S b S tSub-Systems for HF

A li tiApplication

Rafi Hana M.Sc.E.EGeneral Manager

MOBAT

A Tadiran Communications Division

The New HF Systems AdvantagesAdvantages

Stable and Accurate Frequencies - Improves the Quality q p y

ALE STD (141B) - Simplifies the OperationALE STD (141B) Simplifies the Operation

N MODEM T h l E d d th U f D t ANew MODEM Technology - Expanded the Use of Data App.

New Digitized Voice Technique - Improves the Voice Quality &Reduces the HF Noise.

Voice & Data Applicationsb d based on

VOCODER & HF Data Modem

VOCODER 1200, 2400 bps

MODEM MIL-STD-188-110B

Side Effect : Encryption AES Standard Encryption AES Standard

B i Bl k DiBasic Block Diagram

HOSTCPU

PCRS232

Interface

CPU

AES 188-110B

RS232USB

Interface

1200,2400

Encryptor MODEM

AudioHandset ,

VOCODERHandset

Fixed Lvel

Basic System Basic System Configuration

Secure

Plain VoiceVoice & Data

S i l F tSpecial Features

V-AMD Allows Voice- Messages that t t ti SNR h lpenetrate negative-SNR channels

for emergency application

Operational features: REC. Recording messages. SEL. Selecting one / five.

E tEncryptor AES Advanced Encryption Standard.

The New Federal Information P i St d d (FIPS)Processing Standard (FIPS)

#Keys 7 + technician-key (option 31k) #Keys 7 + technician-key (option 31k) HMI PC-menu or MICOM front panel. OTAR Select Keys (Option: Key Loading)y ( p y g)

Two approaches for Voice coding : Waveform Coders

Among popular methods : CVSD , ADPCM , PCM …(16K 32K 64K bps)(16K,32K,64K bps)

Parametric representation (Vocoders) Speech model derived from speech characteristics

Low bandwidth (600,1200,2400 bps)

PI TCH

PERI ODI CEXCI TATI ON

VOI CED/ UNVOI CEDSWI TCH

SPECTRALPARAMETERS

GAI N

SPECTRALENVELOPE

MODEL

SPEECH

RANDOMNOI SE

Speech model

Two principal families of Voice Coders: Source Codecs - operate based on the p

speech model ( LPC) Hybrid Codecs - attempt to bridge between

Source Codecs and Waveform Codecs (MPE, RPE, CELP, MBE, MELP).

MOS(1-5) Bit Rate Algorithm

4.3 64K PCM(G.711)

2.3 2.4K LPC-10e(FS1015) ( )

3.47 13K RPE-LTP(GSM)

3.2 4.8K CELP(FS1016)

3.62.4K AMBE (DVSI)( )

3.3 2.4K MELP

3.1 1.2K TADIRAN-Mobat3.5 2.4K TADIRAN - Mobat

3.8 4.8K TADIRAN - Mobat

MOS - Mean Opinion Score : Voice Quality measure

Link Quality CVSD Vocoder 2400

5% BER Speech with Noise Good

8% BER Speech with Noise Goodp

5% BER + 30% JAM

Noisy Speech (intelligibility limited)

Good

50% JAM Very Noisy(no intelligibility)

Good with few disturbances

Digital voice is the New Generation Requirement

MODEM

MIL-STD-188-110B 75-4800 bpswith better & Adopt performance.p p

DSP Implementation Ready for FutureDSP Implementation Ready for Future Growth

Basic MODEM BLOCK DIAGRAMBasic MODEM BLOCK DIAGRAM

TRANSMITERTRANSMITER

INTERLEAVERFEC MAPPER SCRAMBLER

DATA

MOD

DATA

RECEIVERRECEIVER

DEMOD EQUALIZER DECODER DATA

RECEIVERRECEIVER

SYNCLOOPS

CONSTELLATION FORCONSTELLATION FORCONSTELLATION FOR CONSTELLATION FOR MILMIL--STDSTD--188188--110110B sec. B sec. 55..33..22

M d P fModem Performance Performance is NOT essentially dictated by

SNR.

ISI-length & Doppler-Spreadcan cause modem collapse in spite of verycan cause modem collapse in spite of very

high SNR.

“Surface” Performance“Surface” PerformanceSurface PerformanceSurface Performance

a a 300 300 bit/secbit/sec88PSK Serial Tone PSK Serial Tone

MODEMMODEM

MOBATMOBAT--MODEM PERFORMANCEMODEM PERFORMANCEVERSUSVERSUS

STANDARD PERFORMANCE:STANDARD PERFORMANCE:MILMIL--STDSTD--188188--110110B sec. B sec. 55..33..22

U Ch l M lti th F di SNR BER MOBATUserData Rate

[bps]

ChannelMulti-Paths

Multipath[ms]

FadingBW[Hz]

SNR[dB]

BERAs Required

by 110A & 110B STDs

MOBATMODEM

BER

4800 1 Fixed 17 1 0 E 3 9 0 E 64800 1 Fixed - - 17 1.0 E-3 9.0 E-6

4800 2 Fading 2 0.5 27 1.0 E-3 3.3 E-4

2400 1 Fixed - - 10 1.0 E-5 0

2400 2 Fading 2 1 18 1 0 E-5 1 0 E-62400 2 Fading 2 1 18 1.0 E-5 1.0 E-6

2400 2 Fading 2 5 30 1.0 E-3 0

2400 2 Fading 5 1 30 1.0 E-5 0

1200 2 Fading 2 1 11 1.0 E-5 01200 2 Fading 2 1 11 1.0 E 5 0

600 2 Fading 2 1 7 1.0 E-5 1.8 E-6

300 2 Fading 5 5 7 1.0 E-5 0

150 2 Fading 5 5 5 1.0 E-5 0g

75 2 Fading 5 5 2 1.0 E-5 0

HF CHANNEL Multi-Path (RAYS)IN STANDARDS & LITERATUREIN STANDARDS & LITERATURE

Watterson [1970] Measurements::•• Found up to Found up to 44--Rays (Multi Path).Rays (Multi Path).•• Two MagnetoTwo Magneto--ionic components.ionic components.

ETSI DRM STANDARD (Digital Radio Mondiale)•• Up to Up to 44--Rays should be tested.Rays should be tested.•• FieldField--test found test found 55--Rays.Rays.yy

MIL-STD-188-110A, 110B, STANAG-4539, …, …•• Only TwoOnly Two--Rays should be tested.Rays should be tested.Only TwoOnly Two Rays should be tested.Rays should be tested.

•In Real HF Conditions There are More than 2 Rays.

MODEM Visualization ToolsMODEM Visualization ToolsMODEM Visualization ToolsMODEM Visualization ToolsScatterScatter--Diagram & ImpulseDiagram & Impulse--ResponseResponse

MOBAT HFMOBAT HF--MODEMMODEMMULTIMULTI--RAYRAY

OVEROVER--STANDARD TESTINGSTANDARD TESTING•• Up toUp to 55--RaysRays were tested.were tested.•• Up to Up to 55 RaysRays were tested.were tested.

UserData-Rate

[bps]

ChannelMulti-Paths

Multipath [msec]

Fading BW[Hz]

SNR[dB]

MOBATMODEM

BER

4800 5 5 FadingFading 2 0.5 32 4.5 E-3

2400 5 5 FadingFading 2 1 23 1.3 E-5

2400 5 5 FadingFading 2 5 35 7.0 E-4

2400 5 5 FadingFading 5 1 35 2.6 E-6

1200 5 5 FadingFading 2 1 16 5.0 E-5

600 5 5 FadingFading 2 1 12 0

300 5 5 FadingFading 5 5 12 0

150 5 5 FadingFading 5 5 10 0

75 5 5 FadingFading 5 5 7 0

FIELDFIELD--TESTSTESTSRESULTSRESULTS

Conducted Nov Conducted Nov 28 28 –– Dec Dec 10 200210 2002LinkLink--Range = Range = 200 200 KMKM

Rate[bps]

Intrlvr RFFreq

[MHz]

FreqQualityBy ALE% -> %

TransDuration

[min]

StartTime

DetFading

BW[Hz]

DetNum

ofRays

DetChannel

Impulse R.LengthRays [msec]

2400 long 9.387 90->89 2x6 10:00 0.1-0.7 2 3-5

150 long 9.387 76->77 1x26+4 13:32 0.1-1.3 1-3 1.25-5.4

2400 long 5.395 47->59 2x6 14:55 0-1 2-4 1.25-4.15

Summary of field test results from 9/12/2002

Received Signal for the 3 cases aboveFrom field test results of 9/12/2002

66dB/DivdB/Div

Despite the severe conditions, reception was achieved with BER=0.

Spectrum for 2400, long, 9.387MHz, time 10:01:00

66dB/DivdB/Div

Spectrum for 150, long, 9.387MHz, time 13:38:00

Signal for 2400, long, 5.395MHz, time 14:58:50, length 40 sec

66dB/DivdB/Div

Spectrum for 2400 long 5 395MHzSpectrum for 2400, long, 5.395MHz,time 14:59:30

S & R d tiSummary & Recommendations We presented the MICOM MD-4800:

As a new Technology application for Digital Secure Data and VoiceData and Voice

Our recommendations: To add one more ray to the 110B STD. To specify a voice coder for HF application. To add a Voice-AMD to the STD.

MICOM MD-4800

Technology for the New GenerationNew Generation