Asymmetric energy allocation strategies to improve turbo codes performance

We study the effect of asymmetric energy allocations to the output bits of turbo codes. We show that the error floor improves as more energy is given to the non-systematic bits. The standard (symmetric) energy allocation scheme achieves the best results in the waterfall region. However, the degradation observed in the waterfall region is practically non-existent when asymmetric energy allocation schemes close to the standard one are utilized. This implies that by using an appropriate energy allocation strategy, significant improvement in the error floor can be achieved with no practical degradation in the waterfall region