diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/doxygen/Doxyfile.in | 3 | ||||
| -rw-r--r-- | docs/doxygen/other/group_defs.dox | 13 | ||||
| -rw-r--r-- | docs/doxygen/other/main_page.dox | 7 | ||||
| -rw-r--r-- | docs/doxygen/other/pfb_intro.dox | 82 |
4 files changed, 95 insertions, 10 deletions
diff --git a/docs/doxygen/Doxyfile.in b/docs/doxygen/Doxyfile.in index 1f544e5bd..356ababfe 100644 --- a/docs/doxygen/Doxyfile.in +++ b/docs/doxygen/Doxyfile.in @@ -587,7 +587,6 @@ EXCLUDE = @abs_top_builddir@/docs/doxygen/html \ @abs_top_builddir@/docs/doxygen/xml-swig \ @abs_top_builddir@/docs/doxygen/other/doxypy.py \ @abs_top_builddir@/dtools \ - @abs_top_srcdir@/gcell/ibm \ @abs_top_builddir@/gnuradio-core/src/lib/bug_work_around_6.cc \ @abs_top_builddir@/gnuradio-core/src/lib/filter/assembly.h \ @abs_top_builddir@/gnuradio-core/src/lib/filter/generate_all.py \ @@ -1308,7 +1307,7 @@ SEARCH_INCLUDES = YES # contain include files that are not input files but should be processed by # the preprocessor. -INCLUDE_PATH = +INCLUDE_PATH = @top_builddir@/gruel/src/lib/pmt/ # You can use the INCLUDE_FILE_PATTERNS tag to specify one or more wildcard # patterns (like *.h and *.hpp) to filter out the header-files in the diff --git a/docs/doxygen/other/group_defs.dox b/docs/doxygen/other/group_defs.dox index 6f2e1ac7f..6288d1f0a 100644 --- a/docs/doxygen/other/group_defs.dox +++ b/docs/doxygen/other/group_defs.dox @@ -27,6 +27,11 @@ /*! \defgroup misc_blk Miscellaneous Blocks */ /*! \defgroup slicedice_blk Slicing and Dicing Streams */ /*! \defgroup vocoder_blk Voice Encoders and Decoders */ +/*! \defgroup digital Digital Modulation Blocks */ +/*! \defgroup qtgui_blk QT Graphical Interfaces */ +/*! \defgroup uhd_blk UHD Interface */ +/*! \defgroup audio_blk Audio Interface */ +/*! \defgroup pfb_blk Polyphase Filterbank */ /*! * \defgroup base_blk Base classes for GR Blocks @@ -66,12 +71,4 @@ /*! \defgroup usrp USRP */ /*! \defgroup usrp2 USRP2 */ -/*! - * \defgroup gcell gcell: Cell Broadband Engine SPE Scheduler & RPC Mechanism - * - * For additional information please see the - * <a href="http://gnuradio.org/trac/wiki/Gcell">gcell wiki page</a> - * and <a href="http://comsec.com/papers/gcell-sdrf-2008.pdf">gcell-sdrf-2008.pdf</a>. - */ - /*! \defgroup hardware Misc Hardware Control */ diff --git a/docs/doxygen/other/main_page.dox b/docs/doxygen/other/main_page.dox index 43fcbf67a..7d78bbbbb 100644 --- a/docs/doxygen/other/main_page.dox +++ b/docs/doxygen/other/main_page.dox @@ -9,4 +9,11 @@ provide unified documentation for the C++ parts of the system and the parts written in Python (mostly hierarchical blocks). Until this gets worked out, please bear with us, or better yet, solve it for us! +More details on packages in GNU Radio: +\li \ref page_audio +\li \ref page_digital +\li \ref page_qtgui +\li \ref page_uhd +\li \ref page_vocoder +\li \ref page_pfb */ diff --git a/docs/doxygen/other/pfb_intro.dox b/docs/doxygen/other/pfb_intro.dox new file mode 100644 index 000000000..8b82d96d7 --- /dev/null +++ b/docs/doxygen/other/pfb_intro.dox @@ -0,0 +1,82 @@ +/*! \page page_pfb Polyphase Filterbanks + +\section Introduction + +Polyphase filterbanks (PFB) are a very powerful set of filtering tools +that can efficiently perform many multi-rate signal processing +tasks. GNU Radio has a set of polyphase filterbank blocks to be used +in all sorts of applications. These blocks and their documentation can +be found in \ref pfb_blk. + +\section Usage + +See the documentation for the individual blocks for details about what +they can do and how they should be used. Furthermore, there are +examples for these blocks in <b>gnuradio-examples/python/pfb</b>. + +The main issue when using the PFB blocks is defining the prototype +filter, which is passed to all of the blocks as a vector of \p +taps. The taps from the prototype filter which get partitioned among +the \p N channels of the channelizer. + +An example of creating a set of filter taps for a PFB channelizer is +found on line 49 of <b>gnuradio-examples/python/pfb/channelizer.py</b> +and reproduced below. Notice that the sample rate is the sample rate +at the input to the channelizer while the bandwidth and transition +width are defined for the channel bandwidths. This makes a fairly long +filter that is then split up between the \p N channels of the PFB. + +\code + self._fs = 9000 # input sample rate + self._M = 9 # Number of channels to channelize + + self._taps = gr.firdes.low_pass_2(1, self._fs, 475.50, 50, + attenuation_dB=100, + window=gr.firdes.WIN_BLACKMAN_hARRIS) +\endcode + +In this example, the signal into the channelizer is sampled at 9 ksps +(complex, so 9 kHz of bandwidth). The filter uses 9 channels, so each +output channel will have a bandwidth and sample rate of 1 kHz. We want +to pass most of the channel, so we define the channel bandwidth to be +a low pass filter with a bandwidth of 475.5 Hz and a transition +bandwidth of 50 Hz, but we have defined this using a sample rate of +the original 9 kHz. The prototype filter has 819 taps to be divided up +between the 9 channels, so each channel uses 91 taps. This is probably +over-kill for a channelizer, and we could reduce the amount of taps +per channel to a couple of dozen with no ill effects. + +The basic rule when defining a set of taps for a PFB block is to think +about the filter running at the highest rate it will see while the +bandwidth is defined for the size of the channels. In the channelizer +case, the highest rate is defined as the rate of the incoming signal, +but in other PFB blocks, this is not so obvious. + +Two very useful blocks to use are the arbitrary resampler and the +clock synchronizer (for PAM signals). These PFBs are defined with a +set number of filters based on the fidelity required from them, not +the rate changes. By default, the \p filter_size is set to 32 for +these blocks, which is a reasonable default for most tasks. Because +the PFB uses this number of filters in the filterbank, the maximum +rate of the bank is defined from this (see the theory of a polyphase +interpolator for a justification of this). So the prototype filter is +defined to use a sample rate of \p filter_size times the signal's +sampling rate. + +A helpful wrapper for the arbitrary resampler is found in +<b>gnuradio-core/src/python/gnuradio/blks2impl/pfb_arb_resampler.py</b>, +which is exposed in Python as <b>blks2.pfb_arb_resampler_ccf</b> and +<b>blks2.pfb_arb_resampler_fff</b>. This block is set up so that the +user only needs to pass it the real number \p rate as the resampling +rate. With just this information, this hierarchical block +automatically creates a filter that fully passes the signal bandwidth +being resampled but does not pass any out-of-band noise. See the code +for this block for details of how the filter is constructed. + +Of course, a user can create his or her own taps and use them in the +arbitrary resampler for more specific requirements. Some of the UHD +examples (<b>gr-uhd/examples</b>) use this ability to create a +received matched filter or channel filter that also resamples the +signal. + +*/ |