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WSJT-X/lib/qra/qracodes/main.c
Bill Somerville 84891dde37 Apply Nico's QRA changes as of 2016/06/23 
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6801 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
2016-06-23 10:36:18 +00:00

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// main.c
// Word Error Rate test example for Q-ary RA codes over GF(64)
//
// (c) 2016 - Nico Palermo, IV3NWV
//
// Thanks to Andrea Montefusco IW0HDV for his help on adapting the sources
// to OSs other than MS Windows
//
// ------------------------------------------------------------------------------
// This file is part of the qracodes project, a Forward Error Control
// encoding/decoding package based on Q-ary RA (Repeat and Accumulate) LDPC codes.
//
// Files in this package:
// main.c - this file
// normrnd.c/.h - random gaussian number generator
// npfwht.c/.h - Fast Walsh-Hadamard Transforms
// pdmath.c/.h - Elementary math on probability distributions
// qra12_63_64_irr_b.c/.h - Tables for a QRA(12,63) irregular RA code over GF(64)
// qra13_64_64_irr_e.c/.h - Tables for a QRA(13,64) irregular RA code " "
// qracodes.c/.h - QRA codes encoding/decoding functions
//
// -------------------------------------------------------------------------------
//
// qracodes 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 3 of the License, or
// (at your option) any later version.
// qracodes 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 qracodes source distribution.
// If not, see <http://www.gnu.org/licenses/>.
// -----------------------------------------------------------------------------
// Two codes are available for simulations in this sowftware release:
// QRA12_63_64_IRR_B: K=12 N=63 Q=64 irregular QRA code (defined in qra12_63_64_irr_b.h /.c)
// QRA13_64_64_IRR_E: K=13 N=64 Q=64 irregular QRA code (defined in qra13_64_64_irr_b.h /.c)
// Codes with K=13 are designed to include a CRC as the 13th information symbol
// and improve the code UER (Undetected Error Rate).
// The CRC symbol is not sent along the channel (the codes are punctured) and the
// resulting code is still a (12,63) code with an effective code rate of R = 12/63.
// ------------------------------------------------------------------------------
// OS dependent defines and includes --------------------------------------------
#if _WIN32 // note the underscore: without it, it's not msdn official!
// Windows (x64 and x86)
#include <windows.h> // required only for GetTickCount(...)
#include <process.h> // _beginthread
#endif
#if __linux__
#include <unistd.h>
#include <time.h>
GetTickCount(void) {
struct timespec ts;
theTick = 0U;
clock_gettime( CLOCK_REALTIME, &ts );
theTick = ts.tv_nsec / 1000000;
theTick += ts.tv_sec * 1000;
return theTick;
}
#endif
#if __APPLE__
#endif
#include <stdlib.h>
#include <stdio.h>
#include "qracodes.h"
#include "normrnd.h" // gaussian numbers generator
#include "pdmath.h" // operations on probability distributions
// defined codes
#include "qra12_63_64_irr_b.h"
#include "qra13_64_64_irr_e.h"
// -----------------------------------------------------------------------------------
#define NTHREADS_MAX 24
// channel types
#define CHANNEL_AWGN 0
#define CHANNEL_RAYLEIGH 1
// amount of a-priori information provided to the decoder
#define AP_NONE 0
#define AP_28 1
#define AP_44 2
#define AP_56 3
const char ap_str[4][16] = {
"None",
"28 bit",
"44 bit",
"56 bit"
};
const char fnameout_pfx[2][64] = {
"wer-awgn-",
"wer-rayleigh-"
};
const char fnameout_sfx[4][64] = {
"-ap00.txt",
"-ap28.txt",
"-ap44.txt",
"-ap56.txt"
};
const int ap_masks_jt65[4][13] = {
// Each row must be 13 entries long (to handle puntc. codes 13,64)
// The mask of 13th symbol (crc) is alway initializated to 0
// AP0 - no a-priori knowledge
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
// AP28 - 1st field known [cq ? ?] or [dst ? ?]
{0x3F,0x3F,0x3F,0x3F,0x3C, 0, 0, 0, 0, 0, 0, 0},
// AP44 - 1st and 3rd fields known [cq ? 0] or [dst ? 0]
{0x3F,0x3F,0x3F,0x3F,0x3C, 0, 0, 0, 0,0x0F,0x3F,0x3F},
// AP56 - 1st and 2nd fields known [dst src ?]
{0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x30, 0, 0}
};
void ix_mask(const qracode *pcode, float *r, const int *mask, const int *x);
void printword(char *msg, int *x, int size)
{
int k;
printf("\n%s ",msg);
for (k=0;k<size;k++)
printf("%02hx ",x[k]);
printf("\n");
}
typedef struct {
int channel_type;
float EbNodB;
volatile int nt;
volatile int nerrs;
volatile int nerrsu;
volatile int stop;
volatile int done;
int ap_index; // index to the a priori knowledge mask
const qracode *pcode; // pointer to the code descriptor
int *x; //[qra_K]; input message buffer
int *y, *ydec; //[qra_N]; encoded/decoded codewords buffers
float *qra_v2cmsg; //[qra_NMSG*qra_M]; MP decoder v->c msg buffer
float *qra_c2vmsg; //[qra_NMSG*qra_M]; MP decoder c->v msg buffer
float *rp; // [qra_N*qra_M]; received samples (real component) buffer
float *rq; // [qra_N*qra_M]; received samples (imag component) buffer
float *chp; //[qra_N]; channel gains (real component) buffer
float *chq; //[qra_N]; channel gains (imag component) buffer
float *r; //[qra_N*qra_M]; received samples (amplitude) buffer
float *ix; // [qra_N*qra_M]; // intrinsic information to the MP algorithm
float *ex; // [qra_N*qra_M]; // extrinsic information from the MP algorithm
} wer_test_ds;
typedef void( __cdecl *pwer_test_thread)(wer_test_ds*);
// crc-6 generator polynomial
// g(x) = x^6 + a5*x^5 + ... + a1*x + a0
// g(x) = x^6 + x + 1
#define CRC6_GEN_POL 0x30 // MSB=a0 LSB=a5
// g(x) = x^6 + x^2 + x + 1 (as suggested by Joe. See: https://users.ece.cmu.edu/~koopman/crc/)
// #define CRC6_GEN_POL 0x38 // MSB=a0 LSB=a5. Simulation results are similar
int calc_crc6(int *x, int sz)
{
int k,j,t,sr = 0;
for (k=0;k<sz;k++) {
t = x[k];
for (j=0;j<6;j++) {
if ((t^sr)&0x01)
sr = (sr>>1) ^ CRC6_GEN_POL;
else
sr = (sr>>1);
t>>=1;
}
}
return sr;
}
void wer_test_thread(wer_test_ds *pdata)
{
const qracode *pcode=pdata->pcode;
const int qra_K = pcode->K;
const int qra_N = pcode->N;
const int qra_M = pcode->M;
const int qra_m = pcode->m;
const int NSAMPLES = pcode->N*pcode->M;
const float No = 1.0f; // noise spectral density
const float sigma = (float)sqrt(No/2.0f); // std dev of noise I/Q components
const float sigmach = (float)sqrt(1/2.0f); // std dev of channel I/Q gains
// Eb/No value for which we optimize the bessel metric
const float EbNodBMetric = 2.8f;
const float EbNoMetric = (float)pow(10,EbNodBMetric/10);
int k,t,j,diff;
float R;
float EsNoMetric;
float EbNo, EsNo, Es, A;
int channel_type, code_type;
int nt=0; // transmitted codewords
int nerrs = 0; // total number of errors
int nerrsu = 0; // number of undetected errors
int rc;
// inizialize pointer to required buffers
int *x=pdata->x; // message buffer
int *y=pdata->y, *ydec=pdata->ydec; // encoded/decoded codeword buffers
float *qra_v2cmsg=pdata->qra_v2cmsg; // table of the v->c messages
float *qra_c2vmsg=pdata->qra_c2vmsg; // table of the c->v messages
float *rp=pdata->rp; // received samples (real component)
float *rq=pdata->rq; // received samples (imag component)
float *chp=pdata->chp; // channel gains (real component)
float *chq=pdata->chq; // channel gains (imag component)
float *r=pdata->r; // received samples amplitudes
float *ix=pdata->ix; // intrinsic information to the MP algorithm
float *ex=pdata->ex; // extrinsic information from the MP algorithm
channel_type = pdata->channel_type;
code_type = pcode->type;
// define the (true) code rate accordingly to the code type
switch(code_type) {
case QRATYPE_CRC:
R = 1.0f*(qra_K-1)/qra_N;
break;
case QRATYPE_CRCPUNCTURED:
R = 1.0f*(qra_K-1)/(qra_N-1);
break;
case QRATYPE_NORMAL:
default:
R = 1.0f*(qra_K)/(qra_N);
}
EsNoMetric = 1.0f*qra_m*R*EbNoMetric;
EbNo = (float)pow(10,pdata->EbNodB/10);
EsNo = 1.0f*qra_m*R*EbNo;
Es = EsNo*No;
A = (float)sqrt(Es);
// encode the input
if (code_type==QRATYPE_CRC || code_type==QRATYPE_CRCPUNCTURED) {
// compute the information message symbol check as the (negated) xor of all the
// information message symbols
for (k=0;k<(qra_K-1);k++)
x[k]=k%qra_M;
x[k]=calc_crc6(x,qra_K-1);
}
else
for (k=0;k<qra_K;k++)
x[k]=k%qra_M;
qra_encode(pcode,y,x);
while (pdata->stop==0) {
// simulate the channel
// NOTE: in the case that the code is punctured, for simplicity
// we compute the channel outputs and the metric also for the crc symbol
// then we ignore its observation.
normrnd_s(rp,NSAMPLES,0,sigma);
normrnd_s(rq,NSAMPLES,0,sigma);
if (channel_type == CHANNEL_AWGN) {
for (k=0;k<qra_N;k++)
rp[k*qra_M+y[k]]+=A;
}
else if (channel_type == CHANNEL_RAYLEIGH) {
normrnd_s(chp,qra_N,0,sigmach);
normrnd_s(chq,qra_N,0,sigmach);
for (k=0;k<qra_N;k++) {
rp[k*qra_M+y[k]]+=A*chp[k];
rq[k*qra_M+y[k]]+=A*chq[k];
}
}
else {
pdata->done = 1;
return; // unknown channel type
}
// compute the squares of the amplitudes of the received samples
for (k=0;k<NSAMPLES;k++)
r[k] = rp[k]*rp[k] + rq[k]*rq[k];
// compute the intrinsic symbols probabilities
qra_mfskbesselmetric(ix,r,pcode->m,pcode->N,EsNoMetric);
if (code_type==QRATYPE_CRCPUNCTURED) {
// ignore observations of the CRC symbol as it is not actually sent
// over the channel
pd_init(PD_ROWADDR(ix,qra_M,qra_K),pd_uniform(qra_m),qra_M);
}
if (pdata->ap_index!=0)
// mask channel observations with a priori knowledge
ix_mask(pcode,ix,ap_masks_jt65[pdata->ap_index],x);
// compute the extrinsic symbols probabilities with the message-passing algorithm
// stop if extrinsic information does not converges to 1 within the given number of iterations
rc = qra_extrinsic(pcode,ex,ix,100,qra_v2cmsg,qra_c2vmsg);
if (rc>=0) { // the MP algorithm converged to Iex~1 in rc iterations
// decode the codeword
qra_mapdecode(pcode,ydec,ex,ix);
// look for undetected errors
if (code_type==QRATYPE_CRC || code_type==QRATYPE_CRCPUNCTURED) {
j = 0; diff = 0;
for (k=0;k<(qra_K-1);k++)
diff |= (ydec[k]!=x[k]);
t = calc_crc6(ydec,qra_K-1);
if (t!=ydec[k]) // error detected - crc doesn't matches
nerrs += 1;
else
if (diff) { // decoded message is not equal to the transmitted one but
// the crc test passed
// add as undetected error
nerrsu += 1;
nerrs += 1;
// uncomment to see what the undetected error pattern looks like
//printword("U", ydec);
}
}
else
for (k=0;k<qra_K;k++)
if (ydec[k]!=x[k]) { // decoded msg differs from the transmitted one
nerrsu += 1; // it's a false decode
nerrs += 1;
// uncomment to see what the undetected error pattern looks like
// printword("U", ydec);
break;
}
}
else // failed to converge to a solution within the given number of iterations
nerrs++;
nt = nt+1;
pdata->nt=nt;
pdata->nerrs=nerrs;
pdata->nerrsu=nerrsu;
}
pdata->done=1;
_endthread();
}
void ix_mask(const qracode *pcode, float *r, const int *mask, const int *x)
{
// mask intrinsic information (channel observations) with a priori knowledge
int k,kk, smask;
const int qra_K=pcode->K;
const int qra_M=pcode->M;
const int qra_m=pcode->m;
for (k=0;k<qra_K;k++) {
smask = mask[k];
if (smask) {
for (kk=0;kk<qra_M;kk++)
if (((kk^x[k])&smask)!=0)
*(PD_ROWADDR(r,qra_M,k)+kk) = 0.f;
pd_norm(PD_ROWADDR(r,qra_M,k),qra_m);
}
}
}
int wer_test_proc(const qracode *pcode, int nthreads, int chtype, int ap_index, float *EbNodB, int *nerrstgt, int nitems)
{
int k,nn,j,nt,nerrs,nerrsu,nd;
int cini,cend;
char fnameout[128];
FILE *fout;
wer_test_ds wt[NTHREADS_MAX];
float pe,avgt;
nn = sizeof(EbNodB)/sizeof(float); // size of the EbNo array to test
if (nthreads>NTHREADS_MAX) {
printf("Error: nthreads should be <=%d\n",NTHREADS_MAX);
return -1;
}
sprintf(fnameout,"%s%s%s",
fnameout_pfx[chtype],
pcode->name,
fnameout_sfx[ap_index]);
fout = fopen(fnameout,"w");
fprintf(fout,"# Channel (0=AWGN,1=Rayleigh), Eb/No (dB), Transmitted codewords, Errors, Undetected Errors, Avg dec. time (ms), WER\n");
printf("\nTesting the code %s over the %s channel\nSimulation data will be saved to %s\n",
pcode->name,
chtype==CHANNEL_AWGN?"AWGN":"Rayleigh",
fnameout);
fflush (stdout);
// init fixed thread parameters and preallocate buffers
for (j=0;j<nthreads;j++) {
wt[j].channel_type=chtype;
wt[j].ap_index = ap_index;
wt[j].pcode = pcode;
wt[j].x = (int*)malloc(pcode->K*sizeof(int));
wt[j].y = (int*)malloc(pcode->N*sizeof(int));
wt[j].ydec = (int*)malloc(pcode->N*sizeof(int));
wt[j].qra_v2cmsg = (float*)malloc(pcode->NMSG*pcode->M*sizeof(float));
wt[j].qra_c2vmsg = (float*)malloc(pcode->NMSG*pcode->M*sizeof(float));
wt[j].rp = (float*)malloc(pcode->N*pcode->M*sizeof(float));
wt[j].rq = (float*)malloc(pcode->N*pcode->M*sizeof(float));
wt[j].chp = (float*)malloc(pcode->N*sizeof(float));
wt[j].chq = (float*)malloc(pcode->N*sizeof(float));
wt[j].r = (float*)malloc(pcode->N*pcode->M*sizeof(float));
wt[j].ix = (float*)malloc(pcode->N*pcode->M*sizeof(float));
wt[j].ex = (float*)malloc(pcode->N*pcode->M*sizeof(float));
}
for (k=0;k<nitems;k++) {
printf("\nTesting at Eb/No=%4.1f dB...",EbNodB[k]);
fflush (stdout);
for (j=0;j<nthreads;j++) {
wt[j].EbNodB=EbNodB[k];
wt[j].nt=0;
wt[j].nerrs=0;
wt[j].nerrsu=0;
wt[j].done = 0;
wt[j].stop = 0;
_beginthread((void*)(void*)wer_test_thread,0,&wt[j]);
}
nd = 0;
cini = GetTickCount();
while (1) {
// count errors
nerrs = 0;
for (j=0;j<nthreads;j++)
nerrs += wt[j].nerrs;
// stop the working threads
// if number of errors reached at this Eb/No value
if (nerrs>=nerrstgt[k]) {
for (j=0;j<nthreads;j++)
wt[j].stop = 1;
break;
}
else { // continue with the simulation
Sleep(2);
nd = (nd+1)%100;
if (nd==0) {
printf(".");
fflush (stdout);
}
}
}
cend = GetTickCount();
// wait for the working threads to exit
for (j=0;j<nthreads;j++)
while(wt[j].done==0)
Sleep(1);
printf("\n");
fflush (stdout);
// compute the total number of transmitted codewords
// the total number of errors and the total number of undetected errors
nt = 0;
nerrs =0;
nerrsu = 0;
for (j=0;j<nthreads;j++) {
nt += wt[j].nt;
nerrs += wt[j].nerrs;
nerrsu += wt[j].nerrsu;
}
pe = 1.0f*nerrs/nt; // word error rate
avgt = 1.0f*(cend-cini)/nt; // average time per decode (ms)
printf("Elapsed Time=%6.1fs (%5.2fms/word)\nTransmitted=%8d - Errors=%6d - Undetected=%3d - WER=%.2e\n",
0.001f*(cend-cini),
avgt, nt, nerrs, nerrsu, pe);
fflush (stdout);
// save simulation data to output file
fprintf(fout,"%01d %.2f %d %d %d %.2f %.2e\n",
chtype,
EbNodB[k],
nt,
nerrs,
nerrsu,
avgt,
pe);
}
fclose(fout);
return 0;
}
const qracode *codetotest[] = {
&qra_12_63_64_irr_b,
&qra_13_64_64_irr_e
};
void syntax(void)
{
printf("\nQ-ary Repeat-Accumulate Code Word Error Rate Simulator\n");
printf("2016, Nico Palermo - IV3NWV\n\n");
printf("Syntax: qracodes [-q<code_index>] [-t<threads>] [-c<ch_type>] [-a<ap_index>] [-f<fnamein>[-h]\n");
printf("Options: \n");
printf(" -q<code_index>: code to simulate. 0=qra_12_63_64_irr_b\n");
printf(" 1=qra_13_64_64_irr_e (default)\n");
printf(" -t<threads> : number of threads to be used for the simulation [1..24]\n");
printf(" (default=8)\n");
printf(" -c<ch_type> : channel_type. 0=AWGN 1=Rayleigh \n");
printf(" (default=AWGN)\n");
printf(" -a<ap_index> : amount of a-priori information provided to decoder. \n");
printf(" 0= No a-priori (default)\n");
printf(" 1= 28 bit \n");
printf(" 2= 44 bit \n");
printf(" 3= 56 bit \n");
printf(" -f<fnamein> : name of the file containing the Eb/No values to be simulated\n");
printf(" (default=ebnovalues.txt)\n");
printf(" This file should contain lines in this format:\n");
printf(" # Eb/No(dB) Target Errors\n");
printf(" 0.1 5000\n");
printf(" 0.6 5000\n");
printf(" 1.1 1000\n");
printf(" 1.6 1000\n");
printf(" ...\n");
printf(" (lines beginning with a # are treated as comments\n\n");
}
#define SIM_POINTS_MAX 20
int main(int argc, char* argv[])
{
float EbNodB[SIM_POINTS_MAX];
int nerrstgt[SIM_POINTS_MAX];
FILE *fin;
char fnamein[128]= "ebnovalues.txt";
char buf[128];
int nitems = 0;
int code_idx = 1;
int nthreads = 8;
int ch_type = CHANNEL_AWGN;
int ap_index = AP_NONE;
// parse command line
while(--argc) {
argv++;
if (strncmp(*argv,"-h",2)==0) {
syntax();
return 0;
}
else
if (strncmp(*argv,"-q",2)==0) {
code_idx = (int)atoi((*argv)+2);
if (code_idx>1) {
printf("Invalid code index\n");
syntax();
return -1;
}
}
else
if (strncmp(*argv,"-t",2)==0) {
nthreads = (int)atoi((*argv)+2);
if (nthreads>NTHREADS_MAX) {
printf("Invalid number of threads\n");
syntax();
return -1;
}
}
else
if (strncmp(*argv,"-c",2)==0) {
ch_type = (int)atoi((*argv)+2);
if (ch_type>CHANNEL_RAYLEIGH) {
printf("Invalid channel type\n");
syntax();
return -1;
}
}
else
if (strncmp(*argv,"-a",2)==0) {
ap_index = (int)atoi((*argv)+2);
if (ap_index>AP_56) {
printf("Invalid a-priori information index\n");
syntax();
return -1;
}
}
else
if (strncmp(*argv,"-f",2)==0) {
strncpy(fnamein,(*argv)+2,127);
}
else
if (strncmp(*argv,"-h",2)==0) {
syntax();
return -1;
}
else {
printf("Invalid option\n");
syntax();
return -1;
}
}
// parse points to be simulated from the input file
fin = fopen(fnamein,"r");
if (!fin) {
printf("Can't open file: %s\n",fnamein);
syntax();
}
while (fgets(buf,128,fin)!=0)
if (*buf=='#' || *buf=='\n' )
continue;
else
if (nitems==SIM_POINTS_MAX)
break;
else
if (sscanf(buf,"%f %u",&EbNodB[nitems],&nerrstgt[nitems])!=2) {
printf("Invalid input file format\n");
syntax();
return -1;
}
else
nitems++;
fclose(fin);
if (nitems==0) {
printf("No Eb/No point specified in file %s\n",fnamein);
syntax();
return -1;
}
printf("\nQ-ary Repeat-Accumulate Code Word Error Rate Simulator\n");
printf("2016, Nico Palermo - IV3NWV\n\n");
printf("Nthreads = %d\n",nthreads);
printf("Channel = %s\n",ch_type==CHANNEL_AWGN?"AWGN":"Rayleigh");
printf("Codename = %s\n",codetotest[code_idx]->name);
printf("A-priori = %s\n",ap_str[ap_index]);
printf("Eb/No input file = %s\n\n",fnamein);
wer_test_proc(codetotest[code_idx], nthreads, ch_type, ap_index, EbNodB, nerrstgt, nitems);
return 0;
}
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