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POCSAG RX now runs at 3.072MHz, like NFM audio

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This commit is contained in:
furrtek
2017-02-01 11:40:01 +00:00
parent 8662ed4024
commit 394331ebd2
4 changed files with 15 additions and 12 deletions
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15
firmware/baseband/proc_pocsag.cpp
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@@ -37,17 +37,18 @@
#define POCSAG_BATCH_LENGTH (9 * 32)
void POCSAGProcessor::execute(const buffer_c8_t& buffer) {
// Samplerate is 1.536MHz, gets 2048 samples, called at 750Hz
// This is called at 1500Hz
if (!configured) return;
// Get 24kHz audio
const auto decim_0_out = decim_0.execute(buffer, dst_buffer);
const auto decim_1_out = decim_1.execute(decim_0_out, dst_buffer);
auto audio = demod.execute(decim_1_out, audio_buffer);
const auto channel_out = channel_filter.execute(decim_1_out, dst_buffer);
auto audio = demod.execute(channel_out, audio_buffer);
// End up with 32 samples
for (uint32_t c = 0; c < 32; c++) {
// End up with 16 samples
for (uint32_t c = 0; c < 16; c++) {
const int32_t audio_sample = audio.p[c] * 32768.0f;
//const int32_t audio_sample = __SSAT(sample_int, 16);
@@ -168,11 +169,15 @@ void POCSAGProcessor::configure(const POCSAGConfigureMessage& message) {
constexpr size_t decim_1_input_fs = decim_0_output_fs;
constexpr size_t decim_1_output_fs = decim_1_input_fs / decim_1.decimation_factor;
constexpr size_t channel_filter_input_fs = decim_1_output_fs;
const size_t channel_filter_output_fs = channel_filter_input_fs / 2;
const size_t demod_input_fs = decim_1_output_fs;
const size_t demod_input_fs = channel_filter_output_fs;
decim_0.configure(taps_11k0_decim_0.taps, 33554432);
decim_1.configure(taps_11k0_decim_1.taps, 131072);
channel_filter.configure(taps_11k0_channel.taps, 2);
demod.configure(demod_input_fs, 4500);
bitrate = message.bitrate;

4
firmware/baseband/proc_pocsag.hpp
View File

@@ -57,7 +57,7 @@ private:
//END_OF_MESSAGE = 69
};
static constexpr size_t baseband_fs = 1536000;
static constexpr size_t baseband_fs = 3072000;
BasebandThread baseband_thread { baseband_fs, this, NORMALPRIO + 20, baseband::Direction::Receive };
RSSIThread rssi_thread { NORMALPRIO + 10 };
@@ -75,7 +75,7 @@ private:
dsp::decimate::FIRC8xR16x24FS4Decim8 decim_0 { };
dsp::decimate::FIRC16xR16x32Decim8 decim_1 { };
dsp::decimate::FIRAndDecimateComplex channel_filter { };
dsp::demodulate::FM demod { };
uint32_t sync_timeout { 0 };