# US 12,004,060 B2 · Pilot design for uplink (UL) narrow-band internet of things (NB-IoT) > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,004,060 B2 - Document ID: US12004060B2 - Status: Granted - Kind: B2 - Application number: 18/160,486 - Filed: 2023-01-27 - Published: 2023-06-08 - Granted: 2024-06-04 - Earliest claimed: 2016-02-08 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Seyed Ali Akbar Fakoorian; Peter Gaal; Alberto Rico Alvarino; Xiao Feng Wang; Wanshi Chen; Renqiu Wang; Hao Xu - Web page: https://patentgrep.com/patent/US12004060B2 ## CPC - H04W 4/70: Services for machine-to-machine communication [M2M] or machine type communication [MTC] - H04L 5/0051: {of dedicated pilots, i.e. pilots destined for a single user or terminal} - H04L 5/0064: {Rate requirement of the data, e.g. scalable bandwidth, data priority} - H04L 27/2613: {Structure of the reference signals} - H04W 72/542: using measured or perceived quality - H04B 7/0684: {using different training sequences per antenna} - H04L 5/0094: {Indication of how sub-channels of the path are allocated} - H04L 25/0226: {sounding signals per se} - 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) - H04B: TRANSMISSION ## Abstract Certain aspects of the present disclosure relate to methods and apparatus for pilot design for Narrow-Band Internet of Things (NB-IoT). In certain aspects, the method generally includes determining at least one binary code sequence to use as a demodulation reference signal (DMRS) for a channel transmitted across one or more subframes using one or more tones within a resource block (RB) allocated to the UE for narrowband communication, and transmitting the channel including the DMRS using the one or more tones and the determined binary code sequence. In certain aspects, the binary code sequence may be determined based on a binary random sequence, such as pseudo noise (PN) or Gold sequence. ## Claims ### Claim 1 A method for wireless communications by a user equipment (UE), comprising: determining at least one code sequence for use for a demodulation reference signal (DMRS) for a channel transmitted across one or more subframes within a bandwidth of a resource block (RB) allocated to the UE for communication, wherein the at least one code sequence for use for the DMRS is determined based at least in part on a product of a Hadamard sequence and a random sequence, wherein a length of the at least one code sequence for use for the DMRS depends, at least in part, on a bundling length of the channel; and transmitting the channel including the DMRS. ### Claim 2 (depends on 1) The method of claim 1, wherein the Hadamard sequence is length 16. ### Claim 3 (depends on 1) The method of claim 1, wherein the Hadamard sequence is cell-ID dependent. ### Claim 4 (depends on 1) The method of claim 1, wherein the random sequence comprises a pseudo noise (PN) sequence or a Gold sequence. ### Claim 5 (depends on 4) The method of claim 4, wherein the PN or Gold sequence is reset in a first symbol of the at least one code sequence. ### Claim 6 (depends on 4) The method of claim 4, wherein the pseudo noise (PN) sequence and Gold sequence are common among multiple cells, and wherein the Hadamard sequence is cell ID dependent. ### Claim 7 (depends on 1) The method of claim 1, wherein the at least one code sequence is determined based at least in part on a product of a codeword from a linear cyclic code and a random sequence. ### Claim 8 (depends on 1) The method of claim 1, wherein: the at least one code sequence is obtained from a code block having a high minimum Hamming distance, wherein the code block having the high minimum Hamming distance comprises a cyclic code block. ### Claim 9 (depends on 1) The method of claim 1, wherein the at least one code sequence is determined as a linear combination of a set of known basis vectors. ### Claim 10 (depends on 1) The method of claim 1, wherein the at least one code sequence is determined from a Hadamard matrix formed with orthogonal columns. ### Claim 11 (depends on 1) The method of claim 1, wherein the at least one code sequence is determined from at least first and second Hadamard matrices, wherein the first Hadamard matrix is formed with orthogonal columns and the second Hadamard matrix that is formed by flipping the first Hadamard matrix. ### Claim 12 (depends on 1) The method of claim 1, wherein the determining comprises determining: a first code sequence for transmitting a first DMRS on a first tone selected from a first Hadamard matrix formed with orthogonal columns; and a second code sequence for transmitting a second DMRS on a second tone selected from a second Hadamard matrix formed with orthogonal columns. ### Claim 13 (depends on 12) The method of claim 12, wherein the second Hadamard matrix is formed by flipping the first Hadamard matrix. ### Claim 14 (depends on 1) The method of claim 1, wherein: a first code sequence for transmitting a first DMRS on a first tone is selected from a first Hadamard matrix; and a second code sequence for transmitting a second DMRS on a second tone is also selected from the first Hadamard matrix. ### Claim 15 (depends on 1) The method of claim 1, further comprising: receiving a system information block (SIB) message, wherein the SIB message comprises an indication of a base sequence, wherein determining the at least one code sequence is based at least in part on the indication. ### Claim 16 (depends on 1) The method of claim 1, wherein determining the at least one code sequence comprises determining a base sequence based on a cell-ID. ### Claim 17 (depends on 1) The method of claim 1, wherein the channel and the DMRS are transmitted using one or more tones within the bandwidth, wherein the determination of the at least one code sequence is based on three cyclic shifts if the one or more tones comprise three tones, and wherein the determination of the at least one code sequence is based on four cyclic shifts if the one or more tones comprise six tones. ### Claim 18 (depends on 1) The method of claim 1, further comprising: receiving a system information block (SIB) message, wherein the SIB message comprises an indication of a number of cyclic shifts, wherein determining the at least one code sequence is based at least in part on the indication. ### Claim 19 (depends on 1) The method of claim 1, wherein the channel and the DMRS are transmitted using one or more tones within the bandwidth, wherein the at least one code sequence is determined from 12 base sequences if the one or more tones comprise three tones, and wherein the at least one code sequence is determined from 14 base sequences if the one or more tones comprise six tones. ### Claim 20 (depends on 1) The method of claim 1, wherein the at least one code sequence is transmitted with a Quadrature Phase Shift Keying (QPSK) modulation scheme in frequency domain. ### Claim 21 (depends on 1) The method of claim 1, further comprising applying a cyclic shift to the at least one code sequence, wherein the cyclic shift is determined based on at least one of a cell ID, a UE ID, or a slot index. ### Claim 22 (depends on 1) The method of claim 1, wherein the one or more subframes comprise a plurality of subframes and the determining comprises determining different code sequences for use for a DMRS for each of the plurality of subframes. ### Claim 23 (depends on 1) The method of claim 1, wherein the at least one code sequence is randomized using a scrambling sequence, wherein the scrambling sequence is determined based on at least one of a cell ID, a UE ID, or a slot number. ### Claim 24 (depends on 1) The method of claim 1, wherein the channel and the DMRS are transmitted using one or more tones within the bandwidth, wherein the one or more tones comprise multiple tones, and wherein determining the at least one code sequence comprises determining different code sequences for each of the multiple tones. ### Claim 25 A method for wireless communications by a base station, comprising: determining at least one code sequence for use for a demodulation reference signal (DMRS) for a channel transmitted, by a user equipment (UE), across one or more subframes within a bandwidth of a resource block (RB) allocated to the UE for communication, wherein the at least one code sequence for use for the DMRS is determined based at least in part on a product of a Hadamard sequence and a random sequence, wherein a length of the at least one code sequence for use for the DMRS depends, at least in part, on a bundling length of the channel; and monitoring during the one or more subframes for the channel including the DMRS. ### Claim 26 (depends on 25) The method of claim 25, wherein the Hadamard sequence is length 16. ### Claim 27 (depends on 25) The method of claim 25, wherein the Hadamard sequence is cell-ID dependent. ### Claim 28 (depends on 25) The method of claim 25, wherein the random sequence comprises a pseudo noise (PN) sequence or a Gold sequence. ### Claim 29 (depends on 28) The method of claim 28, wherein the PN sequence or the Gold sequence is reset in a first symbol of the at least one code sequence. ### Claim 30 (depends on 28) The method of claim 28, wherein the pseudo noise (PN) sequence and Gold sequence are common among multiple cells, and wherein the Hadamard sequence is cell ID dependent. ### Claim 31 (depends on 25) The method of claim 25, wherein the at least one code sequence is determined based at least in part on a product of a codeword from a linear cyclic code and a random sequence. ### Claim 32 (depends on 25) The method of claim 25, wherein: the at least one code sequence is obtained from a code block having a high minimum Hamming distance, wherein the code block having the high minimum Hamming distance comprises a cyclic code block. ### Claim 33 (depends on 25) The method of claim 25, wherein the at least one code sequence is determined as a linear combination of a set of known basis vectors. ### Claim 34 (depends on 25) The method of claim 25, wherein the at least one code sequence is determined from at least a first Hadamard matrix formed with orthogonal columns. ### Claim 35 (depends on 25) The method of claim 25, wherein the at least one code sequence is determined from at least first and second Hadamard matrices, wherein the first Hadamard matrix is formed with orthogonal columns and the second Hadamard matrix that is formed by flipping the first Hadamard matrix. ### Claim 36 (depends on 25) The method of claim 25, wherein: a first code sequence for transmitting a first DMRS on a first tone is selected from a first Hadamard matrix formed with orthogonal columns; and a second code sequence for transmitting a second DMRS on a second tone is selected from a second Hadamard matrix formed with orthogonal columns. ### Claim 37 (depends on 36) The method of claim 36, wherein the second Hadamard matrix is formed by flipping the first Hadamard matrix. ### Claim 38 (depends on 25) The method of claim 25, wherein: a first code sequence is determined for a first DMRS on a first tone is selected from a first Hadamard matrix; and a second code sequence is determined for a second DMRS on a second tone is also selected from the first Hadamard matrix. ### Claim 39 (depends on 25) The method of claim 25, further comprising: transmitting a system information block (SIB) message, wherein the SIB message comprises an indication of a base sequence used to determine the at least one code sequence. ### Claim 40 (depends on 25) The method of claim 25, wherein determining the at least one code sequence comprises determining a base sequence based on a cell-ID. ### Claim 41 (depends on 25) The method of claim 25, wherein the channel and the DMRS are transmitted using one or more tones within the bandwidth, wherein monitoring the one or more subframes comprises monitoring the one or more tones, wherein the determination of the at least one code sequence is based on three cyclic shifts if the one or more tones comprise three tones, and wherein the determination of the at least one code sequence is based on four cyclic shifts if the one or more tones comprise six tones. ### Claim 42 (depends on 25) The method of claim 25, further comprising: transmitting a system information block (SIB) message, wherein the SIB message comprises an indication of a number of cyclic shifts used to determine the at least one code sequence. ### Claim 43 (depends on 25) The method of claim 25, wherein the channel and the DMRS are transmitted using one or more tones within the bandwidth, wherein monitoring the one or more subframes comprises monitoring the one or more tones, wherein the at least one code sequence is determined from 12 base sequences if the one or more tones comprise three tones, and wherein the at least one code sequence is determined from 14 base sequences if the one or more tones comprise six tones. ### Claim 44 (depends on 25) The method of claim 25, wherein the at least one code sequence is transmitted with a Quadrature Phase Shift Keying (QPSK) modulation scheme in frequency domain. ### Claim 45 (depends on 25) The method of claim 25, wherein the monitoring comprises monitoring for a cyclic shift applied to the at least one code sequence by the UE, wherein the cyclic shift is determined based on at least one of a cell ID, a UE ID, or slot index. ### Claim 46 (depends on 25) The method of claim 25, wherein the one or more subframes comprise a plurality of subframes and the determining comprises determining different code sequences for use as a DMRS for each of the plurality of subframes. ### Claim 47 (depends on 25) The method of claim 25, wherein the at least one code sequence comprises a scrambling sequence, wherein the scrambling sequence is determined based on at least one of a cell ID, a UE ID, or a slot number. ### Claim 48 (depends on 25) The method of claim 25, wherein the channel and the DMRS are transmitted using one or more tones within the bandwidth, wherein monitoring the one or more subframes comprises monitoring the one or more tones, wherein the one or more tones comprise multiple tones, and wherein determining the at least one code sequence comprise determining different code sequences for each of the multiple tones. ### Claim 49 An apparatus for wireless communications by a user equipment (UE), comprising: means for determining at least one code sequence for use for a demodulation reference signal (DMRS) for a channel transmitted across one or more subframes within a bandwidth of a resource block (RB) allocated to the UE for communication, wherein the at least one code sequence for use for the DMRS is determined based at least in part on a product of a Hadamard sequence and a random sequence, wherein a length of the at least one code sequence for use for the DMRS depends, at least in part, on a bundling length of the channel; and means for transmitting the channel including the DMRS. ### Claim 50 An apparatus for wireless communications by a base station, comprising: means for determining at least one code sequence for use for a demodulation reference signal (DMRS) for a channel transmitted, by a user equipment (UE), across one or more subframes within a bandwidth of a resource block (RB) allocated to the UE for communication, wherein the at least one code sequence for use for the DMRS is determined based at least in part on a product of a Hadamard sequence and a random sequence, wherein a length of the at least one code sequence for use for the DMRS depends, at least in part, on a bundling length of the channel; and means for monitoring during the one or more subframes for the channel including the DMRS. ### Claim 51 An apparatus for wireless communications by a user equipment (UE), comprising: one or more processors; and memory coupled to the one or more processors, the memory comprising instructions executable by the one or more processors, individually or collectively, to cause the apparatus to: determine at least one code sequence for use for a demodulation reference signal (DMRS) for a channel transmitted across one or more subframes within a bandwidth of a resource block (RR) allocated to the TIE for communication, wherein the at least one code sequence for use for the DMRS is determined based at least in part on a product of a Hadamard sequence and a random sequence, wherein a length of the at least one code sequence for use for the DMRS depends, at least in part, on a bundling length of the channel; and transmit the channel including the DMRS. ### Claim 52 An apparatus for wireless communications by a base station, comprising: one or more processors; and memory coupled to the one or more processors, the memory comprising instructions executable by the one or more processors, individually or collectively, to cause the apparatus to: determine at least one code sequence for use for a demodulation reference signal (DMRS) for a channel transmitted, by a user equipment (UE), across one or more subframes within a bandwidth of a resource block (RB) allocated to the UE for communication, wherein the at least one code sequence for use for the DMRS is determined based at least in part on a product of a Hadamard sequence and a random sequence, wherein a length of the at least one code sequence for use for the DMRS depends, at least in part, on a bundling length of the channel; and monitor during the one or more subframes for the channel including the DMRS. ### Claim 53 A non-transitory computer-readable medium for wireless communication by a user equipment (UE), the non-transitory computer-readable medium comprising code, which when executed by at least one processor, causes the at least one processor to: determine at least one code sequence for use for a demodulation reference signal (DMRS) for a channel transmitted across one or more subframes within a bandwidth of a resource block (RB) allocated to the UE for communication, wherein the at least one code sequence for use for the DMRS is determined based at least in part on a product of a Hadamard sequence and a random sequence, wherein a length of the at least one code sequence for use for the DMRS depends, at least in part, on a bundling length of the channel; and transmit the channel including the DMRS. ### Claim 54 A non-transitory computer-readable medium for wireless communication by a base station, the non-transitory computer-readable medium comprising code, which when executed by at least one processor, causes the at least one processor to: determine at least one code sequence for use for a demodulation reference signal (DMRS) for a channel transmitted, by a user equipment (UE), across one or more subframes within a bandwidth of a resource block (RB) allocated to the UE for communication, wherein the at least one code sequence for use for the DMRS is determined based at least in part on a product of a Hadamard sequence and a random sequence, wherein a length of the at least one code sequence for use for the DMRS depends, at least in part, on a bundling length of the channel; and monitor during the one or more subframes for the channel including the DMRS.