def test_002_frozen_bit_positions(self):
for snr in np.arange(-1.5, 3.5, .25):
for inv_coderate in np.array([8, 6, 5, 4, 3, 2, 1.5, 1.2]):
for n in range(6, 11):
N = 2**n
K = int(N / inv_coderate)
# print(N, K, inv_coderate)
cf = pypolar.frozen_bits(N, K, snr)
eta = design_snr_to_bec_eta(snr, 1. * K / N)
polar_capacities = calculate_bec_channel_capacities(eta, N)
pf = get_frozenBitPositions(polar_capacities, N - K)
pf = np.sort(pf)
decoder = pypolar.PolarDecoder(N, 1, cf, "mixed")
pd = decoder.frozenBits()
self.assertListEqual(cf, pd)
self.assertListEqual(cf, list(pf))
def search_code_weights(N, K, design_snr_db):
f = pypolar.frozen_bits(N, K, design_snr_db)
p = pypolar.PolarEncoder(N, f)
numInfoWords = 2**K
weights = {}
for i in range(numInfoWords):
b = np.binary_repr(i, K)
u = np.array([int(l) for l in b], dtype=np.uint8)
nbp = np.packbits(u)
cw = p.encode_vector(nbp)
c = np.unpackbits(cw)
weight = np.sum(c)
if weight in weights:
weights[weight] += 1
else:
weights[weight] = 1
weights.pop(0)
print(weights)
return weights
def _generate_frozen_bit_positions(self):
return np.array(
frozen_bits(self._block_length, self._info_length, self._dSNR))
def calculate_code_properties(N, K, design_snr_db):
eta = design_snr_to_bec_eta(design_snr_db, 1.0 * K / N)
polar_capacities = calculate_bec_channel_capacities(eta, N)
frozenBitMap = get_frozenBitMap(polar_capacities, N - K)
f = pypolar.frozen_bits(N, K, design_snr_db)
p = pypolar.PolarEncoder(N, f)
Gp = get_polar_generator_matrix(int(np.log2(N)))
print(Gp)
assert np.all(np.where(frozenBitMap > -1) == f)
numInfoWords = 2 ** K
n_prepend_bits = int(8 * np.ceil(K / 8.) - K)
print(n_prepend_bits)
weights = {}
for i in range(numInfoWords):
# b = np.binary_repr(i, K + n_prepend_bits)
b = np.binary_repr(i, K)
u = np.array([int(l) for l in b], dtype=np.uint8)
# nb = np.concatenate((np.zeros(n_prepend_bits, dtype=nb.dtype), nb))
nbp = np.packbits(u)
cw = p.encode_vector(nbp)
# xm = encode_systematic_matrix(u, N, frozenBitMap)
c = np.unpackbits(cw)
# assert np.all(xm == c)
weight = np.sum(c)
if weight in weights:
weights[weight] += 1
else:
weights[weight] = 1
# nb = bin(i)
# print(i, b, u, nbp, c)
print(f)
print(frozenBitMap)
# print(n_prepend_bits)
weights.pop(0)
print(weights)
dmin_ext_search = np.min(weights.keys())
print(dmin_ext_search)
# validate_systematic_matrix(N, f, frozenBitMap)
Gs = get_polar_encoder_matrix_systematic(N, f)
P = Gs[:, f]
# print(P)
G = np.hstack((np.identity(K, dtype=Gs.dtype), P))
H = np.hstack((P.T, np.identity(N - K, dtype=Gs.dtype)))
# print(P)
print(H)
# print(G.dot(H.T) % 2)
#
# print(Gs.dot(Gs.T) % 2)
print(np.linalg.matrix_rank(H))
dmin_H = np.min(np.sum(H, axis=1))
dmin_P = 1 + np.min(np.sum(P, axis=1))
print(np.sum(H, axis=1))
print(np.sum(P, axis=1))
print('search {} vs {} H, P{}'.format(dmin_ext_search, dmin_H, dmin_P))
assert dmin_ext_search == dmin_P