Multi-user downlink linear MIMO precoding system
AssigneeNEC Laboratories America, Inc.
InventorsMohammad A. Khojastepour, Xiaodong Wang, Mohammad Madihian
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Abstract
A method implemented in a base station used for a downlink multi-user (MU) multi-input multi-output (MIMO) system is disclosed. The method includes receiving an indication of a quantized matrix from each of a plurality of scheduled user equipments, precoding data streams for the plurality of scheduled user equipments, transmitting the precoded data to the plurality of scheduled user equipments. Other methods and some apparatuses for wireless communications also are disclosed.
Claims6
A method implemented in a base station used for a downlink multi-user (MU) multi-input multi-output (MIMO) system, comprising:
- receiving an indication of a quantized matrix from each of a plurality of scheduled user equipments;
- precoding data streams for the plurality of scheduled user equipments;
- and
- transmitting the precoded data to the plurality of scheduled user equipments,
- wherein the precoded data is expressed by equation
- x=Gu
- where x is the precoded data, u denotes the data streams, and G is a precoder,
- wherein each scheduled user equipment corresponds to at least one of the data streams, said at least one of the data streams being precoded with a column of the quantized matrix indicated by said each scheduled user equipment,
- wherein the number of the data streams is equal to or greater than the number of the scheduled user equipments, and
- wherein a set of indications restricts a set of channel conditions for the plurality of scheduled user equipments.
A base station used for a downlink multi-user (MU) multi-input multi-output (MIMO) system, comprising:
- a receiving unit to receive an indication of a quantized vector from each of a plurality of user equipments;
- a precoding unit to precode data streams for the plurality of user equipments;
- and
- a transmission unit to transmit the precoded data to the plurality of user equipments,
- wherein the precoded data is expressed by equation
- x=Gu
- where x is the precoded data, u denotes the data streams, and G is a precoder,
- wherein each scheduled user equipment corresponds to at least one of the data streams, said at least one of the data streams being precoded with a column of the quantized matrix indicated by said each scheduled user equipment,
- wherein the number of the data streams is equal to or greater than the number of the scheduled user equipments, and
- wherein a set of indications restricts a set of channel conditions for the plurality of scheduled user equipments.
A method implemented in a user equipment used for a downlink multi-user (MU) multi-input multi-output (MIMO) system, comprising:
- transmitting an indication of a quantized vector to a base station;
- and
- receiving precoded data from the base station,
- wherein the precoded data is precoded from data streams for a plurality of user equipments,
- wherein the precoded data is expressed by equation
- x=Gu
- where x is the precoded data, u denotes the data streams, and G is a precoder,
- wherein each scheduled user equipment corresponds to at least one of the data streams, said at least one of the data streams being precoded with a column of the quantized matrix indicated by said each scheduled user equipment,
- wherein the number of the data streams is equal to or greater than the number of the scheduled user equipments, and
- wherein a set of indications restricts a set of channel conditions for the plurality of scheduled user equipments.
Dependencies are inferred from the claim text.