GNU Radio 3.7.1 C++ API
packet_sink.h
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00001 /* -*- c++ -*- */
00002 /*
00003  * Copyright 2005,2012 Free Software Foundation, Inc.
00004  *
00005  * This file is part of GNU Radio
00006  *
00007  * GNU Radio is free software; you can redistribute it and/or modify
00008  * it under the terms of the GNU General Public License as published by
00009  * the Free Software Foundation; either version 3, or (at your option)
00010  * any later version.
00011  *
00012  * GNU Radio is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015  * GNU General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU General Public License
00018  * along with GNU Radio; see the file COPYING.  If not, write to
00019  * the Free Software Foundation, Inc., 51 Franklin Street,
00020  * Boston, MA 02110-1301, USA.
00021  */
00022 
00023 #ifndef INCLUDED_GR_PACKET_SINK_H
00024 #define INCLUDED_GR_PACKET_SINK_H
00025 
00026 #include <gnuradio/digital/api.h>
00027 #include <gnuradio/sync_block.h>
00028 #include <gnuradio/msg_queue.h>
00029 
00030 namespace gr {
00031   namespace digital {
00032 
00033     /*!
00034      * \brief process received bits looking for packet sync, header,
00035      * and process bits into packet
00036      * \ingroup packet_operators_blk
00037      *
00038      * \details
00039      * input: stream of symbols to be sliced.
00040      * 
00041      * output: none. Pushes assembled packet into target queue
00042      *
00043      * The packet sink takes in a stream of binary symbols that are
00044      * sliced around 0. The bits are then checked for the \p
00045      * sync_vector to determine find and decode the packet. It then
00046      * expects a fixed length header of 2 16-bit shorts containing the
00047      * payload length, followed by the payload. If the 2 16-bit shorts
00048      * are not identical, this packet is ignored. Better algs are
00049      * welcome.
00050      *
00051      * This block is not very useful anymore as it only works with
00052      * 2-level modulations such as BPSK or GMSK. The block can
00053      * generally be replaced with a correlate access code and frame
00054      * sink blocks.
00055      */
00056     class DIGITAL_API packet_sink : virtual public sync_block
00057     {
00058     public:
00059       // gr::digital::packet_sink::sptr
00060       typedef boost::shared_ptr<packet_sink> sptr;
00061 
00062       /*!
00063        * Make a packet_sink block.
00064        *
00065        * \param sync_vector The synchronization vector as a vector of 1's and 0's.
00066        * \param target_queue The message queue that packets are sent to.
00067        * \param threshold Number of bits that can be incorrect in the \p sync_vector.
00068        */
00069       static sptr make(const std::vector<unsigned char>& sync_vector,
00070                        msg_queue::sptr target_queue,
00071                        int threshold=-1);
00072 
00073       //! return true if we detect carrier
00074       virtual bool carrier_sensed() const = 0;
00075     };
00076 
00077   } /* namespace digital */
00078 } /* namespace gr */
00079 
00080 #endif /* INCLUDED_GR_PACKET_SINK_H */