# US 12,015,465 B2 · Random access procedure based on CSI-RS selection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,015,465 B2 - Document ID: US12015465B2 - Status: Granted - Kind: B2 - Application number: 17/590,058 - Filed: 2022-02-01 - Published: 2022-05-19 - Granted: 2024-06-18 - Earliest claimed: 2017-08-10 - Assignees: Ofinno, LLC - Applicants: Ofinno, LLC - Inventors: Hyoungsuk Jeon; Esmael Hejazi Dinan; Kyungmin Park; Hua Zhou; Alireza Babaei - Web page: https://patentgrep.com/patent/US12015465B2 ## CPC - H04B 7/0626: {Channel coefficients, e.g. channel state information [CSI]} - H04J 11/0073: {Acquisition of primary synchronisation channel, e.g. detection of cell-ID within cell-ID group} - H04J 11/0076: {Acquisition of secondary synchronisation channel, e.g. detection of cell-ID group} - H04J 13/0062: {Zadoff-Chu} - H04W 56/0005: {synchronizing of arrival of multiple uplinks} - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04W 74/0838: using contention-free random access [CFRA] - H04B: TRANSMISSION - H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A wireless device transmits, to a base station, at least one first measurement report of at least one synchronization signal of a cell. An indication, of one or more channel state information reference signals (CSI-RSs) of the cell, is received from the base station based on: the at least one first measurement report. and a first antenna port of the one or more CSI-RSs being quasi-collocated with a second port of the at least one synchronization signal. Based on the indication, at least one second measurement report of the one or more CSI-RSs is transmitted. Based on the at least one second measurement report, a downlink control information is received that initiates a random access procedure of the cell based on at least one first CSI-RS from the one or more CSI-RSs. ## Claims ### Claim 1 A method comprising: transmitting, by a wireless device to a base station, at least one first measurement report of at least one synchronization signal of a cell; receiving, from the base station, an indication of one or more channel state information reference signals (CSI-RSs), of the cell, based on: the at least one first measurement report; and a first antenna port of the one or more CSI-RSs being quasi-collocated with a second port of the at least one synchronization signal; transmitting, based on the indication, at least one second measurement report of the one or more CSI-RSs; and receiving, based on the at least one second measurement report, a downlink control information initiating a random access procedure of the cell based on at least one first CSI-RS from the one or more CSI-RSs. ### Claim 2 (depends on 1) The method of claim 1, wherein the cell is a secondary cell. ### Claim 3 (depends on 1) The method of claim 1, wherein the at least one first measurement report indicates at least one first index of the at least one synchronization signal. ### Claim 4 (depends on 1) The method of claim 1, wherein the at least one first measurement report indicates at least one first received signal strength of the at least one synchronization signal. ### Claim 5 (depends on 1) The method of claim 1, wherein the at least one second measurement report indicates at least one second index of a second CSI-RS selected from the one or more CSI-RSs. ### Claim 6 (depends on 5) The method of claim 5, wherein the at least one second measurement report indicates at least one second received signal strength of the second CSI-RS. ### Claim 7 (depends on 1) The method of claim 1, further comprising receiving, from the base station and via the cell, the at least one synchronization signal, wherein each of the at least one synchronization signal comprises a primary synchronization signal and a secondary synchronization signal. ### Claim 8 (depends on 1) The method of claim 1, wherein the downlink control information is scrambled by a cell radio network temporary identifier. ### Claim 9 A wireless device comprising: one or more processors; and memory storing instructions that, when executed by the one or more processors, cause the wireless device to: transmit, to a base station, at least one first measurement report of at least one synchronization signal of a cell; receive, from the base station, an indication of one or more channel state information reference signals (CSI-RSs), of the cell, based on: the at least one first measurement report; and a first antenna port of the one or more CSI-RSs being quasi-collocated with a second port of the at least one synchronization signal; transmit, based on the indication, at least one second measurement report of the one or more CSI-RSs; and receive, based on the at least one second measurement report, a downlink control information initiating a random access procedure of the cell based on at least one first CSI-RS from the one or more CSI-RSs. ### Claim 10 (depends on 9) The wireless device of claim 9, wherein the cell is a secondary cell. ### Claim 11 (depends on 9) The wireless device of claim 9, wherein the at least one first measurement report indicates at least one first index of the at least one synchronization signal. ### Claim 12 (depends on 9) The wireless device of claim 9, wherein the at least one first measurement report indicates at least one first received signal strength of the at least one synchronization signal. ### Claim 13 (depends on 9) The wireless device of claim 9, wherein the at least one second measurement report indicates at least one second index of a second CSI-RS selected from the one or more CSI-RSs. ### Claim 14 (depends on 13) The wireless device of claim 13, wherein the at least one second measurement report indicates at least one second received signal strength of the second CSI-RS. ### Claim 15 (depends on 9) The wireless device of claim 9, wherein the instructions further cause the wireless device to receive, from the base station and via the cell, the at least one synchronization signal, and wherein each of the at least one synchronization signal comprises a primary synchronization signal and a secondary synchronization signal. ### Claim 16 (depends on 9) The wireless device of claim 9, wherein the downlink control information is scrambled by a cell radio network temporary identifier. ### Claim 17 A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors of a wireless device, cause the wireless device to: transmit, to a base station, at least one first measurement report of at least one synchronization signal of a cell; receive, from the base station, an indication of one or more channel state information reference signals (CSI-RSs), of the cell, based on: the at least one first measurement report; and a first antenna port of the one or more CSI-RSs being quasi-collocated with a second port of the at least one synchronization signal; transmit, based on the indication, at least one second measurement report of the one or more CSI-RSs; and receive, based on the at least one second measurement report, a downlink control information initiating a random access procedure of the cell based on at least one first CSI-RS from the one or more CSI-RSs. ### Claim 18 (depends on 17) The non-transitory computer-readable medium of claim 17, wherein the at least one first measurement report indicates at least one of: one first index of the at least one synchronization signal; or at least one first received signal strength of the at least one synchronization signal. ### Claim 19 (depends on 17) The non-transitory computer-readable medium of claim 17, wherein the at least one second measurement report indicates at least one second index of a second CSI-RS selected from the one or more CSI-RSs and at least one second received signal strength of the second CSI-RS. ### Claim 20 (depends on 17) The non-transitory computer-readable medium of claim 17, wherein the instructions further cause the wireless device to receive, from the base station and via the cell, the at least one synchronization signal, and wherein each of the at least one synchronization signal comprises a primary synchronization signal and a secondary synchronization signal.