CDM8 based CSI-RS designs for MIMO
A network node, wireless device, base station, user equipment and corresponding methods are provided. The network node includes processing circuitry configured to: select a first set and second set of reference signal resources in a subframe and aggregate the first set and second set of reference signal resources in the subframe to form a code division multiplexing, CDM, aggregation configuration. The first set and second set of reference signal resources in the subframe satisfy a temporal criterion such that any two resource elements in the first set and second set of reference signal resources have up to a maximum time separation of six OFDM symbols. The first set and second set of reference signal resources in the subframe satisfy a frequency criterion such that any two resource elements in the first set and second set of reference signal resources have up to a maximum frequency separation of six subcarriers.
1. A user equipment, comprising:
processing circuitry configured to:
receive a code division multiplexing (CDM) aggregation configuration, the CDM aggregation configuration corresponding to an aggregated first set and second set of reference signal resources in a subframe, each of the first set and second set of reference signal resources being a length 4 orthogonal cover code group;
perform channel measurement based on the CDM aggregation configuration;
the aggregated first set and second set of reference signal resources satisfying a temporal criterion such that each resource element in the first set has up to a maximum time separation of six orthogonal frequency division multiplexing (OFDM) symbols with each resource element in the second set of reference signal resources, the first set including a first plurality of resource elements and the second set including a second plurality of resource elements on different OFDM symbols than the first set; and
the aggregated first set and second set of reference signal resources satisfying a frequency criterion such that each resource element in the first set has up to a maximum frequency separation of six subcarriers with each resource element in the second set of reference signal resources, the first set including the first plurality of resource elements on two continuous subcarriers, the second set including the second plurality of resource elements on two continuous subcarriers, the first set and second set being on non-overlapping subcarriers.
2. The user equipment of claim 1 , wherein the first set of reference signal resources corresponds to a first portion of a first reference signal configuration; and
the second set of reference signal resources corresponds to a second portion of a second reference signal configuration.
3. The user equipment of claim 2 , wherein the first reference signal configuration is at least a first channel state information-reference signal, CSI-RS, configuration; and
the second reference signal configuration is at least a second CSI-RS configuration different from the at least first CSI-RS configuration.
4. The user equipment of claim 1 , wherein the CDM aggregation configuration is associated with indices corresponding to the aggregated first set and second set of reference signal resources.
5. The user equipment of claim 1 , wherein the CDM aggregation configuration is an aggregation of two CDM-4 groups across CSI-RS port resource pairs.
6. A method for a user equipment, the method comprising:
receiving a code division multiplexing (CDM) aggregation configuration, the CDM aggregation configuration corresponding to an aggregated first set and second set of reference signal resources in a subframe, each of the first set and second set of reference signal resources being a length 4 orthogonal cover code group;
performing channel measurement based on the CDM aggregation configuration;
the aggregated first set and second set of reference signal resources satisfying a temporal criterion such that each resource element in the first set has up to a maximum time separation of six orthogonal frequency division multiplexing (OFDM) symbols with each resource element in the second set of reference signal resources, the first set including a first plurality of resource elements and the second set including a second plurality of resource elements on different OFDM symbols than the first set; and
the aggregated first set and second set of reference signal resources satisfying a frequency criterion such that each resource element in the first set has up to a maximum frequency separation of six subcarriers with each resource element in the second set of reference signal resources, the first set including the first plurality of resource elements on two continuous subcarriers, the second set including the second plurality of resource elements on two continuous subcarriers, the first set and second set being on non-overlapping subcarriers.
7. The method of claim 6 , wherein the first set of reference signal resources corresponds to a first portion of a first reference signal configuration; and
the second set of reference signal resources corresponds to a second portion of a second reference signal configuration.
8. The method of claim 7 , wherein the first reference signal configuration is at least a first channel state information-reference signal, CSI-RS, configuration; and
the second reference signal configuration is at least a second CSI-RS configuration different from the at least first CSI-RS configuration.
9. The method of claim 6 , wherein the CDM aggregation configuration is associated with indices corresponding to the aggregated first set and second set of reference signal resources.
10. The method of claim 6 , wherein the CDM aggregation configuration is an aggregation of two CDM-4 groups across CSI-RS port resource pairs.
11. A network node, comprising:
processing circuitry configured to:
determine a code division multiplexing (CDM) aggregation configuration, the CDM aggregation configuration corresponding to an aggregated first set and second set of reference signal resources in a subframe, each of the first set and second set of reference signal resources being a length 4 orthogonal cover code group;
signal the CDM aggregation configuration;
the aggregated first set and second set of reference signal resources satisfying a temporal criterion such that each resource element in the first set has up to a maximum time separation of six orthogonal frequency division multiplexing (OFDM) symbols with each resource element in the second set of reference signal resources, the first set including a first plurality of resource elements and the second set including a second plurality of resource elements on different OFDM symbols than the first set; and
the aggregated first set and second set of reference signal resources satisfying a frequency criterion such that each resource element in the first set has up to a maximum frequency separation of six subcarriers with each resource element in the second set of reference signal resources, the first set including the first plurality of resource elements on two continuous subcarriers, the second set including the second plurality of resource elements on two continuous subcarriers, the first set and second set being on non-overlapping subcarriers.
12. The network node of claim 11 , wherein the first set of reference signal resources corresponds to a first portion of a first reference signal configuration; and
the second set of reference signal resources corresponds to a second portion of a second reference signal configuration.
13. The network node of claim 12 , wherein the first reference signal configuration is at least a first channel state information-reference signal, CSI-RS, configuration; and
the second reference signal configuration is at least a second CSI-RS configuration different from the at least first CSI-RS configuration.
14. The network node of claim 11 , wherein the CDM aggregation configuration is associated with indices corresponding to the aggregated first set and second set of reference signal resources.
15. The network node of claim 11 , wherein the CDM aggregation configuration is an aggregation of two CDM-4 groups across CSI-RS port resource pairs.