# US 10,455,580 B2 · Method for determining carrier center frequency and apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,455,580 B2 - Document ID: US10455580B2 - Status: Granted - Kind: B2 - Application number: 15/926,764 - Filed: 2018-03-20 - Published: 2018-08-23 - Granted: 2019-10-22 - Earliest claimed: 2015-11-06 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Zhe Jin; Qian Wu - Web page: https://patentgrep.com/patent/US10455580B2 ## CPC - H04W 72/0453: Resources in frequency domain, e.g. a carrier in FDMA - H04J 11/0069: {Cell search, i.e. determining cell identity [cell-ID] (design of multiplexing codes H04J13/00; processing access restriction or access information H04W48/16; discovery of network devices for network data management H04W8/005; sounding signals for channel estimation H04L25/0226; structure of reference signals in multicarrier modulation systems H04L27/2613; frame, time or carrier synchronisation in multicarrier modulation systems H04L27/2655)} - H04L 27/2657: {Carrier synchronisation} - H04W 48/10: using broadcasted information - Y02D 30/70: in wireless communication networks - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - 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 The present application relates to the mobile communications field, and in particular, to a technology for determining a carrier center frequency in a wireless communications system. In a method for determining a carrier center frequency, a carrier center frequency used by a base station and UE to communicate is determined according to a frequency band starting frequency, an absolute radio frequency channel number, a frequency band offset, and a relative radio frequency channel number. According to a solution provided in this application, a time for searching for a cell by a terminal can be reduced, power consumption of the terminal can be reduced, and a battery life can be extended. ## Claims ### Claim 1 A method for determining a carrier center frequency, comprises: determining a frequency band starting frequency, an absolute radio frequency channel number, a frequency band offset, and a relative radio frequency channel number; and determining the carrier center frequency according to the frequency band starting frequency, the absolute radio frequency channel number, the frequency band offset, and the relative radio frequency channel number that are determined, wherein, when the carrier center frequency is a downlink carrier center frequency FNBDL, determining the carrier center frequency comprises: FNBDL=FDL_low+0.1*(NDL−NOffs-DL)+0.0025*(2MDL+1); wherein FDL_low is a downlink frequency band starting frequency, NDL is a downlink absolute radio frequency channel number, and NOffs-DL is a downlink frequency band offset; and MDL is a downlink relative radio frequency channel number, a value range of which comprises any one in the following set: −10, −9, −8, −7, −6, −5, −4, −3, −2, −1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9; or wherein, when the carrier center frequency is an uplink carrier center frequency FNBUL, determining the carrier center frequency comprises: FNBUL=FUL_low+0.1*(NUL−NOffs-UL)+0.0025*(2MUL); wherein FUL_low is an uplink frequency band starting frequency, NUL is an uplink absolute radio frequency channel number, and NOffs-UL is an uplink frequency band offset; and MUL is an uplink relative radio frequency channel number, a value range of which comprises any one in the following set: −10, −9, −8, −7, −6, −5, −4, −3, −2, −1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. ### Claim 2 User equipment (UE) comprises: a processor configured to determine a frequency band starting frequency, an absolute radio frequency channel number, a frequency band offset, and a relative radio frequency channel number; determine a carrier center frequency according to the frequency band starting frequency, the absolute radio frequency channel number, the frequency band offset, and the relative radio frequency channel number that are determined; and a transmitter configured to cooperate with the processor to exchange a signal with a base station according to the determined carrier center frequency; wherein the carrier center frequency is a downlink carrier center frequency FNBDL, and the processor determines the carrier center frequency according to: FNBDL=FDL_low+0.1*(NDL−NOffs-DL)+0.0025*(2MDL+1); wherein FDL_low is a downlink frequency band starting frequency, NDL is a downlink absolute radio frequency channel number, and NOffs-DL is a downlink frequency band offset; and MDL is a downlink relative radio frequency channel number, a value range of which comprises any one in the following set: −10, −9, −8, −7, −6, −5, −4, −3, −2, −1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. ### Claim 3 User equipment (UE) comprises: a processor configured to determine a frequency band starting frequency, an absolute radio frequency channel number, a frequency band offset, and a relative radio frequency channel number; determine a carrier center frequency according to the frequency band starting frequency, the absolute radio frequency channel number, the frequency band offset, and the relative radio frequency channel number that are determined; and a transmitter configured to cooperate with the processor to exchange a signal with a base station according to the determined carrier center frequency; wherein the carrier center frequency is an uplink carrier center frequency FNBUL, and the processor determines the carrier center frequency according to: FNBUL=FUL_low+0.1*(NUL−NOffs-UL)+0.0025*(2MUL+1); wherein FUL_low is an uplink frequency band starting frequency, NUL is an uplink absolute radio frequency channel number, and NOffs-UL is an uplink frequency band offset; and MUL is an uplink relative radio frequency channel number, a value range of which comprises any one in the following set: −10, −9, −8, −7, −6, −5, −4, −3, −2, −1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.