From 4d10d9f404b10232e65f1be58a159e08fb692f14 Mon Sep 17 00:00:00 2001
From: c vw <dl1ycf@darc.de>
Date: Mon, 15 Nov 2021 14:00:45 +0100
Subject: [PATCH] SOAPY: normalize TX IQ samples to unity.
---
transmitter.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/transmitter.c b/transmitter.c
index 525dfd7..1e4ef52 100644
--- a/transmitter.c
+++ b/transmitter.c
@@ -1139,7 +1139,7 @@ static void full_tx_buffer(TRANSMITTER *tx) {
break;
#ifdef SOAPYSDR
case SOAPYSDR_PROTOCOL:
- gain=32767.0; // 16 bit
+ // gain is not used, since samples are floating point
break;
#endif
}
@@ -1181,7 +1181,7 @@ static void full_tx_buffer(TRANSMITTER *tx) {
// by about 20 dB and at 1000 Hz by about 10 dB.
// Natural speech has much energy at frequencies below 1000 Hz
// which will therefore aquire only little energy, such that
- // FM sounds rather silent.
+ // FM sounds rather "thin".
//
// At the expense of having some distortion for the highest
// frequencies, we amplify the mic samples here by 15 dB
@@ -1259,7 +1259,8 @@ static void full_tx_buffer(TRANSMITTER *tx) {
// 7.5 dB we have to damp significantly at this place, which may affect IMD.
//
// NOTE: When doing adaptive pre-distortion (PURESIGNAL), IQ scaling cannot
- // be used.
+ // be used because the the TX ADC samples reported back also never
+ // reach their "SetPK" amplitude and PURESIGNAL does not jump in
//
int power;
double f,g;
@@ -1342,11 +1343,9 @@ static void full_tx_buffer(TRANSMITTER *tx) {
// the only difference to the P2 treatment is that we do not
// generate audio samples to be sent to the radio
//
- isample=0;
for(j=0;j<tx->output_samples;j++) {
ramp=cw_shape_buffer192[j]; // between 0.0 and 1.0
- qsample=floor(gain*ramp+0.5); // always non-negative, isample is just the pulse envelope
- soapy_protocol_iq_samples((float)isample,(float)qsample);
+ soapy_protocol_iq_samples(0.0F,(float)ramp); // SOAPY: just convert double to float
}
break;
#endif
@@ -1375,7 +1374,8 @@ static void full_tx_buffer(TRANSMITTER *tx) {
break;
#ifdef SOAPYSDR
case SOAPYSDR_PROTOCOL:
- soapy_protocol_iq_samples((float)isample,(float)qsample);
+ // SOAPY: just convert the double IQ sampels (is,qs) to float.
+ soapy_protocol_iq_samples((float)is,(float)qs);
break;
#endif
}
--
2.45.2