void CSt4285::tx_psk8( int tribit )
{
FComplex symbol;
tx_frame_state();
symbol.re = cmultReal(symbol_psk8[tribit],scrambler_table[tx_scramble_count]);
symbol.im = cmultImag(symbol_psk8[tribit],scrambler_table[tx_scramble_count]);
tx_scramble_count++;
tx_symbol( symbol );
}
void CSt4285::tx_bpsk( int bit )
{
FComplex symbol;
tx_frame_state();
// BPSK because the data is a single bit. But the scrambler_table is an
// 8-PSK symbol, so the result is also 8-PSK.
symbol.re = cmultReal(symbol_psk2[bit],scrambler_table[tx_scramble_count]);
symbol.im = cmultImag(symbol_psk2[bit],scrambler_table[tx_scramble_count]);
tx_scramble_count++;
tx_symbol( symbol );
}
FDemodulate CSt4285::demodulate_bpsk( FComplex symbol )
{
FDemodulate symd;
FComplex sym;
sym.re = cmultRealConj(symbol,scrambler_table[rx_scramble_count]);
sym.im = cmultImagConj(symbol,scrambler_table[rx_scramble_count]);
save_constellation_symbol( sym );
if( sym.re > 0.0 )
{
symd.data = 0;
/* Soft decision information */
sd[soft_index++] = sym.re*get_mse_divisor();
symd.dx_symbol.re = (float)0.01;
symd.dx_symbol.im = (float)0.0;
}
else
{
symd.data = 1;
/* Soft decision information */
sd[soft_index++] = sym.re*get_mse_divisor();
symd.dx_symbol.re = -(float)0.01;
symd.dx_symbol.im = (float)0.0;
}
sym.re = cmultReal(symd.dx_symbol,scrambler_table[rx_scramble_count]);
sym.im = cmultImag(symd.dx_symbol,scrambler_table[rx_scramble_count]);
symd.dx_symbol = sym;
/* Calculate the error */
symd.error.re = sym.re - symbol.re;
symd.error.im = sym.im - symbol.im;
update_mse_average( symd.error );
/* Save the actual symbol */
symd.rx_symbol = symbol;
return symd;
}
FDemodulate CSt4285::demodulate_qpsk( FComplex symbol )
{
FDemodulate symd;
FComplex sym;
float rabs,iabs;
float soft;
sym.re = cmultRealConj(symbol,scrambler_table[rx_scramble_count]);
sym.im = cmultImagConj(symbol,scrambler_table[rx_scramble_count]);
save_constellation_symbol( sym );
rabs = (float)fabs( sym.re );
iabs = (float)fabs( sym.im );
if( rabs > iabs )
{
/* Real component greater */
soft = (rabs - iabs) * get_mse_divisor();
if( sym.re >= 0.0 )
{
symd.data = 0;
sd[soft_index++] = soft;
sd[soft_index++] = soft;
symd.dx_symbol.re = (float)0.01;
symd.dx_symbol.im = (float)0.00;
}
else
{
symd.data = 3;
sd[soft_index++] = -soft;
sd[soft_index++] = -soft;
symd.dx_symbol.re = -(float)0.01;
symd.dx_symbol.im = (float)0.00;
}
}
else
{
/* Imaginary component greater */
soft = (iabs - rabs) * get_mse_divisor();
if( sym.im >= 0.0 )
{
symd.data = 1;
sd[soft_index++] = soft;
sd[soft_index++] = -soft;
symd.dx_symbol.re = (float)0.00;
symd.dx_symbol.im = (float)0.01;
}
else
{
symd.data = 2;
sd[soft_index++] = -soft;
sd[soft_index++] = soft;
symd.dx_symbol.re = (float)0.00;
symd.dx_symbol.im = -(float)0.01;
}
}
/* Calculate the perfect symbol */
sym.re = cmultReal(symd.dx_symbol,scrambler_table[rx_scramble_count]);
sym.im = cmultImag(symd.dx_symbol,scrambler_table[rx_scramble_count]);
symd.dx_symbol = sym;
/* Calculate the error */
symd.error.re = sym.re - symbol.re;
symd.error.im = sym.im - symbol.im;
update_mse_average( symd.error );
/* Save the actual symbol */
symd.rx_symbol = symbol;
return symd;
}
FDemodulate CSt4285::demodulate_8psk( FComplex symbol )
{
FDemodulate symd;
float val;
float rabs,iabs;
float soft;
int angle;
FComplex sym;
sym.re = cmultRealConj(symbol,scrambler_table[rx_scramble_count]);
sym.im = cmultImagConj(symbol,scrambler_table[rx_scramble_count]);
save_constellation_symbol( sym );
rabs = (float)fabs(sym.re);
iabs = (float)fabs(sym.im);
val = iabs/rabs;
if( val <= 0.41421356237 ) /* 22.5 deg */
{
soft = (float)0.38268343237*rabs - (float)0.92387953251*iabs; /* Metric */
angle = 0;
}
else
{
if( val <=1 ) /* 45 deg */
{
soft = (float)0.92387953251*iabs - (float)0.38268343237*rabs; /* Metric */
angle = 45;
}
else
{
if( val <= 2.4142135624 ) /* 67.5 deg */
{
soft = (float)(0.92387953251*rabs - 0.38268343237*iabs); /* Metric */
angle = 45;
}
else
{
soft = (float)(0.38268343237*iabs - 0.92387953251*rabs); /* Metric */
angle = 90;
}
}
}
soft = soft*get_mse_divisor();
/* Find region */
if( sym.re >= 0.0 )
{
if( sym.im < 0.0 )
{
angle = 360 - angle;
}
}
else
{
if( sym.im >= 0.0 )
{
angle = 180 - angle;
}
else
{
angle = 180 + angle;
}
}
switch( angle )
{
case 0:
case 360:
symd.data = 1;
sd[soft_index++] = soft;
sd[soft_index++] = soft;
sd[soft_index++] = -soft;
sd[soft_index++] = 0;
symd.dx_symbol.re = (float)0.01000000;
symd.dx_symbol.im = (float)0.00000000;
break;
case 45:
symd.data = 0;
sd[soft_index++] = soft;
sd[soft_index++] = soft;
sd[soft_index++] = soft;
sd[soft_index++] = 0;
symd.dx_symbol.re = (float)0.00707107;
symd.dx_symbol.im = (float)0.00707107;
break;
case 90:
symd.data = 2;
sd[soft_index++] = soft;
sd[soft_index++] = -soft;
sd[soft_index++] = soft;
sd[soft_index++] = 0;
symd.dx_symbol.re = (float)0.00000000;
symd.dx_symbol.im = (float)0.01000000;
break;
case 135:
symd.data = 3;
sd[soft_index++] = soft;
sd[soft_index++] = -soft;
sd[soft_index++] = -soft;
sd[soft_index++] = 0;
symd.dx_symbol.re = -(float)0.00707107;
symd.dx_symbol.im = (float)0.00707107;
break;
case 180:
symd.data = 7;
sd[soft_index++] = -soft;
sd[soft_index++] = -soft;
sd[soft_index++] = -soft;
sd[soft_index++] = 0;
symd.dx_symbol.re = -(float)0.01000000;
symd.dx_symbol.im = (float)0.00000000;
break;
case 225:
symd.data = 6;
sd[soft_index++] = -soft;
sd[soft_index++] = -soft;
sd[soft_index++] = soft;
sd[soft_index++] = 0;
symd.dx_symbol.re = -(float)0.00707107;
symd.dx_symbol.im = -(float)0.00707107;
break;
case 270:
symd.data = 4;
sd[soft_index++] = -soft;
sd[soft_index++] = soft;
sd[soft_index++] = soft;
sd[soft_index++] = 0;
symd.dx_symbol.re = (float)0.00000000;
symd.dx_symbol.im = -(float)0.01000000;
break;
case 315:
symd.data = 5;
sd[soft_index++] = -soft;
sd[soft_index++] = soft;
sd[soft_index++] = -soft;
sd[soft_index++] = 0;
symd.dx_symbol.re = (float)0.00707107;
symd.dx_symbol.im = -(float)0.00707107;
break;
default:
break;
}
sym.re = cmultReal(symd.dx_symbol,scrambler_table[rx_scramble_count]);
sym.im = cmultImag(symd.dx_symbol,scrambler_table[rx_scramble_count]);
symd.dx_symbol = sym;
/* Calculate the error */
symd.error.re = sym.re - symbol.re;
symd.error.im = sym.im - symbol.im;
update_mse_average( symd.error );
/* Save the actual symbol */
symd.rx_symbol = symbol;
return symd;
}
