WIFI测试技术介绍课件

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Team2015.07WLAN概述WLAN

是无线局域网（Wireless

WLAN）的简

称.采用2.4GHz或5GHz无线频率，无线缆限制，提供高速数据传输。传输距离几十米。IEEE802.11包括一系列的标准来规范WLAN，主要用于解决办公室局域网和校园网中，用户与用户终端的无线接入ANRITSU

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ANRISTU2802.11标准的速率与频段54Mb/s22Mb/s11Mb/s1

Mb/sIEEE

802.11bIEEE

802.11gIEEE

802.11a2,4

GHz5

GHz2

Mb/sIEEE

802.11nIEEE

802.11nIEEE

802.112003ANRITSU

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ANRISTU3199920091999199711n

1T1R

150Mb/s11n

2T2R

300Mb/s2009IEEE

802.11ac2011WLAN标准ANRITSU

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ANRISTU42.4GHz

信道分布每个信道的带宽是22MHz，不同国家能够使用的信道是不一样的只有3个互不重叠的信道：1,6,11(或者2,7,12…)1-13信道频率：2412+(n-1)*5

MHzANRITSU

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ANRISTU5不同国家的2.4GHz信道ANRITSU

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ANRISTU6信道标识符频率（单位：MHz）调整域美国EMEA日本世界其它地区12412●●●●22417●●●●32422●●●●42427●●●●52432●●●●62437●●●●72442●●●●82447●●●●92452●●●●102457●●●●112462●●●●122467-●●●132472-●●●142484--●-5GHz

信道分布不同国家能够使用的5GHz频段很不相同，因此802.11a信道更为零散；每个信道的带宽是20MHz，而且互不重叠ANRITSU

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ANRISTU7不同国家的5GHz

信道ANRITSU

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ANRISTU8调整区域信道标识符频率（单位：MHz）美国EMEA日本世界其它地区345170--●-365180●●-●385190--●-405200●●-●425210--●-445220●●-●465230--●-485240●●-●525260●●-●565280●●-●605300●●-●645320●●-●1005500-●-●1045520-●-●1085540-●-●1125560-●-●1165580-●-●1205600-●-●1245620-●-●1285640-●-●1325660-●-●1365680-●-●1405700-●-●1495745●--●1535765●--●1575785●--●1615805●--●802.11b概述ANRITSU

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ANRISTU9工作频率2.4GHz支持1M，2M，5.5M，11Mbps速率采用DSSS802.11a概述ANRITSU

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ANRISTU10工作频率5GHz支持6M，9M，12M，18M，36M，48M，54Mbps速率采用OFDMOFDMANRITSU

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ANRISTU11802.11a

OFDMANRITSU

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ANRISTU12802.11a

OFDM48data+4

pilot=52子载波

1

DC子载波11无用子载波实际上20M总共64个子载波ANRITSU

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ANRISTU13802.11a

Modulation-dependentparametersANRITSU

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ANRISTU14802.11g概述工作频率2.4GHz支持802.11b/a速率采用DSSS和OFDMANRITSU

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ANRISTU15802.11n概述ANRITSU

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ANRISTU16工作频率2.4/5GHz兼容802.11a/b/gMIMO

（up

to

4

spatialstreams）20MHz和40MHz带宽速率最高可达600Mbps802.11n

MCS

indexANRITSU

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ANRISTU17802.11ac概述ANRITSU

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ANRISTU18工作频率5GHz兼容共存802.11a/n更多MIMO空间流（up

to

8spatial

streams）20MHz,40MHz,80MHz,160MHz带宽64，128，256，512QAM也称为VHT，very

high

throughput802.11ac

featuresANRITSU

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ANRISTU19Mandatory

Features Single

spatial

stream80

MHz

channelbandwidths800

ns

Regular

Guard

IntervalBinary

Convolutional

Coding

(BCC)Optional

Features2

or

more

spatialstreams160

MHz

channelbandwidths80+80

MHz

channel

bondingMCS

8/9

(256-QAM)Low-Density

Parity

Check

Codes(LDPC)Space-Time

BlockCoding(STBC)Transmit

Beamforming

(TxBF)400

ns

Short

Guard

Interval(SGI)802.11ac

Typical

1x1

Data

RatesANRITSU

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ANRISTU20WLAN

802.11

RF测试ANRITSU

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ANRISTU21ANRITSU

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ANRISTUIEEE

802.11b802.11b

Radio

LayerTestsANRITSU

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ANRISTU2318.4.7.1

Transmit

PowerLevelsTransmit

Power

is

a

measurement

of

the

average

power

across

aWLAN

packet.The

IEEE

specification

does

not

define

the

conditions

of

test

suchas

the

packet

length,

data

rate,

or

channel

number. The

maximumpermissible

output

power

is

set

by

the

regulatory

body

of

thecountry

or

region.The

average

power

of

an

802.11b

device

istypically+10

dBm

to

+16

dBm.

For

802.11b,

the

difference

between

peakand

average

power

is

typically

3

to

4

dB.ANRITSU

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ANRISTU2418.4.7.1

Transmit

Power

Levels

(cont.)ANRITSU

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ANRISTU2518.4.7.3

Transmit

SpectrumMaskThis

measurement

checks

for

modulation

spreading

and

spectralspurs

that

would

interfere

with

transmissions

on

other

channels.To

meet

the

requirements

of

the

specification, uses

a

100kHzmeasurement

filter

to

display

the

results.A

mask

is

automatically

set

at

the

highest

point

in

the

spectrum,and

all

power

sample

measurements

made

within

the

gate

are

usedto

generate

the

spectral

profile.The

table

beneath

the

spectrum

displays

the

highest

signal

level

foreach

segment

of

the

mask.ANRITSU

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ANRISTU2618.4.7.3

Transmit

Spectrum

Mask

(Cont.)ANRITSU

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ANRISTU27ANRITSU

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ANRISTU2818.4.7.4

Transmit

Centre

Frequency

ToleranceThis

measurement

shows

the

average

frequency

offset

from

thetrue

centre

frequency

of

the

selectedchannel.The

value

is

displayed

as

a

absolute

value

(kHz)

and

as

aproportional

value

(ppm).The

specification

states

that

the

centre

frequency

accuracy

shall

be±25

ppm

relative

to

the

true

channel

centrefrequency.ANRITSU

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ANRISTU2918.4.7.4

Transmit

Centre

Frequency

Tolerance

(Cont.)ANRITSU

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ANRISTU3018.4.7.8

Transmit

Modulation

AccuracyModulation

accuracy

is

an

EVM

measurement;

it

is

thebestindication

of

overall

modulation

quality.Modulation

accuracy

is

determined

by

measuring

the

peak

errorvector

magnitude

during

each

chipperiod.The

worst

error

vector

over

1000

samples

should

be

nogreaterthan

0.35

(i.e.,

35%).ANRITSU

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ANRISTU31EVMANRITSU

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ANRISTU3218.4.7.8

Transmit

Modulation

Accuracy

(Cont.)ANRITSU

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ANRISTU3318.4.8.1

Receiver

Minimum

Input

SensitivityThis

measurement

tests

the

ability

of

the

device

to

receive

packetsat

low

power

levels.For

data

packets

at

11

Mbps

the

FER

should

be

less

than

8%

forpackets

received

at

-76

dBm.ANRITSU

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INC.Copyright©

ANRISTU3418.4.8.2

Receiver

Maximum

Input

SensitivityThis

measurement

tests

the

ability

of

the

device

to

receive

packetsat

high

power

levels.The

FER

should

be

less

than

8%

for

packets

received

at

the

DUTantenna

port

at

-10

dBm.ANRITSU

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INC.Copyright©

ANRISTU35ANRITSU

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ANRISTUIEEE

802.11g802.11g

Radio

LayerTestsANRITSU

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INC.Copyright©

ANRISTU3719.4.7.1

Transmit

PowerLevelsTransmit

Power

is

a

measurement

of

the

average

power

across

aWLAN

packet.The

IEEE

specification

does

not

define

the

conditions

of

test

suchas

the

packet

length,

data

rate,

or

channel

number.The

maximum

permissible

output

power

is

set

by

the

regulatorybody

of

the

country

orregion. The

average

power

of

an

802.11gdevice

is

typically

+8

dBm

to

+12

dBm. Results

are

displayed

inLanLook

beneath

the

trace. For

802.11g

the

differencebetweenpeak

and

average

power

is

typically

8

to

10

dB.ANRITSU

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ANRISTU3819.4.7.1

Transmit

Power

Levels

(cont.)ANRITSU

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ANRISTU3919.4.7.2

Transmit

Centre

Frequency

ToleranceThis

measurement

shows

the

average

frequency

offset

from

thetrue

centre

frequency

of

the

selectedchannel.The

value

is

displayed

as

a

absolute

value

(kHz)

and

as

aproportional

value

(ppm).The

specification

states

that

the

centre

frequency

tolerance

shall

be±25

ppm.ANRITSU

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INC.Copyright©

ANRISTU4019.4.7.2

Transmit

Centre

Frequency

Tolerance

(Cont.)ANRITSU

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ANRISTU4119.4.7

Transmit

Spectral

FlatnessThe

pointsdisplayed represent

the

power

at

each

of

theindividualOFDMsub-carriers.Sub-carriers

-1

to

-16

and

+1

to

+16

must

not

deviate

more

than

±2dB

from

the

average.Other

sub-carriers

must

not

deviate

more than

+2

to

-4

dB.ANRITSU

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INC.Copyright©

ANRISTU4219.4.7

Transmit

Spectral

Flatness

(Cont.)ANRITSU

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INC.Copyright©

ANRISTU4319.5.4

Transmit

SpectrumMaskThis

measurement

checks

for

modulation

spreading

and

spectralspurs

that

would

interfere

with

transmissions

on

other

channels.To

meet

the

requirements

of

the

specification,

uses

a

100

kHzmeasurement

filter

to

display

the

results.A

mask

is

automatically

set

at

the

highest

point

in

the

spectrum,and

all

power

sample

measurements

made

within

the

gate

are

usedto

generate

the

spectral

profile.The

table

beneath

the

spectrum

displays

the

highest

signal

level

foreach

segment

of

the

mask.ANRITSU

COMPANY,

INC.Copyright©

ANRISTU4419.5.4

Transmit

Spectrum

Mask

(Cont.)ANRITSU

COMPANY,

INC.Copyright©

ANRISTU4519.7.2.7

Transmit

Constellation

ErrorModulation

accuracy

is

an

EVM

measurement;

it

is

thebestindication

of

overall

modulation

quality.Modulation

accuracy

is

determined

by

measuring

the

average

errorvector

magnitude

during

each

chipperiod.ANRITSU

COMPANY,

INC.Copyright©

ANRISTU4619.7.2.7

Transmit

Constellation

Error

(Cont.)ANRITSU

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INC.Copyright©

ANRISTU4719.5.1

Receiver

Minimum

Input

SensitivityThis

measurement

tests

the

ability

of

the

device

to

receive

packetsat

low

power

levels.the

FER

should

be

less

than

10%

for

packetsreceivedANRITSU

COMPANY,

INC.Copyright©

ANRISTU4819.5.3

Receiver

Maximum

Input

SensitivityThis

measurement

tests

the

ability

of

the

device

to

receive

packetsat

high

power

levels.The

FER

should

be

less

than

10%

for

packets

received

at

-20

dBmfor

all

datarates.ANRITSU

COMPANY,

INC.Copyright©

ANRISTU49ANRITSU

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INC.50 Copyright©

ANRISTUIEEE

802.11a802.11a

Radio

LayerTestsANRITSU

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INC.Copyright©

ANRISTU51The

802.11a

measurements

are

fundamentally

the

same

as

the802.11g

measurements

but

performed

in

the

5

GHz

frequencyband.ANRITSU

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INC.Copyright©

ANRISTU52ANRITSU

COMPANY,

INC.53 Copyright©

ANRISTUIEEE

802.11n802.11n

Radio

LayerTestsANRITSU

COMPANY,

INC.Copyright©

ANRISTU5420.3.21.1

Transmit

SpectrumMask20MHzOFDMANRITSU

COMPANY,

INC.Copyright©

ANRISTU5520.3.21.1

Transmit

SpectrumMask40MHzOFDMANRITSU

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INC.Copyright©

ANRISTU5620.3.21.2

Transmit

Spectral

FlatnessANRITSU

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INC.Copyright©

ANRISTU57For

20

MHz

channels,sub-carriers

-1

to

-16

and

+1

to

+16

mustnot

deviate

more

than

2

dB

from

the

average.Other

sub-carriersmust

not

deviate

more

than+2/-4dB.For

40

MHz

channels,sub-carriers

-2

to

-42

and

+2

to

+42

mustnot

deviate

more

than

2

dB

from

the

average.Other

sub-carriersmust

not

deviate

more

than+2/-4dB.20.3.21.2

Transmit

Spectral

Flatness

(Cont.)ANRITSU

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ANRISTU5820.3.21.7.3

Transmitter

constellation

errorANRITSU

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ANRISTU5920.3.22.1

Receiver

minimum

input

sensitivityThe

packet

error

rate

(PER)

shall

be

less

than

10%

for

a

PSDUlength

of

4096

octets

with

the

rate-dependent

input

levels

listed

inTable

20-22

or

lessANRITSU

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ANRISTU6020.3.22.4

Receiver

maximum

input

levelThe

receiver

shall

provide

a

maximum

PER

of

10%

at

a

PSDUlength

of

4096

octets,

for

a

maximum

input

level

of

–30

dBm

inthe

5

GHz

band

and

–20

dBm

in

the

2.4

GHz

band,

measured

ateach

antenna

for

any

basebandmodulation.ANRITSU

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INC.Copyright©

ANRISTU61ANRITSU

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INC.62 Copyright©

ANRISTUIEEE

802.11ac802.11ac

Radio

LayerTestsANRITSU

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INC.Copyri