A METHOD AND TRANSMITTER NODE FOR TRANSMITTING DM-RS PATTERN

摘要

The present invention relates to a transmitter node for transmitting a demodulation reference signal pattern in a resource block to a receiver node (12) using more than two transmission layers over a plurality of transmit antennas in a radio communications network. The transmitter node (10) comprises a mapping circuit (1301) configured to map a plurality of codewords to the more than two transmission layers. Furthermore, the transmitter comprises an additional mapping circuit (1302) configured to map each of the more than two transmission layers to a respective demodulation reference signal port according to a fixed pattern based on a transmission rank. Each of the demodulation reference signal ports is arranged to add a demodulation reference signal pattern to the resource block and the demodulation reference signal ports are associated to two code division multiplexing groups according to an association pattern. The transmission layers of each the two code division multiplexing groups are code division multiplexed and the transmission layers of different code division multiplexing groups are frequency division multiplexed In addition, the transmitter node (10) comprises a precoding circuit (1303) configured to precode each codeword and demodulation reference signal pattern, carried over respective transmission layer, and a transmitting circuit (1304) comprising the plurality of transmit antennas and configured to transmit the precoded demodulation reference signal pattern in the resource block to the receiver node (12).