# US 12,004,210 B2 · Triggering of aperiodic channel state information reference signals with mixed numerology > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,004,210 B2 - Document ID: US12004210B2 - Status: Granted - Kind: B2 - Application number: 17/298,890 - Filed: 2019-12-02 - Published: 2022-02-03 - Granted: 2024-06-04 - Earliest claimed: 2018-11-30 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget Lm Ericsson (Publ) - Inventors: Sebastian Faxér; Sorour Falahati; Robert Baldemair - Web page: https://patentgrep.com/patent/US12004210B2 ## CPC - H04L 5/005: {of common pilots, i.e. pilots destined for multiple users or terminals} - H04W 72/542: using measured or perceived quality - H04L 5/0051: {of dedicated pilots, i.e. pilots destined for a single user or terminal} - H04L 27/26025: {Numerology, i.e. varying one or more of symbol duration, subcarrier spacing, Fourier transform size, sampling rate or down-clocking (allocating sub-channels of the transmission path H04L5/003)} - H04W 72/0446: Resources in time domain, e.g. slots or frames - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04L 5/0007: {the frequencies being orthogonal, e.g. OFDM(A) or DMT} - H04L 5/0057: {Physical resource allocation for CQI} - 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 Devices, systems, and methods described herein may improve aperiodic CSI-RS handling in mixed numerology environments. An exemplary method includes operations of receiving a downlink control information (DCI) message carried by a Physical Downlink Control Channel (PDCCH) on a second carrier, wherein the second carrier uses a second OFDM numerology, obtaining an aperiodic CSI-RS slot offset from the DCI message, determining a reference slot in the first numerology, determining the slot of the aperiodic CSI-RS based on the reference slot and the aperiodic CSI-RS slot offset, and receiving or transmitting the aperiodic CSI-RS in the determined slot. ## Claims ### Claim 1 A method, performed by a wireless device, for receiving an aperiodic channel state information reference signal (CSI-RS) on a first carrier, where the first carrier uses a first orthogonal frequency division multiplexing (OFDM) numerology, the method comprising, receiving a downlink control information (DCI) message carried by a Physical Downlink Control Channel (PDCCH) on a second carrier, wherein the second carrier uses a second OFDM numerology; obtaining an aperiodic CSI-RS slot offset from the DCI message; determining a reference slot in the first numerology; determining the slot of the aperiodic CSI-RS based on the reference slot and the aperiodic CSI-RS slot offset; and receiving or transmitting the aperiodic CSI-RS in the determined slot. ### Claim 2 (depends on 1) The method of claim 1, wherein the first OFDM numerology is different from the second OFDM numerology. ### Claim 3 (depends on 1) The method of claim 1, wherein the OFDM numerology is characterized by its subcarrier spacing. ### Claim 4 (depends on 1) The method of claim 1, where additionally the wireless device transmits a Channel State Information (CSI) report based on a measurement of the received aperiodic CSI-RS. ### Claim 5 (depends on 1) The method of claim 1, wherein the slot of the aperiodic CSI-RS is determined as the slot X slots later than the reference slot, where X is the aperiodic CSI-RS slot offset. ### Claim 6 (depends on 1) The method of claim 1, wherein determining the slot of the aperiodic CSI-RS based on the reference slot and the aperiodic CSI-RS slot offset comprises calculating a slot ⌈ ( n + 1 ) ⁢ 2 μ CSIRS 2 μ P ⁢ D ⁢ C ⁢ C ⁢ H - 1 ⌉ + X , wherein: n is the slot with the triggering DCI in the numerology of the PDCCH, X is the CSI-RS triggering offset in the numerology of CSI-RS according to the higher layer parameter aperiodicTriggeringOffset, and μCSIRS and μPDCCH are the subcarrier spacing configurations for CSI-RS and PDCCH, respectively. ### Claim 7 A user equipment (UE) for receiving an aperiodic channel state information reference signal (CSI-RS) on a first carrier, where the first carrier uses a first orthogonal frequency division multiplexing (OFDM) numerology, the UE comprising: an antenna configured to send and receive wireless signals; radio front-end circuitry connected to the antenna and to processing circuitry, and configured to condition signals communicated between the antenna and the processing circuitry; the processing circuitry being configured to perform operations comprising: receiving a downlink control information (DCI) message carried by a Physical Downlink Control Channel (PDCCH) on a second carrier, wherein the second carrier uses a second OFDM numerology; obtaining an aperiodic CSI-RS slot offset from the DCI message; determining, on the first carrier, a reference slot in the first numerology; determining the slot of the aperiodic CSI-RS based on the reference slot and the aperiodic CSI-RS slot offset; and receiving the aperiodic CSI-RS in the determined slot of the aperiodic CSI-RS or transmitting an associated CSI-RS report in the determined slot; and a battery connected to the processing circuitry and configured to supply power to the UE. ### Claim 8 (depends on 7) The user equipment of claim 7, wherein the first OFDM numerology is different from the second OFDM numerology. ### Claim 9 (depends on 7) The user equipment of claim 7, wherein the OFDM numerology is characterized by its subcarrier spacing. ### Claim 10 (depends on 7) The user equipment of claim 7, where the wireless device transmits a Channel State Information (CSI) report based on a measurement of the received aperiodic CSI-RS. ### Claim 11 (depends on 1) The method of claim 1, wherein the slot of the aperiodic CSI-RS is determined as the slot X slots later than the reference slot, where X is the aperiodic CSI-RS slot offset. ### Claim 12 (depends on 1) The method of claim 1, wherein determining the slot of the aperiodic CSI-RS based on the reference slot and the aperiodic CSI-RS slot offset comprises calculating a slot ⌈ ( n + 1 ) ⁢ 2 μ CSIRS 2 μ P ⁢ D ⁢ C ⁢ C ⁢ H - 1 ⌉ + X , wherein: n is the slot with the triggering DCI in the numerology of the PDCCH, X is the CSI-RS triggering offset in the numerology of CSI-RS according to the higher layer parameter aperiodicTriggeringOffset, and μCSIRS and μPDCCH are the subcarrier spacing configurations for CSI-RS and PDCCH, respectively. ### Claim 13 A communication system comprising: processing circuitry configured to provide user data; and a communication interface configured to forward the user data to a cellular network for transmission to a user equipment (UE), wherein the cellular network comprises at least a first base station and a second base station, the first and second base stations having radio interfaces and processing circuitry, wherein the first base station transmits via a first carrier and the second base station transmits via a second carrier the processing circuitry being configured to: transmit a downlink control information (DCI) message carried by a Physical Downlink Control Channel (PDCCH) on the first carrier, wherein the DCI message includes an aperiodic CSI-RS slot offset; transmitting the aperiodic CSI-RS in the determined slot of the aperiodic CSI-RS on the second carrier according to an aperiodic CSI-RS slot offset. ### Claim 14 (depends on 13) The communication system of claim 13, wherein the first base station and the second base station are non-collocated base stations. ### Claim 15 (depends on 13) The communication system of claim 13, further including the UE, wherein the UE is configured to communicate with the base station. ### Claim 16 A method, performed by a base station, for transmitting an aperiodic channel state information reference signal (CSI-RS) on a first carrier, the method comprising, transmitting a downlink control information (DCI) message carried by a Physical Downlink Control Channel (PDCCH) on a second carrier, wherein the DCI message includes an aperiodic CSI-RS slot offset; transmitting the aperiodic CSI-RS in the determined slot of the aperiodic CSI-RS according to the aperiodic CSI-RS slot offset. ### Claim 17 (depends on 16) The method of claim 16, wherein the first carrier uses a first OFDM numerology and the second carrier uses a second OFDM numerology that is different than the first OFDM numerology. ### Claim 18 (depends on 17) The method of claim 17, wherein the first OFDM numerology and the second OFDM numerology are characterized by respective subcarrier spacings. ### Claim 19 (depends on 16) The method of claim 16, further comprising receiving, from a wireless device, a Channel State Information (CSI) report based on a measurement of the received aperiodic CSI-RS. ### Claim 20 (depends on 16) The method of claim 16, wherein the slot of the aperiodic CSI-RS is determined as the slot X slots later than the reference slot, where X is the aperiodic CSI-RS slot offset.