A base station comprising an allocator configured to allocate a plurality of dedicated reference (DR) signals to selected resource elements. In the even-numbered time slot in a first resource block, a first group of DR signals are: i) allocated to a first group of adjacent resource elements; and ii) allocated to a second group of adjacent resource elements. In the contiguous odd-numbered time slot in the first resource block, the first group of DR signals are allocated to a third group of adjacent resource elements. In the even-numbered time slot in a second resource block, the first group of adjacent DR signals are allocated to a fourth group of resource elements. In the contiguous odd-numbered time slot in the second resource block, the first group of DR signals are: i) allocated to a fifth group of adjacent resource elements; and ii) allocated to a sixth group of adjacent resource elements.