# US 12,224,884 B2 · DMRS-free operation of new radio (NR) shared channels > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,224,884 B2 - Document ID: US12224884B2 - Status: Granted - Kind: B2 - Application number: 17/712,934 - Filed: 2022-04-04 - Published: 2023-10-05 - Granted: 2025-02-11 - Earliest claimed: 2022-04-04 - Assignees: Charter Communications Operating, LLC - Applicants: Charter Communications Operating, LLC - Inventors: Amitav Mukherjee - Web page: https://patentgrep.com/patent/US12224884B2 ## CPC - H04L 25/0204: {of multiple channels} - H04L 5/0044: {Allocation of payload; Allocation of data channels, e.g. PDSCH or PUSCH} - H04L 5/0051: {of dedicated pilots, i.e. pilots destined for a single user or terminal} - H04L 5/0094: {Indication of how sub-channels of the path are allocated} - 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: 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 One or more shared data channels, e.g., PDSCH, PUSCH, PSSCH, are configured to be DMRS-free, thus allowing the resources which would be used for DMRS to be used to convey additional traffic data signals. Channel estimation based on control channel DMRS, e.g., PDCCH DMRS, PUCCH DMRS, or PSSCH/PSCCH DMRS, is used to demodulate and/or decode the traffic channel signals communicated on the DMRS-free shared traffic channel resources. Antenna port hopping is implemented as part of the PDCCH configuration to support a DMRS-free PDSCH. The antenna port hopping of the PDCCH is used to obtain a set of channel estimates based on PDDCH DMRS corresponding to different antenna ports which will match the antenna ports used for the PDSCH. ## Claims ### Claim 1 A method of operating a base station, the method comprising: transmitting to a first user equipment (UE) information indicating a physical downlink control channel (PDCCH) configuration to be used as part of a demodulation reference signal (DMRS) free physical downlink shared channel (PDSCH) reception mode of operation to be implemented by the first user equipment (UE); and transmitting to the first UE, on PDCCH resources, i) PDCCH control information and ii) DMRS signals. ### Claim 2 (depends on 1) The method of claim 1, wherein transmitting to a first user equipment (UE) information indicating a PDCCH configuration to be used includes transmitting PDCCH configuration information indicating at least a number of ports to be used for PDCCH operation. ### Claim 3 (depends on 2) The method of claim 2, wherein transmitting to a first user equipment (UE) information indicating a PDCCH configuration to be used further includes transmitting information indicating a port hopping sequence to be used for PDCCH operation. ### Claim 4 (depends on 3) The method of claim 3, wherein the PDCCH control information indicates DMRS free PDSCH resources allocated to the first UE. ### Claim 5 (depends on 4) The method of claim 4, further comprising: transmitting PDSCH signals to the first UE on the DMRS free PDSCH resources allocated to the first UE. ### Claim 6 (depends on 1) The method of claim 1, wherein transmitting to the first UE, on PDDCH resources, i) PDCCH control information and ii) DMRS signals includes: identifying a first particular antenna port for a first upcoming PDCCH time interval portion in accordance with the PDCCH configuration indicated to the first UE; and transmitting at least some: i) PDCCH control information and ii) DMRS signals to the first UE using the first particular antenna port. ### Claim 7 (depends on 6) The method of claim 6, wherein said identifying a first particular antenna port is based on a port hopping pattern indicated to the first UE. ### Claim 8 (depends on 6) The method of claim 6, further comprising: determining that there is another upcoming PDCCH time interval portion; identifying a second particular antenna port for the additional upcoming PDCCH time interval portion in accordance with the PDCCH configuration indicated to the first UE; and transmitting i) PDCCH control information and ii) DMRS signals to the first UE using the second particular antenna port. ### Claim 9 A base station comprising: a wireless transmitter; and a processor configured to: operate the base station to transmit to a first user equipment (UE) information indicating a physical downlink control channel (PDCCH) configuration to be used as part of a demodulation reference signal (DMRS) free physical downlink shared channel (PDSCH) reception mode of operation to be implemented by the first UE; and operate the base station to transmit to the first UE, on PDCCH resources, i) PDCCH control information and ii) DMRS signals. ### Claim 10 (depends on 9) The base station of claim 9, wherein said processor is further configured to: operate the base station to transmit PDCCH configuration information indicating at least a number of ports to be used for PDCCH operation, as part of being configured to operate the base station to transmit to a first user equipment (UE) information indicating a PDCCH configuration to be used. ### Claim 11 (depends on 10) The base station of claim 10, wherein said processor is further configured to: operate the base station to transmit information indicating a port hopping sequence to be used for PDCCH operation, as part of being configured to operate the base station to transmit to first user equipment (UE) information indicating a PDCCH configuration to be used. ### Claim 12 (depends on 11) The base station of claim 11, wherein the PDCCH control information indicates DMRS free PDSCH resources allocated to the first UE. ### Claim 13 (depends on 12) The base station of claim 12, wherein said processor is further configured to: operate the base station to transmit PDSCH signals to the first UE on the DMRS free PDSCH resources allocated to the first UE. ### Claim 14 (depends on 9) The base station of claim 9, wherein said processor is further configured to: identify a first particular antenna port for a first upcoming PDCCH time interval portion in accordance with the PDCCH configuration indicated to the first UE; and operate the base station to transmit at least some i) PDCCH control information and ii) DMRS signals to the first UE using the first particular antenna port, as part of being configured to operate the base station to transmit to the first UE, on PDCCH resources, i) PDCCH control information and ii) DMRS signals. ### Claim 15 A method of operating a user equipment (UE) comprising: receiving from a base station information indicating a demodulation reference signal free (DMRS-free) physical downlink shared channel (PDSCH) reception mode of operation to be used and physical downlink control channel (PDCCH) configuration information corresponding to said DMRS-free PDSCH reception mode of operation; and receiving PDSCH signals including traffic data directed to the UE on DMRS-free PDSCH resources allocated to the UE. ### Claim 16 (depends on 15) The method of claim 15, wherein the PDSCH resources allocated to the UE do not include any DMRS resources. ### Claim 17 (depends on 15) The method of claim 15, wherein said received PDCCH configuration information indicates a number of ports and a port hopping sequence to be used for PDCCH signals. ### Claim 18 (depends on 17) The method of claim 17, further comprising: receiving first PDCCH signals including first PDCCH control signals and first PDCCH DMRS signals corresponding to a first port during a first PDCCH time interval portion; and making a first downlink (DL) channel estimate based on PDCCH DMRS signals received during the first PDCCH time interval portion. ### Claim 19 (depends on 18) The method of claim 18, further comprising: storing the first DL channel estimate corresponding to the first antenna port. ### Claim 20 (depends on 19) The method of claim 19, further comprising: demodulating received PDSCH signals using at least said first DL channel estimate corresponding to the first port. ### Claim 21 (depends on 20) The method of claim 20, further comprising: decoding received PDSCH signals using said first DL channel estimate. ### Claim 22 (depends on 21) The method of claim 21, wherein demodulating includes using a channel estimate derived from PDCCH DMRS corresponding an antenna port which is the same as an antenna port used to transmit the PDSCH signal communicating traffic data directed to the UE. ### Claim 23 (depends on 20) The method of claim 20, further comprising: receiving second PDCCH signals including second PDCCH control signals and second PDCCH DMRS signals corresponding to a second port during a second PDCCH time interval portion; and making a second DL channel estimate based on PDCCH DMRS signals received during the second PDCCH time interval portion. ### Claim 24 A user equipment (UE) comprising: a wireless receiver; a memory; and a processor configured to: operate the UE to receive from a base station information indicating a demodulation reference signal free (DMRS-free) physical downlink shared channel (PDSCH) reception mode of operation to be used and physical downlink control channel (PDCCH) configuration information corresponding to said DMRS-free PDSCH reception mode of operation; and operate the UE to receive PDSCH signals including traffic data directed to the UE on DMRS-free PDSCH resources allocated to the UE. ### Claim 25 (depends on 24) The UE of claim 24, wherein said received PDCCH configuration information indicates a number of ports and a port hopping sequence to be used for PDCCH signals. ### Claim 26 (depends on 25) The UE of claim 25, wherein said processor is further configured to: operate the UE to receive first PDCCH signals including first PDCCH control signals and first PDCCH DMRS signals corresponding to a first port during a first PDCCH time interval portion; and make a first downlink (DL) channel estimate based on PDCCH DMRS signals received during the first PDCCH time interval portion. ### Claim 27 (depends on 26) The UE of claim 26, wherein said processor is further configured to: store, in memory, the first DL channel estimate corresponding to the first antenna port. ### Claim 28 (depends on 27) The UE of claim 27, wherein the processor is further configured to: operate the UE to demodulate received PDSCH signals using at least said first DL channel estimate corresponding to the first port. ### Claim 29 (depends on 28) The UE of claim 28, wherein said processor is further configured to: decode received PDSCH signals using said first DL channel estimate; and wherein demodulating includes using a channel estimate derived from PDCCH DMRS corresponding an antenna port which is the same as an antenna port used to transmit the PDSCH signal communicating traffic data directed to the UE. ### Claim 30 (depends on 28) The UE of claim 28, wherein said processor is further configured to: operate the UE to receive second PDCCH signals including second PDCCH control signals and second PDCCH DMRS signals corresponding to a second port during a second PDCCH time interval portion; and make a second DL channel estimate based on PDCCH DMRS signals received during the second PDCCH time interval portion.