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Public Slots | Signals | Public Member Functions | Private Types | Private Attributes

FaxDemodulator Class Reference

#include <FaxDemodulator.hpp>

Collaboration diagram for FaxDemodulator:
Collaboration graph
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List of all members.

Public Slots

void newSamples (short *audio, int n)

Signals

void data (int *, int)

Public Member Functions

 FaxDemodulator (QObject *parent)
void init (int sampleRate)

Private Types

typedef FirFilter< double > LPF

Private Attributes

LookUpTable< double > arcSine
LookUpTable< double > cosine
int deviation
bool fm
double ifirold
LPF iLpf
std::valarray< double > lowPassFilter [3]
double qfirold
LPF qLpf
int rate
LookUpTable< double > sine

Detailed Description

AM and FM demodulator. The demodulator takes the raw stream from the sound device as input and outputs the black/white signal.

 \htmlonly
 \verbatim
                                    I_t       I_{t-1}
             +----------+  +-------+     +----+  +---+
          +->|*sin(f_c) |->|FIR-LPF|--*->|z^-1|->|mul|--+
          |  +----------+  +-------+  |  +----+  +---+  |
          |                           *-->--     /      |
          |                           |     \   /       |+  y_{t-1}
          |                  +-------------+ \ /      +---+   +----+
 --+                  |normalization|  X       |add|-->|asin|--
          |                  +-------------+ / \      +---+   +----+       
          |                           |     /   \       |-
          |                           *-->--     \      |
          |  +----------+  +-------+  |  +----+  +---+  |
          +->|*cos(f_c )|->|FIR-LPF|--*->|z^-1|->|mul|--+
             +----------+  +-------+     +----+  +---+
                                    Q_t       Q_{t-1}
 \endverbatim

 \f[ y_{t-1} = I_{t-1} Q_t - Q_{t-1} I_t \f]
 \f[ y_{t-1} = sin(2\pi ft - 2\pi f) \f]

Definition at line 53 of file FaxDemodulator.hpp.


The documentation for this class was generated from the following files:

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