MMDVM/DMRDMOTX.cpp

157 lines
4.2 KiB
C++

/*
* Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
* Copyright (C) 2016 by Colin Durbridge G4EML
* Copyright (C) 2017 by Andy Uribe CA6JAU
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "Config.h"
#include "Globals.h"
#include "DMRSlotType.h"
// Generated using rcosdesign(0.2, 8, 5, 'sqrt') in MATLAB
static q15_t RRC_0_2_FILTER[] = {0, 0, 0, 0, 850, 219, -720, -1548, -1795, -1172, 237, 1927, 3120, 3073, 1447, -1431, -4544, -6442,
-5735, -1633, 5651, 14822, 23810, 30367, 32767, 30367, 23810, 14822, 5651, -1633, -5735, -6442,
-4544, -1431, 1447, 3073, 3120, 1927, 237, -1172, -1795, -1548, -720, 219, 850}; // numTaps = 45, L = 5
const uint16_t RRC_0_2_FILTER_PHASE_LEN = 9U; // phaseLength = numTaps/L
const q15_t DMR_LEVELA = 1362;
const q15_t DMR_LEVELB = 454;
const q15_t DMR_LEVELC = -454;
const q15_t DMR_LEVELD = -1362;
const uint8_t BIT_MASK_TABLE[] = {0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04U, 0x02U, 0x01U};
#define WRITE_BIT1(p,i,b) p[(i)>>3] = (b) ? (p[(i)>>3] | BIT_MASK_TABLE[(i)&7]) : (p[(i)>>3] & ~BIT_MASK_TABLE[(i)&7])
#define READ_BIT1(p,i) (p[(i)>>3] & BIT_MASK_TABLE[(i)&7])
const uint8_t DMR_SYNC = 0x5FU;
CDMRDMOTX::CDMRDMOTX() :
m_fifo(),
m_modFilter(),
m_modState(),
m_poBuffer(),
m_poLen(0U),
m_poPtr(0U),
m_txDelay(240U) // 200ms
{
::memset(m_modState, 0x00U, 16U * sizeof(q15_t));
m_modFilter.L = DMR_RADIO_SYMBOL_LENGTH;
m_modFilter.phaseLength = RRC_0_2_FILTER_PHASE_LEN;
m_modFilter.pCoeffs = RRC_0_2_FILTER;
m_modFilter.pState = m_modState;
}
void CDMRDMOTX::process()
{
if (m_poLen == 0U && m_fifo.getData() > 0U) {
if (!m_tx) {
for (uint16_t i = 0U; i < m_txDelay; i++)
m_poBuffer[i] = DMR_SYNC;
m_poLen = m_txDelay;
} else {
for (unsigned int i = 0U; i < 72U; i++)
m_poBuffer[i] = DMR_SYNC;
for (unsigned int i = 0U; i < DMR_FRAME_LENGTH_BYTES; i++)
m_poBuffer[i + 39U] = m_fifo.get();
m_poLen = 72U;
}
m_poPtr = 0U;
}
if (m_poLen > 0U) {
uint16_t space = io.getSpace();
while (space > (4U * DMR_RADIO_SYMBOL_LENGTH)) {
uint8_t c = m_poBuffer[m_poPtr++];
writeByte(c);
space -= 4U * DMR_RADIO_SYMBOL_LENGTH;
if (m_poPtr >= m_poLen) {
m_poPtr = 0U;
m_poLen = 0U;
return;
}
}
}
}
uint8_t CDMRDMOTX::writeData(const uint8_t* data, uint8_t length)
{
if (length != (DMR_FRAME_LENGTH_BYTES + 1U))
return 4U;
uint16_t space = m_fifo.getSpace();
if (space < DMR_FRAME_LENGTH_BYTES)
return 5U;
for (uint8_t i = 0U; i < DMR_FRAME_LENGTH_BYTES; i++)
m_fifo.put(data[i + 1U]);
return 0U;
}
void CDMRDMOTX::writeByte(uint8_t c)
{
q15_t inBuffer[4U];
q15_t outBuffer[DMR_RADIO_SYMBOL_LENGTH * 4U];
const uint8_t MASK = 0xC0U;
for (uint8_t i = 0U; i < 4U; i++, c <<= 2) {
switch (c & MASK) {
case 0xC0U:
inBuffer[i] = DMR_LEVELA;
break;
case 0x80U:
inBuffer[i] = DMR_LEVELB;
break;
case 0x00U:
inBuffer[i] = DMR_LEVELC;
break;
default:
inBuffer[i] = DMR_LEVELD;
break;
}
}
::arm_fir_interpolate_q15(&m_modFilter, inBuffer, outBuffer, 4U);
io.write(STATE_DMR, outBuffer, DMR_RADIO_SYMBOL_LENGTH * 4U);
}
uint8_t CDMRDMOTX::getSpace() const
{
return m_fifo.getSpace() / (DMR_FRAME_LENGTH_BYTES + 2U);
}
void CDMRDMOTX::setTXDelay(uint8_t delay)
{
m_txDelay = 600U + uint16_t(delay) * 12U; // 500ms + tx delay
if (m_txDelay > 1200U)
m_txDelay = 1200U;
}