Patent ID: 9112534
Filing Date: 2015-08-18
Classification: H03M

Abstract:
1. A communications apparatus comprising: a constrained interleaver configured to receive a sequence of N=r 2 m input bits that corresponds to r 2 ρ 2 number of multi-bit codewords that were generated from r 2 ρ 2 number of independent encoders, and the constrained interleaver is further configured to rearrange an ordering of the sequence of N=r 2 m input bits in accordance with a permutation function in order to produce a permuted sequence of output bits, wherein N, r 2 , ρ 2 , and m are positive integers with r 2 >1 and the rearrangement of the ordering in accordance with the permutation function is equivalent to performing the following operations: applying a codeword-level pseudo-random permutation function to pseudo-randomly rearrange an ordering of a plurality of multi-bit codewords embedded in the sequence of N=r 2 m input bits; loading the N=r 2 m number of input bits into a r 2 ×m array of bits, wherein the r 2 ×m array has r 2 rows and m columns, and the bits are serially loaded into the r 2 ×m array of bits along rows, applying an i th pseudo-random row permutation function to each row i, for i=1, 2, . . . r, wherein the i th pseudo-random row permutation function pseudo-randomly rearranges an ordering of m bits in the i th row, reading bits out of the r 2 ×m array along r 2 -bit columns to form the permuted sequence of output bits, wherein at least one respective one of the r