punct_convcode.cpp
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#include <itpp/comm/punct_convcode.h>
namespace itpp
{
// --------------------- Punctured_Conv_Code --------------------------------
//------- Protected functions -----------------------
int Punctured_Convolutional_Code::weight(int state, int input, int time)
{
int i, j, temp, out, w = 0, shiftreg = state;
shiftreg = shiftreg | (int(input) << m);
for (j = 0; j < n; j++) {
if (puncture_matrix(j, time) == bin(1)) {
out = 0;
temp = shiftreg & gen_pol(j);
for (i = 0; i < K; i++) {
out ^= (temp & 1);
temp = temp >> 1;
}
w += out;
}
}
return w;
}
int Punctured_Convolutional_Code::weight_reverse(int state, int input, int time)
{
int i, j, temp, out, w = 0, shiftreg = state;
shiftreg = shiftreg | (int(input) << m);
for (j = 0; j < n; j++) {
if (puncture_matrix(j, Period - 1 - time) == bin(1)) {
out = 0;
temp = shiftreg & gen_pol_rev(j);
for (i = 0; i < K; i++) {
out ^= (temp & 1);
temp = temp >> 1;
}
w += out;
}
}
return w;
}
void Punctured_Convolutional_Code::weight(int state, int &w0, int &w1, int time)
{
int i, j, temp, out, shiftreg = state;
w0 = 0;
w1 = 0;
shiftreg = shiftreg | (1 << m);
for (j = 0; j < n; j++) {
if (puncture_matrix(j, time) == bin(1)) {
out = 0;
temp = shiftreg & gen_pol(j);
for (i = 0; i < m; i++) {
out ^= (temp & 1);
temp = temp >> 1;
}
w0 += out;
w1 += out ^(temp & 1);
}
}
}
void Punctured_Convolutional_Code::weight_reverse(int state, int &w0, int &w1, int time)
{
int i, j, temp, out, shiftreg = state;
w0 = 0;
w1 = 0;
shiftreg = shiftreg | (1 << m);
for (j = 0; j < n; j++) {
if (puncture_matrix(j, Period - 1 - time) == bin(1)) {
out = 0;
temp = shiftreg & gen_pol_rev(j);
for (i = 0; i < m; i++) {
out ^= (temp & 1);
temp = temp >> 1;
}
w0 += out;
w1 += out ^(temp & 1);
}
}
}
//------- Public functions -----------------------
void Punctured_Convolutional_Code::set_puncture_matrix(const bmat &pmatrix)
{
it_error_if((pmatrix.rows() != n) || (pmatrix.cols() == 0), "Wrong size of puncture matrix");
puncture_matrix = pmatrix;
Period = puncture_matrix.cols();
int p, j;
total = 0;
for (j = 0; j < n; j++) {
for (p = 0; p < Period; p++)
total = total + (int)(puncture_matrix(j, p));
}
rate = (double)Period / total;
}
void Punctured_Convolutional_Code::encode(const bvec &input, bvec &output)
{
switch (cc_method) {
case Trunc:
encode_trunc(input, output);
break;
case Tail:
encode_tail(input, output);
break;
case Tailbite:
encode_tailbite(input, output);
break;
default:
encode_tail(input, output);
break;
};
}
void Punctured_Convolutional_Code::encode_trunc(const bvec &input, bvec &output)
{
Convolutional_Code::encode_trunc(input, output);
int nn = 0, i, p = 0, j;
for (i = 0; i < int(output.size() / n); i++) {
for (j = 0; j < n; j++) {
if (puncture_matrix(j, p) == bin(1)) {
output(nn) = output(i * n + j);
nn++;
}
}
p = (p + 1) % Period;
}
output.set_size(nn, true);
}
void Punctured_Convolutional_Code::encode_tail(const bvec &input, bvec &output)
{
Convolutional_Code::encode_tail(input, output);
int nn = 0, i, p = 0, j;
for (i = 0; i < int(output.size() / n); i++) {
for (j = 0; j < n; j++) {
if (puncture_matrix(j, p) == bin(1)) {
output(nn) = output(i * n + j);
nn++;
}
}
p = (p + 1) % Period;
}
output.set_size(nn, true);
}
void Punctured_Convolutional_Code::encode_tailbite(const bvec &input, bvec &output)
{
Convolutional_Code::encode_tailbite(input, output);
int nn = 0, i, p = 0, j;
for (i = 0; i < int(output.size() / n); i++) {
for (j = 0; j < n; j++) {
if (puncture_matrix(j, p) == bin(1)) {
output(nn) = output(i * n + j);
nn++;
}
}
p = (p + 1) % Period;
}
output.set_size(nn, true);
}
// --------------- Hard-decision decoding is not implemented --------------------------------
void Punctured_Convolutional_Code::decode(const bvec &, bvec &)
{
it_error("Punctured_Convolutional_Code::decode(bvec, bvec); hard-decision decoding is not implemented");
}
bvec Punctured_Convolutional_Code::decode(const bvec &)
{
it_error("Punctured_Convolutional_Code::decode(bvec, bvec); hard-decision decoding is not implemented");
return bvec();
}
/*
Decode a block of encoded data using specified method
*/
void Punctured_Convolutional_Code::decode(const vec &received_signal, bvec &output)
{
switch (cc_method) {
case Trunc:
decode_trunc(received_signal, output);
break;
case Tail:
decode_tail(received_signal, output);
break;
case Tailbite:
decode_tailbite(received_signal, output);
break;
default:
decode_tail(received_signal, output);
break;
};
}
// Viterbi decoder using TruncLength (=5*K if not specified)
void Punctured_Convolutional_Code::decode_trunc(const vec &received_signal, bvec &output)
{
int nn = 0, i = 0, p = received_signal.size() / total, j;
int temp_size = p * Period * n;
// number of punctured bits in a fraction of the puncture matrix
// correcponding to the end of the received_signal vector
p = received_signal.size() - p * total;
// precise calculation of the number of unpunctured bits
// (in the above fraction of the puncture matrix)
while (p > 0) {
for (j = 0; j < n; j++) {
if (puncture_matrix(j, nn) == bin(1))
p--;
}
nn++;
}
temp_size += n * nn;
if (p != 0) {
it_warning("Punctured_Convolutional_Code::decode(): Improper length of "
"the received punctured block, dummy bits have been added");
}
vec temp(temp_size);
nn = 0;
j = 0;
p = 0;
while (nn < temp.size()) {
if ((puncture_matrix(j, p) == bin(1)) && (i < received_signal.size())) {
temp(nn) = received_signal(i);
i++;
}
else { // insert dummy symbols with the same contribution for 0 and 1
temp(nn) = 0;
}
nn++;
j++;
if (j == n) {
j = 0;
p = (p + 1) % Period;
}
} // while
Convolutional_Code::decode_trunc(temp, output);
}
// Viterbi decoder using TruncLength (=5*K if not specified)
void Punctured_Convolutional_Code::decode_tail(const vec &received_signal, bvec &output)
{
int nn = 0, i = 0, p = received_signal.size() / total, j;
int temp_size = p * Period * n;
// number of punctured bits in a fraction of the puncture matrix
// correcponding to the end of the received_signal vector
p = received_signal.size() - p * total;
// precise calculation of the number of unpunctured bits
// (in the above fraction of the puncture matrix)
while (p > 0) {
for (j = 0; j < n; j++) {
if (puncture_matrix(j, nn) == bin(1))
p--;
}
nn++;
}
temp_size += n * nn;
if (p != 0) {
it_warning("Punctured_Convolutional_Code::decode_tail(): Improper length "
"of the received punctured block, dummy bits have been added");
}
vec temp(temp_size);
nn = 0;
j = 0;
p = 0;
while (nn < temp.size()) {
if ((puncture_matrix(j, p) == bin(1)) && (i < received_signal.size())) {
temp(nn) = received_signal(i);
i++;
}
else { // insert dummy symbols with same contribution for 0 and 1
temp(nn) = 0;
}
nn++;
j++;
if (j == n) {
j = 0;
p = (p + 1) % Period;
}
} // while
Convolutional_Code::decode_tail(temp, output);
}
// Decode a block of encoded data where encode_tailbite has been used. Tries all start states.
void Punctured_Convolutional_Code::decode_tailbite(const vec &received_signal, bvec &output)
{
int nn = 0, i = 0, p = received_signal.size() / total, j;
int temp_size = p * Period * n;
// number of punctured bits in a fraction of the puncture matrix
// correcponding to the end of the received_signal vector
p = received_signal.size() - p * total;
// precise calculation of the number of unpunctured bits
// (in the above fraction of the puncture matrix)
while (p > 0) {
for (j = 0; j < n; j++) {
if (puncture_matrix(j, nn) == bin(1))
p--;
}
nn++;
}
temp_size += n * nn;
if (p != 0) {
it_warning("Punctured_Convolutional_Code::decode_tailbite(): Improper "
"length of the received punctured block, dummy bits have been "
"added");
}
vec temp(temp_size);
nn = 0;
j = 0;
p = 0;
while (nn < temp.size()) {
if ((puncture_matrix(j, p) == bin(1)) && (i < received_signal.size())) {
temp(nn) = received_signal(i);
i++;
}
else { // insert dummy symbols with same contribution for 0 and 1
temp(nn) = 0;
}
nn++;
j++;
if (j == n) {
j = 0;
p = (p + 1) % Period;
}
} // while
Convolutional_Code::decode_tailbite(temp, output);
}
/*
Calculate the inverse sequence
Assumes that encode_tail is used in the encoding process. Returns false if there is an
error in the coded sequence (not a valid codeword). Does not check that the tail forces
the encoder into the zeroth state.
*/
bool Punctured_Convolutional_Code::inverse_tail(const bvec coded_sequence, bvec &input)
{
int state = 0, zero_state, one_state, zero_temp, one_temp, i, j, p = 0, prev_pos = 0, no_symbols;
int block_length = 0;
bvec zero_output(n), one_output(n), temp_output(n);
block_length = coded_sequence.size() * Period / total - m;
it_error_if(block_length <= 0, "The input sequence is to short");
input.set_length(block_length, false); // not include the tail in the output
p = 0;
for (i = 0; i < block_length; i++) {
zero_state = state;
one_state = state | (1 << m);
no_symbols = 0;
for (j = 0; j < n; j++) {
if (puncture_matrix(j, p) == bin(1)) {
zero_temp = zero_state & gen_pol(j);
one_temp = one_state & gen_pol(j);
zero_output(no_symbols) = xor_int_table(zero_temp);
one_output(no_symbols) = xor_int_table(one_temp);
no_symbols++;
}
}
if (coded_sequence.mid(prev_pos, no_symbols) == zero_output.left(no_symbols)) {
input(i) = bin(0);
state = zero_state >> 1;
}
else if (coded_sequence.mid(prev_pos, no_symbols) == one_output.left(no_symbols)) {
input(i) = bin(1);
state = one_state >> 1;
}
else
return false;
prev_pos += no_symbols;
p = (p + 1) % Period;
}
return true;
}
/*
It is possible to do this more efficiently by registrating all (inputs,states,Periods)
that has zero metric (just and with the generators). After that build paths from a input=1 state.
*/
bool Punctured_Convolutional_Code::catastrophic(void)
{
int max_stack_size = 50000;
ivec S_stack(max_stack_size), t_stack(max_stack_size);
int start, S, W0, W1, S0, S1, pos, t = 0;
int stack_pos = -1;
for (pos = 0; pos < Period; pos++) { // test all start positions
for (start = 0; start < (1 << m); start++) {
stack_pos = -1;
S = start;
t = 0;
node1:
if (t > (1 << m) * Period) { return true; }
S0 = next_state(S, 0);
S1 = next_state(S, 1);
weight(S, W0, W1, (pos + t) % Period);
if (W1 > 0) { goto node0; }
if ((W0 == 0) && (S0 == start) && (((pos + t + 1) % Period) == pos)) { return true; }
if ((W0 == 0) && (S0 == 0) && (S != 0)) { return true; }
if ((S0 != 0) && (W0 == 0)) {
stack_pos++;
if (stack_pos >= max_stack_size) {
max_stack_size = 2 * max_stack_size;
S_stack.set_size(max_stack_size, true);
t_stack.set_size(max_stack_size, true);
}
S_stack(stack_pos) = S0;
t_stack(stack_pos) = t + 1;
}
if ((W1 == 0) && (S1 == start) && (((pos + t + 1) % Period) == pos)) { return true; }
S = S1;
t++;
goto node1;
node0:
if (W0 > 0) goto stack;
if ((W0 == 0) && (S0 == start) && (((pos + t + 1) % Period) == pos)) { return true; }
if ((W0 == 0) && (S0 == 0) && (S != 0)) { return true; }
if (S0 != 0) {
S = S0;
t++;
goto node1;
}
else {
goto stack;
}
stack:
if (stack_pos >= 0) {
S = S_stack(stack_pos);
t = t_stack(stack_pos);
stack_pos--;
goto node1;
}
}
}
return false;
}
void Punctured_Convolutional_Code::distance_profile(ivec &dist_prof, int start_time, int dmax, bool reverse)
{
int max_stack_size = 50000;
ivec S_stack(max_stack_size), W_stack(max_stack_size), t_stack(max_stack_size);
int stack_pos = -1, t, S, W, W0, w0, w1;
dist_prof.zeros();
dist_prof += dmax; // just select a big number!
if (reverse)
W = weight_reverse(0, 1, start_time);
else
W = weight(0, 1, start_time);
S = next_state(0, 1); // start from zero state and a one input
t = 0;
dist_prof(0) = W;
node1:
if (reverse)
weight_reverse(S, w0, w1, (start_time + t + 1) % Period);
else
weight(S, w0, w1, (start_time + t + 1) % Period);
if (t < m) {
W0 = W + w0;
if (W0 < dist_prof(m)) { // store node0 (S, W0, and t+1)
stack_pos++;
if (stack_pos >= max_stack_size) {
max_stack_size = 2 * max_stack_size;
S_stack.set_size(max_stack_size, true);
W_stack.set_size(max_stack_size, true);
t_stack.set_size(max_stack_size, true);
}
S_stack(stack_pos) = next_state(S, 0);
W_stack(stack_pos) = W0;
t_stack(stack_pos) = t + 1;
}
}
else goto stack;
W += w1;
if (W > dist_prof(m))
goto stack;
t++;
S = next_state(S, 1);
if (W < dist_prof(t))
dist_prof(t) = W;
if (t == m) goto stack;
goto node1;
stack:
if (stack_pos >= 0) {
// get root node from stack
S = S_stack(stack_pos);
W = W_stack(stack_pos);
t = t_stack(stack_pos);
stack_pos--;
if (W < dist_prof(t))
dist_prof(t) = W;
if (t == m) goto stack;
goto node1;
}
}
int Punctured_Convolutional_Code::fast(Array<ivec> &spectrum, int start_time, int dfree, int no_terms,
int d_best_so_far, bool test_catastrophic)
{
int cat_treshold = (1 << m) * Period;
int i, j, t = 0;
ivec dist_prof(K), dist_prof_rev(K), dist_prof_temp(K);
//calculate distance profile
distance_profile(dist_prof, start_time, dfree);
distance_profile(dist_prof_rev, 0, dfree, true); // for the reverse code
int dist_prof_rev0 = dist_prof_rev(0);
bool reverse = true; // true = use reverse dist_prof
// choose the lowest dist_prof over all periods
for (i = 1; i < Period; i++) {
distance_profile(dist_prof_temp, i, dfree, true);
// switch if new is lower
for (j = 0; j < K; j++) {
if (dist_prof_temp(j) < dist_prof_rev(j)) {
dist_prof_rev(j) = dist_prof_temp(j);
}
}
}
dist_prof_rev0 = dist_prof(0);
dist_prof = dist_prof_rev;
int d = dfree + no_terms - 1;
int max_stack_size = 50000;
ivec S_stack(max_stack_size), W_stack(max_stack_size), b_stack(max_stack_size);
ivec c_stack(max_stack_size), t_stack(max_stack_size);
int stack_pos = -1;
// F1.
int mf = 1, b = 1;
spectrum.set_size(2);
spectrum(0).set_size(dfree + no_terms, 0); // ad
spectrum(1).set_size(dfree + no_terms, 0); // cd
spectrum(0).zeros();
spectrum(1).zeros();
int S, S0, S1, W0, W1, w0, w1, c = 0;
S = next_state(0, 1); // start in zero state and one input
int W = d - dist_prof_rev0;
t = 1;
F2:
S0 = next_state(S, 0);
S1 = next_state(S, 1);
if (reverse) {
weight(S, w0, w1, (start_time + t) % Period);
}
else {
weight_reverse(S, w0, w1, (start_time + t) % Period);
}
W0 = W - w0;
W1 = W - w1;
if (mf < m) goto F6;
//F3:
if (W0 >= 0) {
spectrum(0)(d - W0)++;
spectrum(1)(d - W0) += b;
}
//Test on d_best_so_far
if ((d - W0) < d_best_so_far) { return -1; }
F4:
if ((W1 < dist_prof(m - 1)) || (W < dist_prof(m))) goto F5;
// select node 1
if (test_catastrophic && (W == W1)) {
c++;
if (c > cat_treshold)
return 0;
}
else {
c = 0;
}
W = W1;
S = S1;
t++;
mf = 1;
b++;
goto F2;
F5:
if (stack_pos == -1) goto end;
// get node from stack
S = S_stack(stack_pos);
W = W_stack(stack_pos);
b = b_stack(stack_pos);
c = c_stack(stack_pos);
t = t_stack(stack_pos);
stack_pos--;
mf = 1;
goto F2;
F6:
if (W0 < dist_prof(m - mf - 1)) goto F4;
//F7:
if ((W1 >= dist_prof(m - 1)) && (W >= dist_prof(m))) {
// save node 1
if (test_catastrophic && (stack_pos > 40000))
return 0;
stack_pos++;
if (stack_pos >= max_stack_size) {
max_stack_size = 2 * max_stack_size;
S_stack.set_size(max_stack_size, true);
W_stack.set_size(max_stack_size, true);
b_stack.set_size(max_stack_size, true);
c_stack.set_size(max_stack_size, true);
t_stack.set_size(max_stack_size, true);
}
S_stack(stack_pos) = S1;
W_stack(stack_pos) = W1;
b_stack(stack_pos) = b + 1; // because gone to node 1
c_stack(stack_pos) = c;
t_stack(stack_pos) = t + 1;
}
// select node 0
S = S0;
t++;
if (test_catastrophic && (W == W0)) {
c++;
if (c > cat_treshold)
return false;
}
else {
c = 0;
}
W = W0;
mf++;
goto F2;
end:
return 1;
}
void Punctured_Convolutional_Code::calculate_spectrum(Array<ivec> &spectrum, int dmax, int no_terms)
{
Array<ivec> temp_spectra(2);
spectrum.set_size(2);
spectrum(0).set_size(dmax + no_terms, false);
spectrum(1).set_size(dmax + no_terms, false);
spectrum(0).zeros();
spectrum(1).zeros();
for (int pos = 0; pos < Period; pos++) {
calculate_spectrum(temp_spectra, pos, dmax, no_terms);
spectrum(0) += temp_spectra(0);
spectrum(1) += temp_spectra(1);
}
}
void Punctured_Convolutional_Code::calculate_spectrum(Array<ivec> &spectrum, int time, int dmax, int no_terms, int block_length)
{
imat Ad_states(1 << (K - 1), dmax + no_terms), Cd_states(1 << m, dmax + no_terms);
imat Ad_temp(1 << (K - 1), dmax + no_terms), Cd_temp(1 << m, dmax + no_terms);
ivec mindist(1 << (K - 1)), mindist_temp(1 << m);
spectrum.set_size(2);
spectrum(0).set_size(dmax + no_terms, false);
spectrum(1).set_size(dmax + no_terms, false);
spectrum(0).zeros();
spectrum(1).zeros();
Ad_states.zeros();
Cd_states.zeros();
mindist.zeros();
int wmax = dmax + no_terms;
ivec visited_states(1 << m), visited_states_temp(1 << m);
bool proceede, expand_s1;
int t, d, w0, w1, s, s0, s1 = 0, s_start;
// initial phase. Evolv trellis up to time K.
visited_states.zeros(); // 0 = false
s1 = next_state(0, 1); // Start in state 0 and 1 input
visited_states(s1) = 1; // 1 = true.
w1 = weight(0, 1, time);
Ad_states(s1, w1) = 1;
Cd_states(s1, w1) = 1;
mindist(s1) = w1;
if (block_length > 0) {
s0 = next_state(0, 0);
visited_states(s0) = 1; // 1 = true. Expand also the zero-path
w0 = weight(0, 0, time);
Ad_states(s0, w0) = 1;
Cd_states(s0, w0) = 0;
mindist(s0) = w0;
s_start = 0;
}
else {
s_start = 1;
}
t = 1;
proceede = true;
while (proceede) {
proceede = false;
Ad_temp.zeros();
Cd_temp.zeros();
mindist_temp.zeros();
visited_states_temp.zeros(); //false
for (s = s_start; s < (1 << m); s++) {
if (visited_states(s) == 1) {
if ((mindist(s) >= 0) && (mindist(s) < wmax)) {
proceede = true;
weight(s, w0, w1, (time + t) % Period);
s0 = next_state(s, 0);
for (d = mindist(s); d < (wmax - w0); d++) {
Ad_temp(s0, d + w0) += Ad_states(s, d);
Cd_temp(s0, d + w0) += Cd_states(s, d);
}
if (visited_states_temp(s0) == 0) { mindist_temp(s0) = mindist(s) + w0; }
else { mindist_temp(s0) = ((mindist(s) + w0) < mindist_temp(s0)) ? mindist(s) + w0 : mindist_temp(s0); }
visited_states_temp(s0) = 1; //true
expand_s1 = false;
if ((block_length == 0) || (t < (block_length - (K - 1)))) {
expand_s1 = true;
}
if (expand_s1) {
s1 = next_state(s, 1);
for (d = mindist(s); d < (wmax - w1); d++) {
Ad_temp(s1, d + w1) += Ad_states(s, d);
Cd_temp(s1, d + w1) += Cd_states(s, d) + Ad_states(s, d);
}
if (visited_states_temp(s1) == 0) { mindist_temp(s1) = mindist(s) + w1; }
else { mindist_temp(s1) = ((mindist(s) + w1) < mindist_temp(s1)) ? mindist(s) + w1 : mindist_temp(s1); }
visited_states_temp(s1) = 1; //true
}
}
}
}
Ad_states = Ad_temp;
Cd_states = Cd_temp;
if (block_length == 0) {
spectrum(0) += Ad_temp.get_row(0);
spectrum(1) += Cd_temp.get_row(0);
}
visited_states = visited_states_temp;
mindist = elem_mult(mindist_temp, visited_states);
t++;
if ((t > block_length) && (block_length > 0)) { proceede = false; }
}
if (block_length > 0) {
spectrum(0) = Ad_states.get_row(0);
spectrum(1) = Cd_states.get_row(0);
}
}
} // namespace itpp
itpp::Array
General array class.
Definition array.h:105
itpp::Array::size
int size() const
Returns the number of data elements in the array object.
Definition array.h:155
itpp::Array::set_size
void set_size(int n, bool copy=false)
Resizing an Array<T>.
Definition array.h:257
itpp::Convolutional_Code::rate
double rate
The rate of the code.
Definition convcode.h:429
itpp::Convolutional_Code::next_state
int next_state(const int instate, const int input)
Next state from instate given the input.
Definition convcode.h:374
itpp::Convolutional_Code::encode_tailbite
void encode_tailbite(const bvec &input, bvec &output)
Encode an input binary vector using tailbiting.
Definition convcode.cpp:692
itpp::Convolutional_Code::encode_tail
void encode_tail(const bvec &input, bvec &output)
Encoding that starts and ends in the zero state.
Definition convcode.cpp:662
itpp::Convolutional_Code::K
int K
Constraint length.
Definition convcode.h:413
itpp::Convolutional_Code::decode_tailbite
virtual void decode_tailbite(const vec &received_signal, bvec &output)
Decode a block of encoded data where encode_tailbite has been used.
Definition convcode.cpp:879
itpp::Convolutional_Code::decode_tail
virtual void decode_tail(const vec &received_signal, bvec &output)
Decode a block of encoded data where encode_tail has been used.
Definition convcode.cpp:771
itpp::Convolutional_Code::encode_trunc
void encode_trunc(const bvec &input, bvec &output)
Encode a binary vector starting from the previous encoder state.
Definition convcode.cpp:642
itpp::Convolutional_Code::n
int n
Number of generators.
Definition convcode.h:411
itpp::Convolutional_Code::m
int m
Memory of the encoder.
Definition convcode.h:415
itpp::Convolutional_Code::gen_pol_rev
ivec gen_pol_rev
Generator polynomials for the reverse code.
Definition convcode.h:421
itpp::Convolutional_Code::decode_trunc
virtual void decode_trunc(const vec &received_signal, bvec &output)
Viterbi decoding using truncation of memory (default = 5*K)
Definition convcode.cpp:965
itpp::Convolutional_Code::cc_method
CONVOLUTIONAL_CODE_METHOD cc_method
encoding and decoding method
Definition convcode.h:435
itpp::Convolutional_Code::xor_int_table
bvec xor_int_table
Auxilary table used by the codec.
Definition convcode.h:431
itpp::Convolutional_Code::gen_pol
ivec gen_pol
Generator polynomials.
Definition convcode.h:419
itpp::Punctured_Convolutional_Code::fast
int fast(Array< ivec > &spectrum, int time, int dfree, int no_terms, int d_best_so_far=0, bool test_catastrophic=false)
Cederwall's fast algorithm.
Definition punct_convcode.cpp:589
itpp::Punctured_Convolutional_Code::decode_trunc
void decode_trunc(const vec &received_signal, bvec &output)
Viterbi decoding using truncation of memory (default = 5*K)
Definition punct_convcode.cpp:244
itpp::Punctured_Convolutional_Code::weight_reverse
int weight_reverse(const int state, const int input, int time)
Weight of the reverse code from state with input (0 or 1) at transition time.
Definition punct_convcode.cpp:57
itpp::Punctured_Convolutional_Code::encode_trunc
void encode_trunc(const bvec &input, bvec &output)
Encode a binary vector of inputs starting from state set by the set_state function.
Definition punct_convcode.cpp:154
itpp::Punctured_Convolutional_Code::encode
void encode(const bvec &input, bvec &output)
Encode a binary vector of inputs using specified method.
Definition punct_convcode.cpp:136
itpp::Punctured_Convolutional_Code::puncture_matrix
bmat puncture_matrix
The puncture matrix (n rows and Period columns)
Definition punct_convcode.h:264
itpp::Punctured_Convolutional_Code::calculate_spectrum
void calculate_spectrum(Array< ivec > &spectrum, int dmax, int no_terms)
Calculate spectrum.
Definition punct_convcode.cpp:734
itpp::Punctured_Convolutional_Code::encode_tailbite
void encode_tailbite(const bvec &input, bvec &output)
Encode a binary vector of inputs using tailbiting.
Definition punct_convcode.cpp:190
itpp::Punctured_Convolutional_Code::total
int total
The number of "1" in the puncture matrix.
Definition punct_convcode.h:262
itpp::Punctured_Convolutional_Code::decode_tailbite
void decode_tailbite(const vec &received_signal, bvec &output)
Decode a block of encoded data where encode_tailbite has been used. Tries all start states.
Definition punct_convcode.cpp:345
itpp::Punctured_Convolutional_Code::distance_profile
void distance_profile(ivec &dist_prof, int time, int dmax=100000, bool reverse=false)
Calculate distance profile. If reverse = true calculate for the reverse code instead.
Definition punct_convcode.cpp:516
itpp::Punctured_Convolutional_Code::weight
int weight(const int state, const int input, int time)
The weight of path from state with input (0 or 1) at transition time.
Definition punct_convcode.cpp:38
itpp::Punctured_Convolutional_Code::decode_tail
void decode_tail(const vec &received_signal, bvec &output)
Decode a block of encoded data where encode_tail has been used.
Definition punct_convcode.cpp:294
itpp::Punctured_Convolutional_Code::catastrophic
bool catastrophic(void)
Check if the code is catastrophic. Returns true if catastrophic.
Definition punct_convcode.cpp:455
itpp::Punctured_Convolutional_Code::encode_tail
void encode_tail(const bvec &input, bvec &output)
Encoding that begins and ends in the zero state.
Definition punct_convcode.cpp:172
itpp::Punctured_Convolutional_Code::Period
int Period
The puncture period (i.e. the number of columns in the puncture matrix)
Definition punct_convcode.h:260
itpp::Punctured_Convolutional_Code::decode
virtual void decode(const vec &received_signal, bvec &output)
Viterbi decoding using specified method.
Definition punct_convcode.cpp:224
itpp::Punctured_Convolutional_Code::set_puncture_matrix
void set_puncture_matrix(const bmat &pmatrix)
Set puncture matrix (size n*Period)
Definition punct_convcode.cpp:120
itpp::bin
Binary arithmetic (boolean) class.
Definition binary.h:57
it_error_if
#define it_error_if(t, s)
Abort if t is true.
Definition itassert.h:117
it_error
#define it_error(s)
Abort unconditionally.
Definition itassert.h:126
it_warning
#define it_warning(s)
Display a warning message.
Definition itassert.h:173
itpp::reverse
Vec< T > reverse(const Vec< T > &in)
Reverse the input vector.
Definition matfunc.h:777
itpp::spectrum
vec spectrum(const vec &v, int nfft, int noverlap)
Power spectrum calculation.
Definition sigfun.cpp:267
bmat
Mat< bin > bmat
bin matrix
Definition mat.h:508
itpp
itpp namespace
Definition itmex.h:37
itpp::elem_mult
Mat< Num_T > elem_mult(const Mat< Num_T > &m1, const Mat< Num_T > &m2)
Element wise multiplication of two matrices.
Definition mat.h:1582
punct_convcode.h
Definitions of a Binary Punctured Convolutional Encoder class.

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