Orthogonality in cyclic shift (CS) and orthogonal cover code (OCC) selection for DMRS in MIMO is improved by new nDMRS to nDMRS(2) mapping patterns. Values in the mapping tables are arranged in sets, with minimum CS separation between the values in each set. Additionally, the semi-static nDMRS is independently configurable for each UL component carrier (CC) in the case of cross-CC scheduling in carrier aggregation, and the PHICH allocation formula that defines the allocation of the PHICH process relative to the kth codeword (CW) on the cth UL CC is a function of both the CS index nDMRS,k,c(2) that is dynamically assigned to a certain layer of the considered CW and the semi-static CS offset nDMRS,c(1) for the cth CC.