Weak signal software for PC vers 1.11
Test functionsThis program still contains the functions of vers 1.00 The speed is a bit improved, so it will run on slightly slower computers than before. These functions are unchanged from vers 1.10
These test functions will be removed in later versions (to be replaced by other and far more efficient algorithms). To run the primitive test functions a 486 or above is required. The speed of the graphics is very important, and selecting a simpler graphics display may make this program run on old computers.
Real algorithmsThis software preprocesses the input signal pair, left and right line input, assuming they come from a cross yagi system using a stereo receiver with common local oscillators. A MMX processor is required, but no test is done (yet) for support of these instructions, so if the program option C under the menu is run on a PC without MMX the reset button will probably be the only way to recover...
The output is a group of signals from which it should be particularly simple and efficient to remove impulse noise even if strong signals are present in the pass band. These signals can be stored on the hard disk and recovered for later use in program development.
The source code contains a fft floating point routine optimised for the watcom C++ compiler with options as specified in the .MAK file. The optimised routine is in RXSUB1.C. The optimised fft calculates two complex transforms simultaneously using a window function from a table. ( sine squared )
The source code also contains a back transformation written in assembly using the MMX instructions.
These routines may be used together with the fast 16 bit real to 32 bit complex interrupt routine for various signal processing purposes.
The complete source code SRCE111.ZIP is intended to run in its own subdirectory with the Watcom files under a separate directory \WATCOM directly under the root. If the WATCOM header files are placed elsewhere, DSP.MAK has to be changed.
The files are:
Tha WATCOM directory needs WPP386.EXE, W32RUN.EXE, WLINK.EXE, WSTUB.EXE WASM.EXE WMAKE.EXE, a subdirectory \LIB for the libraries (CLIB3R,PLIB3R,MATH387R,EMU387,GRAPH) and a subdirectory \H, including \H\SYS for the header files. This is a small sub set of WATCOM, about 4 megabytes.
Liability, Copyright.....The software on this page is completely my own. It is presented here to be used by anyone interested on his/her own risk. I take no responsibility for any damage that may be caused by malfunction of the software.
I do not claim any copyright. The source code is here to encourage particularly radio amateurs to make their own additions and changes for whatever purpose of their own. If you make your own software from the source code here, please give it a new name of your own - even if you have changed only a single line. Please, change also the menu text in main.c.