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14432 Albemarle Point Place • Chantilly VA 20151 • Phone (703) 488-2555 • Fax (703) 488-2555 • www.avtec.com - PowerPoint PPT Presentation


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14432 Albemarle Point Place • Chantilly VA 20151 • Phone (703) 488-2555 • Fax (703) 488-2555 • www.avtec.com . EMWIN S/W Receiver April 27, 2004. Presentation Agenda. EMWIN System Introduction EMWIN Demodulator Software Overview System Requirements Installation Instructions Overview

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14432 Albemarle Point Place • Chantilly VA 20151 • Phone (703) 488-2555 • Fax (703) 488-2555 • www.avtec.com

EMWIN S/W Receiver

April 27, 2004


Presentation Agenda

  • EMWIN System Introduction

  • EMWIN Demodulator Software Overview

  • System Requirements

  • Installation Instructions Overview

  • Prototype Demonstration

  • On-going Work / Potential Upgrades


EMWIN-N S/W Receiver Introduction

  • S/W Demodulation, Bit-Synchronization

  • CCSDS Concatenated R-S + Convolution, Bitstream Service

  • Signal must be acquired for coding gain to apply

  • EMWIN-N Reduced TX Power Performance Goals

    • 3 dB Margin with 1 meter antenna @ 5 degree elevation

    • BER 10-6 @ 5 degree elevation

  • Implementation Goals

    • Support EMWIN-I Series FSK & EMWIN-N Series BPSK

    • S/W Loading < 25% CPU (1 GHz P4)

    • Re-use Antenna & RF components

    • Additional H/W costs < $300

  • Current Test Results

    • 4.5 dB Margin with 1 meter antenna @ 5 degree elevation achievable

    • Link Margin enough to support transition to 2x data rate & QPSK


EMWIN Receiver Architecture


EMWIN Demodulator Software Overview


System Requirements


Installation Overview

  • Download S/W and Manuals from NWS

  • Antenna / LNB Amplifier

  • IF Adapter

  • Consumer PC / Sound card / Serial card

  • EMWIN Demodulator

  • EMWIN data processing & display S/W


(a) Antenna/LNB Amplifier

  • Assemble the dish and position the antenna.

  • Connect the LNB to the antenna.


(b) IF Adapter

  • Construct or Purchase UHF/VHF Frequency Adapter.

  • Connectorized component version. Surface/through hole

  • schematic available.


(b) UHF/VHF Frequency Adapter (cont.)

  • Connect the UHF/VHF Frequency adapter to the LNB using an SMA or appropriate RF cable. Note –60 dBm maximum input for the reference design.

  • Connect the adapter to an A/D or soundcard when installed. If using the Avtec Data Source Service, channel 0 of the soundcard must be used at this time.

  • Connect the power supply to the rear power jack.

  • Turn on the DC BIAS for the adapter.

  • Turn main power on.


(c) Consumer PC / Sound Card / Serial Card

  • Install Windows 2000 or XP and corresponding service packs on PC if not already pre-installed.

  • Install Sound card or A/D converter.

  • Install Serial expansion card if the PC does not contain two RS-232 com ports and connect loop back cable.

  • Login to the system as the local administrator and install necessary device drivers. Insure TCP/IP Protocol stack is active.


(c) Consumer PC / Sound Card / Serial Card (cont.)

  • Configure the A/D or Sound card and test operation by recording and playing audio.


(c) Consumer PC / Sound Card / Serial Card (cont.)

  • Configure the Serial card if necessary. Test using HyperTerminal.


(d) EMWIN Demodulator

  • Unpack the archived EMWINSetup.exe to a temporary directory and verify.

  • Initiate EMWIN installer.


(d) EMWIN Demodulator (cont.)

17. Review and acknowledge the welcome screen.

18. Review and acknowledge the license agreement.


(d) EMWIN Demodulator (cont.)

19. Review and acknowledge the information screen.

20. Select program location.


(d) EMWIN Demodulator (cont.)

21. Select the installation type.

22. Select icon access location.


(d) EMWIN Demodulator (cont.)

  • 23. Install EMWIN Demodulator Services.

  • 24. Reboot the PC.

  • 25. Verify EMWIN Data Source and Demodulator Service are active.

    • Select START->EMWIN Demodulator->EMWIN Config.

    • Select Data Source Service Tab and note activity icon.

    • Select Demodulator Service Tab and note activity icon.


(d) EMWIN Demodulator (cont.)

  • Pertinent Data Source Parameters:

  • Input Device – Selects the desired sound card.

  • Input Gain – Selects the sound card gain value.

  • Data range is between -32768 and 32768.

  • TCP Port Number – Selects a valid TCP/IP Port.

  • Port range is between 1 to 65535.

  • Avoid system reserved ports.


(d) EMWIN Demodulator (cont.)

Pertinent Demodulator Parameters:

Data Source Host – IP address that the Data Source Service resides at. IP address 127.0.0.1 represents the local systems address.

Signal Format – Selects between EMWIN I (0) or EMWIN N (1).

COM Port Number – Defines the desired COM port to write out for the EMWIN display software.

TCP Port Number – Selects a valid TCP/IP Port. Must match the Data Source Service assigned port address.


(d) EMWIN Demodulator (cont.)

Pertinent FSK Demodulator Parameters:

Sample Rate – The sample rate will be 96 KHz for the sound card solution.

Signal Present Threshold – The threshold which used to indicate whether a valid signal is present.

AGC Gain – The gain bandwidth setting value that corresponds to about a 10 Hz bandwidth at the given input sample rate.

Tuner Frequency – Initial tuner frequency that represents the frequency as seen by the A/D converter. The nominal center frequency has been designed for approximately 25 KHz.


(d) EMWIN Demodulator (cont.)

Pertinent FSK Symbol Parameters:

Symbol Rate – Specifies the number of symbols that are transmitted in one second. EMWIN I requires a symbol rate of 9600.

Error Threshold – Maximum allowable number of errors before the demodulator symbol tracker is reset.


(d) EMWIN Demodulator (cont.)

Pertinent BPSK Demodulator Parameters:

Sample Rate – The sample rate will be 96 KHz for the sound card solution.

Signal Present Threshold – The threshold which used to indicate whether a valid signal is present.

AGC Gain – The gain bandwidth setting value.

Tuner Frequency – Initial tuner frequency that represents the frequency as seen by the A/D converter.


(d) EMWIN Demodulator (cont.)

Pertinent BPSK Symbol Parameters:

Symbol Rate – Specifies the number of symbols that are transmitted in one second. EMWIN I requires a symbol rate of 22000.

Error Threshold – Maximum allowable number of errors before the demodulator symbol tracker is reset.


(e) COTS EMWIN S/W

26. Install EMWIN data processing & display S/W. Register license.

27. Start EMWIN S/W, configure serial com ports (if used) and file repository.

28. Start EMWIN Ingest and process EMWIN service products.


Ongoing Efforts

  • De-Couple RX layer from Coding layer

    • Allows use of RX function only, or decoder only

  • Provide example application that interfaces with the EMWIN S/W RX

    • Example S/W that allows users/vendors to build on-top of S/W RX

    • Control and monitor examples, indicates receiver performance

    • Available in 1-2 Weeks

  • Modify EMWIN S/W RX to allow use with “lower performance” Sound Cards

    • Use both L & R channels

    • Minimal (< $15 in components) changes to IF Adapter H/W design

    • I&Q Recombination in S/W

  • Higher data rate options

    • QPSK

    • CCSDS Turbo Convolution Codes

    • Low Density Parity Check


Questions?


Backup - S/W Demod BitSync Block Diagram

A/D

I & Q used to simplify tracking


Backup - Software FSK Demod/Bitsync Module

  • Acquires data from TCP socket connection

  • Required for EMWIN-I reception and decoding


Backup - Bit Synchronizer and Matched Filter

  • Performs bit clock recovery and soft symbols for PSK and BPSK signals

  • Outputs Soft symbols to second processor through Global Memory


Backup - Frame Synch and Bit Decoding

  • Soft symbols are input from Demod BitSync

  • If required, Viterbi decoding is performed followed by a frame synchronizer function

  • Application software is not a deliverable item, but if supplied GFE will be included


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