Controlling DL MIMO transmissions in a communication system
AssigneeGoogle Inc.
InventorsClement Huang, Chih-Hsiang Wu
Life of this patent
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Abstract
To control transmissions to a user equipment (UE) over a downlink (DL) multiple-input, multiple-output (MIMO) channel, a base station determining that the UE is configured to support N DL MIMO layers and transmit reference signals over L antenna chains (852). In response to determining that L<N (870), the base station generates channel information for the DL MIMO channel using (i) L uplink reference signals, each transmitted by the UE over a respective one of the L antenna chains (880), and (ii) one or more additional transmissions received from the UE (882). The base station transmits data streams over the DL MIMO channel in accordance with the generated channel information.
Claims20
A method in a base station for controlling transmissions to a user equipment (UE) over a downlink (DL) multiple-input, multiple-output (MIMO) channel, the method comprising:
- determining that the UE is configured to support N DL MIMO layers and transmit reference signals over L antenna chains;
- receiving L uplink reference signals, each transmitted by the UE over a respective one of the L antenna chains;
- receiving, from the UE, one or more additional transmissions including a hybrid automatic repeat request (HARQ) message or a scheduling request;
- in response to determining that L<N, generating channel information for the DL MIMO channel using (i) the L uplink reference signals and (ii) the one or more additional transmissions received from the UE;
- and
- transmitting a plurality of data streams over the DL MIMO channel in accordance with the generated channel information.
A base station comprising a processing hardware and configured to:
- determine that a UE is configured to support N DL MIMO layers and transmit reference signals over L antenna chains;
- receive L uplink reference signals, each transmitted by the UE over a respective one of the L antenna chains;
- receive, from the UE, one or more additional transmissions including a hybrid automatic repeat request (HARQ) message or a scheduling request;
- in response to determining that L<N, generate channel information for the DL MIMO channel using (i) the L uplink reference signals and (ii) the one or more additional transmissions received from the UE;
- and
- transmit a plurality of data streams over the DL MIMO channel in accordance with the generated channel information.
Dependencies are inferred from the claim text.