Trellis-coded quadrature amplitude modulation with 2N-dimensional constellations for mobile radio channels

Using a modified Wei method, originally designed for additive white Gaussian noise (AWGN) channels, we have constructed four-dimensional (4-D) and six-dimensional (6-D) trellis codes with rectangular signal constellations for frequency-nonselective mobile radio channels. Applying a novel way of partitioning the two-dimensional (2-D) constituent constellations, both into subsets with enlarged minimum Euclidean distance and subrings including equal energy signal points, we have obtained partitions of the 2N-D signal sets into subsets with a Hamming distance between signal points which equals N. This is fundamental for constructing good trellis codes to transmit data over flat fading channels.