Turbo Codes With Rate-<tex>$m/(m+ 1)$</tex>Constituent Convolutional Codes

Abstract

The original turbo codes (TCs), presented in 1993 by Berrou et al., consist of the parallel concatenation of two rate-1/2 binary recursive systematic convolutional (RSC) codes. This paper explains how replacing rate-1/2 binary component codes by rate-(+ 1) binary RSC codes can lead to better global performance. The encoding scheme can be designed so that decoding can be achieved closer to the theoretical limit, while showing better performance in the region of low error rates. These results are illustrated with some examples based on double-binary (= 2) 8-state and 16-state TCs, easily adaptable to a large range of data block sizes and coding rates. The double-binary 8-state code has already been adopted in several telecommunication standards.

Low Computational Algorithm of Soft-Decision Extended BCH Decoding Algorithm for Next Generation DVB-RCS Systems

“…초기의 DVB-RCS 표준안으로 채택되어진 이중이 진 Turbo 부호의 성능이 오류 마루(error floor) 현상 이 발생하여 [1] , 이를 개선하기 위해 새로운 알고리즘 들이 DVB-RCS NG(Next Generation)에서 제시되고 있다 [2], [3] . 새롭게 제시되고 있는 부호화 방식으로는 비선형 위성 채널에서 효율적인 CPM(Continuous Phase Modulation) 기반의 연판정 e-BCH(extended-BCH) 부호가 효과적임이 입증되었다.…”

Coding for Shared Satellite Channel Communications

“…A code matched symbol interleaver of length symbols is used. A symbol interleaver allows symbol probabilities to be exchanged during the iterative process, which gives improved convergence [11]. The design of the symbol interleaver has to take into account Turbo code crossed error events similar to the (information weight ) example shown in Fig.…”

“…This corresponds to a decoder treating user B as interference. It can be shown that (9) becomes 1 (11) This can be split into two separate decoders with (12) where is a multiplicative constant, and . In (12) the MAP summation is performed over the state space of only one user.…”

Bit-Level Extrinsic Information Exchange Method for Double-Binary Turbo Codes

“…Recently, nonbinary turbo codes have received a great deal of attention and are adopted in several mobile radio systems such as DVB-RCS and IEEE 802.16 standard (WiMAX) [2], as they can offer many advantages over single-binary turbo codes [3].…”