From 9d1ebc0f8f1f80283223a0be9e6062c0add925b0 Mon Sep 17 00:00:00 2001 From: Jonathan Naylor Date: Mon, 10 Jul 2017 19:41:01 +0100 Subject: [PATCH 1/5] Small refactor. --- Config.h | 2 +- DMRDMORX.cpp | 2 +- DMRSlotRX.cpp | 2 +- DStarRX.cpp | 2 +- Globals.h | 4 ++-- IO.cpp | 8 ++++---- MMDVM.cpp | 2 +- MMDVM.ino | 2 +- P25RX.cpp | 2 +- YSFRX.cpp | 2 +- 10 files changed, 14 insertions(+), 14 deletions(-) diff --git a/Config.h b/Config.h index c7fb2b8..b201991 100644 --- a/Config.h +++ b/Config.h @@ -27,7 +27,7 @@ // Frequencies such as 10.0 Mhz (48000 * 208.333) or 20 Mhz (48000 * 416.666) are not suitable. // // For 12 MHz -// #define EXTERNAL_OSC 12000000 +#define EXTERNAL_OSC 12000000 // For 12.288 MHz // #define EXTERNAL_OSC 12288000 // For 14.4 MHz diff --git a/DMRDMORX.cpp b/DMRDMORX.cpp index 69956b2..d11957e 100644 --- a/DMRDMORX.cpp +++ b/DMRDMORX.cpp @@ -88,7 +88,7 @@ bool CDMRDMORX::processSample(q15_t sample, uint16_t rssi) m_rssi[m_dataPtr] = rssi; m_bitBuffer[m_bitPtr] <<= 1; - if (sample < m_dc_level) + if (sample < m_dcLevel) m_bitBuffer[m_bitPtr] |= 0x01U; if (m_state == DMORXS_NONE) { diff --git a/DMRSlotRX.cpp b/DMRSlotRX.cpp index 86c273c..377aa41 100644 --- a/DMRSlotRX.cpp +++ b/DMRSlotRX.cpp @@ -104,7 +104,7 @@ bool CDMRSlotRX::processSample(q15_t sample, uint16_t rssi) m_rssi[m_dataPtr] = rssi; m_bitBuffer[m_bitPtr] <<= 1; - if (sample < m_dc_level) + if (sample < m_dcLevel) m_bitBuffer[m_bitPtr] |= 0x01U; if (m_state == DMRRXS_NONE) { diff --git a/DStarRX.cpp b/DStarRX.cpp index 60ede7f..4159c0d 100644 --- a/DStarRX.cpp +++ b/DStarRX.cpp @@ -279,7 +279,7 @@ void CDStarRX::samples(const q15_t* samples, const uint16_t* rssi, uint8_t lengt m_rssiAccum += rssi[i]; m_rssiCount++; - bool bit = samples[i] < m_dc_level; + bool bit = samples[i] < m_dcLevel; if (bit != m_prev) { if (m_pll < (PLLMAX / 2U)) diff --git a/Globals.h b/Globals.h index 27f62e4..e99022f 100644 --- a/Globals.h +++ b/Globals.h @@ -1,5 +1,5 @@ /* - * Copyright (C) 2015,2016 by Jonathan Naylor G4KLX + * Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX * * 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 @@ -93,7 +93,7 @@ extern bool m_duplex; extern bool m_tx; extern bool m_dcd; -extern q15_t m_dc_level; +extern q15_t m_dcLevel; extern CSerialPort serial; extern CIO io; diff --git a/IO.cpp b/IO.cpp index 222b876..f47542d 100644 --- a/IO.cpp +++ b/IO.cpp @@ -169,7 +169,7 @@ void CIO::process() if (m_lockout) return; - q31_t dc_level = 0; + q31_t dcLevel = 0; q31_t dcVals[20]; q31_t intSamp[20]; @@ -177,11 +177,11 @@ void CIO::process() ::arm_biquad_cascade_df1_q31(&m_dcFilter, intSamp, dcVals, RX_BLOCK_SIZE); for (uint8_t i = 0U; i < RX_BLOCK_SIZE; i++) - dc_level += dcVals[i]; + dcLevel += dcVals[i]; - dc_level /= RX_BLOCK_SIZE; + dcLevel /= RX_BLOCK_SIZE; - m_dc_level = (q15_t) (dc_level >> 16); + m_dcLevel = q15_t(dcLevel >> 16); if (m_modemState == STATE_IDLE) { if (m_dstarEnable) { diff --git a/MMDVM.cpp b/MMDVM.cpp index 91cf1f3..4fda95c 100644 --- a/MMDVM.cpp +++ b/MMDVM.cpp @@ -36,7 +36,7 @@ bool m_duplex = true; bool m_tx = false; bool m_dcd = false; -q15_t m_dc_level = 0; +q15_t m_dcLevel = 0; CDStarRX dstarRX; CDStarTX dstarTX; diff --git a/MMDVM.ino b/MMDVM.ino index 7f83abd..a7d694e 100644 --- a/MMDVM.ino +++ b/MMDVM.ino @@ -33,7 +33,7 @@ bool m_duplex = true; bool m_tx = false; bool m_dcd = false; -q15_t m_dc_level = 0; +q15_t m_dcLevel = 0; CDStarRX dstarRX; CDStarTX dstarTX; diff --git a/P25RX.cpp b/P25RX.cpp index 479b25c..f77bb7d 100644 --- a/P25RX.cpp +++ b/P25RX.cpp @@ -95,7 +95,7 @@ void CP25RX::samples(const q15_t* samples, uint16_t* rssi, uint8_t length) m_rssiCount++; m_bitBuffer[m_bitPtr] <<= 1; - if (sample < m_dc_level) + if (sample < m_dcLevel) m_bitBuffer[m_bitPtr] |= 0x01U; m_buffer[m_dataPtr] = sample; diff --git a/YSFRX.cpp b/YSFRX.cpp index 91af557..e405634 100644 --- a/YSFRX.cpp +++ b/YSFRX.cpp @@ -91,7 +91,7 @@ void CYSFRX::samples(const q15_t* samples, uint16_t* rssi, uint8_t length) m_rssiCount++; m_bitBuffer[m_bitPtr] <<= 1; - if (sample < m_dc_level) + if (sample < m_dcLevel) m_bitBuffer[m_bitPtr] |= 0x01U; m_buffer[m_dataPtr] = sample; From 8540964097f69d84952c4ca85856889da3de8912 Mon Sep 17 00:00:00 2001 From: Jonathan Naylor Date: Sun, 16 Jul 2017 18:57:15 +0100 Subject: [PATCH 2/5] Remove any DC offset from before any further filtering takes place. --- DMRDMORX.cpp | 2 +- DMRSlotRX.cpp | 2 +- DStarRX.cpp | 2 +- Globals.h | 2 -- IO.cpp | 22 ++++++++++++---------- IO.h | 12 ++++++------ MMDVM.cpp | 2 -- P25RX.cpp | 2 +- YSFRX.cpp | 2 +- 9 files changed, 23 insertions(+), 25 deletions(-) diff --git a/DMRDMORX.cpp b/DMRDMORX.cpp index d11957e..2c3bdef 100644 --- a/DMRDMORX.cpp +++ b/DMRDMORX.cpp @@ -88,7 +88,7 @@ bool CDMRDMORX::processSample(q15_t sample, uint16_t rssi) m_rssi[m_dataPtr] = rssi; m_bitBuffer[m_bitPtr] <<= 1; - if (sample < m_dcLevel) + if (sample < 0) m_bitBuffer[m_bitPtr] |= 0x01U; if (m_state == DMORXS_NONE) { diff --git a/DMRSlotRX.cpp b/DMRSlotRX.cpp index 377aa41..0d34560 100644 --- a/DMRSlotRX.cpp +++ b/DMRSlotRX.cpp @@ -104,7 +104,7 @@ bool CDMRSlotRX::processSample(q15_t sample, uint16_t rssi) m_rssi[m_dataPtr] = rssi; m_bitBuffer[m_bitPtr] <<= 1; - if (sample < m_dcLevel) + if (sample < 0) m_bitBuffer[m_bitPtr] |= 0x01U; if (m_state == DMRRXS_NONE) { diff --git a/DStarRX.cpp b/DStarRX.cpp index 4159c0d..103176b 100644 --- a/DStarRX.cpp +++ b/DStarRX.cpp @@ -279,7 +279,7 @@ void CDStarRX::samples(const q15_t* samples, const uint16_t* rssi, uint8_t lengt m_rssiAccum += rssi[i]; m_rssiCount++; - bool bit = samples[i] < m_dcLevel; + bool bit = samples[i] < 0; if (bit != m_prev) { if (m_pll < (PLLMAX / 2U)) diff --git a/Globals.h b/Globals.h index e99022f..7b80226 100644 --- a/Globals.h +++ b/Globals.h @@ -93,8 +93,6 @@ extern bool m_duplex; extern bool m_tx; extern bool m_dcd; -extern q15_t m_dcLevel; - extern CSerialPort serial; extern CIO io; diff --git a/IO.cpp b/IO.cpp index f47542d..8f290e1 100644 --- a/IO.cpp +++ b/IO.cpp @@ -33,7 +33,7 @@ static q15_t GAUSSIAN_0_5_FILTER[] = {8, 104, 760, 3158, 7421, 9866, 7421, 315 const uint16_t GAUSSIAN_0_5_FILTER_LEN = 12U; // One symbol boxcar filter -static q15_t BOXCAR_FILTER[] = {3000, 3000, 3000, 3000, 3000, 0}; +static q15_t BOXCAR_FILTER[] = {12000, 12000, 12000, 12000, 12000, 0}; const uint16_t BOXCAR_FILTER_LEN = 6U; // Generated using [b, a] = butter(1, 0.001) in MATLAB @@ -73,7 +73,7 @@ m_dcState() ::memset(m_rrcState, 0x00U, 70U * sizeof(q15_t)); ::memset(m_gaussianState, 0x00U, 40U * sizeof(q15_t)); ::memset(m_boxcarState, 0x00U, 30U * sizeof(q15_t)); - ::memset(m_dcState, 0x00U, 4U * sizeof(q31_t)); + ::memset(m_dcState, 0x00U, 4U * sizeof(q31_t)); m_rrcFilter.numTaps = RRC_0_2_FILTER_LEN; m_rrcFilter.pState = m_rrcState; @@ -88,8 +88,8 @@ m_dcState() m_boxcarFilter.pCoeffs = BOXCAR_FILTER; m_dcFilter.numStages = DC_FILTER_STAGES; - m_dcFilter.pState = m_dcState; - m_dcFilter.pCoeffs = DC_FILTER; + m_dcFilter.pState = m_dcState; + m_dcFilter.pCoeffs = DC_FILTER; m_dcFilter.postShift = 0; initInt(); @@ -171,17 +171,19 @@ void CIO::process() q31_t dcLevel = 0; q31_t dcVals[20]; - q31_t intSamp[20]; - - ::arm_q15_to_q31((q15_t*)samples, intSamp, RX_BLOCK_SIZE); - ::arm_biquad_cascade_df1_q31(&m_dcFilter, intSamp, dcVals, RX_BLOCK_SIZE); + q31_t q31Samples[20U]; + + ::arm_q15_to_q31(samples, q31Samples, RX_BLOCK_SIZE); + ::arm_biquad_cascade_df1_q31(&m_dcFilter, q31Samples, dcVals, RX_BLOCK_SIZE); for (uint8_t i = 0U; i < RX_BLOCK_SIZE; i++) dcLevel += dcVals[i]; - dcLevel /= RX_BLOCK_SIZE; + + q15_t offset = q15_t(dcLevel >> 16); - m_dcLevel = q15_t(dcLevel >> 16); + for (uint8_t i = 0U; i < RX_BLOCK_SIZE; i++) + samples[i] -= offset; if (m_modemState == STATE_IDLE) { if (m_dstarEnable) { diff --git a/IO.h b/IO.h index aa718a5..07e6d2d 100644 --- a/IO.h +++ b/IO.h @@ -60,12 +60,12 @@ private: CSampleRB m_txBuffer; CRSSIRB m_rssiBuffer; - arm_fir_instance_q15 m_rrcFilter; - arm_fir_instance_q15 m_gaussianFilter; - arm_fir_instance_q15 m_boxcarFilter; - q15_t m_rrcState[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 + arm_fir_instance_q15 m_rrcFilter; + arm_fir_instance_q15 m_gaussianFilter; + arm_fir_instance_q15 m_boxcarFilter; + q15_t m_rrcState[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 arm_biquad_casd_df1_inst_q31 m_dcFilter; q31_t m_dcState[4]; diff --git a/MMDVM.cpp b/MMDVM.cpp index 4fda95c..6e2be23 100644 --- a/MMDVM.cpp +++ b/MMDVM.cpp @@ -36,8 +36,6 @@ bool m_duplex = true; bool m_tx = false; bool m_dcd = false; -q15_t m_dcLevel = 0; - CDStarRX dstarRX; CDStarTX dstarTX; diff --git a/P25RX.cpp b/P25RX.cpp index f77bb7d..9228c5b 100644 --- a/P25RX.cpp +++ b/P25RX.cpp @@ -95,7 +95,7 @@ void CP25RX::samples(const q15_t* samples, uint16_t* rssi, uint8_t length) m_rssiCount++; m_bitBuffer[m_bitPtr] <<= 1; - if (sample < m_dcLevel) + if (sample < 0) m_bitBuffer[m_bitPtr] |= 0x01U; m_buffer[m_dataPtr] = sample; diff --git a/YSFRX.cpp b/YSFRX.cpp index e405634..88c6f83 100644 --- a/YSFRX.cpp +++ b/YSFRX.cpp @@ -91,7 +91,7 @@ void CYSFRX::samples(const q15_t* samples, uint16_t* rssi, uint8_t length) m_rssiCount++; m_bitBuffer[m_bitPtr] <<= 1; - if (sample < m_dcLevel) + if (sample < 0) m_bitBuffer[m_bitPtr] |= 0x01U; m_buffer[m_dataPtr] = sample; From ba81fa7396129046298832157bf90b84404878a8 Mon Sep 17 00:00:00 2001 From: Jonathan Naylor Date: Sun, 16 Jul 2017 18:58:12 +0100 Subject: [PATCH 3/5] Forgot this file. --- MMDVM.ino | 2 -- 1 file changed, 2 deletions(-) diff --git a/MMDVM.ino b/MMDVM.ino index a7d694e..0aaedb4 100644 --- a/MMDVM.ino +++ b/MMDVM.ino @@ -33,8 +33,6 @@ bool m_duplex = true; bool m_tx = false; bool m_dcd = false; -q15_t m_dcLevel = 0; - CDStarRX dstarRX; CDStarTX dstarTX; From 669acb99e84ec4bdaab852b76c327aa73ea6dc9e Mon Sep 17 00:00:00 2001 From: Jonathan Naylor Date: Mon, 31 Jul 2017 21:54:26 +0100 Subject: [PATCH 4/5] Remove the DC blocker from DMR. --- DStarRX.cpp | 31 +++++++++++++++++++++++++++---- DStarRX.h | 4 +++- IO.cpp | 30 +----------------------------- IO.h | 14 ++++++-------- P25RX.cpp | 31 ++++++++++++++++++++++++++++--- P25RX.h | 4 +++- YSFRX.cpp | 31 ++++++++++++++++++++++++++++--- YSFRX.h | 4 +++- 8 files changed, 99 insertions(+), 50 deletions(-) diff --git a/DStarRX.cpp b/DStarRX.cpp index 103176b..c55edd5 100644 --- a/DStarRX.cpp +++ b/DStarRX.cpp @@ -241,6 +241,10 @@ const uint16_t CCITT_TABLE[] = { 0xf78fU, 0xe606U, 0xd49dU, 0xc514U, 0xb1abU, 0xa022U, 0x92b9U, 0x8330U, 0x7bc7U, 0x6a4eU, 0x58d5U, 0x495cU, 0x3de3U, 0x2c6aU, 0x1ef1U, 0x0f78U}; +// Generated using [b, a] = butter(1, 0.001) in MATLAB +static q31_t DC_FILTER[] = {3367972, 0, 3367972, 0, 2140747704, 0}; // {b0, 0, b1, b2, -a1, -a2} +const uint32_t DC_FILTER_STAGES = 1U; // One Biquad stage + CDStarRX::CDStarRX() : m_pll(0U), m_prev(false), @@ -257,8 +261,16 @@ m_pathMemory2(), m_pathMemory3(), m_fecOutput(), m_rssiAccum(0U), -m_rssiCount(0U) +m_rssiCount(0U), +m_dcFilter(), +m_dcState() { + ::memset(m_dcState, 0x00U, 4U * sizeof(q31_t)); + + m_dcFilter.numStages = DC_FILTER_STAGES; + m_dcFilter.pState = m_dcState; + m_dcFilter.pCoeffs = DC_FILTER; + m_dcFilter.postShift = 0; } void CDStarRX::reset() @@ -273,13 +285,24 @@ void CDStarRX::reset() m_rssiCount = 0U; } -void CDStarRX::samples(const q15_t* samples, const uint16_t* rssi, uint8_t length) -{ +void CDStarRX::samples(q15_t* samples, const uint16_t* rssi, uint8_t length) +{ + q31_t dcLevel = 0; + q31_t dcVals[20U]; + q31_t q31Samples[20U]; + + ::arm_q15_to_q31(samples, q31Samples, length); + ::arm_biquad_cascade_df1_q31(&m_dcFilter, q31Samples, dcVals, length); + + for (uint8_t i = 0U; i < length; i++) + dcLevel += dcVals[i]; + dcLevel /= length; + for (uint16_t i = 0U; i < length; i++) { m_rssiAccum += rssi[i]; m_rssiCount++; - bool bit = samples[i] < 0; + bool bit = (q31Samples[i] - dcLevel) < 0; if (bit != m_prev) { if (m_pll < (PLLMAX / 2U)) diff --git a/DStarRX.h b/DStarRX.h index d636cde..49dab0b 100644 --- a/DStarRX.h +++ b/DStarRX.h @@ -32,7 +32,7 @@ class CDStarRX { public: CDStarRX(); - void samples(const q15_t* samples, const uint16_t* rssi, uint8_t length); + void samples(q15_t* samples, const uint16_t* rssi, uint8_t length); void reset(); @@ -53,6 +53,8 @@ private: uint8_t m_fecOutput[42U]; uint32_t m_rssiAccum; uint16_t m_rssiCount; + arm_biquad_casd_df1_inst_q31 m_dcFilter; + q31_t m_dcState[4]; void processNone(bool bit); void processHeader(bool bit); diff --git a/IO.cpp b/IO.cpp index 8f290e1..0188d62 100644 --- a/IO.cpp +++ b/IO.cpp @@ -36,10 +36,6 @@ const uint16_t GAUSSIAN_0_5_FILTER_LEN = 12U; static q15_t BOXCAR_FILTER[] = {12000, 12000, 12000, 12000, 12000, 0}; const uint16_t BOXCAR_FILTER_LEN = 6U; -// Generated using [b, a] = butter(1, 0.001) in MATLAB -static q31_t DC_FILTER[] = {3367972, 0, 3367972, 0, 2140747704, 0}; // {b0, 0, b1, b2, -a1, -a2} -const uint32_t DC_FILTER_STAGES = 1U; // One Biquad stage - const uint16_t DC_OFFSET = 2048U; CIO::CIO() : @@ -66,14 +62,11 @@ m_detect(false), m_adcOverflow(0U), m_dacOverflow(0U), m_watchdog(0U), -m_lockout(false), -m_dcFilter(), -m_dcState() +m_lockout(false) { ::memset(m_rrcState, 0x00U, 70U * sizeof(q15_t)); ::memset(m_gaussianState, 0x00U, 40U * sizeof(q15_t)); ::memset(m_boxcarState, 0x00U, 30U * sizeof(q15_t)); - ::memset(m_dcState, 0x00U, 4U * sizeof(q31_t)); m_rrcFilter.numTaps = RRC_0_2_FILTER_LEN; m_rrcFilter.pState = m_rrcState; @@ -87,11 +80,6 @@ m_dcState() m_boxcarFilter.pState = m_boxcarState; m_boxcarFilter.pCoeffs = BOXCAR_FILTER; - m_dcFilter.numStages = DC_FILTER_STAGES; - m_dcFilter.pState = m_dcState; - m_dcFilter.pCoeffs = DC_FILTER; - m_dcFilter.postShift = 0; - initInt(); } @@ -168,22 +156,6 @@ void CIO::process() if (m_lockout) return; - - q31_t dcLevel = 0; - q31_t dcVals[20]; - q31_t q31Samples[20U]; - - ::arm_q15_to_q31(samples, q31Samples, RX_BLOCK_SIZE); - ::arm_biquad_cascade_df1_q31(&m_dcFilter, q31Samples, dcVals, RX_BLOCK_SIZE); - - for (uint8_t i = 0U; i < RX_BLOCK_SIZE; i++) - dcLevel += dcVals[i]; - dcLevel /= RX_BLOCK_SIZE; - - q15_t offset = q15_t(dcLevel >> 16); - - for (uint8_t i = 0U; i < RX_BLOCK_SIZE; i++) - samples[i] -= offset; if (m_modemState == STATE_IDLE) { if (m_dstarEnable) { diff --git a/IO.h b/IO.h index 07e6d2d..80a6d28 100644 --- a/IO.h +++ b/IO.h @@ -60,14 +60,12 @@ private: CSampleRB m_txBuffer; CRSSIRB m_rssiBuffer; - arm_fir_instance_q15 m_rrcFilter; - arm_fir_instance_q15 m_gaussianFilter; - arm_fir_instance_q15 m_boxcarFilter; - q15_t m_rrcState[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 - arm_biquad_casd_df1_inst_q31 m_dcFilter; - q31_t m_dcState[4]; + arm_fir_instance_q15 m_rrcFilter; + arm_fir_instance_q15 m_gaussianFilter; + arm_fir_instance_q15 m_boxcarFilter; + q15_t m_rrcState[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 bool m_pttInvert; q15_t m_rxLevel; diff --git a/P25RX.cpp b/P25RX.cpp index 9228c5b..6c1d0af 100644 --- a/P25RX.cpp +++ b/P25RX.cpp @@ -38,6 +38,10 @@ const uint16_t NOENDPTR = 9999U; const unsigned int MAX_SYNC_FRAMES = 4U + 1U; +// Generated using [b, a] = butter(1, 0.001) in MATLAB +static q31_t DC_FILTER[] = {3367972, 0, 3367972, 0, 2140747704, 0}; // {b0, 0, b1, b2, -a1, -a2} +const uint32_t DC_FILTER_STAGES = 1U; // One Biquad stage + CP25RX::CP25RX() : m_state(P25RXS_NONE), m_bitBuffer(), @@ -60,8 +64,16 @@ m_threshold(), m_thresholdVal(0), m_averagePtr(NOAVEPTR), m_rssiAccum(0U), -m_rssiCount(0U) +m_rssiCount(0U), +m_dcFilter(), +m_dcState() { + ::memset(m_dcState, 0x00U, 4U * sizeof(q31_t)); + + m_dcFilter.numStages = DC_FILTER_STAGES; + m_dcFilter.pState = m_dcState; + m_dcFilter.pCoeffs = DC_FILTER; + m_dcFilter.postShift = 0; } void CP25RX::reset() @@ -86,10 +98,23 @@ void CP25RX::reset() m_rssiCount = 0U; } -void CP25RX::samples(const q15_t* samples, uint16_t* rssi, uint8_t length) +void CP25RX::samples(q15_t* samples, uint16_t* rssi, uint8_t length) { + q31_t dcLevel = 0; + q31_t dcVals[20U]; + q31_t q31Samples[20U]; + + ::arm_q15_to_q31(samples, q31Samples, length); + ::arm_biquad_cascade_df1_q31(&m_dcFilter, q31Samples, dcVals, length); + + for (uint8_t i = 0U; i < length; i++) + dcLevel += dcVals[i]; + dcLevel /= length; + + q15_t offset = q15_t(__SSAT((dcLevel >> 16), 16));; + for (uint8_t i = 0U; i < length; i++) { - q15_t sample = samples[i]; + q15_t sample = samples[i] - offset; m_rssiAccum += rssi[i]; m_rssiCount++; diff --git a/P25RX.h b/P25RX.h index 0bdf3c5..16f6cf3 100644 --- a/P25RX.h +++ b/P25RX.h @@ -32,7 +32,7 @@ class CP25RX { public: CP25RX(); - void samples(const q15_t* samples, uint16_t* rssi, uint8_t length); + void samples(q15_t* samples, uint16_t* rssi, uint8_t length); void reset(); @@ -59,6 +59,8 @@ private: uint8_t m_averagePtr; uint32_t m_rssiAccum; uint16_t m_rssiCount; + arm_biquad_casd_df1_inst_q31 m_dcFilter; + q31_t m_dcState[4]; void processNone(q15_t sample); void processHdr(q15_t sample); diff --git a/YSFRX.cpp b/YSFRX.cpp index 88c6f83..f3be78c 100644 --- a/YSFRX.cpp +++ b/YSFRX.cpp @@ -38,6 +38,10 @@ const uint16_t NOENDPTR = 9999U; const unsigned int MAX_SYNC_FRAMES = 4U + 1U; +// Generated using [b, a] = butter(1, 0.001) in MATLAB +static q31_t DC_FILTER[] = {3367972, 0, 3367972, 0, 2140747704, 0}; // {b0, 0, b1, b2, -a1, -a2} +const uint32_t DC_FILTER_STAGES = 1U; // One Biquad stage + CYSFRX::CYSFRX() : m_state(YSFRXS_NONE), m_bitBuffer(), @@ -58,8 +62,16 @@ m_threshold(), m_thresholdVal(0), m_averagePtr(NOAVEPTR), m_rssiAccum(0U), -m_rssiCount(0U) +m_rssiCount(0U), +m_dcFilter(), +m_dcState() { + ::memset(m_dcState, 0x00U, 4U * sizeof(q31_t)); + + m_dcFilter.numStages = DC_FILTER_STAGES; + m_dcFilter.pState = m_dcState; + m_dcFilter.pCoeffs = DC_FILTER; + m_dcFilter.postShift = 0; } void CYSFRX::reset() @@ -82,10 +94,23 @@ void CYSFRX::reset() m_rssiCount = 0U; } -void CYSFRX::samples(const q15_t* samples, uint16_t* rssi, uint8_t length) +void CYSFRX::samples(q15_t* samples, uint16_t* rssi, uint8_t length) { + q31_t dcLevel = 0; + q31_t dcVals[20U]; + q31_t q31Samples[20U]; + + ::arm_q15_to_q31(samples, q31Samples, length); + ::arm_biquad_cascade_df1_q31(&m_dcFilter, q31Samples, dcVals, length); + + for (uint8_t i = 0U; i < length; i++) + dcLevel += dcVals[i]; + dcLevel /= length; + + q15_t offset = q15_t(__SSAT((dcLevel >> 16), 16));; + for (uint8_t i = 0U; i < length; i++) { - q15_t sample = samples[i]; + q15_t sample = samples[i] - offset; m_rssiAccum += rssi[i]; m_rssiCount++; diff --git a/YSFRX.h b/YSFRX.h index 556280a..f00d6c4 100644 --- a/YSFRX.h +++ b/YSFRX.h @@ -31,7 +31,7 @@ class CYSFRX { public: CYSFRX(); - void samples(const q15_t* samples, uint16_t* rssi, uint8_t length); + void samples(q15_t* samples, uint16_t* rssi, uint8_t length); void reset(); @@ -56,6 +56,8 @@ private: uint8_t m_averagePtr; uint32_t m_rssiAccum; uint16_t m_rssiCount; + arm_biquad_casd_df1_inst_q31 m_dcFilter; + q31_t m_dcState[4]; void processNone(q15_t sample); void processData(q15_t sample); From 04ca97e5f81371175ea7013a8610e7beb63ff7a8 Mon Sep 17 00:00:00 2001 From: Jonathan Naylor Date: Sun, 13 Aug 2017 18:51:09 +0100 Subject: [PATCH 5/5] Add enhancements suggested by IZ1MLT. --- DStarRX.cpp | 32 ++++++++++---------------------- 1 file changed, 10 insertions(+), 22 deletions(-) diff --git a/DStarRX.cpp b/DStarRX.cpp index c55edd5..4f65f6f 100644 --- a/DStarRX.cpp +++ b/DStarRX.cpp @@ -28,11 +28,7 @@ const uint32_t PLLMAX = 0x10000U; const uint32_t PLLINC = PLLMAX / DSTAR_RADIO_BIT_LENGTH; const uint32_t INC = PLLINC / 32U; -const unsigned int MAX_SYNC_BITS = 50U * DSTAR_DATA_LENGTH_BITS; - -const unsigned int SYNC_POS = 21U * DSTAR_DATA_LENGTH_BITS; -const unsigned int SYNC_SCAN_START = SYNC_POS - 3U; -const unsigned int SYNC_SCAN_END = SYNC_POS + 3U; +const unsigned int MAX_SYNC_BITS = 100U * DSTAR_DATA_LENGTH_BITS; // D-Star bit order version of 0x55 0x55 0x6E 0x0A const uint32_t FRAME_SYNC_DATA = 0x00557650U; @@ -372,7 +368,7 @@ void CDStarRX::processNone(bool bit) ::memset(m_rxBuffer, 0x00U, DSTAR_DATA_LENGTH_BYTES + 2U); m_rxBufferBits = 0U; - m_dataBits = 0U; + m_dataBits = MAX_SYNC_BITS; m_rxState = DSRXS_DATA; return; } @@ -401,8 +397,8 @@ void CDStarRX::processHeader(bool bit) ::memset(m_rxBuffer, 0x00U, DSTAR_DATA_LENGTH_BYTES + 2U); m_rxBufferBits = 0U; - m_rxState = DSRXS_DATA; - m_dataBits = SYNC_POS - DSTAR_DATA_LENGTH_BITS + 1U; + m_rxState = DSRXS_DATA; + m_dataBits = MAX_SYNC_BITS; } else { // The checksum failed, return to looking for syncs m_rxState = DSRXS_NONE; @@ -434,37 +430,29 @@ void CDStarRX::processData(bool bit) // Fuzzy matching of the data sync bit sequence bool syncSeen = false; - if (m_dataBits >= SYNC_SCAN_START && m_dataBits <= (SYNC_POS + 1U)) { + if (m_rxBufferBits >= (DSTAR_DATA_LENGTH_BITS - 3U)) { if (countBits32((m_patternBuffer & DATA_SYNC_MASK) ^ DATA_SYNC_DATA) <= DATA_SYNC_ERRS) { - if (m_dataBits < SYNC_POS) - DEBUG2("DStarRX: found data sync in Data, early", SYNC_POS - m_dataBits); - else - DEBUG1("DStarRX: found data sync in Data"); - m_rxBufferBits = DSTAR_DATA_LENGTH_BITS; - m_dataBits = 0U; - syncSeen = true; + m_dataBits = MAX_SYNC_BITS; + syncSeen = true; } } // Check to see if the sync is arriving late - if (m_dataBits == SYNC_POS) { + if (m_rxBufferBits == DSTAR_DATA_LENGTH_BITS && !syncSeen) { for (uint8_t i = 1U; i <= 3U; i++) { uint32_t syncMask = DATA_SYNC_MASK >> i; uint32_t syncData = DATA_SYNC_DATA >> i; if (countBits32((m_patternBuffer & syncMask) ^ syncData) <= DATA_SYNC_ERRS) { - DEBUG2("DStarRX: found data sync in Data, late", i); m_rxBufferBits -= i; - m_dataBits -= i; break; } } } - m_dataBits++; + m_dataBits--; - // We've not seen a data sync for too long, signal RXLOST and change to RX_NONE - if (m_dataBits >= MAX_SYNC_BITS) { + if (m_dataBits == 0U) { DEBUG1("DStarRX: data sync timed out, lost lock"); io.setDecode(false);