From: drowe67 <drowe67@01035d8c-6547-0410-b346-abe4f91aad63>
Date: Sun, 25 Mar 2018 10:11:04 +0000 (+0000)
Subject: first pass working ofdm demod cmd line program
X-Git-Url: http://git.whiteaudio.com/gitweb/?a=commitdiff_plain;h=256177284b9b3300880ff5460b74f7933b858b45;p=freetel-svn-tracking.git

first pass working ofdm demod cmd line program

git-svn-id: https://svn.code.sf.net/p/freetel/code@3435 01035d8c-6547-0410-b346-abe4f91aad63
---

diff --git a/codec2-dev/src/ofdm_demod.c b/codec2-dev/src/ofdm_demod.c
new file mode 100644
index 00000000..3bb5ceeb
--- /dev/null
+++ b/codec2-dev/src/ofdm_demod.c
@@ -0,0 +1,208 @@
+/*---------------------------------------------------------------------------*\
+
+  FILE........: ofdm_demod.c
+  AUTHOR......: David Rowe
+  DATE CREATED: Mar 2018
+
+  Given an input file of raw file (8kHz, 16 bit shorts) of OFDM modem
+  samples.  Optionally outputs one char per bit (hard decision), or
+  soft decision rx_np and rx_amp QPSK symbols information for LDPC decoder.
+
+\*---------------------------------------------------------------------------*/
+
+/*
+  Copyright (C) 2015 David Rowe
+
+  All rights reserved.
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License version 2, as
+  published by the Free Software Foundation.  This program 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 Lesser General Public License
+  along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <errno.h>
+
+#include "codec2_ofdm.h"
+#include "ofdm_internal.h"
+#include "octave.h"
+#include "test_bits_ofdm.h"
+
+#define ASCALE  (2E5*1.1491/2.0) /* scale from shorts back to floats */
+#define NFRAMES 100              /* just log the first 100 frames    */
+
+int opt_exists(char *argv[], int argc, char opt[]) {
+    int i;
+    for (i=0; i<argc; i++) {
+        if (strcmp(argv[i], opt) == 0) {
+            return i;
+        }
+    }
+    return 0;
+}
+
+int main(int argc, char *argv[])
+{
+    FILE          *fin, *fout, *foct;
+    struct OFDM   *ofdm;
+    int            nin_frame;
+
+    float          phase_est_pilot_log[OFDM_ROWSPERFRAME*NFRAMES][OFDM_NC];
+    COMP           rx_np_log[OFDM_ROWSPERFRAME*OFDM_NC*NFRAMES];
+    float          rx_amp_log[OFDM_ROWSPERFRAME*OFDM_NC*NFRAMES];
+    float          foff_hz_log[NFRAMES];
+    int            timing_est_log[NFRAMES];
+
+    int            i, j, f, oct, logframes, arg, sd;
+
+    if (argc < 3) {
+        fprintf(stderr, "\n");
+	printf("usage: %s InputModemRawFile OutputFile [-o OctaveLogFile] [--sd]\n", argv[0]);
+        fprintf(stderr, "\n");
+        fprintf(stderr, "              Default output file format is one byte per bit hard decision\n");
+        fprintf(stderr, "  -o          Octave log file for testing\n");
+        fprintf(stderr, "  --sd        soft decision output, four doubles per QPSK symbol\n");
+        fprintf(stderr, "\n");
+	exit(1);
+    }
+
+    if (strcmp(argv[1], "-")  == 0) fin = stdin;
+    else if ( (fin = fopen(argv[1],"rb")) == NULL ) {
+	fprintf(stderr, "Error opening input modem sample file: %s: %s.\n",
+         argv[1], strerror(errno));
+	exit(1);
+    }
+
+    if (strcmp(argv[2], "-") == 0) fout = stdout;
+    else if ( (fout = fopen(argv[2],"wb")) == NULL ) {
+	fprintf(stderr, "Error opening output file: %s: %s.\n",
+         argv[2], strerror(errno));
+	exit(1);
+    }
+
+    foct = NULL;
+    oct = 0;
+    if ((arg = opt_exists(argv, argc, "-o")) != 0) {
+        if ( (foct = fopen(argv[arg+1],"wt")) == NULL ) {
+            fprintf(stderr, "Error opening output Octave file: %s: %s.\n",
+                    argv[4], strerror(errno));
+	exit(1);
+        }
+        oct = 1;
+        logframes = NFRAMES;
+    }
+
+    sd = 0;
+    if (opt_exists(argv, argc, "--sd")) {
+        sd = 1;
+    }
+
+    ofdm = ofdm_create(OFDM_CONFIG_700D);
+    assert(ofdm != NULL);
+
+    int Nbitsperframe = ofdm_get_bits_per_frame(ofdm);
+    int Nmaxsamperframe = ofdm_get_max_samples_per_frame();
+    
+    short  rx_scaled[Nmaxsamperframe];
+    COMP   rxbuf_in[Nmaxsamperframe];
+    int    rx_bits[Nbitsperframe];
+    char   rx_bits_char[Nbitsperframe];
+    int    state, next_state;
+
+    state = OFDM_SEARCHING;
+    f = 0;
+
+    nin_frame = ofdm_get_nin(ofdm);
+    while(fread(rx_scaled, sizeof(short), nin_frame, fin) == nin_frame) {
+
+	/* scale and demod */
+
+	for(i=0; i<nin_frame; i++) {
+	    rxbuf_in[i].real = (float)rx_scaled[i]/ASCALE;
+            rxbuf_in[i].imag = 0.0;
+        }
+
+        next_state = state;
+        switch(state) {
+        case OFDM_SEARCHING:
+            if (ofdm_sync_search(ofdm, rxbuf_in)) {
+                next_state = OFDM_SYNCED;
+            }
+            break;
+        case OFDM_SYNCED:
+            ofdm_demod(ofdm, rx_bits, rxbuf_in);
+            break;
+        }
+        state = next_state;
+
+        nin_frame = ofdm_get_nin(ofdm);
+
+        if (sd == 0) {
+            /* simple hard decision output for uncoded testing */
+            for(i=0; i<Nbitsperframe; i++) {
+                rx_bits_char[i] = rx_bits[i];
+            }
+            fwrite(rx_bits_char, sizeof(char), Nbitsperframe, fout);
+        }
+
+        if (oct) {
+            /* note corrected phase (rx no phase) is one big linear array for frame */
+
+            for (i = 0; i < OFDM_ROWSPERFRAME*OFDM_NC; i++) {
+                rx_np_log[OFDM_ROWSPERFRAME*OFDM_NC*f + i].real = crealf(ofdm->rx_np[i]);
+                rx_np_log[OFDM_ROWSPERFRAME*OFDM_NC*f + i].imag = cimagf(ofdm->rx_np[i]);
+            }
+
+            /* note phase/amp ests the same for each col, but check them all anyway */
+
+            for (i = 0; i < OFDM_ROWSPERFRAME; i++) {
+                for (j = 0; j < OFDM_NC; j++) {
+                    phase_est_pilot_log[OFDM_ROWSPERFRAME*f+i][j] = ofdm->aphase_est_pilot_log[OFDM_NC*i+j];
+                    rx_amp_log[OFDM_ROWSPERFRAME*OFDM_NC*f+OFDM_NC*i+j] = ofdm->rx_amp[OFDM_NC*i+j];
+                }
+            }
+
+            foff_hz_log[f] = ofdm->foff_est_hz;
+            timing_est_log[f] = ofdm->timing_est + 1;     /* offset by 1 to match Octave */
+            if (f == (logframes-1))
+                oct = 0;
+        }
+
+	/* if this is in a pipeline, we probably don't want the usual
+	   buffering to occur */
+
+        if (fout == stdout) fflush(stdout);
+        if (fin == stdin) fflush(stdin);
+
+        f++;
+    }
+
+    fclose(fin);
+    fclose(fout);
+
+    /* optionally dump Octave files */
+
+    if (foct != NULL) {
+        octave_save_float(foct, "phase_est_pilot_log_c", (float*)phase_est_pilot_log, OFDM_ROWSPERFRAME*NFRAMES, OFDM_NC, OFDM_NC);
+        octave_save_complex(foct, "rx_np_log_c", (COMP*)rx_np_log, 1, OFDM_ROWSPERFRAME*OFDM_NC*NFRAMES, OFDM_ROWSPERFRAME*OFDM_NC*NFRAMES);
+        octave_save_float(foct, "rx_amp_log_c", (float*)rx_amp_log, 1, OFDM_ROWSPERFRAME*OFDM_NC*NFRAMES, OFDM_ROWSPERFRAME*OFDM_NC*NFRAMES);
+        octave_save_float(foct, "foff_hz_log_c", foff_hz_log, NFRAMES, 1, 1);
+        octave_save_int(foct, "timing_est_log_c", timing_est_log, NFRAMES, 1);
+        fclose(foct);
+    }
+
+    ofdm_destroy(ofdm);
+
+    return 0;
+}
diff --git a/codec2-dev/src/ofdm_put_test_bits.c b/codec2-dev/src/ofdm_put_test_bits.c
new file mode 100644
index 00000000..fa3b8ef8
--- /dev/null
+++ b/codec2-dev/src/ofdm_put_test_bits.c
@@ -0,0 +1,111 @@
+/*---------------------------------------------------------------------------*\
+
+  FILE........: ofdm_put_test_bits.c
+  AUTHOR......: David Rowe
+  DATE CREATED: Mar 2018
+
+  Slurps up a stream of test bits generated by ofdm_get_test_bits, useful for
+  testing ofdm_mod and ofdm_demod.
+
+\*---------------------------------------------------------------------------*/
+
+/*
+  Copyright (C) 2018 David Rowe
+
+  All rights reserved.
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License version 2, as
+  published by the Free Software Foundation.  This program 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 Lesser General Public License
+  along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <errno.h>
+
+#include "codec2_ofdm.h"
+#include "test_bits_ofdm.h"
+
+#define LOG_FRAMES 100
+
+int opt_exists(char *argv[], int argc, char opt[]) {
+    int i;
+    for (i=0; i<argc; i++) {
+        if (strcmp(argv[i], opt) == 0) {
+            return i;
+        }
+    }
+    return 0;
+}
+
+int main(int argc, char *argv[])
+{
+    FILE         *fin;
+    int           i, f, Nerrs, Terrs, Tbits, verbose;
+    float         aber;
+    struct OFDM  *ofdm;
+
+    if (argc < 2) {
+	fprintf(stderr, "\n");
+	fprintf(stderr, "usage: %s InputOneCharPerBitFile [-v]\n", argv[0]);
+	fprintf(stderr, "\n");
+	exit(1);
+    }
+
+    if (strcmp(argv[1], "-") == 0) fin = stdin;
+    else if ( (fin = fopen(argv[1],"rb")) == NULL ) {
+	fprintf(stderr, "Error opening input file: %s: %s.\n",
+         argv[1], strerror(errno));
+	exit(1);
+    }
+
+    verbose = 0;
+    if (opt_exists(argv, argc, "-v")) {
+        verbose = 1;
+    }
+
+    ofdm = ofdm_create(OFDM_CONFIG_700D);
+    assert(ofdm != NULL);
+    int Nbitsperframe = ofdm_get_bits_per_frame(ofdm);
+    char rx_bits[Nbitsperframe];
+  
+    f = Terrs = Tbits = 0;
+    while (fread(rx_bits, sizeof(char), Nbitsperframe, fin) == Nbitsperframe) {
+        f++;
+        
+        Nerrs = 0;
+        for(i=0; i<Nbitsperframe; i++) {
+            if (test_bits_ofdm[i] != rx_bits[i]) {
+                Nerrs++;
+            }
+        }
+        aber = (float)Nerrs/Nbitsperframe;
+
+        if (aber < 0.2) {
+            Terrs += Nerrs;
+            Tbits += Nbitsperframe;
+        }
+
+        if (verbose) {
+            printf("f: %d Nerrs: %d aber: %3.2f\n", f, Nerrs, aber);
+        }
+        
+        if (fin == stdin) fflush(stdin);
+     }
+    
+    fclose(fin);
+    fprintf(stderr, "BER..: %5.4f Tbits: %5d Terrs: %5d\n", (float)Terrs/Tbits, Tbits, Terrs);
+
+    return 0;
+}
+