Dual-Layer Beam Forming in Cellular Networks

Method for receiving in a downlink channel of a cellular network, the method comprising:

• receiving at a user equipment (UE) a rank indicator from a base station (eNB) indicating one transmission layer or two transmission layers;
• when one transmission layer is indicated:
• receiving an indicator from the eNB to indicate which demodulation reference signal (DMRS) sequence was selected by the eNB from a first DMRS sequence or a second DMRS sequence;
• receiving a first transmission layer from the eNB with the selected DMRS;
• and
• demodulating the selected DMRS and the first transmission layer, wherein the first transmission layer and the selected DMRS have a same precoding.

A base station for a cellular network, the device comprising:

• a transceiver configured to couple to a plurality of antenna, wherein the transceiver is configured to transmit to and receiver from user equipment via the plurality of antenna in the cellular network;
• a processor coupled to a memory configured to execute a control program in the memory for controlling the transceiver;
• wherein the transceiver is configured to select to transmit either one or two transmission layers;
• when one transmission layer is selected, the transceiver is configured to:
• precode a first transmission layer with a first precoder;
• select a first demodulation reference signal (DMRS) sequence or a second DMRS sequence and precode the selected DMRS sequence using the first precoder;
• transmit the first transmission layer with the selected precoded DMRS from the base station to a user equipment (UE);
• and
• transmit an indicator to the UE to indicate which DMRS sequence is selected and transmitted.