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Testing low pass filter for P25 RX

c4fmdemod
Andy CA6JAU 2017-04-16 10:25:34 -03:00
parent f31cceac18
commit 68dfdf0c21
2 changed files with 14 additions and 31 deletions
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39
IO.cpp
View File

@ -28,18 +28,13 @@ static q15_t RRC_0_2_FILTER[] = {401, 104, -340, -731, -847, -553, 112, 909, 147
-553, -847, -731, -340, 104, 401, 0};
const uint16_t RRC_0_2_FILTER_LEN = 42U;
// Generated using rcosdesign(0.2, 8, 5, 'normal') in MATLAB
static q15_t RC_0_2_FILTER[] = {0, -413, -750, -845, -587, 0, 741, 1347, 1520, 1062, 0, -1383, -2582, -3021, -2222, 0, 3434, 7487, 11318, 14054, 15044, 14054,
11318, 7487, 3434, 0, -2222, -3021, -2582, -1383, 0, 1062, 1520, 1347, 741, 0, -587, -845, -750, -413};
const uint16_t RC_0_2_FILTER_LEN = 40U;
// Generated using gaussfir(0.5, 4, 5) in MATLAB
static q15_t GAUSSIAN_0_5_FILTER[] = {8, 104, 760, 3158, 7421, 9866, 7421, 3158, 760, 104, 8, 0};
const uint16_t GAUSSIAN_0_5_FILTER_LEN = 12U;
// One symbol boxcar filter
static q15_t BOXCAR_FILTER[] = {3000, 3000, 3000, 3000, 3000, 0};
const uint16_t BOXCAR_FILTER_LEN = 6U;
static q15_t LP_FILTER[] = {130, -392, -1347, 3758, 14235, 14235, 3758, -1347, -392, 130};
const uint16_t LP_FILTER_LEN = 10U;
const uint16_t DC_OFFSET = 2048U;
@ -49,13 +44,11 @@ m_rxBuffer(RX_RINGBUFFER_SIZE),
m_txBuffer(TX_RINGBUFFER_SIZE),
m_rssiBuffer(RX_RINGBUFFER_SIZE),
m_rrcFilter(),
m_rcFilter(),
m_gaussianFilter(),
m_boxcarFilter(),
m_lpFilter(),
m_rrcState(),
m_rcState(),
m_gaussianState(),
m_boxcarState(),
m_lpState(),
m_pttInvert(false),
m_rxLevel(128 * 128),
m_cwIdTXLevel(128 * 128),
@ -72,25 +65,20 @@ m_watchdog(0U),
m_lockout(false)
{
::memset(m_rrcState, 0x00U, 70U * sizeof(q15_t));
::memset(m_rcState, 0x00U, 70U * sizeof(q15_t));
::memset(m_gaussianState, 0x00U, 40U * sizeof(q15_t));
::memset(m_boxcarState, 0x00U, 30U * sizeof(q15_t));
::memset(m_lpState, 0x00U, 40U * sizeof(q15_t));
m_rrcFilter.numTaps = RRC_0_2_FILTER_LEN;
m_rrcFilter.pState = m_rrcState;
m_rrcFilter.pCoeffs = RRC_0_2_FILTER;
m_rcFilter.numTaps = RC_0_2_FILTER_LEN;
m_rcFilter.pState = m_rcState;
m_rcFilter.pCoeffs = RC_0_2_FILTER;
m_gaussianFilter.numTaps = GAUSSIAN_0_5_FILTER_LEN;
m_gaussianFilter.pState = m_gaussianState;
m_gaussianFilter.pCoeffs = GAUSSIAN_0_5_FILTER;
m_boxcarFilter.numTaps = BOXCAR_FILTER_LEN;
m_boxcarFilter.pState = m_boxcarState;
m_boxcarFilter.pCoeffs = BOXCAR_FILTER;
m_lpFilter.numTaps = LP_FILTER_LEN;
m_lpFilter.pState = m_lpState;
m_lpFilter.pCoeffs = LP_FILTER;
initInt();
}
@ -179,7 +167,7 @@ void CIO::process()
if (m_p25Enable) {
q15_t P25Vals[RX_BLOCK_SIZE];
::arm_fir_fast_q15(&m_boxcarFilter, samples, P25Vals, RX_BLOCK_SIZE);
::arm_fir_fast_q15(&m_lpFilter, samples, P25Vals, RX_BLOCK_SIZE);
p25RX.samples(P25Vals, rssi, RX_BLOCK_SIZE);
}
@ -229,13 +217,10 @@ void CIO::process()
}
} else if (m_modemState == STATE_P25) {
if (m_p25Enable) {
q15_t P25Vals1[RX_BLOCK_SIZE];
::arm_fir_fast_q15(&m_boxcarFilter, samples, P25Vals1, RX_BLOCK_SIZE);
q15_t P25Vals[RX_BLOCK_SIZE];
::arm_fir_fast_q15(&m_lpFilter, samples, P25Vals, RX_BLOCK_SIZE);
q15_t P25Vals2[RX_BLOCK_SIZE];
::arm_fir_fast_q15(&m_rcFilter, P25Vals1, P25Vals2, RX_BLOCK_SIZE);
p25RX.samples(P25Vals2, rssi, RX_BLOCK_SIZE);
p25RX.samples(P25Vals, rssi, RX_BLOCK_SIZE);
}
} else if (m_modemState == STATE_DSTARCAL) {
q15_t GMSKVals[RX_BLOCK_SIZE];

6
IO.h
View File

@ -61,13 +61,11 @@ private:
CRSSIRB m_rssiBuffer;
arm_fir_instance_q15 m_rrcFilter;
arm_fir_instance_q15 m_rcFilter;
arm_fir_instance_q15 m_gaussianFilter;
arm_fir_instance_q15 m_boxcarFilter;
arm_fir_instance_q15 m_lpFilter;
q15_t m_rrcState[70U]; // NoTaps + BlockSize - 1, 42 + 20 - 1 plus some spare
q15_t m_rcState[70U]; // NoTaps + BlockSize - 1, 42 + 20 - 1 plus some spare
q15_t m_gaussianState[40U]; // NoTaps + BlockSize - 1, 12 + 20 - 1 plus some spare
q15_t m_boxcarState[30U]; // NoTaps + BlockSize - 1, 6 + 20 - 1 plus some spare
q15_t m_lpState[40U]; // NoTaps + BlockSize - 1, 18 + 20 - 1 plus some spare
bool m_pttInvert;
q15_t m_rxLevel;