Methods and systems for signal transmission in millimeter wave (mmW) range. A set of sequences is used to encode a data signal for one layer in a group of layers. Each sequence in the set of sequences has a length equal to the number of resources shared among the group of layers. At least a portion of the sequences have a low density of non-zero values, and the non-zero values are assigned to a subset of the shared resources. Each sequence assigns a non-zero value to at most one resource of the subset of shared resources, and all non-zero values assigned by all sequences have equal power amplitudes.