From a6fd81bae4190d5fff6fd8d89930dfe10e7fa621 Mon Sep 17 00:00:00 2001 From: Jonathan Naylor Date: Mon, 11 Apr 2016 11:06:52 +0100 Subject: [PATCH] Add level averaging to the DMR slot receiver. --- DMRSlotRX.cpp | 96 ++++++++++++++++++++++++++++++++------------------- DMRSlotRX.h | 7 ++-- 2 files changed, 64 insertions(+), 39 deletions(-) diff --git a/DMRSlotRX.cpp b/DMRSlotRX.cpp index 8bb56bc..c99c0d5 100644 --- a/DMRSlotRX.cpp +++ b/DMRSlotRX.cpp @@ -51,8 +51,9 @@ m_syncPtr(0U), m_endPtr(NOENDPTR), m_delayPtr(0U), m_maxCorr(0), -m_centre(0), -m_threshold(0), +m_centre(), +m_threshold(), +m_averagePtr(0U), m_control(CONTROL_NONE), m_syncCount(0U), m_colorCode(0U), @@ -81,8 +82,6 @@ void CDMRSlotRX::reset() m_maxCorr = 0; m_control = CONTROL_NONE; m_syncCount = 0U; - m_threshold = 0; - m_centre = 0; m_state = DMRRXS_NONE; m_endPtr = NOENDPTR; } @@ -105,20 +104,24 @@ bool CDMRSlotRX::processSample(q15_t sample) if (m_state == DMRRXS_NONE) { if (m_dataPtr >= 420U && m_dataPtr <= 455U) - correlateSync(); + correlateSync(true); } else { uint16_t min = m_syncPtr - 1U; uint16_t max = m_syncPtr + 1U; if (m_dataPtr >= min && m_dataPtr <= max) - correlateSync(); + correlateSync(false); } if (m_dataPtr == m_endPtr) { + // Find the average centre and threshold values + q15_t centre = (m_centre[0U] + m_centre[1U] + m_centre[2U] + m_centre[3U]) >> 2; + q15_t threshold = (m_threshold[0U] + m_threshold[1U] + m_threshold[2U] + m_threshold[3U]) >> 2; + uint8_t frame[DMR_FRAME_LENGTH_BYTES + 1U]; frame[0U] = m_control; uint16_t ptr = m_endPtr - DMR_FRAME_LENGTH_SAMPLES + DMR_RADIO_SYMBOL_LENGTH + 1U; - samplesToBits(ptr, DMR_FRAME_LENGTH_SYMBOLS, frame, 8U, m_centre, m_threshold); + samplesToBits(ptr, DMR_FRAME_LENGTH_SYMBOLS, frame, 8U, centre, threshold); if (m_control == CONTROL_DATA) { // Data sync @@ -135,42 +138,42 @@ bool CDMRSlotRX::processSample(q15_t sample) switch (dataType) { case DT_DATA_HEADER: - DEBUG5("DMRSlotRX: data header found slot/pos/centre/threshold", m_slot ? 2U : 1U, int16_t(m_dataPtr) - 420, m_centre, m_threshold); + DEBUG5("DMRSlotRX: data header found slot/pos/centre/threshold", m_slot ? 2U : 1U, int16_t(m_dataPtr) - 420, centre, threshold); serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U); m_state = DMRRXS_DATA; - m_type = dataType; + m_type = 0x00U; break; case DT_RATE_12_DATA: case DT_RATE_34_DATA: case DT_RATE_1_DATA: if (m_state == DMRRXS_DATA) { - DEBUG5("DMRSlotRX: data payload found slot/pos/centre/threshold", m_slot ? 2U : 1U, int16_t(m_dataPtr) - 420, m_centre, m_threshold); + DEBUG5("DMRSlotRX: data payload found slot/pos/centre/threshold", m_slot ? 2U : 1U, int16_t(m_dataPtr) - 420, centre, threshold); serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U); - m_type = dataType; + m_type = dataType; } break; case DT_VOICE_LC_HEADER: - DEBUG5("DMRSlotRX: voice header found slot/pos/centre/threshold", m_slot ? 2U : 1U, int16_t(m_dataPtr) - 420, m_centre, m_threshold); + DEBUG5("DMRSlotRX: voice header found slot/pos/centre/threshold", m_slot ? 2U : 1U, int16_t(m_dataPtr) - 420, centre, threshold); serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U); m_state = DMRRXS_VOICE; break; case DT_VOICE_PI_HEADER: if (m_state == DMRRXS_VOICE) { - DEBUG5("DMRSlotRX: voice pi header found slot/pos/centre/threshold", m_slot ? 2U : 1U, int16_t(m_dataPtr) - 420, m_centre, m_threshold); + DEBUG5("DMRSlotRX: voice pi header found slot/pos/centre/threshold", m_slot ? 2U : 1U, int16_t(m_dataPtr) - 420, centre, threshold); serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U); } m_state = DMRRXS_VOICE; break; case DT_TERMINATOR_WITH_LC: if (m_state == DMRRXS_VOICE) { - DEBUG5("DMRSlotRX: voice terminator found slot/pos/centre/threshold", m_slot ? 2U : 1U, int16_t(m_dataPtr) - 420, m_centre, m_threshold); + DEBUG5("DMRSlotRX: voice terminator found slot/pos/centre/threshold", m_slot ? 2U : 1U, int16_t(m_dataPtr) - 420, centre, threshold); serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U); m_state = DMRRXS_NONE; m_endPtr = NOENDPTR; } break; default: // DT_CSBK - DEBUG5("DMRSlotRX: csbk found slot/pos/centre/threshold", m_slot ? 2U : 1U, int16_t(m_dataPtr) - 420, m_centre, m_threshold); + DEBUG5("DMRSlotRX: csbk found slot/pos/centre/threshold", m_slot ? 2U : 1U, int16_t(m_dataPtr) - 420, centre, threshold); serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U); m_state = DMRRXS_NONE; m_endPtr = NOENDPTR; @@ -179,7 +182,7 @@ bool CDMRSlotRX::processSample(q15_t sample) } } else if (m_control == CONTROL_VOICE) { // Voice sync - DEBUG5("DMRSlotRX: voice sync found slot/pos/centre/threshold", m_slot ? 2U : 1U, int16_t(m_dataPtr) - 420, m_centre, m_threshold); + DEBUG5("DMRSlotRX: voice sync found slot/pos/centre/threshold", m_slot ? 2U : 1U, int16_t(m_dataPtr) - 420, centre, threshold); serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U); m_state = DMRRXS_VOICE; m_syncCount = 0U; @@ -189,11 +192,8 @@ bool CDMRSlotRX::processSample(q15_t sample) m_syncCount++; if (m_syncCount >= MAX_SYNC_LOST_FRAMES) { serial.writeDMRLost(m_slot); - m_syncCount = 0U; - m_threshold = 0; - m_centre = 0; - m_state = DMRRXS_NONE; - m_endPtr = NOENDPTR; + m_state = DMRRXS_NONE; + m_endPtr = NOENDPTR; } } @@ -207,8 +207,10 @@ bool CDMRSlotRX::processSample(q15_t sample) serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U); } } else if (m_state == DMRRXS_DATA) { - frame[0U] = CONTROL_DATA | m_type; - serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U); + if (m_type != 0x00U) { + frame[0U] = CONTROL_DATA | m_type; + serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U); + } } } } @@ -222,7 +224,7 @@ bool CDMRSlotRX::processSample(q15_t sample) return m_state != DMRRXS_NONE; } -void CDMRSlotRX::correlateSync() +void CDMRSlotRX::correlateSync(bool first) { uint8_t errs = countBits32((m_bitBuffer[m_bitPtr] & DMR_SYNC_SYMBOLS_MASK) ^ DMR_MS_DATA_SYNC_SYMBOLS); @@ -270,12 +272,23 @@ void CDMRSlotRX::correlateSync() errs += countBits8((sync[i] & DMR_SYNC_BYTES_MASK[i]) ^ DMR_MS_DATA_SYNC_BYTES[i]); if (errs <= MAX_SYNC_BYTES_ERRS) { - m_maxCorr = corr; - m_centre = centre; - m_threshold = threshold; - m_control = CONTROL_DATA; - m_syncPtr = m_dataPtr; - m_endPtr = m_dataPtr + DMR_SLOT_TYPE_LENGTH_SAMPLES / 2U + DMR_INFO_LENGTH_SAMPLES / 2U - 1U; + if (first) { + m_threshold[0U] = m_threshold[1U] = m_threshold[2U] = m_threshold[3U] = threshold; + m_centre[0U] = m_centre[1U] = m_centre[2U] = m_centre[3U] = centre; + m_averagePtr = 0U; + } else { + m_threshold[m_averagePtr] = threshold; + m_centre[m_averagePtr] = centre; + + m_averagePtr++; + if (m_averagePtr >= 4U) + m_averagePtr = 0U; + } + + m_maxCorr = corr; + m_control = CONTROL_DATA; + m_syncPtr = m_dataPtr; + m_endPtr = m_dataPtr + DMR_SLOT_TYPE_LENGTH_SAMPLES / 2U + DMR_INFO_LENGTH_SAMPLES / 2U - 1U; } } else { // if (voice) uint8_t errs = 0U; @@ -283,12 +296,23 @@ void CDMRSlotRX::correlateSync() errs += countBits8((sync[i] & DMR_SYNC_BYTES_MASK[i]) ^ DMR_MS_VOICE_SYNC_BYTES[i]); if (errs <= MAX_SYNC_BYTES_ERRS) { - m_maxCorr = corr; - m_centre = centre; - m_threshold = threshold; - m_control = CONTROL_VOICE; - m_syncPtr = m_dataPtr; - m_endPtr = m_dataPtr + DMR_SLOT_TYPE_LENGTH_SAMPLES / 2U + DMR_INFO_LENGTH_SAMPLES / 2U - 1U; + if (first) { + m_threshold[0U] = m_threshold[1U] = m_threshold[2U] = m_threshold[3U] = threshold; + m_centre[0U] = m_centre[1U] = m_centre[2U] = m_centre[3U] = centre; + m_averagePtr = 0U; + } else { + m_threshold[m_averagePtr] = threshold; + m_centre[m_averagePtr] = centre; + + m_averagePtr++; + if (m_averagePtr >= 4U) + m_averagePtr = 0U; + } + + m_maxCorr = corr; + m_control = CONTROL_VOICE; + m_syncPtr = m_dataPtr; + m_endPtr = m_dataPtr + DMR_SLOT_TYPE_LENGTH_SAMPLES / 2U + DMR_INFO_LENGTH_SAMPLES / 2U - 1U; } } } diff --git a/DMRSlotRX.h b/DMRSlotRX.h index d924e40..6c3c446 100644 --- a/DMRSlotRX.h +++ b/DMRSlotRX.h @@ -51,8 +51,9 @@ private: uint16_t m_endPtr; uint16_t m_delayPtr; q31_t m_maxCorr; - q15_t m_centre; - q15_t m_threshold; + q15_t m_centre[4U]; + q15_t m_threshold[4U]; + uint8_t m_averagePtr; uint8_t m_control; uint8_t m_syncCount; uint8_t m_colorCode; @@ -61,7 +62,7 @@ private: uint8_t m_n; uint8_t m_type; - void correlateSync(); + void correlateSync(bool first); void samplesToBits(uint16_t start, uint8_t count, uint8_t* buffer, uint16_t offset, q15_t centre, q15_t threshold); };