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Add ChannelDecimator decimate by 2 and no-shift options.

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This commit is contained in:
Jared Boone 2015-11-19 12:24:20 -08:00
parent ccd64f3cd9
commit 060da5d227
2 changed files with 29 additions and 14 deletions
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23
firmware/baseband/channel_decimator.cpp
View File

@ -39,14 +39,10 @@ buffer_c16_t ChannelDecimator::execute_decimation(buffer_c8_t buffer) {
* -> gain of 256
* -> decimation by 2
* -> 1.544MHz complex<int16_t>[1024], [-32768, 32512] */
const auto stage_0_out = translate.execute(buffer, work_baseband_buffer);
//if( fs_over_4_downconvert ) {
// // TODO:
//} else {
// Won't work until cic_0 will accept input type of buffer_c8_t.
// stage_0_out = cic_0.execute(buffer, work_baseband_buffer);
//}
auto stage_0_out = execute_stage_0(buffer, work_baseband_buffer);
if( decimation_factor == DecimationFactor::By2 ) {
return stage_0_out;
}
/* 1.536MHz complex<int16_t>[1024], [-32768, 32512]
* -> 3rd order CIC: -0.1dB @ 0.028fs, -1dB @ 0.088fs, -60dB @ 0.468fs
@ -82,3 +78,14 @@ buffer_c16_t ChannelDecimator::execute_decimation(buffer_c8_t buffer) {
return cic_4_out;
}
buffer_c16_t ChannelDecimator::execute_stage_0(
buffer_c8_t buffer,
buffer_c16_t work_baseband_buffer
) {
if( fs_over_4_downconvert ) {
return translate.execute(buffer, work_baseband_buffer);
} else {
return cic_0.execute(buffer, work_baseband_buffer);
}
}

20
firmware/baseband/channel_decimator.hpp
View File

@ -32,6 +32,7 @@
class ChannelDecimator {
public:
enum class DecimationFactor {
By2,
By4,
By8,
By16,
@ -39,13 +40,16 @@ public:
};
constexpr ChannelDecimator(
) : decimation_factor { DecimationFactor::By32 }
) : decimation_factor { DecimationFactor::By32 },
fs_over_4_downconvert { true }
{
}
constexpr ChannelDecimator(
const DecimationFactor decimation_factor
) : decimation_factor { decimation_factor }
const DecimationFactor decimation_factor,
const bool fs_over_4_downconvert = true
) : decimation_factor { decimation_factor },
fs_over_4_downconvert { fs_over_4_downconvert }
{
}
@ -62,18 +66,22 @@ public:
private:
std::array<complex16_t, 1024> work_baseband;
//const bool fs_over_4_downconvert = true;
dsp::decimate::TranslateByFSOver4AndDecimateBy2CIC3 translate;
//dsp::decimate::DecimateBy2CIC3 cic_0;
dsp::decimate::Complex8DecimateBy2CIC3 cic_0;
dsp::decimate::DecimateBy2CIC3 cic_1;
dsp::decimate::DecimateBy2CIC3 cic_2;
dsp::decimate::DecimateBy2CIC3 cic_3;
dsp::decimate::DecimateBy2CIC3 cic_4;
DecimationFactor decimation_factor;
const bool fs_over_4_downconvert;
buffer_c16_t execute_decimation(buffer_c8_t buffer);
buffer_c16_t execute_stage_0(
buffer_c8_t buffer,
buffer_c16_t work_baseband_buffer
);
};
#endif/*__CHANNEL_DECIMATOR_H__*/