viterbi decoder: add viterbi decoder base class

Add a viterbi decoder base class that viterbi decoder implementations can inherit from.
2016-11-07 15:00:30 -05:00
parent 9cf628359b
commit 528536e3f2
7 changed files with 185 additions and 240 deletions
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2016 Bastian Bloessl <bloessl@ccs-labs.org>
+ *
+ * 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
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * 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 General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "base.h"
+#include <cstring>
+#include <iostream>
+
+using namespace gr::ieee802_11;
+
+base::base() :
+	d_store_pos(0) {
+}
+
+base::~base() {
+}
+
+uint8_t*
+base::depuncture(uint8_t *in) {
+
+	int count;
+	int n_cbps = d_ofdm->n_cbps;
+	uint8_t *depunctured;
+
+	if (d_ntraceback == 5) {
+		count = d_frame->n_sym * n_cbps;
+		depunctured = in;
+
+	} else {
+		depunctured = d_depunctured;
+		count = 0;
+		for(int i = 0; i < d_frame->n_sym; i++) {
+			for(int k = 0; k < n_cbps; k++) {
+				while (d_depuncture_pattern[count % (2 * d_k)] == 0) {
+					depunctured[count] = 2;
+					count++;
+				}
+
+				// Insert received bits
+				depunctured[count] = in[i * n_cbps + k];
+				count++;
+
+				while (d_depuncture_pattern[count % (2 * d_k)] == 0) {
+					depunctured[count] = 2;
+					count++;
+				}
+			}
+		}
+	}
+
+	return depunctured;
+}
+
+/* Parity lookup table */
+const unsigned char base::PARTAB[256] = {
+	0, 1, 1, 0, 1, 0, 0, 1,
+	1, 0, 0, 1, 0, 1, 1, 0,
+	1, 0, 0, 1, 0, 1, 1, 0,
+	0, 1, 1, 0, 1, 0, 0, 1,
+	1, 0, 0, 1, 0, 1, 1, 0,
+	0, 1, 1, 0, 1, 0, 0, 1,
+	0, 1, 1, 0, 1, 0, 0, 1,
+	1, 0, 0, 1, 0, 1, 1, 0,
+	1, 0, 0, 1, 0, 1, 1, 0,
+	0, 1, 1, 0, 1, 0, 0, 1,
+	0, 1, 1, 0, 1, 0, 0, 1,
+	1, 0, 0, 1, 0, 1, 1, 0,
+	0, 1, 1, 0, 1, 0, 0, 1,
+	1, 0, 0, 1, 0, 1, 1, 0,
+	1, 0, 0, 1, 0, 1, 1, 0,
+	0, 1, 1, 0, 1, 0, 0, 1,
+	1, 0, 0, 1, 0, 1, 1, 0,
+	0, 1, 1, 0, 1, 0, 0, 1,
+	0, 1, 1, 0, 1, 0, 0, 1,
+	1, 0, 0, 1, 0, 1, 1, 0,
+	0, 1, 1, 0, 1, 0, 0, 1,
+	1, 0, 0, 1, 0, 1, 1, 0,
+	1, 0, 0, 1, 0, 1, 1, 0,
+	0, 1, 1, 0, 1, 0, 0, 1,
+	0, 1, 1, 0, 1, 0, 0, 1,
+	1, 0, 0, 1, 0, 1, 1, 0,
+	1, 0, 0, 1, 0, 1, 1, 0,
+	0, 1, 1, 0, 1, 0, 0, 1,
+	1, 0, 0, 1, 0, 1, 1, 0,
+	0, 1, 1, 0, 1, 0, 0, 1,
+	0, 1, 1, 0, 1, 0, 0, 1,
+	1, 0, 0, 1, 0, 1, 1, 0,
+};
+
+const unsigned char base::PUNCTURE_1_2[2] = {1, 1};
+const unsigned char base::PUNCTURE_2_3[4] = {1, 1, 1, 0};
+const unsigned char base::PUNCTURE_3_4[6] = {1, 1, 1, 0, 0, 1};