Collision free row column S-random interleaver

Generation of New Collision Free S-Random Interleavers of Turbo Codes

“…Since the spreading factor, S, is much greater than those of previous collision free interleavers [10], [11], superior performance of the proposed CFS interleavers can be verified in the next section. Table 1, Generation of new collision free S-random interleaver…”

“…Previous RCS-random interleavers [10] or similar interleavers [11] are particularly designed to satisfy (2) for a specific degree of parallelism, M, however, their spreading factor, S, are actually very limited because of the restriction of their algorithms. To improve the performance of collision free S-random interleavers, a novel algorithm for generating S-random interleavers with large S parameter and constraint ( 2) is presented as Table 1.…”

“…Since an excellent interleaver can result in excellent free distance of a turbo code and thus a low error floor for turbo decoding. In this section, the free distance of turbo codes is used to evaluate and compare the performance of the proposed CFS, previous RCS [10], and S-random interleavers.…”

“…Early, a collision-free interleaver was generated in a systematic way in [9], where it puts the permutated data sequence into a matrix and only lets the elements in each column do cyclic shifts. Since only collision free constraint is involved, the performance of interleavers in [9] only overtake the UTMS turbo code interleavers and it inferior to the row column S-random (RCS-random) ones [10] proposed in 2009. A RCS-random interleaver [10] puts its data sequence into a matrix, where each row is interleaved by distinct small S-random interleavers and so does each column.…”

“…Since only collision free constraint is involved, the performance of interleavers in [9] only overtake the UTMS turbo code interleavers and it inferior to the row column S-random (RCS-random) ones [10] proposed in 2009. A RCS-random interleaver [10] puts its data sequence into a matrix, where each row is interleaved by distinct small S-random interleavers and so does each column. As a result, the value of spreading factor, S, for the whole interleaver is very limited.…”