# US 11,116,005 B2 · Method and device for transmitting NPRACH preamble in narrowband IoT system supporting frame structure type 2 > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,116,005 B2 - Document ID: US11116005B2 - Status: Granted - Kind: B2 - Application number: 16/623,318 - Filed: 2018-06-25 - Published: 2020-06-04 - Granted: 2021-09-07 - Earliest claimed: 2017-06-26 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Seokmin Shin; Changhwan Park; Joonkui Ahn; Daesung Hwang; Seunggye Hwang - Web page: https://patentgrep.com/patent/US11116005B2 ## CPC - H04W 74/004: {in the uplink, i.e. towards network} - H04L 5/001: {the frequencies being arranged in component carriers} - H04L 5/0012: {Hopping in multicarrier systems} - H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals} - H04L 5/0092: {Indication of how the channel is divided} - H04L 5/1469: {using time-sharing} - H04L 27/2605: {Symbol extensions, e.g. Zero Tail, Unique Word [UW]} - H04L 27/2607: {Cyclic extensions} - H04L 27/261: {Details of reference signals} - H04L 27/2646: {using feedback from receiver for adjusting OFDM transmission parameters, e.g. transmission timing or guard interval length} - H04W 72/0453: Resources in frequency domain, e.g. a carrier in FDMA - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04L 1/1861: {Physical mapping arrangements (for ACK signaling see also H04L5/0053)} - H04L 5/0026: {Division using four or more dimensions, e.g. beam steering or quasi-co-location [QCL]} - 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 27/26025: {Numerology, i.e. varying one or more of symbol duration, subcarrier spacing, Fourier transform size, sampling rate or down-clocking (allocating sub-channels of the transmission path H04L5/003)} - H04W 74/0838: using contention-free random access [CFRA] - 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) - 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 specification provides a method for transmitting a narrowband physical random access channel (NPRACH) preamble in a narrow band (NB)-Internet of things (IoT) system supporting a frame structure type 2. More specifically, the method performed by a user equipment includes receiving, from a base station, control information related to an uplink-downlink configuration; and transmitting, to the base station, the NPRACH preamble based on parameters related to a NPRACH preamble transmission related to the received control information. ## Claims ### Claim 1 A method for transmitting, by a user equipment, a narrowband physical random access channel (NPRACH) preamble in a narrow band (NB)-Internet of things (IoT) system supporting time division duplexing (TDD), the method comprising: receiving, from a base station, first information for a NPRACH configuration; and transmitting, to the base station, the NPRACH preamble based on the received first information, wherein the NPRACH preamble is repeatedly transmitted as a plurality of preamble repetition units, with each preamble repetition unit consisting of a plurality of symbol groups, and with each symbol group consisting of one cyclic prefix (CP) and at least one symbol, wherein not all symbols groups comprising the each preamble repetition unit are contiguous in time, wherein a subcarrier spacing for the NPRACH preamble is configured as 3.75 kHz, wherein (i) a number of symbols included in each symbol group and (ii) a length of the CP included in each symbol group depend on an uplink-downlink configuration that is related to controlling in which subframes uplink or downlink transmissions take place in a frame, and wherein the number of symbols in each symbol group is less than 5, and the length of the CP in each symbol group is shorter than a length of one symbol of each symbol group. ### Claim 2 (depends on 1) The method of claim 1, wherein the plurality of symbol groups are transmitted using a frequency-hopping. ### Claim 3 (depends on 2) The method of claim 2, wherein each preamble repetition unit consists of four symbol groups. ### Claim 4 (depends on 3) The method of claim 3, wherein a first two symbol groups of each preamble repetition unit are contiguous in time, and wherein a second two symbol groups of the each preamble repetition unit are contiguous in time. ### Claim 5 (depends on 4) The method of claim 4, wherein the first two symbol groups and the second two symbol groups are discontinuous in time. ### Claim 6 (depends on 1) The method of claim 1, further comprising: receiving, from the base station, second information for the uplink-downlink configuration. ### Claim 7 (depends on 6) The method of claim 6, wherein a plurality of preamble formats in which the length of CP and the number of symbols comprising the each symbol group are configured differently are pre-defined, and wherein a specific preamble format applied to the NPRACH preamble is determined based on the uplink-downlink configuration. ### Claim 8 (depends on 6) The method of claim 6, wherein a number of symbol groups comprising each preamble repetition unit is configured based on the second information. ### Claim 9 (depends on 1) The method of claim 1, wherein the length of the CP is shorter than a length of a CP of a NPRACH preamble for frequency division duplexing, FDD. ### Claim 10 A user equipment (UE) configured to transmit narrowband physical random access channel (NPRACH) preamble in a narrow band (NB)-Internet of things (IoT) system supporting a frame structure type 2, the UE comprising: a radio frequency (RF) module configured to transmit and receive a radio signal; and a processor configured to control the RF module, wherein the processor is configured to: receive, from a base station, first information for a NPRACH configuration; and transmit, to the base station, the NPRACH preamble based on the received first information, wherein the NPRACH preamble is repeatedly transmitted as a plurality of preamble repetition units, with each preamble repetition unit consisting of a plurality of symbol groups, and with each symbol group consisting of one cyclic prefix (CP) and at least one symbol, wherein not all symbols groups comprising the each preamble repetition unit are contiguous in time, wherein a subcarrier spacing for the NPRACH preamble is configured as 3.75 kHz, wherein (i) a number of symbols included in each symbol group and (ii) a length of the CP included in each symbol group depend on an uplink-downlink configuration that is related to controlling in which subframes uplink or downlink transmissions take place in a frame, and wherein the number of symbols in each symbol group is less than 5, and the length of the CP in each symbol group is shorter than a length of one symbol of each symbol group. ### Claim 11 (depends on 10) The UE of claim 10, wherein the operations further comprising: receiving, from the base station, second information for the uplink-downlink configuration. ### Claim 12 (depends on 11) The UE of claim 11, wherein a plurality of preamble formats in which the length of CP and the number of symbols comprising the each symbol group are configured differently are pre-defined, and wherein a specific preamble format applied to the NPRACH preamble is determined based on the uplink-downlink configuration. ### Claim 13 (depends on 11) The UE of claim 11, wherein a number of symbol groups comprising each preamble repetition unit is configured based on the second information. ### Claim 14 (depends on 10) The UE of claim 10, wherein each preamble repetition unit consists of four symbol groups. ### Claim 15 (depends on 14) The UE of claim 14, wherein a first two symbol groups of each preamble repetition unit are contiguous in time, and wherein a second two symbol groups of the each preamble repetition unit are contiguous in time. ### Claim 16 (depends on 15) The UE of claim 15, wherein the first two symbol groups and the second two symbol groups are discontiguous in time.