each

antenna

will

be

exposed

to

a

different

interference

environment.

Thus,

if

one

antenna

is

undergoing

a

deep

fade,

it

is

likely

that

another

has

a

sufficient

signal.

Collectively

such

a

system

can

provide

a

robust

link.

Antenna

diversity

requires

a

separation

between

the

antennas;

this

is

done

by

using

a

dual

‐

polarization

antenna

or

by

two

spatially

separated

antennas.

Use

Diversity

instead

of

Spatial

Multiplexing

in

the

following

situations:

•

When

the

system

cannot

operate

in

Spatial

Multiplexing

Mode

•

When

one

of

the

receivers

has

high

interference

compared

to

the

second

receiver

(i.e.

the

system

is

“unbalanced”)

•

When

you

achieve

higher

capacity

in

Diversity

Mode

than

in

Spatial

Multiplexing

Mode

•

When

high

robustness

is

of

importance

and

the

capacity

of

Diversity

Mode

is

sufficient

(up

to

25

Mbps

full

duplex)

C.2.2

Single

Antennas

at

Both

Sites

By

selecting

a

single

antenna

at

both

sites,

the

radio

units

operate

with

a

single

radio

that

is

connected

to

the

ANT

1

connector.

The

second

radio

is

automatically

shut

down.

C.2.3

Single

at

One

Site,

Dual

Antennas

at

the

Other

In

this

mode

one

of

the

sites

uses

the

radio

unit

with

a

single

antenna

while

the

other

site

uses

the

radio

unit

with

a

dual

antenna.

The

advantages

in

this

mode

in

comparison

to

using

a

single

antenna

in

both

sites

are

doubled

total

Tx

Power

and

additional

polarization

and/or

space

diversity

(depending

on

the

polarization

of

installed

antennas).

The

air

rates

used

in

this

mode

are

same

as

when

using

single

antennas

in

both

sites.