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| author | Johnathan Corgan <johnathan@corganlabs.com> | 2015-12-07 16:15:31 -0800 |
|---|---|---|
| committer | Johnathan Corgan <johnathan@corganlabs.com> | 2015-12-07 16:15:31 -0800 |
| commit | 422271f1e025bd1835e4a7ee68e2a60e23167b45 (patch) | |
| tree | f49812df4a01de3d40af40e80ee9b6d62db6064c /gr-fec/python/fec/polar/decoder.py | |
| parent | a96c1dd97ecb6ca9a40522d297df27bbdeca5d7f (diff) | |
| parent | 9ac7203fffb37fd456b82b737a71d4c7a1607b06 (diff) | |
Merge remote-tracking branch 'jdemel/polar-systematic'
Diffstat (limited to 'gr-fec/python/fec/polar/decoder.py')
| -rw-r--r-- | gr-fec/python/fec/polar/decoder.py | 75 |
1 files changed, 52 insertions, 23 deletions
diff --git a/gr-fec/python/fec/polar/decoder.py b/gr-fec/python/fec/polar/decoder.py index ae62943275..8748d284f7 100644 --- a/gr-fec/python/fec/polar/decoder.py +++ b/gr-fec/python/fec/polar/decoder.py @@ -202,6 +202,33 @@ class PolarDecoder(PolarCommon): data = np.packbits(data) return data + def _extract_info_bits_reversed(self, y): + info_bit_positions_reversed = self._vector_bit_reversed(self.info_bit_position, self.power) + return y[info_bit_positions_reversed] + + def decode_systematic(self, data): + if not len(data) == self.N: + raise ValueError("len(data)={0} is not equal to n={1}!".format(len(data), self.N)) + # data = self._reverse_bits(data) + data = self._lr_sc_decoder_efficient(data) + data = self._encode_natural_order(data) + data = self._extract_info_bits_reversed(data) + return data + + +def test_systematic_decoder(): + ntests = 1000 + n = 16 + k = 8 + frozenbitposition = np.array((0, 1, 2, 3, 4, 5, 8, 9), dtype=int) + encoder = PolarEncoder(n, k, frozenbitposition) + decoder = PolarDecoder(n, k, frozenbitposition) + for i in range(ntests): + bits = np.random.randint(2, size=k) + y = encoder.encode_systematic(bits) + u_hat = decoder.decode_systematic(y) + assert (bits == u_hat).all() + def test_reverse_enc_dec(): n = 16 @@ -240,29 +267,31 @@ def compare_decoder_impls(): def main(): - power = 3 - n = 2 ** power - k = 4 - frozenbits = np.zeros(n - k, dtype=int) - frozenbitposition = np.array((0, 1, 2, 4), dtype=int) - frozenbitposition4 = np.array((0, 1), dtype=int) - - - encoder = PolarEncoder(n, k, frozenbitposition, frozenbits) - decoder = PolarDecoder(n, k, frozenbitposition, frozenbits) - - bits = np.ones(k, dtype=int) - print "bits: ", bits - evec = encoder.encode(bits) - print "froz: ", encoder._insert_frozen_bits(bits) - print "evec: ", evec - - evec[1] = 0 - deced = decoder._lr_sc_decoder(evec) - print 'SC decoded:', deced - - test_reverse_enc_dec() - compare_decoder_impls() + # power = 3 + # n = 2 ** power + # k = 4 + # frozenbits = np.zeros(n - k, dtype=int) + # frozenbitposition = np.array((0, 1, 2, 4), dtype=int) + # frozenbitposition4 = np.array((0, 1), dtype=int) + # + # + # encoder = PolarEncoder(n, k, frozenbitposition, frozenbits) + # decoder = PolarDecoder(n, k, frozenbitposition, frozenbits) + # + # bits = np.ones(k, dtype=int) + # print "bits: ", bits + # evec = encoder.encode(bits) + # print "froz: ", encoder._insert_frozen_bits(bits) + # print "evec: ", evec + # + # evec[1] = 0 + # deced = decoder._lr_sc_decoder(evec) + # print 'SC decoded:', deced + # + # test_reverse_enc_dec() + # compare_decoder_impls() + + test_systematic_decoder() if __name__ == '__main__': |