This GNU Radio component implements (will implement) common radiopager
signaling protocols such as POCSAG and FLEX.

Current status (9/13/06):

FLEX receiving is in mid-stream of implemention.

pager.slicer_fb()       Accepts a complex baseband downconverted channel 
                        and outputs 4-level FSK symbols [0-3] as bytes.
			This may migrate into gnuradio-core at some point.

pager.flex_deframer()   Accepts a symbol stream from slicer_fb() and
                        outputs received 32-bit FLEX codewords for each
                        defined phase.  Auto adjusts for 1600 or 3200 bps, 
                        and 2 or 4 level FSK encoding based on received
                        synchronization word.  The sync portion of this
                        block may factor out into its own block for
                        purposes of clarity and code complexity.

pager.bch3221_ecd()     (not yet implemented) Accepts a stream of 32-bit
                        FLEX codewords and applies BCH (32,21) error
                        detection/correction (up to 2 bits), the emits
                        corrected stream. This may be absorbed into the
                        deframer at some point.

pager.message_decode()  (not yet implemented) Accepts a stream of 32-bit
                        FLEX codewords and separates individual paging
                        messages into output stream as bytes.

pager.flex_decode()     Combines the above blocks correctly to convert
                        from downconverted baseband to pager messages

usrp_flex.py            Instantiates USRP receive chain to receive FLEX
                        protocol pages.  See command-line help for options.
                        This will probably make it into gnuradio-examples.

Johnathan Corgan
jcorgan@aeinet.com