Modified suboptimal iterative decoding for regular repeat-accumulate coded signals

الملخص EN

In this work, two algorithms are suggested in order to improve the performance of systematic Repeat-Accumulate ( ) decoding.

The first one is accomplished by the insertion of pilot symbols among the data stream that entering the encoder.

The positions where pilots should be inserted are chosen in such a way that to improve the minimum Hamming distance and/or to reduce the error coefficients of the code.

The second proposed algorithm includes the utilization of the inserted pilots to estimate scaling (correction) factors.

Two-dimensional correction factor was suggested in order to enhance the performance of traditional Minimum-Sum decoding of regular repeat accumulate codes.

An adaptive method can be achieved for getting the correction factors by calculating the mean square difference between the values of received pilots and the a-posteriori data of bit and check node related to them which created by the minimum-sum ( ) decoder