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SigLib p/4 D-QPSK Modem Example Programs |
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SigLib p/4 D-QPSK Modem Example Programs |
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The files in this folder provide a example of a complete p/4 D-QPSK modem.
The input data sequence is taken from the file "base.txt" this data is used to modulate the carrier (using dqpskmod.exe) and the data is written to a .sig file. The program sig2wav is then used to convert this data to .wav file format before the data is passed to dqpskdem.exe which demodulates the data. The demodulated data is written to the file demodout.dat - the data sequence should be the same as base.txt.
The application uses V.26B modulation with the following configuration :
Sampling Rate = 48 KHz
Data format = 8 bit
Symbol Rate = 1200 baud
Bit Rate = 2400 bps
Carrier Frequency = 1800 Hz
| Dibit | Phase change Alternative B |
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| 00 | + 45° | |
| 01 | + 135° | |
| 11 | + 225° | |
| 10 | + 315° |
This example can be compiled "as is" with the Signal Visualizer API.
| Filename | Description | |
| dqpskdem.c | Demodulator source code | |
| dqpskmod.c | Modulator source code | |
| Rx_FIR.h | FIR filter for demodulator | |
| Tx_FIR.h | FIR filter for modulator |
For further
information, please contact : Email : numerix@numerix-dsp.com |
Indigo Consulting Ltd.., 7 Dauphine
Close, Coalville, Leics., LE67 4QQ, UK. Phone : +44 (0)208 020 0046, Fax : +44 (0)208 020 0047 |
Copyright © 2008, Indigo Consulting Ltd..
Permission is granted to create WWW pointers to this document.
SigLib and Digital Filter Plus are trademarks of Indigo Consulting Ltd.. All
other trademarks acknowledged.
Numerix are continuously increasing the functionality of SigLib
and reserve the right to alter the product at any time.