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85 lines
1.9 KiB
Python
85 lines
1.9 KiB
Python
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# Authors: Veeresh Taranalli <veeresht@gmail.com>
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# License: BSD 3-Clause
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""" Interleavers and De-interleavers """
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from numpy import array, arange, zeros
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from numpy.random import mtrand
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__all__ = ['RandInterlv']
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class _Interleaver:
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def interlv(self, in_array):
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""" Interleave input array using the specific interleaver.
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Parameters
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----------
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in_array : 1D ndarray of ints
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Input data to be interleaved.
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Returns
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-------
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out_array : 1D ndarray of ints
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Interleaved output data.
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"""
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out_array = array(map(lambda x: in_array[x], self.p_array))
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return out_array
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def deinterlv(self, in_array):
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""" De-interleave input array using the specific interleaver.
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Parameters
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----------
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in_array : 1D ndarray of ints
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Input data to be de-interleaved.
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Returns
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-------
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out_array : 1D ndarray of ints
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De-interleaved output data.
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"""
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out_array = zeros(len(in_array), in_array.dtype)
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for index, element in enumerate(self.p_array):
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out_array[element] = in_array[index]
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return out_array
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class RandInterlv(_Interleaver):
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""" Random Interleaver.
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Parameters
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----------
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length : int
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Length of the interleaver.
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seed : int
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Seed to initialize the random number generator
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which generates the random permutation for
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interleaving.
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Returns
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-------
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random_interleaver : RandInterlv object
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A random interleaver object.
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Note
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----
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The random number generator is the
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RandomState object from NumPy,
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which uses the Mersenne Twister algorithm.
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"""
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def __init__(self, length, seed):
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rand_gen = mtrand.RandomState(seed)
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self.p_array = rand_gen.permutation(arange(length))
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#class SRandInterlv(_Interleaver):
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#class QPPInterlv(_Interleaver):
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