Throughput enhancing concatenated codes

Throughput enhancing concatenated codes with a second uncoded implicit stream

“…Multi-constellation signalling [5] also uses implicit transmission by employing a constellation with clusters and selecting a particular constellation based on a set of implicit bits during every interval. The implicit transmission principle presented in SM and in [5], has been applied to construct a novel class of throughput enhancing concatenated codes (TECCs) presented in [6].…”

“…TECCs are designed to transmit a separate coded sequence implicitly while transmitting a coded sequence explicitly over a channel thereby increasing the throughput at the expense of increased decoding complexity [6]. In [6], it has been shown that TECCs can be constructed with the turbo codes employed in the 4G long-term evolution (LTE) standard to increase the throughput by 25% without sacrificing performance at a modest increase in complexity. In this study, TECC schemes with two separate implicit streams, which are referred to here as TECC-2 schemes, are constructed by extending TECC schemes presented in [6], which are referred here as TECC-1 schemes.…”

“…In [6], it has been shown that TECCs can be constructed with the turbo codes employed in the 4G long-term evolution (LTE) standard to increase the throughput by 25% without sacrificing performance at a modest increase in complexity. In this study, TECC schemes with two separate implicit streams, which are referred to here as TECC-2 schemes, are constructed by extending TECC schemes presented in [6], which are referred here as TECC-1 schemes. It is shown here that TECC-2 schemes can significantly increase the throughput expansion achieved by TECC-1 while maintaining the same performance.…”

“…Summarising, each iteration requires soft decoding of C and C ′ , passing of soft information through the mapper and the demapper which can be done similar to soft decoding of a linear block code, and calculating the soft information transfer through the modulo 2 addition operation. According to (3) of [6], the LLR of z = x ⊕ y, L(z), can be expressed in terms of the LLR values of x and y, L(x) and L(y) respectively as…”

“…Therefore, in practice, the value of n should be carefully chosen to maintain TECC performance similar to that of original C decoding at the desired BER value. Conclusions: In this study, TECC schemes presented in [6] have been extended to include a second implicit stream to form TECC-2 schemes. The second implicit stream flips one bit of every n ′ bits of the first implicit stream based on up to log 2 n ′ bits of the second implicit stream, while one bit out of every n coded bits of the explicit code is flipped based on up to log 2 n bits of the first implicit steam.…”