GNU Radio 3.6.4.1 C++ API
digital_ofdm_frame_sink.h
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1 /* -*- c++ -*- */
2 /*
3  * Copyright 2007,2011 Free Software Foundation, Inc.
4  *
5  * This file is part of GNU Radio
6  *
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
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14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15  * GNU General Public License for more details.
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22 
23 #ifndef INCLUDED_DIGITAL_OFDM_FRAME_SINK_H
24 #define INCLUDED_DIGITAL_OFDM_FRAME_SINK_H
25 
26 #include <digital_api.h>
27 #include <gr_sync_block.h>
28 #include <gr_msg_queue.h>
29 
32 
34 digital_make_ofdm_frame_sink (const std::vector<gr_complex> &sym_position,
35  const std::vector<unsigned char> &sym_value_out,
36  gr_msg_queue_sptr target_queue, unsigned int occupied_tones,
37  float phase_gain=0.25, float freq_gain=0.25*0.25/4.0);
38 
39 /*!
40  * \brief Takes an OFDM symbol in, demaps it into bits of 0's and 1's, packs
41  * them into packets, and sends to to a message queue sink.
42  * \ingroup sink_blk
43  * \ingroup ofdm_blk
44  *
45  * NOTE: The mod input parameter simply chooses a pre-defined demapper/slicer. Eventually,
46  * we want to be able to pass in a reference to an object to do the demapping and slicing
47  * for a given modulation type.
48  */
50 {
52  digital_make_ofdm_frame_sink (const std::vector<gr_complex> &sym_position,
53  const std::vector<unsigned char> &sym_value_out,
54  gr_msg_queue_sptr target_queue, unsigned int occupied_tones,
55  float phase_gain, float freq_gain);
56 
57  private:
58  enum state_t {STATE_SYNC_SEARCH, STATE_HAVE_SYNC, STATE_HAVE_HEADER};
59 
60  static const int MAX_PKT_LEN = 4096;
61  static const int HEADERBYTELEN = 4;
62 
63  gr_msg_queue_sptr d_target_queue; // where to send the packet when received
64  state_t d_state;
65  unsigned int d_header; // header bits
66  int d_headerbytelen_cnt; // how many so far
67 
68  unsigned char *d_bytes_out; // hold the current bytes produced by the demapper
69 
70  unsigned int d_occupied_carriers;
71  unsigned int d_byte_offset;
72  unsigned int d_partial_byte;
73 
74  unsigned char d_packet[MAX_PKT_LEN]; // assembled payload
75  int d_packetlen; // length of packet
76  int d_packet_whitener_offset; // offset into whitener string to use
77  int d_packetlen_cnt; // how many so far
78 
79  gr_complex * d_derotated_output; // Pointer to output stream to send deroated symbols out
80 
81  std::vector<gr_complex> d_sym_position;
82  std::vector<unsigned char> d_sym_value_out;
83  std::vector<gr_complex> d_dfe;
84  unsigned int d_nbits;
85 
86  unsigned char d_resid;
87  unsigned int d_nresid;
88  float d_phase;
89  float d_freq;
90  float d_phase_gain;
91  float d_freq_gain;
92  float d_eq_gain;
93 
94  std::vector<int> d_subcarrier_map;
95 
96  protected:
97  digital_ofdm_frame_sink(const std::vector<gr_complex> &sym_position,
98  const std::vector<unsigned char> &sym_value_out,
99  gr_msg_queue_sptr target_queue, unsigned int occupied_tones,
100  float phase_gain, float freq_gain);
101 
102  void enter_search();
103  void enter_have_sync();
104  void enter_have_header();
105 
106  bool header_ok()
107  {
108  // confirm that two copies of header info are identical
109  return ((d_header >> 16) ^ (d_header & 0xffff)) == 0;
110  }
111 
112  unsigned char slicer(const gr_complex x);
113  unsigned int demapper(const gr_complex *in,
114  unsigned char *out);
115 
116  bool set_sym_value_out(const std::vector<gr_complex> &sym_position,
117  const std::vector<unsigned char> &sym_value_out);
118 
119  public:
121 
122  int work(int noutput_items,
123  gr_vector_const_void_star &input_items,
124  gr_vector_void_star &output_items);
125 };
126 
127 #endif /* INCLUDED_GR_OFDM_FRAME_SINK_H */