Abstract: Systems and methods are provided for spreading symbols over multiple time-frequency resources that rely on simple base constellations that can be sent over a frequency tone or time slot. A set of input bits (or an input symbol) are mapped to K symbols, and a symbol-to-resource-element mapping is applied that maps the K symbols to resource units. The mapping to the K symbols may be a linear mapping that maps an input symbol to K target tones through a 2K×2 real matrix, where input symbol is a complex point in a base constellation, and is considered as a 2-dimensional real vector. Up to K co-orthogonal 2K×2 real matrices (whose columns are orthogonal to each other) can be associated with the subset of K target tones. Each of the K co-orthogonal matrices can be used for mapping of an independent symbol from a separate steam of symbols which can be associated to a single UE or separate UEs.