# US 10,374,768 B2 · Efficient SRS resource indication methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,768 B2 - Document ID: US10374768B2 - Status: Granted - Kind: B2 - Application number: 16/195,959 - Filed: 2018-11-20 - Published: 2019-04-04 - Granted: 2019-08-06 - Earliest claimed: 2017-10-02 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget Lm Ericsson (Publ) - Inventors: Robert Mark Harrison; Sebastian Faxér; Andreas Nilsson; Sven Petersson - Web page: https://patentgrep.com/patent/US10374768B2 ## CPC - H04B 7/0421: {utilizing implicit feedback, e.g. steered pilot signals} - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04B 7/0456: Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting - H04B 7/0691: {using subgroups of transmit antennas} - H04L 5/0023: {Time-frequency-space} - H04L 5/005: {of common pilots, i.e. pilots destined for multiple users or terminals} - H04L 5/0091: {Signalling for the administration of the divided path, e.g. signalling of configuration information} - H04L 5/0092: {Indication of how the channel is divided} - H04W 72/21: in the uplink direction of a wireless link, i.e. towards the network - H04L 5/0007: {the frequencies being orthogonal, e.g. OFDM(A) or DMT} - H04L 5/1469: {using time-sharing} - H04W 72/046: {the resource being in the space domain, e.g. beams} - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A method of identifying reference signal resources to be used in a transmission by a wireless device is disclosed. The method comprises a wireless device receiving signaling configuring the wireless device with a plurality of reference signal resource groups, each group comprising a plurality of reference signal resources. The wireless device subsequently receives an indication, in a control channel, of a selection of reference signal resources to be used. Each of the plurality of reference signal resources to be used is selected from a different one of the plurality of reference signal resource groups such that reference signal resources belonging to the same reference signal resource group are not selected for simultaneous use. A reference signal is then transmitted to a network node in the network using the indicated selection of reference signal resources. ## Claims ### Claim 1 A method in a wireless device, operable in a cellular wireless communication network, of identifying reference signal resources to be used in a transmission by the wireless device, the method comprising: receiving signaling configuring the wireless device with a plurality of reference signal resource groups, each group comprising a plurality of reference signal resources; receiving an indication, in a control channel, of a selection of reference signal resources to be used, wherein each of the plurality of reference signal resources to be used is selected from a different one of the plurality of reference signal resource groups such that reference signal resources belonging to the same reference signal resource group are not selected for simultaneous use; and transmitting a reference signal to a network node in the network using the indicated selection of reference signal resources, wherein the indication of the plurality of reference signal resources to be used includes a bit field, the length of the bit field depending on a maximum number of MIMO layers that the wireless device is capable of transmitting and a number of reference signal resources in a corresponding one of the reference signal resource groups. ### Claim 2 (depends on 1) The method of claim 1, wherein the reference signal resources are sounding reference signal (SRS) resources. ### Claim 3 (depends on 1) The method of claim 1, wherein the transmitted reference signal is an SRS. ### Claim 4 (depends on 1) The method of claim 1, wherein the length of the bit field is sufficient to indicate S combinations of SRS resources, wherein: S = ∑ L = 1 L max ⁢ ( N L ) , and where Lmax is a maximum number of MIMO layers that the wireless device is capable of transmitting and N is the number of resources in the first reference signal resource group. ### Claim 5 (depends on 1) The method of claim 1, wherein the reference signal is transmitted for beam management usage. ### Claim 6 (depends on 1) The method of claim 1, wherein the wireless device includes multiple antenna panels, each one of the plurality of reference signal resource groups corresponding to a different one of the antenna panels. ### Claim 7 (depends on 1) The method of claim 1, wherein receiving signaling configuring the wireless device with a plurality of reference signal resource groups includes receiving a radio resource control message that defines a control channel trigger associated with the plurality of reference signal resource groups; and wherein receiving an indication, in a control channel, of a selection of reference signal resources to be used includes receiving a trigger associated with the plurality of reference signal resource groups and a resource indicator that indicates reference signal resources selected from among reference signal resources within the triggered plurality of reference signal resource groups. ### Claim 8 A wireless device for facilitating communications in a cellular wireless communication network by obtaining an indication of reference signal resources to be used, the wireless device comprising: a memory containing computer readable instructions; and processing circuitry configured to execute the computer readable instructions, whereby the wireless device is operable to: receive signaling that configures the wireless device with a plurality of reference signal resource groups, each group comprising a plurality of reference signal resources; receive an indication, in a control channel, of a selection of reference signal resources to be used, wherein each of the plurality of reference signal resources to be used is selected from a different one of the plurality of reference signal resource groups such that reference signal resources belonging to the same reference signal resource group are not selected for simultaneous use; and transmit a reference signal to a network node in the network using the indicated selection of reference signal resources, wherein the indication of the plurality of reference signal resources to be used includes a bit field, the length of the bit field depending on a maximum number of MIMO layers that the wireless device is capable of transmitting and a number of reference signal resources in a corresponding one of the reference signal resource groups. ### Claim 9 (depends on 8) The wireless device of claim 8, wherein the reference signal resources are sounding reference signal (SRS) resources. ### Claim 10 (depends on 8) The wireless device of claim 8, wherein the length of the bit field is sufficient to indicate S combinations of SRS resources, wherein: S = ∑ L = 1 L max ⁢ ( N L ) , and where Lmax is a maximum number of MIMO layers that the wireless device is capable of transmitting and N is the number of resources in the first reference signal resource group. ### Claim 11 (depends on 8) The wireless device of claim 8, wherein the reference signal is transmitted for beam management usage. ### Claim 12 (depends on 8) The wireless device of claim 8, wherein the wireless device includes multiple antenna panels, each one of the plurality of reference signal resource groups corresponding to a different one of the antenna panels. ### Claim 13 A method in a network node, of configuring and indicating use of reference signal transmission settings in a wireless device operable in a cellular wireless communication network, the method comprising: transmitting signaling configuring the wireless device with a plurality of reference signal resource groups, each group comprising a plurality of reference signal resources; and transmitting an indication, in a control channel, of a selection of reference signal resources to be used, wherein the network node selects each of the plurality of reference signal resources to be used from a different one of the plurality of reference signal resource groups such that reference signal resources belonging to the same reference signal resource group are not selected for simultaneous use; and receiving a reference signal from the wireless device using the indicated selection of reference signal resources, wherein the indication of the plurality of reference signal resources to be used includes a bit field, the length of the bit field depending on a maximum number of MIMO layers that the wireless device is capable of transmitting and a number of reference signal resources in a corresponding one of the reference signal resource groups. ### Claim 14 (depends on 13) The method of claim 13, wherein the reference signal resources are sounding reference signal (SRS) resources. ### Claim 15 (depends on 13) The method of claim 13, wherein the length of the bit field is sufficient to indicate combinations of SRS resources, wherein: S = ∑ L = 1 L ma ⁢ ⁢ x ⁢ ( N L ) , and where Lmax is a maximum number of MIMO layers that the wireless device is capable of transmitting and N is the number of resources in the first reference signal resource group. ### Claim 16 (depends on 13) The method of claim 13, wherein the received reference signal is used for beam management. ### Claim 17 (depends on 13) The method of claim 13, wherein the wireless device includes multiple antenna panels, each one of the plurality of reference signal resource groups corresponding to a different one of the antenna panels. ### Claim 18 (depends on 13) The method of claim 13, wherein transmitting signaling configuring the wireless device with a plurality of reference signal resource groups includes transmitting a radio resource control message that defines a control channel trigger associated with the plurality of reference signal resource groups; and wherein transmitting an indication, in a control channel, of a selection of reference signal resources to be used includes transmitting a trigger associated with the plurality of reference signal resource groups and a resource indicator that indicates reference signal resources selected from among reference signal resources within the triggered plurality of reference signal resource groups.