mirror
/
usdx
kopia lustrzana https://github.com/threeme3/usdx
1
0
Forkuj 0
Kod Zgłoszenia Projekty Wydania Wiki Aktywność

Fix sample-rate reduction issue (that was introduced with improved Hilbert transformer).

pull/11/head
guido 2020-07-28 16:52:05 +02:00
rodzic c34c4061f9
commit fc0d84d02a
1 zmienionych plików z 49 dodań i 0 usunięć
Pokaż statystyki Ściągnij plik aktualizacji Ściągnij plik porównania Expand all files Collapse all files

49
QCX-SSB.ino
Wyświetl plik

@ -1754,6 +1754,53 @@ inline int16_t filt_var(int16_t za0) //filters build with www.micromodeler.com
}
}
/*
inline int16_t filt_var(int16_t v) //filters build with www.micromodeler.com
{
int16_t zx0 = v;
static int16_t za1,za2;
if(filt < 4){ // for SSB filters
// 1st Order (SR=8kHz) IIR in Direct Form I, 8x8:16
static int16_t zz1,zz2;
zx0=(29*(zx0-zz1)+50*za1)/64; //300-Hz
zz2=zz1;
zz1=v;
}
za2=za1;
za1=zx0;
// 4th Order (SR=8kHz) IIR in Direct Form I, 8x8:16
//static int16_t za1,za2;
static int16_t zb1,zb2;
switch(filt){
case 1: break; //0-4000Hz (pass-through)
case 2: zx0=(10*(zx0+2*za1+za2)+16*zb1-17*zb2)/32; break; //0-2500Hz elliptic -60dB@3kHz
case 3: zx0=(7*(zx0+2*za1+za2)+48*zb1-18*zb2)/32; break; //0-1700Hz elliptic
case 4: zx0=(zx0+2*za1+za2+41*zb1-23*zb2)/32; break; //500-1000Hz
case 5: zx0=(5*(zx0-2*za1+za2)+105*zb1-58*zb2)/64; break; //650-840Hz
case 6: zx0=(3*(zx0-2*za1+za2)+108*zb1-61*zb2)/64; break; //650-750Hz
case 7: zx0=((2*zx0-3*za1+2*za2)+111*zb1-62*zb2)/64; break; //630-680Hz
}
zb2=zb1;
zb1=zx0;
static int16_t zc1,zc2;
switch(filt){
case 1: break; //0-4000Hz (pass-through)
case 2: zx0=(8*(zx0+zb2)+13*zb1-43*zc1-52*zc2)/64; break; //0-2500Hz elliptic -60dB@3kHz
case 3: zx0=(4*(zx0+zb1+zb2)+22*zc1-47*zc2)/64; break; //0-1700Hz elliptic
case 4: zx0=(16*(zx0-2*zb1+zb2)+105*zc1-52*zc2)/64; break; //500-1000Hz
case 5: zx0=((zx0+2*zb1+zb2)+97*zc1-57*zc2)/64; break; //650-840Hz
case 6: zx0=((zx0+zb1+zb2)+104*zc1-60*zc2)/64; break; //650-750Hz
case 7: zx0=((zb1)+109*zc1-62*zc2)/64; break; //630-680Hz
}
zc2=zc1;
zc1=zx0;
return zx0;
}
*/
static uint32_t absavg256 = 0;
volatile uint32_t _absavg256 = 0;
volatile int16_t i, q;
@ -1961,6 +2008,7 @@ void sdr_rx_q()
qh = ((v[0] - ac2) + (v[2] - v[12]) * 4) / 64 + ((v[4] - v[10]) + (v[6] - v[8])) / 8 + ((v[4] - v[10]) * 5 - (v[6] - v[8]) ) / 128 + (v[6] - v[8]) / 2; // Hilbert transform, 43dB side-band rejection in 650..3400Hz (@8kSPS) when used in image-rejection scenario; (Hilbert transform require 4 additional bits)
//qh = ((v[0] - ac2) * 2 + (v[2] - v[12]) * 8 + (v[4] - v[10]) * 21 + (v[6] - v[8]) * 15) / 128 + (v[6] - v[8]) / 2; // Hilbert transform, 40dB side-band rejection in 400..1900Hz (@4kSPS) when used in image-rejection scenario; (Hilbert transform require 5 additional bits)
for(uint8_t j = 0; j != 13; j++) v[j] = v[j + 1]; v[13] = ac2;
//v[0] = v[1]; v[1] = v[2]; v[2] = v[3]; v[3] = v[4]; v[4] = v[5]; v[5] = v[6]; v[6] = v[7]; v[7] = v[8]; v[8] = v[9]; v[9] = v[10]; v[10] = v[11]; v[11] = v[12]; v[12] = v[13]; v[13] = ac2;
}
rx_state = 0; return;
#ifdef M4
@ -2088,6 +2136,7 @@ void sdr_rx()
qh = ((v[0] - ac2) + (v[2] - v[12]) * 4) / 64 + ((v[4] - v[10]) + (v[6] - v[8])) / 8 + ((v[4] - v[10]) * 5 - (v[6] - v[8]) ) / 128 + (v[6] - v[8]) / 2; // Hilbert transform, 43dB side-band rejection in 650..3400Hz (@8kSPS) when used in image-rejection scenario; (Hilbert transform require 4 additional bits)
//qh = ((v[0] - ac2) * 2 + (v[2] - v[12]) * 8 + (v[4] - v[10]) * 21 + (v[6] - v[8]) * 15) / 128 + (v[6] - v[8]) / 2; // Hilbert transform, 40dB side-band rejection in 400..1900Hz (@4kSPS) when used in image-rejection scenario; (Hilbert transform require 5 additional bits)
for(uint8_t j = 0; j != 13; j++) v[j] = v[j + 1]; v[13] = ac2;
//v[0] = v[1]; v[1] = v[2]; v[2] = v[3]; v[3] = v[4]; v[4] = v[5]; v[5] = v[6]; v[6] = v[7]; v[7] = v[8]; v[8] = v[9]; v[9] = v[10]; v[10] = v[11]; v[11] = v[12]; v[12] = v[13]; v[13] = ac2;
}
#ifdef M4
} else { p->_z2 = p->_z1; p->_z1 = _ac * 4; }