Known Bits(KB) method is a way of increasing the performance of turbo code by inserting known bits periodically in a code word without increasing in complexity. KB method normally causes uneven protection due to the process of random interleaving. This problem can be solved with a KB interleaver to ensure uniform distribution of KB. It is found that KB interleaver can improve the performance of turbo code with pseudo random interleaver or S-random interleavers. This method also makes a rate-matching to be easy which is fairly important for systems using turbo codes.
T.T.A.Korea TTA,Global CDMA I:MULTIBAND dIRCT-Sequence CDMA System RTT System Description,Sept,30,1998.[2]D.Divsalar,S.Dolinar,R.J.McEliece,F.Pollara,Transfer function bounds on the performance of trubo codes,JPL TED Progress Report 42-122,1995,Aug,44-55.[3]E.K.Hall,S.G.Wilson,Design and analysis of turbo codes on Rayleigh fading channels.IEEE J.on SAC,1998,16(2),160-174.
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