Optimal energy allocations for turbo codes based on distributions of low weight codewords

Improve the BER Performance of Turbo Codes with Large Size Based on BER Distributions

“…One of them is to reallocate the energy of the bit in the bit stream of the codeword. These schemes have previously been proposed in the literature [7][8][9][10][11][12][13][14][15]. In reference [7], the author assigned less and less power to the parity bits as the noise level increases to avoid the traditional negative "coding gain" associated with all error correcting codes at high noise levels.…”

“…In reference [14], the authors allocated the bits' energies among the codewords that have different weights instead of between the systematic and parity bits. In this scheme more energy is assigned to the codewords that have minimum (and second minimum) weight and the simulation results showed that the "error floor" of turbo codes was improved with no practical degradation in the waterfall region.…”

Improving the bit error rate performance by optimising energy allocation based on union bound

“…In [14], the authors allocated the bits' energies among the codewords that have different weights instead of between the systematic and parity bits. In this scheme, more energy is assigned to the codewords that have minimum (and second minimum) weight and the simulation results showed that the 'error floor' of turbo codes was improved with no practical degradation in the waterfall region.…”

“…Firstly, an optimal energy distribution for every bit is given based on the union bound. Instead of only considering the codeword with minimum weight of the code such as in [14], all the codewords with minimum weight connecting to each bit in the bit stream of the codeword sequence and their multiplicities are considered. Then, with a BER distribution produced by simulation at a specific SNR, this method is modified.…”

A New Scheme to Improve the BER Performance Based on Optimizing Energy Allocation

“…Such as in [3] and [4], the authors presented asymmetric energy allocation strategies to design different energies to the systemic bits and parity check bits. In [5], based on the low weight distributions of turbo codes, the authors allocated the energies among the codeword that have different weights instead of between the systematic and parity bits. In this scheme more energy is assigned to the lowest codeword to improve the "error floor" of Turbo codes.…”