# US 10,320,542 B2 · Method and device for transmitting control information to be used in terminal > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,320,542 B2 - Document ID: US10320542B2 - Status: Granted - Kind: B2 - Application number: 15/573,072 - Filed: 2015-10-30 - Published: 2018-05-17 - Granted: 2019-06-11 - Earliest claimed: 2015-06-18 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Sangrim Lee; Hojae Lee; Hyunsoo Ko; Kwangseok Noh; Dongkyu Kim - Web page: https://patentgrep.com/patent/US10320542B2 ## CPC - H04L 27/26265: {Arrangements for sidelobes suppression specially adapted to multicarrier systems, e.g. spectral precoding} - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04L 25/03019: {adaptive, i.e. capable of adjustment during data reception} - H04L 27/26412: {Filtering over the entire frequency band, e.g. filtered orthogonal frequency-division multiplexing [OFDM]} - H04L 27/2646: {using feedback from receiver for adjusting OFDM transmission parameters, e.g. transmission timing or guard interval length} - H04W 56/001: {Synchronization between nodes} - 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 - H04W 72/541: using the level of interference - H04L 5/0005: {Time-frequency} - H04L 5/0051: {of dedicated pilots, i.e. pilots destined for a single user or terminal} - H04L 27/2607: {Cyclic extensions} - H04W 4/70: Services for machine-to-machine communication [M2M] or machine type communication [MTC] - H04W 72/0453: Resources in frequency domain, e.g. a carrier in FDMA - 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 A method and a device for transmitting control information to be used in a terminal are provided. Specifically, an asynchronous level of a terminal supporting an asynchronous transmission mode is measured by using a signal received from the terminal. It is determined whether a measured value of the asynchronous level exceeds a threshold value, and if the asynchronous level is exceeded, a filter length and a CP length, which are to be used in the terminal, are changed. Information on the changed filter length and CP length is transmitted to the terminal. A sum of the filter length and the CP length is fixed, a characteristic of out-of-band emission improves when the filter becomes long in length, and interference occurring due to a multi-path delay can be prevented when the CP length becomes long. ## Claims ### Claim 1 A method for transmitting, by a base station, control information used in a user equipment, comprising: measuring an asynchronous level of a user equipment supporting an asynchronous transmission mode by using a signal received from the user equipment; determining whether or not the measured value of the asynchronous level exceeds a threshold value; in case the measured value of the asynchronous level exceeds the threshold value, varying a filter length and a cyclic prefix (CP) length being used by the user equipment; transmitting information on the varied filter length and CP duration to the user equipment; and wherein a sum of the filter length and the CP duration corresponds to a fixed value. ### Claim 2 (depends on 1) The method of claim 1, wherein, in case the user equipment supports the asynchronous transmission mode, the user equipment performs random access to the base station instead of receiving timing advance (TA) information being related to its time-based synchronization with the base station. ### Claim 3 (depends on 2) The method of claim 2, wherein the TA information is determined based on a delay length (or level of latency) of the signal received from the user equipment. ### Claim 4 (depends on 1) The method of claim 1, wherein the user equipment comprises: a CP inserting unit being connected to an IDFT block performing IDFT in frequency resource block units, and a filter being connected to the CP inserting unit. ### Claim 5 (depends on 1) The method of claim 1, wherein the CP duration is shorter than a length of an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single-Carrier Frequency Division Multiplexing (SC-FDMA) symbol, and wherein the CP having the corresponding CP duration is positioned in-between the OFDM symbols or the SC-FDMA symbols. ### Claim 6 (depends on 1) The method of claim 1, wherein, in case the measured value of the asynchronous level does not exceed the threshold value, the filter length and the CP duration being used by the user equipment are maintained without modification. ### Claim 7 (depends on 1) The method of claim 1, wherein the threshold value is pre-designated by the base station. ### Claim 8 (depends on 1) The method of claim 1, wherein the measured value of the asynchronous level is indicated as a maximum difference value between reception points of signals received from the user equipment. ### Claim 9 (depends on 1) The method of claim 1, wherein the signal received from the user equipment is received through a Physical Random Access Channel (PRACH) or a Sounding Reference Signal (SRS). ### Claim 10 (depends on 1) The method of claim 1, wherein the information on the varied filter length and CP duration is received through a Physical Broadcast Channel (PBCH), a physical layer signal, or a higher layer signal. ### Claim 11 A wireless device transmitting control information used in a user equipment, comprising: radio frequency (RF) unit transmitting and receiving radio signals; and a processor being operatively connected to the RF unit; wherein the processor is configured: to measure an asynchronous level of a user equipment supporting an asynchronous transmission mode by using a signal received from the user equipment, to determine whether or not the measured value of the asynchronous level exceeds a threshold value, in case the measured value of the asynchronous level exceeds the threshold value, to vary a filter length and a cyclic prefix (CP) length being used by the user equipment, and to transmit information on the varied filter length and CP duration to the user equipment; and wherein a sum of the filter length and CP duration corresponds to a fixed value.