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军用话音常用到的CVSD算法

The following files are part of the library:

cvenc13b_S1020.raw	
------------------

A CVSD encoded test bit-stream.

The CVSD encoder input signal, s(k), is a 
1020 Hz sinusoidal sampled at 64000 Hz. The 
signal s(k) is in the interval [-2^12,2^12]
which corresponds to a nominal input power
of -15 dBm0. After sampling, the signal s(k) 
is fed into a reference CVSD encoder whose 
output bit stream constitutes this file. 

This signal is used to measure the difference 
of the nominal input and output powers.


LPFWN_16bMS_new.raw	
-------------------

This file contains low pass filtered (3.6 kHz)
white noise sampled at 8000 Hz. The signal, x(k),
is in the interval [-2^15, 2^15].

This signal is used to measure the amount of 
high frequency noise (4-32 kHz) generated by
the transmitter side.

Note: 

The previously distributed version of
this file (LPFWN_16bMS.raw) was corrupted.
Replace it with this file.


decode_cvsd.c 
-------------

This is the reference CVSD decoder to use for 
the measurements of the amount of HF noise
that is generated by the transmitter.

To compile this file you will need a license
of Matlab. From a terminal window, just run:

>> mex decode_cvsd.c

Then, start Matlab and read the file:

>> fid=fopen('cvenc13b_S1020.raw','r');
>> x=fread(fid,inf,'short');
>> y=decode_cvsd(x);
>> plot(y)
>> zoom

Now you are able to zoom in on the received
and decoded sinusoidal of 1020 Hz.