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Using CMSIS FIR interpolator for all modulators

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This commit is contained in:
Andy CA6JAU 2017-04-01 01:16:56 -03:00
parent 9bcaba0419
commit a49871cd8b
10 changed files with 148 additions and 145 deletions
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36
P25TX.cpp
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@ -26,13 +26,15 @@
#if defined(WIDE_C4FSK_FILTERS_TX)
// Generated using rcosdesign(0.2, 4, 5, 'normal') in MATLAB
// numTaps = 20, L = 5
static q15_t P25_C4FSK_FILTER[] = {-1392, -2602, -3043, -2238, 0, 3460, 7543, 11400, 14153, 15152, 14153, 11400, 7543, 3460, 0, -2238, -3043, -2602, -1392, 0};
const uint16_t P25_C4FSK_FILTER_LEN = 20U;
const uint16_t P25_C4FSK_FILTER_PHASE_LEN = 4U; // phaseLength = numTaps/L
#else
// Generated using rcosdesign(0.2, 8, 5, 'normal') in MATLAB
// numTaps = 40, L = 5
static q15_t P25_C4FSK_FILTER[] = {-413, -751, -845, -587, 0, 740, 1348, 1520, 1063, 0, -1383, -2583, -3021, -2222, 0, 3435, 7488, 11318, 14053, 15044, 14053,
11318, 7488, 3435, 0, -2222, -3021, -2583, -1383, 0, 1063, 1520, 1348, 740, 0, -587, -845, -751, -413, 0};
const uint16_t P25_C4FSK_FILTER_LEN = 40U;
const uint16_t P25_C4FSK_FILTER_PHASE_LEN = 8U; // phaseLength = numTaps/L
#endif
// Generated in MATLAB using the following commands, and then normalised for unity gain
@ -44,10 +46,10 @@ static q15_t P25_LP_FILTER[] = {170, 401, 340, -203, -715, -478, 281, 419, -440,
281, -478, -715, -203, 340, 401, 170};
const uint16_t P25_LP_FILTER_LEN = 44U;
const q15_t P25_LEVELA[] = { 2475, 0, 0, 0, 0};
const q15_t P25_LEVELB[] = { 825, 0, 0, 0, 0};
const q15_t P25_LEVELC[] = {-825, 0, 0, 0, 0};
const q15_t P25_LEVELD[] = {-2475, 0, 0, 0, 0};
const q15_t P25_LEVELA = 2475;
const q15_t P25_LEVELB = 825;
const q15_t P25_LEVELC = -825;
const q15_t P25_LEVELD = -2475;
const uint8_t P25_START_SYNC = 0x77U;
@ -62,12 +64,13 @@ m_poLen(0U),
m_poPtr(0U),
m_txDelay(240U) // 200ms
{
::memset(m_modState, 0x00U, 70U * sizeof(q15_t));
::memset(m_modState, 0x00U, 16U * sizeof(q15_t));
::memset(m_lpState, 0x00U, 70U * sizeof(q15_t));
m_modFilter.numTaps = P25_C4FSK_FILTER_LEN;
m_modFilter.pState = m_modState;
m_modFilter.L = P25_RADIO_SYMBOL_LENGTH;
m_modFilter.phaseLength = P25_C4FSK_FILTER_PHASE_LEN;
m_modFilter.pCoeffs = P25_C4FSK_FILTER;
m_modFilter.pState = m_modState;
m_lpFilter.numTaps = P25_LP_FILTER_LEN;
m_lpFilter.pState = m_lpState;
@ -130,31 +133,30 @@ uint8_t CP25TX::writeData(const uint8_t* data, uint8_t length)
void CP25TX::writeByte(uint8_t c)
{
q15_t inBuffer[P25_RADIO_SYMBOL_LENGTH * 4U];
q15_t inBuffer[4U];
q15_t intBuffer[P25_RADIO_SYMBOL_LENGTH * 4U];
q15_t outBuffer[P25_RADIO_SYMBOL_LENGTH * 4U];
const uint8_t MASK = 0xC0U;
q15_t* p = inBuffer;
for (uint8_t i = 0U; i < 4U; i++, c <<= 2, p += P25_RADIO_SYMBOL_LENGTH) {
for (uint8_t i = 0U; i < 4U; i++, c <<= 2) {
switch (c & MASK) {
case 0xC0U:
::memcpy(p, P25_LEVELA, P25_RADIO_SYMBOL_LENGTH * sizeof(q15_t));
inBuffer[i] = P25_LEVELA;
break;
case 0x80U:
::memcpy(p, P25_LEVELB, P25_RADIO_SYMBOL_LENGTH * sizeof(q15_t));
inBuffer[i] = P25_LEVELB;
break;
case 0x00U:
::memcpy(p, P25_LEVELC, P25_RADIO_SYMBOL_LENGTH * sizeof(q15_t));
inBuffer[i] = P25_LEVELC;
break;
default:
::memcpy(p, P25_LEVELD, P25_RADIO_SYMBOL_LENGTH * sizeof(q15_t));
inBuffer[i] = P25_LEVELD;
break;
}
}
::arm_fir_fast_q15(&m_modFilter, inBuffer, intBuffer, P25_RADIO_SYMBOL_LENGTH * 4U);
::arm_fir_interpolate_q15(&m_modFilter, inBuffer, intBuffer, 4U);
::arm_fir_fast_q15(&m_lpFilter, intBuffer, outBuffer, P25_RADIO_SYMBOL_LENGTH * 4U);