Low correlation interleaved QAM sequences

Three low correlation interleaved QAM sequence families are presented here. In a CDMa setting, these sequences have the ability to transport a larger amount of data as well as enable variable-rate signaling on the reverse link. These constructions have the lowest known value of maximum correlation magnitude of any sequence family with the same alphabet. I nterleaved canonical family ICQ has period N, normalized maximum correlation parameter (theta) over bar (max) bounded above by less than or similar to a root N, where a ranges from 1.41 in the 16-QAM case to 2.12 for large M. Each user is enabled to transfer 2m bits of data per period of the spreading sequence. Interleaved selected family ISQ has a lower value of (theta) over bar (max) but permits only (m + 1)-bit data modulation. The (theta) over bar (max). of sequences in this family is bounded above by less than or similar to a root N, where a ranges from 1.89 in the case of 64-QAM modulation to 1.99 for large M. The third family is over a quadrature-PAM (Q-PAM) subset of size 2M of the M-2-QAM constellation. Interleaved family IP has a lower value Of Lax in comparison with family ISQ, while still permitting (m + I)-bit data modulation. The (theta) over bar (max) of sequences in this family is bounded above by less than or similar to a root N, where a ranges from 1.39 in the 16-ary Q-PAM case to 1.72 for large M.