1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
/* -*- c++ -*- */
/*
* Copyright 2004 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* GNU Radio 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, or (at your option)
* any later version.
*
* GNU Radio 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 GNU Radio; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
/*
* config.h is generated by configure. It contains the results
* of probing for features, options etc. It should be the first
* file included in your .cc file.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gnuradio/io_signature.h>
#include "ofdm_sampler_impl.h"
namespace gr {
namespace dab {
ofdm_sampler::sptr
ofdm_sampler::make(unsigned int fft_length, unsigned int cp_length, unsigned int symbols_per_frame,unsigned int gap)
{
return gnuradio::get_initial_sptr
(new ofdm_sampler_impl(fft_length, cp_length, symbols_per_frame, gap));
}
ofdm_sampler_impl::ofdm_sampler_impl(unsigned int fft_length, unsigned int cp_length, unsigned int symbols_per_frame,unsigned int gap)
: gr::block("ofdm_sampler",
gr::io_signature::make (1, 1, sizeof(gr_complex)),
gr::io_signature::make (1, 1, sizeof(gr_complex)*fft_length)),
d_state(STATE_NS), d_pos(0), d_fft_length(fft_length), d_cp_length(cp_length), d_symbols_per_frame(symbols_per_frame), d_sym_nr(0), d_gap(gap), d_gap_left(0)
{
assert(gap<=cp_length);
set_relative_rate(1/float(fft_length+cp_length));
set_tag_propagation_policy(TPP_DONT);
}
void
ofdm_sampler_impl::forecast (int noutput_items, gr_vector_int &ninput_items_required)
{
int in_req = d_fft_length+d_cp_length-d_gap;
// int in_req = noutput_items * d_fft_length;
unsigned ninputs = ninput_items_required.size ();
for (unsigned i = 0; i < ninputs; i++)
ninput_items_required[i] = in_req;
// printf("dab_ofdm_sampler forecast: noutput_items: %d in_req: %d\n", noutput_items, in_req);
}
int
ofdm_sampler_impl::general_work (int noutput_items,
gr_vector_int &ninput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items)
{
/* partially adapted from gr_ofdm_sampler.cc */
const gr_complex *iptr = (const gr_complex *) input_items[0];
gr_complex *optr = (gr_complex *) output_items[0];
std::vector<int> tag_positions;
int next_tag_position = -1;
int next_tag_position_index = -1;
// Get all stream tags with key "dab_sync", and make a vector of the positions.
// "next_tag_position" contains the position within "iptr where the next "dab_sync" stream tag is found
std::vector<tag_t> tags;
get_tags_in_range(tags, 0, nitems_read(0), nitems_read(0) + ninput_items[0], pmt::mp("dab_sync"));
for(int i=0;i<tags.size();i++) {
int current;
current = tags[i].offset - nitems_read(0);
tag_positions.push_back(current);
next_tag_position_index = 0;
}
if(next_tag_position_index >= 0) {
next_tag_position = tag_positions[next_tag_position_index];
}
unsigned int n_in = ninput_items[0];
unsigned int index = 0;
unsigned int out = 0;
switch (d_state) {
case(STATE_NS):
{
d_pos = 0;
d_sym_nr = 0;
d_gap_left = 0;
bool trigger_now = false;
while (index<n_in) {
if (next_tag_position == index) { /* trigger */
next_tag_position_index++;
if (next_tag_position_index == tag_positions.size()) {
next_tag_position_index = -1;
next_tag_position = -1;
}
else {
next_tag_position = tag_positions[next_tag_position_index];
}
// Action when stream tags is found:
trigger_now = true;
break;
//
}
index++;
}
if (trigger_now)
d_state = STATE_CP;
else
break;
}
case(STATE_CP):
while (d_gap_left > 0 && index<n_in) { /* is there a gap left from the previous symbol? */
index++;
d_gap_left--;
}
while (index<n_in && d_pos < d_cp_length-d_gap) {
index++;
d_pos++;
}
if (d_pos == d_cp_length-d_gap)
d_state = STATE_SYM;
else
break;
case(STATE_SYM):
if (index + d_fft_length <= n_in) {
memcpy(&optr[out], &iptr[index], d_fft_length*sizeof(gr_complex));
d_sym_nr++;
index += d_fft_length;
d_pos = 0;
/* first symbol in frame? */
if (d_sym_nr==1) // A stream tag called "first" is added for the first symbol in frame:
add_item_tag(0, nitems_written(0) + out, pmt::intern("first"), pmt::intern(""), pmt::intern("ofdm_sampler"));
out++;
/* last symbol in frame? */
if (d_sym_nr == d_symbols_per_frame) {
d_state = STATE_NS;
} else {
d_state = STATE_CP;
d_gap_left = d_gap;
}
}
break;
}
consume_each(index);
return out;
}
}
}
|
