GNU Radio 3.6.5.1 C++ API
ofdm_frame_equalizer_vcvc.h
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1 /* -*- c++ -*- */
2 /* Copyright 2012 Free Software Foundation, Inc.
3  *
4  * This file is part of GNU Radio
5  *
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7  * it under the terms of the GNU General Public License as published by
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21 
22 
23 #ifndef INCLUDED_OFDM_FRAME_EQUALIZER_VCVC_H
24 #define INCLUDED_OFDM_FRAME_EQUALIZER_VCVC_H
25 
27 #include <digital/api.h>
28 #include <gr_tagged_stream_block.h>
29 
30 namespace gr {
31  namespace digital {
32 
33  /*!
34  * \brief OFDM frame equalizer
35  * \ingroup ofdm_blk
36  *
37  * This does two things:
38  * First, it removes the coarse carrier offset. If a tag is found on the first
39  * item with the key 'ofdm_sync_carr_offset', this is interpreted as the coarse
40  * frequency offset in number of carriers.
41  * Next, it performs equalization in one or two dimensions on a tagged OFDM frame.
42  * The actual equalization is done by a ofdm_frame_equalizer object, outside of
43  * the block.
44  *
45  * Note that the tag with the coarse carrier offset is not removed. Blocks
46  * downstream from this block must not attempt to also correct this offset.
47  *
48  * Input: a tagged series of OFDM symbols.
49  * Output: The same as the input, but equalized and frequency-corrected.
50  */
52  {
53  public:
55 
56  /*!
57  * \param equalizer The equalizer object that will do the actual work
58  * \param cp_len Length of the cyclic prefix in samples (required to correct the frequency offset)
59  * \param len_tag_key Length tag key
60  * \param propagate_channel_state If true, the channel state after the last symbol
61  * will be added to the first symbol as a tag
62  * \param fixed_frame_len Set if the frame length is fixed throughout,
63  * helps with book keeping.
64  */
65  static sptr make(
67  int cp_len,
68  const std::string &len_tag_key="frame_len",
69  bool propagate_channel_state=false,
70  int fixed_frame_len=0
71  );
72  };
73 
74  } // namespace digital
75 } // namespace gr
76 
77 #endif /* INCLUDED_OFDM_FRAME_EQUALIZER_VCVC_H */
78