# US 10,455,614 B2 · Techniques for configuring preamble and overhead signals for transmissions in an unlicensed radio frequency spectrum band > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,455,614 B2 - Document ID: US10455614B2 - Status: Granted - Kind: B2 - Application number: 14/584,149 - Filed: 2014-12-29 - Published: 2015-09-24 - Granted: 2019-10-22 - Earliest claimed: 2014-03-21 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Tao Luo; Shimman Arvind Patel; Wanshi Chen; Naga Bhushan; Yongbin Wei; Hao Xu; Aleksandar Damnjanovic; Tingfang Ji; Durga Prasad Malladi; Srinivas Yerramalli; Peter Gaal - Web page: https://patentgrep.com/patent/US10455614B2 ## CPC - H04W 74/002: {Transmission of channel access control information} - H04L 5/001: {the frequencies being arranged in component carriers} - H04L 5/003: {Arrangements for allocating sub-channels of the transmission path} - H04L 5/0028: {Variable division (indication of the divided channel H04L5/0092)} - H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals} - H04L 5/0064: {Rate requirement of the data, e.g. scalable bandwidth, data priority} - H04L 5/0091: {Signalling for the administration of the divided path, e.g. signalling of configuration information} - H04L 5/0092: {Indication of how the channel is divided} - H04L 5/14: Two-way operation using the same type of signal, i.e. duplex - H04L 27/261: {Details of reference signals} - H04L 27/2613: {Structure of the reference signals} - H04W 56/00: Synchronisation arrangements - H04W 74/0808: using carrier sensing, e.g. carrier sense multiple access [CSMA] - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04L 5/0023: {Time-frequency-space} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Techniques are described for wireless communication. A first method includes transmitting a first signal to indicate accessing a first channel in a radio frequency spectrum band, and transmitting information with the first signal in the radio frequency spectrum band. A second method includes winning contention to access a radio frequency spectrum band, and after the winning contention to access the radio frequency spectrum band, transmitting a first signal to align a starting point of a second signal with a reference boundary associated with the radio frequency spectrum band. A third method includes winning contention to access a radio frequency spectrum band during a first frame period, the first frame selected from a plurality of different frame periods, and transmitting a signal at a periodicity during one or more subframes of the first frame period for each of the plurality of different frame periods. ## Claims ### Claim 1 A method for wireless communications, comprising: winning contention during a first symbol period to access a radio frequency spectrum band; and after the winning contention to access the radio frequency spectrum band, transmitting, during the first symbol period, a first signal to align a starting point of a second signal in a second symbol period with a reference boundary at an ending point of the first symbol period, the second symbol period beginning subsequent to the first symbol period and following the reference boundary, the reference boundary associated with the radio frequency spectrum band, wherein the first signal comprises a variable length sequence. ### Claim 2 (depends on 1) The method of claim 1, wherein the radio frequency spectrum band comprises an unlicensed radio frequency spectrum band. ### Claim 3 (depends on 1) The method of claim 1, further comprising: accessing timing information; and determining the reference boundary based at least in part on the timing information and the winning contention to access the radio frequency spectrum band. ### Claim 4 (depends on 1) The method of claim 1, wherein the variable length sequence comprises a variable length training sequence. ### Claim 5 (depends on 1) The method of claim 1, wherein the first signal further comprises at least one fixed length training sequence. ### Claim 6 (depends on 1) The method of claim 1, further comprising: operating in a listen before talk (LBT)-load based equipment (LBE) mode of operation in the radio frequency spectrum band. ### Claim 7 (depends on 1) The method of claim 1, wherein the second signal comprises a beacon signal. ### Claim 8 (depends on 1) The method of claim 1, wherein the reference boundary comprises a boundary of an orthogonal frequency-division multiplexing (OFDM) symbol period associated with the radio frequency spectrum band. ### Claim 9 (depends on 8) The method of claim 8, wherein the first signal is associated with a contention priority, and wherein the first signal is transmitted during a portion of the OFDM symbol period based at least in part on the contention priority. ### Claim 10 An apparatus for wireless communications, comprising: a processor; memory in electronic communication with the processor; and instructions stored in the memory, the instructions being executable by the processor to: win contention during a first symbol period to access a radio frequency spectrum band; and after winning contention to access the radio frequency spectrum band, transmit, during the first symbol period, a first signal to align a starting point of a second signal in a second symbol period with a reference boundary at an ending point of the first symbol period, the second symbol period beginning subsequent to the first symbol period and following the reference boundary, the reference boundary associated with the radio frequency spectrum band, wherein the first signal comprises a variable length sequence. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein the second signal comprises a beacon signal.