Dual layer beam forming in cellular networks
AssigneeTexas Instruments Incorporated
InventorsRunhua Chen, Eko Nugroho Onggosanusi
Life of this patent
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Abstract
Single user and multiuser MIMO transmission in a cellular network may be performed by selecting by a base station (eNB) to transmit either one or two transmission layers. When one transmission layer is selected, a first transmission layer is precoded with a first precoder. A first demodulation reference signal (DMRS) sequence or a second DMRS sequence is selected by the eNB and precoded using the first precoder. The first transmission layer is transmitted with the selected precoded DMRS from the eNB to a user equipment (UE), and an indicator is transmitted to the UE to indicate which DMRS sequence is selected and transmitted.
Claims8
A method for transmitting in a downlink channel of a cellular network, the method comprising:
- selecting by a base station (eNB) to transmit either one or two transmission layers;
- when one transmission layer is selected:
- precoding a first transmission layer with a first precoder;
- determining a first demodulation reference signal (DMRS) sequence or a second DMRS sequence and precoding the determined DMRS sequence using the first precoder;
- transmitting the first transmission layer with the determined preceded DMRS from the eNB to a user equipment (UE);
- and
- transmitting a value to the UE to identify the determined and transmitted DMRS sequence.
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 selected:
- receiving a value from the eNB to identify 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;
- determine a first demodulation reference signal (DMRS) sequence or a second DMRS sequence and precode the determined DMRS sequence using the first precoder;
- transmit the first transmission layer with the precoded DMRS from the base station to a user equipment (UE);
- and
- transmit a value to the UE to identify which DMRS sequence is selected and transmitted.
Dependencies are inferred from the claim text.