QRSS Rx Network receiver. A receiver to sample a segment of RF spectrum and send this data to a server for further processing and display. NXP mbed Design Challenge entry (Honorable Mention). Published in Circuit Cellar, Feb 2012
Dependencies: NetServices mbed DNSResolver
DSP.cpp
- Committer:
- claytong
- Date:
- 2012-01-25
- Revision:
- 0:82ff15078322
File content as of revision 0:82ff15078322:
/*--------------------------------------------------------------------------- QRSS Receiver Application by Clayton ZL3TKA/VK1TKA clayton@isnotcrazy.com DSP Processing class ---------------------------------------------------------------------------*/ // include files #include "DSP.h" // Definitions // Macros // Local Data // Global Data // Function Prototypes /* LP FIR Filter calculated from Web calculator http://www-users.cs.york.ac.uk/~fisher/cgi-bin/mkfscript Sample Rate: 35156 Corner Freq: 200 Taps: 511 Beta: 0.5 // Digital filter designed by mkfilter/mkshape/gencode A.J. Fisher // Command line: /www/usr/fisher/helpers/mkshape -c 5.6889293435e-03 5.0000000000e-01 511 -b 16 -l #define NZEROS 510 #define GAIN 8.763528442e+01 static float xv[NZEROS+1]; static float xcoeffs[] = { +0.0006713867, +0.0008544922, +0.0010375977, +0.0012817383, +0.0015258789, +0.0017700195, +0.0020446777, +0.0023498535, +0.0026855469, +0.0030212402, +0.0033874512, +0.0037841797, +0.0041809082, +0.0046081543, +0.0050659180, +0.0055236816, +0.0060119629, +0.0065002441, +0.0070190430, +0.0075378418, +0.0080871582, +0.0086364746, +0.0092163086, +0.0097961426, +0.0103759766, +0.0109558105, +0.0115661621, +0.0121765137, +0.0127868652, +0.0133972168, +0.0140075684, +0.0146179199, +0.0151977539, +0.0158081055, +0.0163879395, +0.0169677734, +0.0175476074, +0.0180969238, +0.0186462402, +0.0191650391, +0.0196533203, +0.0201416016, +0.0205688477, +0.0209960938, +0.0213928223, +0.0217590332, +0.0220947266, +0.0223693848, +0.0226440430, +0.0228576660, +0.0230102539, +0.0231323242, +0.0232238770, +0.0232238770, +0.0232238770, +0.0231323242, +0.0229797363, +0.0227966309, +0.0225219727, +0.0222167969, +0.0218200684, +0.0213623047, +0.0208435059, +0.0202636719, +0.0195922852, +0.0188598633, +0.0180664062, +0.0171813965, +0.0162048340, +0.0151672363, +0.0140380859, +0.0128479004, +0.0115661621, +0.0102233887, +0.0087890625, +0.0072631836, +0.0056762695, +0.0039978027, +0.0022277832, +0.0003967285, -0.0015258789, -0.0035095215, -0.0055847168, -0.0077514648, -0.0099792480, -0.0122680664, -0.0146484375, -0.0170898438, -0.0195922852, -0.0221557617, -0.0248107910, -0.0274963379, -0.0302429199, -0.0330505371, -0.0359191895, -0.0388183594, -0.0417785645, -0.0447692871, -0.0477905273, -0.0508422852, -0.0539245605, -0.0570373535, -0.0601501465, -0.0632934570, -0.0664367676, -0.0695800781, -0.0727233887, -0.0758666992, -0.0789794922, -0.0820922852, -0.0851745605, -0.0881958008, -0.0912170410, -0.0941467285, -0.0970764160, -0.0999145508, -0.1026916504, -0.1054077148, 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+0.1914367676, +0.2050170898, +0.2188110352, +0.2327880859, +0.2469482422, +0.2613220215, +0.2758178711, +0.2904968262, +0.3053283691, +0.3203125000, +0.3353881836, +0.3505859375, +0.3659057617, +0.3812866211, +0.3967590332, +0.4122924805, +0.4279174805, +0.4435424805, +0.4591979981, +0.4748840332, +0.4905700684, +0.5062561035, +0.5219116211, +0.5375366211, +0.5531005859, +0.5686035156, +0.5840148926, +0.5993652344, +0.6145935059, +0.6296997070, +0.6446838379, +0.6595153809, +0.6741943359, +0.6886901855, +0.7030334473, +0.7171325684, +0.7310485840, +0.7447204590, +0.7581787109, +0.7713623047, +0.7843017578, +0.7969665527, +0.8093261719, +0.8214111328, +0.8331604004, +0.8446044922, +0.8557128906, +0.8664855957, +0.8768920898, +0.8869323730, +0.8966064453, +0.9058837891, +0.9147949219, +0.9232788086, +0.9313659668, +0.9390258789, +0.9462585449, +0.9530944824, +0.9594421387, +0.9653625488, +0.9708557129, +0.9758605957, +0.9804077148, +0.9844970703, +0.9880981445, +0.9912414551, +0.9938964844, +0.9960937500, +0.9977722168, +0.9989929199, +0.9997253418, +0.9999694824, +0.9997253418, +0.9989929199, +0.9977722168, +0.9960937500, +0.9938964844, +0.9912414551, +0.9880981445, +0.9844970703, +0.9804077148, +0.9758605957, +0.9708557129, +0.9653625488, +0.9594421387, +0.9530944824, +0.9462585449, +0.9390258789, +0.9313659668, +0.9232788086, +0.9147949219, +0.9058837891, +0.8966064453, +0.8869323730, +0.8768920898, +0.8664855957, +0.8557128906, +0.8446044922, +0.8331604004, +0.8214111328, +0.8093261719, +0.7969665527, +0.7843017578, +0.7713623047, +0.7581787109, +0.7447204590, +0.7310485840, +0.7171325684, +0.7030334473, +0.6886901855, +0.6741943359, +0.6595153809, +0.6446838379, +0.6296997070, +0.6145935059, +0.5993652344, +0.5840148926, +0.5686035156, +0.5531005859, +0.5375366211, +0.5219116211, +0.5062561035, +0.4905700684, +0.4748840332, +0.4591979981, +0.4435424805, +0.4279174805, +0.4122924805, +0.3967590332, +0.3812866211, +0.3659057617, +0.3505859375, +0.3353881836, +0.3203125000, +0.3053283691, +0.2904968262, +0.2758178711, +0.2613220215, +0.2469482422, +0.2327880859, +0.2188110352, +0.2050170898, +0.1914367676, +0.1780700684, +0.1649169922, +0.1520080566, +0.1393432617, +0.1268920898, +0.1147155762, +0.1028137207, +0.0911560059, +0.0797729492, +0.0686645508, +0.0578308105, +0.0473022461, +0.0370483398, +0.0270996094, +0.0174255371, +0.0080871582, -0.0009765625, -0.0097351074, -0.0181579590, -0.0263061523, -0.0341186523, -0.0416564941, -0.0488586426, -0.0557250977, -0.0623168945, -0.0686035156, -0.0745544434, -0.0802001953, -0.0855407715, -0.0906066895, -0.0953369141, -0.0997924805, -0.1039428711, -0.1077880859, -0.1113586426, -0.1146545410, -0.1176452637, -0.1203613281, -0.1228332519, -0.1250000000, -0.1269226074, -0.1286010742, -0.1300048828, -0.1311950684, -0.1321105957, -0.1328125000, -0.1332702637, -0.1335144043, -0.1335754394, -0.1333923340, -0.1329956055, -0.1324462891, -0.1316833496, -0.1307373047, -0.1296386719, 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+0.0208435059, +0.0213623047, +0.0218200684, +0.0222167969, +0.0225219727, +0.0227966309, +0.0229797363, +0.0231323242, +0.0232238770, +0.0232238770, +0.0232238770, +0.0231323242, +0.0230102539, +0.0228576660, +0.0226440430, +0.0223693848, +0.0220947266, +0.0217590332, +0.0213928223, +0.0209960938, +0.0205688477, +0.0201416016, +0.0196533203, +0.0191650391, +0.0186462402, +0.0180969238, +0.0175476074, +0.0169677734, +0.0163879395, +0.0158081055, +0.0151977539, +0.0146179199, +0.0140075684, +0.0133972168, +0.0127868652, +0.0121765137, +0.0115661621, +0.0109558105, +0.0103759766, +0.0097961426, +0.0092163086, +0.0086364746, +0.0080871582, +0.0075378418, +0.0070190430, +0.0065002441, +0.0060119629, +0.0055236816, +0.0050659180, +0.0046081543, +0.0041809082, +0.0037841797, +0.0033874512, +0.0030212402, +0.0026855469, +0.0023498535, +0.0020446777, +0.0017700195, +0.0015258789, +0.0012817383, +0.0010375977, +0.0008544922, +0.0006713867, }; static void filterloop() { for (;;) { float sum; int i; for (i = 0; i < NZEROS; i++) xv[i] = xv[i+1]; xv[NZEROS] = next input value / GAIN; sum = 0.0; for (i = 0; i <= NZEROS; i++) sum += (xcoeffs[i] * xv[i]); next output value = sum; } } */ const int16_t aiFIRCoefficients[DSP_FIR_COEFFICIENTS] = { 22,28,34,42,50,58,67,77, 88,99,111,124,137,151,166,181, 197,213,230,247,265,283,302,321, 340,359,379,399,419,439,459,479, 498,518,537,556,575,593,611,628, 644,660,674,688,701,713,724,733, 742,749,754,758,761,761,761,758, 753,747,738,728,715,700,683,664, 642,618,592,563,531,497,460,421, 379,335,288,238,186,131,73,13, -50,-115,-183,-254,-327,-402,-480,-560, -642,-726,-813,-901,-991,-1083,-1177,-1272, -1369,-1467,-1566,-1666,-1767,-1869,-1971,-2074, -2177,-2280,-2383,-2486,-2588,-2690,-2791,-2890, -2989,-3085,-3181,-3274,-3365,-3454,-3540,-3623, -3703,-3780,-3853,-3923,-3989,-4050,-4107,-4159, -4206,-4248,-4284,-4315,-4340,-4358,-4371,-4377, -4375,-4367,-4352,-4329,-4299,-4260,-4214,-4159, -4096,-4025,-3944,-3855,-3757,-3649,-3532,-3406, -3270,-3124,-2969,-2803,-2628,-2443,-2248,-2042, -1826,-1601,-1365,-1118,-862,-595,-319,-32, 265,571,888,1214,1550,1895,2250,2614, 2987,3369,3759,4158,4566,4981,5404,5835, 6273,6718,7170,7628,8092,8563,9038,9519, 10005,10496,10990,11488,11990,12494,13001,13510, 14022,14534,15047,15561,16075,16589,17102,17614, 18124,18632,19137,19640,20139,20634,21125,21611, 22092,22567,23037,23499,23955,24403,24844,25276, 25700,26115,26520,26916,27301,27676,28040,28393, 28734,29063,29380,29684,29976,30254,30519,30770, 31007,31231,31439,31633,31813,31977,32126,32260, 32378,32481,32568,32640,32695,32735,32759,32767, 32759,32735,32695,32640,32568,32481,32378,32260, 32126,31977,31813,31633,31439,31231,31007,30770, 30519,30254,29976,29684,29380,29063,28734,28393, 28040,27676,27301,26916,26520,26115,25700,25276, 24844,24403,23955,23499,23037,22567,22092,21611, 21125,20634,20139,19640,19137,18632,18124,17614, 17102,16589,16075,15561,15047,14534,14022,13510, 13001,12494,11990,11488,10990,10496,10005,9519, 9038,8563,8092,7628,7170,6718,6273,5835, 5404,4981,4566,4158,3759,3369,2987,2614, 2250,1895,1550,1214,888,571,265,-32, -319,-595,-862,-1118,-1365,-1601,-1826,-2042, -2248,-2443,-2628,-2803,-2969,-3124,-3270,-3406, -3532,-3649,-3757,-3855,-3944,-4025,-4096,-4159, -4214,-4260,-4299,-4329,-4352,-4367,-4375,-4377, -4371,-4358,-4340,-4315,-4284,-4248,-4206,-4159, -4107,-4050,-3989,-3923,-3853,-3780,-3703,-3623, -3540,-3454,-3365,-3274,-3181,-3085,-2989,-2890, -2791,-2690,-2588,-2486,-2383,-2280,-2177,-2074, -1971,-1869,-1767,-1666,-1566,-1467,-1369,-1272, -1177,-1083,-991,-901,-813,-726,-642,-560, -480,-402,-327,-254,-183,-115,-50,13, 73,131,186,238,288,335,379,421, 460,497,531,563,592,618,642,664, 683,700,715,728,738,747,753,758, 761,761,761,758,754,749,742,733, 724,713,701,688,674,660,644,628, 611,593,575,556,537,518,498,479, 459,439,419,399,379,359,340,321, 302,283,265,247,230,213,197,181, 166,151,137,124,111,99,88,77, 67,58,50,42,34,28,22 }; /* Sin table to convert NCO phase to Oscillator outputs */ const int16_t aiSinTable[256] = { 0,6,13,19,25,31,37,44, 50,56,62,68,74,80,86,92, 98,103,109,115,120,126,131,136, 142,147,152,157,162,167,171,176, 180,185,189,193,197,201,205,208, 212,215,219,222,225,228,231,233, 236,238,240,242,244,246,247,249, 250,251,252,253,254,254,255,255, 255,255,255,254,254,253,252,251, 250,249,247,246,244,242,240,238, 236,233,231,228,225,222,219,215, 212,208,205,201,197,193,189,185, 180,176,171,167,162,157,152,147, 142,136,131,126,120,115,109,103, 98,92,86,80,74,68,62,56, 50,44,37,31,25,19,13,6, 0,-6,-13,-19,-25,-31,-37,-44, -50,-56,-62,-68,-74,-80,-86,-92, -98,-103,-109,-115,-120,-126,-131,-136, -142,-147,-152,-157,-162,-167,-171,-176, -180,-185,-189,-193,-197,-201,-205,-208, -212,-215,-219,-222,-225,-228,-231,-233, -236,-238,-240,-242,-244,-246,-247,-249, -250,-251,-252,-253,-254,-254,-255,-255, -255,-255,-255,-254,-254,-253,-252,-251, -250,-249,-247,-246,-244,-242,-240,-238, -236,-233,-231,-228,-225,-222,-219,-215, -212,-208,-205,-201,-197,-193,-189,-185, -180,-176,-171,-167,-162,-157,-152,-147, -142,-136,-131,-126,-120,-115,-109,-103, -98,-92,-86,-80,-74,-68,-62,-56, -50,-44,-37,-31,-25,-19,-13,-6 }; //--------------------------------------------------------------------------- // LOCAL FUNCTIONS //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // // Perform a MAC Operation (multiply and Accumulate) // Assumes data is from samples structure, so skips every 2nd sample // Produces a 64 bit result // int64_t MAC_Samples( int64_t llSum, const int32_t *piSamples, const int16_t *piCoefficients, int iCnt ) { int64_t llMult; while ( iCnt>0 ) { llMult = *piSamples; llMult *= *piCoefficients; llSum += llMult; piSamples++; piSamples++; // skip other sample pair piCoefficients++; iCnt--; } return llSum; } //--------------------------------------------------------------------------- // // Convert a 64 bit sum to a 32 bit output // int32_t ConvertToOutput( int64_t llSum ) { return (int32_t)(llSum>>FIR_SHIFT_FACTOR); } //--------------------------------------------------------------------------- // DSP Methods //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // // Set up NCO Increment from a frequency value // void TDSPProcessor::NCOFrequency( int32_t iFreq ) { int64_t llFreq; int64_t llInc; // Inc (32bit) = Freq * 2^32 / SampleRate // Use long long (64 bit int) for calculations to prevent overflow and get best resolution llFreq = iFreq; llInc = llFreq * 0x10000 * 0x10000 / SAMPLE_RATE; // Convert back to 32 bit unsigned via integer type uiMixerPhaseIncrement = (uint32_t)((int32_t)llInc); printf( "LO Freq set to %d - NCO Inc set to %u\r\n", iFreq, uiMixerPhaseIncrement ); } //--------------------------------------------------------------------------- // // Reset processing // void TDSPProcessor::Reset() { uiMixerPhaseAccumulator = 0; bLPFPartailsValid = false; Release(); } //--------------------------------------------------------------------------- // // Mix samples with LO (local oscillator) // bool TDSPProcessor::MixLO() { int ii; int iLen = Length(); TDataSample * pSample; int16_t iIlo; int16_t iQlo; int32_t iIin; int32_t iQin; for ( ii=0,pSample=SamplePtr(); ii<iLen; ii++,pSample++ ) { // generate quadrature oscillators. LO I=cos Q=sin iIlo = aiSinTable[ (64+(uiMixerPhaseAccumulator>>24))&0xFF ]; // COS iQlo = aiSinTable[ (uiMixerPhaseAccumulator>>24) ]; // SIN // inc NCO uiMixerPhaseAccumulator += uiMixerPhaseIncrement; // scale samples (they are only 24 bits) iIin = pSample->iIData / 256; iQin = pSample->iQData / 256; // complex multiply sample and LO // (A + Bi) * (C + Di) = (AC - BD) + (BC + AD)i pSample->iIData = (iIin * iIlo) - (iQin * iQlo); pSample->iQData = (iQin * iIlo) + (iIin * iQlo); } return true; } //--------------------------------------------------------------------------- // // LPF processing // bool TDSPProcessor::LPF() { /* We just code this up for the parameters defined. It could be dynamically coded, but for simplicity hard-coding will be used */ #if (BUFFERSYS_SIZE!=512) #error BUFFERSYS_SIZE has changed from 512 #endif #if (DSP_FIR_COEFFICIENTS!=511) #error DSP_FIR_COEFFICIENTS has changed from 511 #endif #if (DECIMATION_RATIO!=64) #error DECIMATION_RATIO has changed from 64 #endif #if (LPF_OUTPUTS_SIZE!=8) #error LPF_OUTPUTS_SIZE has changed from 8 #endif int64_t iSum; int ii; bool bRet = false; // Outputs if ( bLPFPartailsValid ) { for ( ii=0; ii<8; ii++ ) { iSum = MAC_Samples( asLPFPartials[ii].iIData, &(SamplePtr(0)->iIData), &(aiFIRCoefficients[448-(ii*64)]), (ii*64)+62 ); asLPFOutputs[ii].iIData = ConvertToOutput( iSum ); iSum = MAC_Samples( asLPFPartials[ii].iQData, &(SamplePtr(0)->iQData), &(aiFIRCoefficients[448-(ii*64)]), (ii*64)+62 ); asLPFOutputs[ii].iQData = ConvertToOutput( iSum ); } bRet = true; } // Partials for ( ii=0; ii<7; ii++ ) { asLPFPartials[ii].iIData = MAC_Samples( 0, &(SamplePtr((ii*64)+64)->iIData), &(aiFIRCoefficients[0]), (7-ii)*64 ); asLPFPartials[ii].iQData = MAC_Samples( 0, &(SamplePtr((ii*64)+64)->iQData), &(aiFIRCoefficients[0]), (7-ii)*64 ); } // Partials[7] = 0 asLPFPartials[7].iIData = 0; asLPFPartials[7].iQData = 0; bLPFPartailsValid = true; return bRet; } //--------------------------------------------------------------------------- // END //---------------------------------------------------------------------------