From 18276a5d2eac39b08caa2ce44e196e7a98f1a108 Mon Sep 17 00:00:00 2001 From: "Matthias P. Braendli" Date: Sat, 30 Dec 2017 09:55:45 +0100 Subject: Calculate PAPR in the OfdmGenerator --- src/OfdmGenerator.cpp | 30 +++++++++++++++++++++++------- 1 file changed, 23 insertions(+), 7 deletions(-) (limited to 'src/OfdmGenerator.cpp') diff --git a/src/OfdmGenerator.cpp b/src/OfdmGenerator.cpp index 915d568..1a819ee 100644 --- a/src/OfdmGenerator.cpp +++ b/src/OfdmGenerator.cpp @@ -27,11 +27,8 @@ #include "OfdmGenerator.h" #include "PcDebug.h" -#include -#include "fftw3.h" #define FFT_TYPE fftwf_complex -#include #include #include #include @@ -56,7 +53,10 @@ OfdmGenerator::OfdmGenerator(size_t nbSymbols, myCfr(enableCfr), myCfrClip(cfrClip), myCfrErrorClip(cfrErrorClip), - myCfrFft(nullptr) + myCfrFft(nullptr), + // Initialise the PAPRStats to a few seconds worth of samples + myPaprBeforeCFR(nbSymbols * 50), + myPaprAfterCFR(nbSymbols * 50) { PDEBUG("OfdmGenerator::OfdmGenerator(%zu, %zu, %zu, %s) @ %p\n", nbSymbols, nbCarriers, spacing, inverse ? "true" : "false", this); @@ -71,6 +71,7 @@ OfdmGenerator::OfdmGenerator(size_t nbSymbols, RC_ADD_PARAMETER(clip, "CFR: Clip to amplitude"); RC_ADD_PARAMETER(errorclip, "CFR: Limit error"); RC_ADD_PARAMETER(clip_stats, "CFR: statistics (clip ratio, errorclip ratio)"); + RC_ADD_PARAMETER(papr, "PAPR measurements (before CFR, after CFR)"); if (inverse) { myPosDst = (nbCarriers & 1 ? 0 : 1); @@ -203,19 +204,25 @@ int OfdmGenerator::process(Buffer* const dataIn, Buffer* dataOut) fftwf_execute(myFftPlan); // IFFT from myFftIn to myFftOut + complexf *symbol = reinterpret_cast(myFftOut); + myPaprBeforeCFR.process_block(symbol, mySpacing); + if (myCfr) { if (myMERCalcIndex == i) { before_cfr.resize(mySpacing); memcpy(before_cfr.data(), myFftOut, mySpacing * sizeof(FFT_TYPE)); } - complexf *symbol = reinterpret_cast(myFftOut); /* cfr_one_iteration runs the myFftPlan again at the end, and * therefore writes the output data to myFftOut. */ const auto stat = cfr_one_iteration(symbol, reference.data()); // i == 0 always zero power, so the MER ends up being NaN + if (i > 0) { + myPaprAfterCFR.process_block(symbol, mySpacing); + } + if (i > 0 and myMERCalcIndex == i) { /* MER definition, ETSI ETR 290, Annex C * @@ -358,8 +365,8 @@ void OfdmGenerator::set_parameter(const std::string& parameter, else if (parameter == "errorclip") { ss >> myCfrErrorClip; } - else if (parameter == "clip_stats") { - throw ParameterError("Parameter 'clip_stats' is read-only"); + else if (parameter == "clip_stats" or parameter == "papr") { + throw ParameterError("Parameter '" + parameter + "' is read-only"); } else { stringstream ss_err; @@ -406,6 +413,15 @@ const std::string OfdmGenerator::get_parameter(const std::string& parameter) con "MER after CFR: " << avg_mer << " dB"; } } + else if (parameter == "papr") { + const double papr_before = myPaprBeforeCFR.calculate_papr(); + const double papr_after = myPaprAfterCFR.calculate_papr(); + + ss << "PAPR [dB]: " << std::fixed << + (papr_before == 0 ? string("N/A") : to_string(papr_before)) << + ", " << + (papr_after == 0 ? string("N/A") : to_string(papr_after)); + } else { ss << "Parameter '" << parameter << "' is not exported by controllable " << get_rc_name(); -- cgit v1.2.3 From c56f572c1026a774bcec768821e64ac31354ceff Mon Sep 17 00:00:00 2001 From: "Matthias P. Braendli" Date: Sat, 30 Dec 2017 10:06:47 +0100 Subject: Clear PAPRStats when config gets changed --- src/OfdmGenerator.cpp | 11 +++++++++++ src/OfdmGenerator.h | 2 ++ src/PAPRStats.cpp | 6 ++++++ src/PAPRStats.h | 2 ++ 4 files changed, 21 insertions(+) (limited to 'src/OfdmGenerator.cpp') diff --git a/src/OfdmGenerator.cpp b/src/OfdmGenerator.cpp index 1a819ee..b00d66b 100644 --- a/src/OfdmGenerator.cpp +++ b/src/OfdmGenerator.cpp @@ -187,6 +187,14 @@ int OfdmGenerator::process(Buffer* const dataIn, Buffer* dataOut) // For performance reasons, do not calculate MER for every symbol. myMERCalcIndex = (myMERCalcIndex + 1) % myNbSymbols; + // The PAPRStats' clear() is not threadsafe, do not access it + // from the RC functions. + if (myPaprClearRequest.load()) { + myPaprBeforeCFR.clear(); + myPaprAfterCFR.clear(); + myPaprClearRequest.store(false); + } + for (size_t i = 0; i < myNbSymbols; ++i) { myFftIn[0][0] = 0; myFftIn[0][1] = 0; @@ -358,12 +366,15 @@ void OfdmGenerator::set_parameter(const std::string& parameter, if (parameter == "cfr") { ss >> myCfr; + myPaprClearRequest.store(true); } else if (parameter == "clip") { ss >> myCfrClip; + myPaprClearRequest.store(true); } else if (parameter == "errorclip") { ss >> myCfrErrorClip; + myPaprClearRequest.store(true); } else if (parameter == "clip_stats" or parameter == "papr") { throw ParameterError("Parameter '" + parameter + "' is read-only"); diff --git a/src/OfdmGenerator.h b/src/OfdmGenerator.h index 8374cf9..cccccf5 100644 --- a/src/OfdmGenerator.h +++ b/src/OfdmGenerator.h @@ -37,6 +37,7 @@ #include #include #include +#include typedef std::complex complexf; @@ -105,6 +106,7 @@ class OfdmGenerator : public ModCodec, public RemoteControllable // Measure PAPR before and after CFR PAPRStats myPaprBeforeCFR; PAPRStats myPaprAfterCFR; + std::atomic myPaprClearRequest; size_t myMERCalcIndex = 0; std::deque myMERs; diff --git a/src/PAPRStats.cpp b/src/PAPRStats.cpp index 2e8bca9..1a72238 100644 --- a/src/PAPRStats.cpp +++ b/src/PAPRStats.cpp @@ -100,6 +100,12 @@ double PAPRStats::calculate_papr() const return 10.0 * std::log10(peak / rms2); } +void PAPRStats::clear() +{ + m_squared_peaks.clear(); + m_squared_mean.clear(); +} + #if defined(TEST) /* Test python code: import numpy as np diff --git a/src/PAPRStats.h b/src/PAPRStats.h index 92e5231..86ad8b0 100644 --- a/src/PAPRStats.h +++ b/src/PAPRStats.h @@ -66,6 +66,8 @@ class PAPRStats */ double calculate_papr(void) const; + void clear(void); + private: size_t m_num_blocks_to_accumulate; std::deque m_squared_peaks; -- cgit v1.2.3