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Proximal decoder now return the decoded dataword instead of the codeword

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This commit is contained in:
Andreas Tsouchlos 2022-11-07 14:07:46 +01:00
parent 3e7dd37827
commit 323b103d6f
2 changed files with 9 additions and 6 deletions
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2
sw/decoders/naive_soft_decision.py
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@ -9,7 +9,7 @@ class SoftDecisionDecoder:
one with the largest correlation.
"""
# TODO: What is the proper name for 'R'? Is it actually 'decoding matrix'?
# TODO: Is 'R' actually called 'decoding matrix'?
def __init__(self, G: np.array, H: np.array, R: np.array):
"""Construct a new SoftDecisionDecoder object.

13
sw/decoders/proximal.py
View File

@ -5,20 +5,23 @@ class ProximalDecoder:
"""Class implementing the Proximal Decoding algorithm. See "Proximal Decoding for LDPC Codes"
by Tadashi Wadayama, and Satoshi Takabe.
"""
# TODO: How large should K be?
# TODO: Is 'R' actually called 'decoding matrix'?
# TODO: How large should eta be?
# TODO: How large should step_size be?
def __init__(self, H: np.array, K: int = 100, step_size: float = 0.5, gamma: float = 0.05,
eta: float = 1.1):
def __init__(self, H: np.array, R: np.array, K: int = 100, step_size: float = 0.5,
gamma: float = 0.05, eta: float = 1.1):
"""Construct a new ProximalDecoder Object.
:param H: Parity Check Matrix
:param R: Decoding matrix
:param K: Max number of iterations to perform when decoding
:param step_size: Step size for the gradient descent process
:param gamma: Positive constant. Arises in the approximation of the prior PDF
:param eta: Positive constant slightly larger than one. See 3.2, p. 3
"""
self._H = H
self._R = R
self._K = K
self._step_size = step_size
self._gamma = gamma
@ -92,7 +95,7 @@ class ProximalDecoder:
:param y: Vector of received values. (y = x + w, where 'x' is element of [-1, 1]^n
and 'w' is noise)
:return: Most probably sent symbol
:return: Most probably sent dataword (element of [0, 1]^k)
"""
s = 0
x_hat = 0
@ -107,4 +110,4 @@ class ProximalDecoder:
if self._check_parity(x_hat):
break
return x_hat
return np.dot(self._R, x_hat)