Robust transmission on downlink discontinuous transmission carrier
First Claim
1. A method in a base station for using common reference symbols, CRS, in conjunction with discontinuous transmission from the base station to a user equipment, UE, the method comprising:
- selecting a transmission mode, the selection being one of a plurality of transmission modes that include at least one of a transmit diversity mode and an open loop multiple-input-multiple-output, MIMO, mode;
transmitting data and CRS discontinuously in sub frames of a frame in accordance with the selected transmission mode, the discontinuous transmission omitting transmission of data and CRS in specified sub frames;
including in the discontinuous transmission at least one CRS, the CRS being transmitted in only a pre-determined subset of the sub frames of the frame and in additional sub frames of the frame where there is transmission of data using a selected transmission mode; and
signaling the UE as to which of one of two reference symbol types the UE is to use for channel state information feedback, the first type being CRS and the second type being channel state interference reference symbols, CSI-RS.
1 Assignment
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Accused Products
Abstract
A method and system for downlink discontinuous transmission are provided. In one embodiment, a base station includes a memory, a processor and a transmitter. The memory stores information to be transmitted in a subset of sub frames to a UE. The information includes transmission mode configuration information. The processor operates to configure the transmitter according to a selected transmission mode configuration that includes one of a transmit diversity mode and a MIMO mode, and configures the transmitter to transmit discontinuously and include CRS in only a subset of sub frames.
8 Citations
24 Claims
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1. A method in a base station for using common reference symbols, CRS, in conjunction with discontinuous transmission from the base station to a user equipment, UE, the method comprising:
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selecting a transmission mode, the selection being one of a plurality of transmission modes that include at least one of a transmit diversity mode and an open loop multiple-input-multiple-output, MIMO, mode; transmitting data and CRS discontinuously in sub frames of a frame in accordance with the selected transmission mode, the discontinuous transmission omitting transmission of data and CRS in specified sub frames; including in the discontinuous transmission at least one CRS, the CRS being transmitted in only a pre-determined subset of the sub frames of the frame and in additional sub frames of the frame where there is transmission of data using a selected transmission mode; and signaling the UE as to which of one of two reference symbol types the UE is to use for channel state information feedback, the first type being CRS and the second type being channel state interference reference symbols, CSI-RS. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A base station for downlink discontinuous transmission, the base station comprising:
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a memory configured to store a common reference symbol, CRS and transmission mode configuration information; a transmitter configured to transmit data and CRS discontinuously in sub frames in accordance with a selected transmission mode, the discontinuous transmission omitting transmission of data and CRS in specified sub frames; and a processor configured to; select a transmission mode from a plurality of transmission modes that include at least one of a transmit diversity mode and an open loop multiple-input-multiple-output, MIMO, mode; include in the discontinuous transmission at least one CRS, the CRS being transmitted in only a pre-determined subset of the sub frames and in additional sub frames where there is transmission of data using a selected transmission mode; and the transmitter being further configured to transmit a signal indicating to a user equipment, UE, which one of CRS and channel state information reference symbols, CSI-RS, are to be used for channel state information feedback. - View Dependent Claims (10, 11, 12, 13, 14)
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15. A method at a user equipment, UE, for reception of discontinuous transmission from a base station, the method comprising:
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storing common reference symbols, CRS, and transmission mode configuration information, a transmission mode being selected from a plurality of transmission modes that include at least one of a transmit diversity mode and an open loop multiple-input-multiple-output, MIMO, mode; receiving discontinuous transmissions that include the stored CRS in a selected subset of sub frames; performing channel estimation based on one of CRS and channel state information symbols, CSI-RS; performing channel state information, CSI, feedback based on CSI-RS; and performing demodulation using CRS. - View Dependent Claims (16, 17, 18, 19)
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20. A user equipment, UE, for reception of discontinuous transmissions from a base station, the UE comprising:
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a memory configured to store common reference symbols, CRS, and transmission mode configuration information, a transmission mode being selected from a plurality of transmission modes that include at least one of a transmit diversity mode and an open loop multiple-input-multiple-output, MIMO, mode; a receiver configured to receive discontinuous transmissions, the discontinuous transmissions including the stored CRS in a selected subset of sub frames; a processor configured to perform channel estimation based on one of CRS and channel state information reference symbols, CSI-RS, and the processor being further configured to perform channel state information, CSI, feedback based on CSI-RS when the receiver is configured to perform demodulation using CRS. - View Dependent Claims (21, 22, 23, 24)
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Specification