# US 10,873,413 B2 · Apparatus and method for link adaptation in uplink grant-less random access > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,873,413 B2 - Document ID: US10873413B2 - Status: Granted - Kind: B2 - Application number: 16/194,972 - Filed: 2018-11-19 - Published: 2019-03-21 - Granted: 2020-12-22 - Earliest claimed: 2015-05-28 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Liqing Zhang; Kelvin Kar Kin Au; Jianglei Ma - Web page: https://patentgrep.com/patent/US10873413B2 ## CPC - H04L 1/0003: {by switching between different modulation schemes} - H04B 7/18543: {for adaptation of transmission parameters, e.g. power control (for detecting or preventing errors in the information received H04L1/00)} - H04L 1/0009: {by adapting the channel coding (H04L1/1812 takes precedence)} - H04L 1/0025: {Transmission of mode-switching indication} - H04L 5/0057: {Physical resource allocation for CQI} - H04L 5/006: {Quality of the received signal, e.g. BER, SNR, water filling} - H04L 1/0016: {involving special memory structures, e.g. look-up tables} - H04W 74/0833: Random access procedures, e.g. with 4-step access - Y02D 30/50: in wire-line communication networks, e.g. low power modes or reduced link rate - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04B: TRANSMISSION - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE ## Abstract Embodiments are provided for a scheme of link adaptation (LA) in uplink grant-less random access (RA) communications. The scheme includes changing a modulation and coding (MCS) of a user, instead of using a fixed MCS over time, as the user link, channel, or non-link conditions vary during the RA communications. In an embodiment, a transmission point (TP) receives from a UE a packet encoded using a MCS, and detects a condition associated with uplink measurements or other non-link based condition of the UE. The TP then initiates an upgrade or a downgrade of the MCS in accordance with the condition, and signals the UE indicating a second MCS as a result. The UE thus sends a second packet encoded using the second MCS. In another embodiment, the UE initiates the MCS change in accordance to detecting a link or non-link based condition, such as change of mobility. ## Claims ### Claim 1 A method for realizing device-to-device communication relay selection, comprising: receiving, by a user equipment, relay-related information sent by a relay node; selecting or configuring, by the user equipment, an access relay node; and in response to determining that the user equipment has not selected the access relay node, or the user equipment has already selected the access relay node and a measurement result that is obtained by the user equipment by performing a measurement on the relay-related information sent by the selected access relay node is less than a relay reselection device-to-device communication link threshold, the user equipment monitoring a relay reception resource pool and receiving the relay-related information sent by the relay node, wherein the relay-related information comprises at least one of: a relay usable time period of the relay node; a relay charging demand of the relay node. ### Claim 2 (depends on 1) The method of claim 1, wherein the network component is one of a base station or a network controller. ### Claim 3 (depends on 1) The method of claim 1, further comprising: before the assigning the first MCS, assigning, to the UE, an initial MCS of the second plurality of MCSs based on the second LUT and the UE; receiving, from the UE, an initial packet encoded using the initial MCS; and measuring the first link quality based on the received initial packet. ### Claim 4 (depends on 1) The method of claim 1, wherein the plurality of link qualities are a plurality of channel quality indicator (CQI) values. ### Claim 5 (depends on 1) The method claim 1, further comprising: before the assigning, measuring the first link quality associated with the UE; and after the assigning, transmitting the first MCS to the UE via a radio resource control (RRC) signal. ### Claim 6 (depends on 1) The method of claim 1, further comprising: measuring a second link quality associated with the UE, the second link quality being higher than the first link quality; assigning, by the network component to the UE, a second MCS of the first plurality of MCSs based on the first LUT and the second link quality, the second MCS being less robust than the first MCS; and receiving, from the UE, a second packet encoded using the second MCS. ### Claim 7 (depends on 6) The method of claim 6, further comprising: measuring a third link quality associated with the UE, the third link quality being lower than the first link quality; assigning, by the network component to the UE, a third MCS of the first plurality of MCSs based on the first LUT and the third link quality, the third MCS being more robust than the first MCS; and receiving, from the UE, a third packet encoded using the third MCS. ### Claim 8 (depends on 1) The method of claim 1, further comprising: transmitting, to the UE, a link adaptation (LA) condition associated with UE transmission or application quality, wherein the LA condition comprises one or more of a long-term link quality measurement, a mobility of the UE, or a quality of service (QoS) requirement for an application of the UE. ### Claim 9 (depends on 1) The method of claim 1, wherein the first LUT is used for slow link adaptation (LA), and the second LUT is used for short term LA. ### Claim 10 A network component for link adaptation, the network component comprising: at least one processor; and a non-transitory computer readable storage medium storing programming for execution by the at least one processor, the programming including instructions for: establishing a first look-up table (LUT) associating a plurality of link qualities with a first plurality of modulation and coding schemes (MCSs); establishing a second LUT associating a plurality of user equipments (UEs) with a second plurality of MCSs, wherein a number of entries in the first LUT is fewer than a number of entries in the second LUT; assigning, to a UE, a first MCS of the first plurality of MCSs based on the first LUT and a first link quality associated with the UE; and receiving, from the UE, a first packet in a grant free transmission, the first packet encoded using the first MCS assigned by the network component. ### Claim 11 A method for realizing device-to-device communication relay selection, comprising: sending or preconfiguring, by a network control node through broadcasting or dedicated signaling, a relay reception resource pool and/or a relay selection threshold, to make a user equipment receive relay-related information sent by a relay node and select or configure an access relay node; wherein the relay selection threshold comprises a relay reselection hysteresis value; and wherein the relay-related information comprises at least one of: a relay usable time period of the relay node; and a relay charging demand of the relay node. ### Claim 12 (depends on 10) The network component of claim 10, the programming further including instructions for: before the assigning the first MCS, assigning, to the UE, an initial MCS of the second plurality of MCSs based on the second LUT and the UE; receiving, from the UE, an initial packet encoded using the initial MCS; and measuring the first link quality based on the received initial packet. ### Claim 13 A user equipment, comprising a processor and a storage device, wherein the storage device communicably connected with the processor and configured for storing processor-executable instructions executable by the processor; wherein the processor-executable instructions when executed by the processor causes the processor to perform a method for realizing device-to-device communication relay selection, wherein the method comprises: receiving, by a user equipment, relay-related information sent by a relay node; and selecting or configuring, by the user equipment, an access relay node; in response to determining that the user equipment has not selected the access relay node, or the user equipment has already selected the access relay node and a measurement result that is obtained by the user equipment by performing a measurement on the relay-related information sent by the selected access relay node is less than a relay reselection device-to-device communication link threshold, the user equipment monitoring a relay reception resource pool and receiving the relay-related information sent by the relay node, wherein the relay-related information comprises at least one of: a relay usable time period of the relay node; a relay charging demand of the relay node. ### Claim 14 (depends on 10) The network component of claim 10, the programming further including instructions for: before the assigning, measuring the first link quality associated with the UE; and after the assigning, transmitting the first MCS to the UE via a radio resource control (RRC) signal. ### Claim 15 (depends on 10) The network component of claim 10, the programming further including instructions for: measuring a second link quality associated with the UE, the second link quality being higher than the first link quality; assigning, to the UE, a second MCS of the first plurality of MCSs based on the first LUT and the second link quality, the second MCS being less robust than the first MCS; and receiving, from the UE, a second packet encoded using the second MCS. ### Claim 16 (depends on 15) The network component of claim 15, the programming further including instructions for: measuring a third link quality associated with the UE, the third link quality being lower than the first link quality; assigning, to the UE, a third MCS of the first plurality of MCSs based on the first LUT and the third link quality, the third MCS being more robust than the first MCS; and receiving, from the UE, a third packet encoded using the third MCS. ### Claim 17 (depends on 10) The network component of claim 10, the programming further including instructions for: transmitting, to the UE, a link adaptation (LA) condition associated with UE transmission or application quality, wherein the LA condition comprises one or more of a long-term link quality measurement, a mobility of the UE, or a quality of service (QoS) requirement for an application of the UE. ### Claim 18 (depends on 10) The network component of claim 10, wherein the first LUT is used for slow link adaptation (LA), and the second LUT is used for short term LA. ### Claim 19 A non-transitory computer-readable device having instructions stored thereon that, when executed by a network component, cause the network component to perform operations, the operations comprising: establishing a first look-up table (LUT) associating a plurality of link qualities with a first plurality of modulation and coding schemes (MCSs); establishing a second LUT associating a plurality of user equipments (UEs) with a second plurality of MCSs, wherein a number of entries in the first LUT is fewer than a number of entries in the second LUT; assigning, to a UE, a first MCS of the first plurality of MCSs based on the first LUT and a first link quality associated with the UE; and receiving, from the UE, a first packet in a grant free transmission, the first packet encoded using the first MCS assigned by the network component. ### Claim 20 (depends on 19) The non-transitory computer-readable device of claim 19, wherein the network component is one of a base station or a network controller. ### Claim 21 (depends on 1) The method of claim 1, wherein the first link quality is based on an uplink (UL) channel measurement of a reference signal, and wherein the reference signal comprises a sounding reference signal (SRS).