文件列表:

src_code\OFDM_SRC\CVSROOT\checkoutlist.txt (508, 2005-01-04)
src_code\OFDM_SRC\CVSROOT\commitinfo.txt (777, 2005-01-04)
src_code\OFDM_SRC\CVSROOT\config..txt (539, 2005-02-06)
src_code\OFDM_SRC\CVSROOT\cvswrappers.txt (778, 2005-02-06)
src_code\OFDM_SRC\CVSROOT\editors.txt (1048, 2005-02-06)
src_code\OFDM_SRC\CVSROOT\loginfo.txt (1169, 2005-02-06)
src_code\OFDM_SRC\CVSROOT\modules.txt (1179, 2005-02-06)
src_code\OFDM_SRC\CVSROOT\notify.txt (578, 2005-02-06)
src_code\OFDM_SRC\CVSROOT\rcsinfo.txt (664, 2005-02-06)
src_code\OFDM_SRC\CVSROOT\taginfo.h (901, 2005-02-06)
src_code\OFDM_SRC\CVSROOT\verifmsg.txt (1049, 2005-02-06)
src_code\OFDM_SRC\SoundModem\afsk\costab.c (4381, 2005-02-05)
src_code\OFDM_SRC\SoundModem\afsk\costab.h (1457, 2005-02-05)
src_code\OFDM_SRC\SoundModem\afsk\gentbl.c (2189, 2005-02-05)
src_code\OFDM_SRC\SoundModem\afsk\makefile.am (312, 2005-02-05)
src_code\OFDM_SRC\SoundModem\afsk\modem.c (13819, 2005-02-05)
src_code\OFDM_SRC\SoundModem\afsk\testcrc.c (2649, 2005-02-05)
src_code\OFDM_SRC\SoundModem\configapp\configapp.glade (39246, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\configure.in (1445, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\configure.txt (82574, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\install.txt (8015, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\makefile.am (705, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\src\app.c (35803, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\src\callbacks.h (5625, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\src\configapp.h (2685, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\src\configapp.rc (1085, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\src\diag.c (34685, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\src\interface.c (103880, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\src\interface.h (423, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\src\main.c (19845, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\src\makefile.am (1257, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\src\scope.c (9859, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\src\scope.h (1994, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\src\soundmodemconfig.8 (798, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\src\spectrum.c (14097, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\src\spectrum.h (2240, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\src\support.c (4734, 2005-02-06)
src_code\OFDM_SRC\SoundModem\configapp\src\support.h (1621, 2005-02-06)
src_code\OFDM_SRC\SoundModem\flxdrv\drv.c (2920, 2005-02-06)
src_code\OFDM_SRC\SoundModem\flxdrv\drv32.h (465, 2005-02-06)
... ...

NEWQPSK modem for the Usermode Soundcard Modem driver ===================================================== This package implements the NEWQPSK protocol (also known as Q15X25) as designed and defined by Pawel Jalocha, SP9VRC, . Pawel's original modem is written in Motorola 56k assembler for the DSP56002EVM evaluation module or the Alef Null DSP Card 4. This code is a port of the original code to C. Most of the features of the original modem are implemented. The most important feature still lacking is the support for tuning the transceiver. The modem has been used for real life QSOs with performance comparable to the original modem. Soundmodem configuration ======================== There is an IMPORTANT detail in soundmodem core configuration concerning NEWQPSK. In the "Channel Access" section one should set "TxDelay" to a non-zero value. The actual value does not matter, the modem will ignore it. (If your transmitter is slow and you need to compensate that then you can increase "Tune length" as explained later.) Equally important is that one sets "TxTail" to zero. Failing to set these will cause the NEWQPSK modem to behave erratically. The actual NEWQPSK modulator and demodulator are subject to five configuration parameters that can be set with the `soundmodemconfig' tool: Bits per second This sets the modem raw bit rate. The available range is 1000 to 5000. Rates 2500bps and 3000bps correspond to sample rates of 8000sps and 9600sps in the original code respectively. Interleave depth Sets the interleave depth. Allowed range is 0...16. Zero disables interleaving. FEC level Sets the used error correcting code. Possible values are: 0 no FEC 1 simple (15,11) FEC 2 BCH (15,7) FEC. 3 Walsh (15,5) FEC Note that BCH (15,7) is NOT compatible with the original EVM56K modem. The FEC overhead can be calculated from the figures in parenthesis. For example Walsh (15,5) lowers the user data rate to 2500*5/15 = 833.3 bps. Tune length On modulator side this sets the length of the tune preamble in symbols. Allowed range is 0...***. On demodulator side this sets the minimum of received tune preamble symbols needed to make a tuning decision. Allowed range is 0...32. Zero means the demodulator will jump directly to waiting sync state. Sync length On modulator side this sets the length of the sync preamble in symbols. Allowed range is 16...***. On demodulator side this sets the minimum of received sync preamble symbols needed to make a symbol sync decision. Allowed range is 8...32. More detailed configuration of the modem parameters can be done at compile time with the modemconfig.h file in this directory. The parameters there are not to be changed unless you know what you are doing... :) NEWQPSK FEATURES ================ NEWQPSK modem was designed primarily with HF in mind. You are supposed to connect it to a normal HF SSB rig. However NEWQPSK might also find some use in VHF/UHF FM packet. As FM has no frequency ambiquity the tune preamble can be disabled (tune length = 0). Also it might make sense to shorten the sync preamble. NEWQPSK is an AX.25 packet modem and can be used for anything regular packet can, including TCP/IP. Here is a short list of NEWQPSK highlights: - AX.25 compatible - 15 carriers spaced by 125 Hz (150 Hz) modulated with DQPSK (differential 4-level phase shift keying) at 83.33 baud (100 baud) - Total raw data rate 2500 bps (3000 bps) - Two phase preamble for frequency shift correction and fast symbol sync. The modem can correct frequency shift up to about 100 Hz. - Forward Error Correction: three simple schemes with different levels of data redundancy - Time/frequency diversity (interleave) to de-localize burst errors (The figures in parenthesis above are for sample rate of 9600 sps.) Note that the envelope of the transmitted signal is NOT constant. The modulation has a crest factor of about XX dB which means that with a 100W transmitter and a power meter that reads average power you should adjust the output reading to about YY Watts. Exceeding this will cause clipping that will not only cause interference to other band users but also make copy at the other end worse. Also keep in mind that this is a WIDE mode (about 2000...2400Hz wide). You should be very careful not to transmit over other band users and you should probably keep away from the narrow band digital segments. DISCLAIMER ========== The sole purpose for me to write this modem implementation was to learn about DSP in general and Pawel's novel modem in particular. I'm fairly new to DSP and this code is mostly a result of countless hours of staring at the original Motorola 56K assembler source and banging my head against the wall... I can't claim I understand all aspects and every detail in the modem. There are probably misunderstandings and errors in the code and if you spot one, please tell me. I want to learn more. Also if you have ideas for further development please share them with me. I have already some ideas of my own. -- Tomi Manninen, OH2BNS

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