3 * Copyright 2005,2006 Free Software Foundation, Inc.
5 * This file is part of GNU Radio
7 * GNU Radio is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2, or (at your option)
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13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with GNU Radio; see the file COPYING. If not, write to
19 * the Free Software Foundation, Inc., 51 Franklin Street,
20 * Boston, MA 02110-1301, USA.
23 #ifndef INCLUDED_GR_OFDM_FRAME_SINK_H
24 #define INCLUDED_GR_OFDM_FRAME_SINK_H
26 #include <gr_sync_block.h>
27 #include <gr_msg_queue.h>
29 class gr_ofdm_frame_sink;
30 typedef boost::shared_ptr<gr_ofdm_frame_sink> gr_ofdm_frame_sink_sptr;
32 gr_ofdm_frame_sink_sptr
33 gr_make_ofdm_frame_sink (gr_msg_queue_sptr target_queue, unsigned int occupied_tones);
36 * \brief Given a stream of bits and access_code flags, assemble packets.
39 * input: stream of bytes from gr_correlate_access_code_bb
40 * output: none. Pushes assembled packet into target queue
42 * The framer expects a fixed length header of 2 16-bit shorts
43 * containing the payload length, followed by the payload. If the
44 * 2 16-bit shorts are not identical, this packet is ignored. Better
47 * The input data consists of bytes that have two bits used.
48 * Bit 0, the LSB, contains the data bit.
49 * Bit 1 if set, indicates that the corresponding bit is the
50 * the first bit of the packet. That is, this bit is the first
51 * one after the access code.
53 class gr_ofdm_frame_sink : public gr_sync_block
55 friend gr_ofdm_frame_sink_sptr
56 gr_make_ofdm_frame_sink (gr_msg_queue_sptr target_queue, unsigned int occupied_tones);
59 enum state_t {STATE_SYNC_SEARCH, STATE_HAVE_SYNC, STATE_HAVE_HEADER};
61 static const int MAX_PKT_LEN = 4096;
62 static const int HEADERBYTELEN = 4;
64 gr_msg_queue_sptr d_target_queue; // where to send the packet when received
66 unsigned int d_header; // header bits
67 int d_headerbytelen_cnt; // how many so far
69 unsigned char *d_bytes_out; // hold the current bytes produced by the demapper
71 unsigned int d_occupied_carriers;
72 unsigned int d_byte_offset;
73 unsigned int d_partial_byte;
75 unsigned char d_packet[MAX_PKT_LEN]; // assembled payload
76 int d_packetlen; // length of packet
77 int d_packet_whitener_offset; // offset into whitener string to use
78 int d_packetlen_cnt; // how many so far
81 gr_ofdm_frame_sink(gr_msg_queue_sptr target_queue, unsigned int occupied_tones);
84 void enter_have_sync();
85 void enter_have_header();
89 // confirm that two copies of header info are identical
90 return ((d_header >> 16) ^ (d_header & 0xffff)) == 0;
93 unsigned char bpsk_slicer(gr_complex x);
94 unsigned int bpsk_demapper(const gr_complex *in,
98 ~gr_ofdm_frame_sink();
100 int work(int noutput_items,
101 gr_vector_const_void_star &input_items,
102 gr_vector_void_star &output_items);
105 #endif /* INCLUDED_GR_OFDM_FRAME_SINK_H */