1. A method for allocating to transmitting devices a stream of complex symbols for transmission in parallel by the transmitting devices, the stream including replications that, for at least some of the symbols, include at least one of a complex conjugate and a negative complex conjugate of the symbol, the parallel transmission being temporally divided into time slots, the time slots being temporally divided into symbol periods each time slot having respective first and second portions, said method comprising: allocating the stream to the transmitting devices and to the symbol periods so that, for at least one of said slots, the symbols in at least one symbol period in the first portion of the at least one slot have at least one of complex conjugate and negative complex conjugate representations in at least one symbol period in the second portion of the at least one slot, said representations and corresponding symbols defining a non-orthogonal-based matrix having dimensions that represent transmitting devices and symbol periods, respectively, said non-orthogonal-based matrix having, as its constituents, orthogonal-based matrices; and transmitting, from the transmitting devices, in parallel and in accordance with said allocating to the devices and the periods, signals having characteristics that are represented by the complex symbols in the allocated stream.