Energy allocation strategies for turbo codes with short frames

Turbo codes have been shown to approach the Shannon limit for error correcting capability at low signal-to-noise ratios given large sized frames. Extensive research efforts have been examining ways to enhance the performance of turbo codes for short frames (e.g., voice transmission). One way of enhancing the performance is to optimize the energy allocated to each bit stream to achieve the best performance possible. In standard turbo codes, all bits are transmitted with equal energy. Changing the energy allocation strategy can enhance the performance of turbo codes with short frame lengths. Using computer simulation and analytic bounds, different strategies are discussed and applicability to short frame applications investigated.