Turbo DeCodulation using Highly Redundant Index Assignments and Multi-Dimensional Mappings

Abstract:
We propose a block coded Turbo DeCodulation scheme, combining iterative demodulation, channel decoding, and source decoding at the receiver. Turbo DeCodulation resembles a serial concatenation of bit-interleaved coded modulation (BICM) and iterative source-channel decoding (ISCD) where the two iterative loops are connected by a single convolutional code. In our contribution, explicit channel (de)coding by a convolutional code, used in most Turbo systems, is omitted. Instead, highly redundant index assignments and multi-dimensional mappings, both based on short block codes, introduce the artificial redundancy. Thus, the proposed receiver possesses only a single iterative loop. The simulations results show a competitive or even superior performance compared to previously known systems. Furthermore, we present an extension to a flexible multi-mode system and a novel, simple design method for the index assignments.