1. A communication system for transmitting an input data symbol stream over a plurality of spatial-subspace channels of a sub-carrier between a transmitter and a receiver, wherein said transmitter comprises: a) an encoder unit for processing a plurality of input data symbol sub-streams for providing a plurality of uncoded/coded input data symbol sub-streams comprising at least one of: 1) at least one uncoded input data symbol sub-stream for allocation on a corresponding at least one uncoded spatial-subspace channel of said plurality of spatial-subspace channels and 2) at least two coded input data symbol sub-streams for allocation on a corresponding at least two coded spatial-subspace channels of said plurality of spatial-subspace channels, said plurality of input data symbol sub-streams being derived from said input data symbol stream; b) a transmitter weighting unit connected to said encoder unit for weighting said plurality of uncoded/coded input data symbol sub-streams with a transmit weight matrix corresponding to said sub-carrier for distributing said plurality of uncoded/coded input data symbol sub-streams along said plurality of spatial-subspace channels and providing transmit-weighted spatial-subspace data; wherein, said receiver comprises: c) a receiver weighting unit for receiving spatial-subspace data related to said transmit-weighted spatial-subspace data and weighting said spatial-subspace data with a receive weight matrix for providing receive-weighted spatial-subspace data; and, d) a data estimation unit connected to said receiver weighting unit for receiving and performing an iterative processing method on said receive-weighted spatial-subspace data to estimate output data related to said input data symbol stream, said iterative processing method comprising successively processing data on each of said plurality of spatial-subspace channels in said receive-weighted spatial-subspace data.