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* Fix/Update copyright notices; Add SPDX annotationHarald Welte2017-11-131-0/+2
| | | | | | | | Let's fix some erroneous/accidential references to wrong license, update copyright information where applicable and introduce a SPDX-License-Identifier to all files. Change-Id: I39af26c6aaaf5c926966391f6565fc5936be21af
* doxygen: unify use of \file across the boardNeels Hofmeyr2017-06-231-7/+5
| | | | | | | | | | | | | | | | | Considering the various styles and implications found in the sources, edit scores of files to follow the same API doc guidelines around the doxygen grouping and the \file tag. Many files now show a short description in the generated API doc that was so far only available as C comment. The guidelines and reasoning behind it is documented at https://osmocom.org/projects/cellular-infrastructure/wiki/Guidelines_for_API_documentation In some instances, remove file comments and add to the corresponding group instead, to be shared among several files (e.g. bitvec). Change-Id: Ifa70e77e90462b5eb2b0457c70fd25275910c72b
* doxygen: enable AUTOBRIEF, drop \briefNeels Hofmeyr2017-06-231-4/+4
| | | | | | | | | | Especially for short descriptions, it is annoying to have to type \brief for every single API doc. Drop all \brief and enable the AUTOBRIEF feature of doxygen, which always takes the first sentence of an API doc as the brief description. Change-Id: I11a8a821b065a128108641a2a63fb5a2b1916e87
* core/conv/conv.c: drop useless assignmentVadim Yanitskiy2017-06-131-1/+1
| | | | Change-Id: I8c3aa5ec100abacf93da1493aa134e42bf612206
* update/extend doxygen documentationHarald Welte2017-06-121-3/+2
| | | | | | | | | It's a pity that even with this patch we still are fare away from having the whole API documented. However, at least we have a more solid foundation. Updates not only extend the documentation, but also make sure it is rendered properly in the doxygen HTML. Change-Id: I1344bd1a6869fb00de7c1899a8db93bba9bafce3
* core/conv: implement optimized Viterbi decoderTom Tsou2017-04-111-0/+9
| | | | | | | | | | | | | | | | | | | | Add a separate, faster convolution decoding implementation for rates up to N=4 and constraint lengths of K=5 and K=7, which covers the most GSM code uses. The decoding algorithm exploits the symmetric structure of the Viterbi add-compare-select (ACS) operation - commonly known as the ACS butterfly. This shift-register optimization can be found in the well-known text by Dave Forney. Forney, G.D., "The Viterbi Algorithm," Proc. of the IEEE, March 1973. Implementation is non-architecture specific and improves performance on x86 as well as ARM processors. Existing API is unchanged with optimized code being called internally for supported codes. The original code was relicensed under GPLv2-or-later with permission of copyright holder - Tom Tsou. Change-Id: I74d355274b4176a7d924f91ef3c96912ce338fb2
* misc: Doxygen tweaks: fixed some typos and minor errorsKaterina Barone-Adesi2013-02-151-1/+1
| | | | | Doxygen generates quite a lot of warnings on libosmocore. Some of them are obvious typos - this patch aims to fix such low-hanging fruit.
* doc: Fix the Doxygen section endingsSylvain Munaut2012-04-181-1/+1
| | | | Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
* core/conv: Add utility methods to know length of coded/decoded vectorsSylvain Munaut2011-11-241-0/+34
| | | | Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
* core/conv: Add support for other termination types (trunc & tail biting)Sylvain Munaut2011-11-241-32/+94
| | | | | | | | Note that this breaks the ABI and the low level API. But it shouldn't break the high level API, nor the conv code definitions (because fields default to 0, and for new fields '0' is the previous behavior) Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
* core/conv: Really only consider error for non-zero soft valuesSylvain Munaut2011-11-241-3/+6
| | | | | | | | This should have been done with 1dd7c84733b20ba776510369e9daba1a822c5b44 but somehow was missed and only applied to the 'finish' method and not the 'scan' method. Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
* core/conv: Minor documentation improvementsSylvain Munaut2011-11-241-0/+1
| | | | Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
* freebsd: Fixes for the compilation of libosmocore on FreeBSDHolger Hans Peter Freyther2011-11-091-1/+3
| | | | | | | | | | | alloca.h is not available on FreeBSD, use the default autoconf function to check for it, there is a complete list[1] of what to do for using alloca but let us see how far we get with this test. Include netinet/in.h for the IPv4 and IPv6 socket address. Check for dlopen in libraries and use this instead of linking -dl. [1] http://www.gnu.org/s/hello/manual/autoconf/Particular-Functions.html
* some more doxygen work (include the notion of modules)Harald Welte2011-08-171-0/+33
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* core/conv: Only consider error for non-zero soft valuesSylvain Munaut2011-04-281-3/+6
| | | | | | | | | | | | If the input value is '0' it should not really affect the error since it's just an indecisive bit. We accept this either an internal '0' (generated via puncture) or as an external '0' (generated via an external puncturing scheme). A real received bit should never be '0', it's always gonna be closer to 1 or the other value ... (thanks to mad@auth.se on the ML for the idea) Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
* core/conv: Add some generic code for convolutional coding/decodingSylvain Munaut2011-04-261-0/+493
Far from perfect but suits our need thus far. The viterbi with softbit input is quite cpu-intensive. Since most received bursts are often mostly error free, you could use a less cpu intensive algorithm (Fano ?) and with hard bit input. Then only switch to viterbi soft bit input if the channel is bad enough to justify it. Soft output is not implemented as its usefulness for the block coding is limited. Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
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