Method for transmitting reference signals in a downlink multiple input multiple output system

A method for receiving a reference signal for channel measurement, the method comprising:

• receiving, by a user equipment (UE),
• first resource configuration information indicating a first time-frequency resource for carrying the reference signal in a first subset of a plurality of subframes,
• first subframe configuration information indicating a transmission period for the first subset of the plurality of subframes,
• second resource configuration information indicating a second time-frequency resource having zero transmission power in a second subset of the plurality of subframes, and
• second subframe configuration information indicating a zero transmission power period for the second time-frequency resource;
• and
• receiving, by the UE, the reference signal in the first time-frequency resource based on the first resource configuration information and the first subframe configuration information and not receiving data on the second time-frequency resource based on the second resource configuration information and the second subframe configuration information,
• wherein power is set to zero in the second time-frequency resource based on the second resource configuration information and the second subframe configuration information,
• wherein each of the first subset of the plurality of subframes and the second subset of the plurality of subframes is comprised of two slots identified as slot 0 and slot 1, each of which includes 7 orthogonal frequency division multiplexing (OFDM) symbols identified as OFDM symbols 0 to 6,
• wherein the first time-frequency resource is within two OFDM symbols in the first subset of the plurality of subframes, and
• wherein the two OFDM symbols are other than OFDM symbols 0, 1, 2 and 4 of the slot 0 and OFDM symbols 0, 1 and 4 of the slot 1.

A base station configured to transmit a reference signal for channel measurement to at least one user equipment, the base station comprising:

• a processor unit;
• and
• a radio frequency unit, electrically connected to the processor unit, configured to
• transmit, to a user equipment (UE), first resource configuration information indicating a first time-frequency resource for carrying the reference signal in a first subset of a plurality of subframes,
• first subframe configuration information indicating a transmission period for the first subset of the plurality of subframes,
• second resource configuration information indicating a second time-frequency resource having zero transmission power in a second subset of the plurality of subframes, and
• second subframe configuration information indicating a zero transmission power period for the second time-frequency resource;
• and
• transmit, to the UE, the reference signal in the first time-frequency resource based on the first resource configuration information and the first subframe configuration information and set power to zero in the second time-frequency resource based on the second resource configuration information and the second subframe configuration information,
• wherein each of the first subset of the plurality of subframes and the second subset of the plurality of subframes is comprised of two slots identified as slot 0 and slot 1, each of which includes 7 orthogonal frequency division multiplexing (OFDM) symbols identified as OFDM symbols 0 to 6,
• wherein the first time-frequency resource is within two OFDM symbols in the first subset of the plurality of subframes, and
• wherein the two OFDM symbols are other than OFDM symbols 0, 1, 2 and 4 of the slot 0 and OFDM symbols 0, 1 and 4 of the slot 1.

A user equipment configured to receive a reference signal for channel measurement, the user equipment comprising:

• a processor unit;
• and
• a radio frequency unit, electrically connected to the processor unit, configured to
• receive
• first resource configuration information indicating a first time-frequency resource for carrying the reference signal in a first subset of a plurality of subframes,
• first subframe configuration information indicating a transmission period for the first subset of the plurality of subframes,
• second resource configuration information indicating a second time-frequency resource having zero transmission power in a second subset of the plurality of subframes, and
• second subframe configuration information indicating a zero transmission power period for the second time-frequency resource;
• and
• receive the reference signal in the first time-frequency resource based on the first resource configuration information and the first subframe configuration information and not receive data on the second time-frequency resource based on the second resource configuration information and the second subframe configuration information,
• wherein power is set to zero in the second time-frequency resource based on the second resource configuration information and the second subframe configuration information,
• wherein each of the first subset of the plurality of subframes and the second subset of the plurality of subframes is comprised of two slots identified as slot 0 and slot 1, each of which includes 7 orthogonal frequency division multiplexing (OFDM) symbols identified as OFDM symbols 0 to 6,
• wherein the first time-frequency resource is within two OFDM symbols in the first subset of the plurality of subframes, and
• wherein the two OFDM symbols are other than OFDM symbols 0, 1, 2 and 4 of the slot 0 and OFDM symbols 0, 1 and 4 of the slot 1.