Orthogonal transmission of block turbo coded MIMO systems with iterative decoding

Block turbo coding (BTC) is a parallel concatenated code using block codes as constituent codes. A frame of data is arranged in n_T dimensions and encoded through each dimension, where n_T is the number of transmit antennas. In this paper, we exploit BTC to provide transmit diversity; row-wise data readings are transmitted through transmit antenna one while column-wise data readings are transmitted through transmit antenna two, and so on. Mappers transform the encoded data streams to the phase shift keying constellation elements using Gray mapping. Except at antenna one, symbol streams are converted to their orthogonal values prior to being sent through the channel. At the receiver, MIMO processing and frame formatting are applied prior to soft-demapping and decoding. BTC decoding is performed iteratively using a sub-optimum maximum-likelihood decoding (MLD) algorithm.