# US 10,374,847 B2 · Modulation coding scheme (MCS) indication in LTE uplink > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,847 B2 - Document ID: US10374847B2 - Status: Granted - Kind: B2 - Application number: 16/059,824 - Filed: 2018-08-09 - Published: 2018-12-27 - Granted: 2019-08-06 - Earliest claimed: 2014-04-25 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Wanshi Chen; Peter Gaal - Web page: https://patentgrep.com/patent/US10374847B2 ## CPC - H04L 27/0008: {arrangements for allowing a transmitter or receiver to use more than one type of modulation (negotiating modulation type for two-way transmission paths H04L5/1453)} - H04L 1/0003: {by switching between different modulation schemes} - H04L 1/0016: {involving special memory structures, e.g. look-up tables} - H04L 1/0025: {Transmission of mode-switching indication} - H04L 1/0029: {Reduction of the amount of signalling, e.g. retention of useful signalling or differential signalling (power control H04W52/04)} - H04L 1/0031: {Multiple signaling transmission (H04L1/1664, F15 take precedence)} - H04W 74/006: {in the downlink, i.e. towards the 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 Methods, systems, and devices for indicating a modulation coding scheme (MCS) in LTE are described. A user equipment (UE) may receive downlink control information (DCI) from an evolved Node B (eNB) that includes an uplink grant of resources. The DCI may be configured and have a format that conveys an MCS table reference. The UE may identify the MCS table reference and, based on the reference, identify a legacy MCS table or a non-legacy MCS table. The legacy MCS table may be associated with quadrature amplitude modulation (QAM) up to a first order, and the non-legacy MCS table may be associated with QAM up to a second order, the second order being higher than the first order. The UE may modulate and code information for uplink transmissions using the identified MCS table. ## Claims ### Claim 1 A method for wireless communications, comprising: determining, by a user equipment (UE), a search space of a physical downlink control channel (PDCCH) for receiving downlink control information (DCI); receiving the DCI comprising an uplink (UL) grant of resources for the UE, the DCI having a DCI format and configured to convey a modulation coding scheme (MCS) table reference; identifying an MCS table from a plurality of MCS tables based at least in part on the MCS table reference conveyed in the DCI; determining a modulation order for UL transmissions based at least in part on the search space of the PDCCH for receiving the DCI and the identified MCS table; and sending one or more UL transmissions according to the determined modulation order. ### Claim 2 (depends on 1) The method of claim 1, wherein the plurality of MCS tables comprise at least a legacy MCS table associated with quadrature amplitude modulation up to a first order and a non-legacy MCS table associated with quadrature amplitude modulation up to a second order, wherein the second order is higher than the first order. ### Claim 3 (depends on 1) The method of claim 1, further comprising: determining whether the DCI is included in a common search space or a UE-specific search space; and selecting a first MCS table based on the DCI being included in the common search space and selecting a second MCS table based on the DCI being included in the UE-specific search space. ### Claim 4 (depends on 3) The method of claim 3, wherein the second MCS table is a non-legacy MCS table associated with a modulation up to at least 256 quadrature amplitude modulation. ### Claim 5 (depends on 1) The method of claim 1, wherein the DCI conveys the MCS table reference based at least on one of a type of a control channel on which the DCI is communicated, a masking code used to mask the DCI, or a subframe of the PDCCH on which the DCI is communicated. ### Claim 6 (depends on 1) The method of claim 1, wherein the DCI format is one or more of a DCI format 0 or a DCI format 4. ### Claim 7 (depends on 1) The method of claim 1, further comprising: receiving a configuration of two or more enhanced physical downlink control channel (EPDCCH) resource sets; and selecting a first MCS table based on the DCI being communicated in a first EPDCCH resource set and selecting a second MCS table based on the DCI being communicated in a second EPDCCH resource set. ### Claim 8 (depends on 1) The method of claim 1, wherein identifying the MCS table comprises: identifying an MCS table index, and determining an entry of a first MCS table or a second MCS table based on the MCS table index, wherein the first MCS table and the second MCS table share one or more common entries. ### Claim 9 (depends on 1) The method of claim 1, further comprising: identifying one or more bits in the DCI, and wherein the determining the modulation order comprises determining the modulation order for the UL transmissions based at least in part on the search space of the PDCCH for receiving the DCI, the identified MCS table, and the identified one or more bits in the DCI. ### Claim 10 (depends on 1) The method of claim 1, further comprising: determining a power offset parameter associated with the identified MCS table, wherein a first power offset parameter is associated with a first MCS table and a second power offset parameter is associated with a second MCS table. ### Claim 11 (depends on 10) The method of claim 10, further comprising determining a transmit power for at least one of the one or more UL transmissions based on the power offset parameter. ### Claim 12 (depends on 1) The method of claim 1, further comprising: determining an uplink control information (UCI) offset parameter associated with the identified MCS table, wherein a first UCI offset parameter is associated with a first MCS table associated and a second UCI offset parameter is associated with a second MCS table. ### Claim 13 (depends on 12) The method of claim 12, further comprising determining a number of resource elements for multiplexing the UCI with at least one of the one or more UL transmissions based on the UCI offset parameter. ### Claim 14 (depends on 13) The method of claim 13, wherein the UCI comprises one or more of a hybrid automatic request repeat acknowledgement (HARQ-ACK), a rank indicator (RI), and a channel quality indicator (CQI). ### Claim 15 (depends on 1) The method of claim 1, wherein the identified MCS table is a non-legacy MCS table associated with a modulation up to at least 256 quadrature amplitude modulation. ### Claim 16 An apparatus for wireless communications, comprising: a processor; memory in communication with the processor; and instructions executable by the processor to: determine, by a user equipment (UE), a search space of a physical downlink control channel (PDCCH) for receiving downlink control information (DCI); receive the DCI comprising an uplink (UL) grant of resources for the UE, the DCI having a DCI format and configured to convey a modulation coding scheme (MCS) table reference; identify an MCS table from a plurality of MCS tables based at least in part on the MCS table reference conveyed in the DCI; determine a modulation order for UL transmissions based at least in part on the search space of the PDCCH for receiving the DCI and the identified MCS table; and send one or more UL transmissions according to the determined modulation order. ### Claim 17 (depends on 16) The apparatus of claim 16, wherein the plurality of MCS tables comprise at least a legacy MCS table being associated with quadrature amplitude modulation up to a first order and a non-legacy MCS table being associated with quadrature amplitude modulation up to a second order, wherein the second order is greater than the first order. ### Claim 18 (depends on 16) The apparatus of claim 16, wherein the instructions are further executable to: determine whether the DCI is included in a common search space or a UE-specific search space; and select a first MCS table based on the DCI being included in the common search space and selecting a second MCS table based on the DCI being included in the UE-specific search space. ### Claim 19 (depends on 18) The apparatus of claim 18, wherein the second MCS table is a non-legacy MCS table associated with a modulation up to at least 256 quadrature amplitude modulation. ### Claim 20 (depends on 16) The apparatus of claim 16, wherein the DCI conveys the MCS table reference based on one of a type of a control channel the DCI is communicated on, a masking code used to mask the DCI, or which subframe of the PDCCH on which the DCI is communicated. ### Claim 21 (depends on 16) The apparatus of claim 16, wherein the DCI format is one or more of a DCI format 0 or a DCI format 4. ### Claim 22 (depends on 16) The apparatus of claim 16, further comprising instructions executable to: receive a configuration of two or more enhanced physical downlink control channel (EPDCCH) resource sets; and select a first MCS table based on the DCI being communicated in a first EPDCCH resource set and selecting a second MCS table based on the DCI being communicated in a second EPDCCH resource set. ### Claim 23 (depends on 16) The apparatus of claim 16, wherein the instructions executable to identify the MCS table are further executable to: identify an MCS table index, and determine an entry of a first MCS table or a second MCS table based on the MCS table index, wherein the first MCS table and the second MCS table share one or more common entries. ### Claim 24 (depends on 16) The apparatus of claim 16, further comprising instructions executable to: identify one or more bits in the DCI, and wherein the instructions executable to determine the modulation order are further executable to determine the modulation order for the UL transmissions based at least in part on the search space of the PDCCH for receiving the DCI, the identified MCS table, and the identified one or more bits in the DCI. ### Claim 25 (depends on 16) The apparatus of claim 16, further comprising instructions executable to: determine a power offset parameter associated with the identified MCS table, wherein a first power offset parameter is associated with a first MCS table and a second power offset parameter is associated with a second MCS table. ### Claim 26 (depends on 25) The apparatus of claim 25, further comprising instructions executable to determine a transmit power for at least one of the one or more UL transmissions based on the power offset parameter. ### Claim 27 A non-transitory computer-readable medium for wireless communications storing instructions executable by a processor to: determine, by a user equipment (UE), a search space of a physical downlink control channel (PDCCH) for receiving downlink control information (DCI); receive the DCI comprising an uplink (UL) grant of resources for the UE, the DCI having a DCI format and configured to convey a modulation coding scheme (MCS) table reference; identify an MCS table from a plurality of MCS tables based at least in part on the MCS table reference conveyed in the DCI; determine a modulation order for UL transmissions based at least in part on the search space of the PDCCH for receiving the DCI and the identified MCS table; and send one or more UL transmissions according to the determined modulation order. ### Claim 28 A method for wireless communications, comprising: configuring downlink control information (DCI) to have a DCI format and to convey a modulation coding scheme (MCS) table reference; sending, to a user equipment (UE), the DCI in one of a common search space or a UE-specific search space of a physical downlink control channel (PDCCH), the DCI comprising an uplink (UL) grant of resources for the UE; and receiving, from the UE, one or more UL transmissions modulated according to a modulation order based at least in part on whether the DCI is sent in the common search space or the UE-specific search space of the PDCCH and an MCS table conveyed by the DCI. ### Claim 29 (depends on 28) The method of claim 28, further comprising: sending one or more bits in the DCI, and wherein the modulation order is based at least in part on whether the DCI is sent in the common search space or the UE-specific search space of the PDCCH, the MCS table conveyed by the DCI, and the one or more bits in the DCI. ### Claim 30 (depends on 28) The method of claim 28, wherein the DCI format is one or more of a DCI format 0 or a DCI format 4.