Orthogonal DMRS ports with resource block reuse in a single cell is provided. ABS comprises: a BBE and RUs. The BS transmits user data to each of a plurality of UEs on a PDSCH using a PRB allocation for the cell. The PRB and cell are the same for all UEs. The PRB comprises DMRS symbols. The BS transmits user data to each UE on the PDSCH using a respective non-intersecting subset of the RUs. No RU transmits user data on the PDSCH using the PRB to more than one UE. The BBE: determines non-intersecting sets of DMRS ports; assigns one set to each UE; and causes the BS to transmit UE-specific DMRS to UE on the DMRS ports in the set assigned to that UE using only a respective non-intersecting subset of RUs used for transmitting user data to that UE on the PDSCH using the PRB.