# US 10,313,167 B2 · Phase rotation for in-band signal generation for narrow band transmission > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,313,167 B2 - Document ID: US10313167B2 - Status: Granted - Kind: B2 - Application number: 15/445,263 - Filed: 2017-02-28 - Published: 2018-02-22 - Granted: 2019-06-04 - Earliest claimed: 2016-08-19 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Alberto Rico Alvarino; Chun-Hao Hsu; Xiao Feng Wang; Peter Gaal; Lei Xiao - Web page: https://patentgrep.com/patent/US10313167B2 ## CPC - H04L 5/0007: {the frequencies being orthogonal, e.g. OFDM(A) or DMT} - H04L 5/003: {Arrangements for allocating sub-channels of the transmission path} - 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 5/005: {of common pilots, i.e. pilots destined for multiple users or terminals} - H04L 27/2082: {for offset or staggered quadrature phase shift keying} - H04L 27/2602: {Signal structure} - H04L 27/2657: {Carrier synchronisation} - H04W 4/70: Services for machine-to-machine communication [M2M] or machine type communication [MTC] - H04L 25/0202: {Channel estimation} - H04L 27/2627: {Modulators} - 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 In order to enable a UE receiving a narrowband signal transmitted using in-band resources to use the LTE reference signals to assist the UE in receiving the narrowband signal using an in-band deployment, a phase rotation employed by the base station may be fixed relative to a known reference position in time. An apparatus for wireless communication at a base station may determine a phase offset for a narrowband signal for transmission using wideband resources, the phase offset having a relationship to a reference point in time and transmit the narrowband signal using the determined phase offset. An apparatus for wireless communication at a UE may receive a narrowband signal having a frequency location within a wideband signal and rotate a symbol of the wideband signal by a per symbol phase offset having a relationship of the phase offset to a reference point in time. ## Claims ### Claim 1 A method for wireless communications at a base station comprising: determining a phase offset for a narrowband signal for transmission using wideband resources, the phase offset having a relationship to a reference point in time; and transmitting the narrowband signal using the determined phase offset. ### Claim 2 (depends on 1) The method of claim 1, wherein the reference point comprises a reference symbol in the wideband resources, and the relationship corresponds to an index relative to the reference symbol. ### Claim 3 (depends on 1) The method of claim 1, wherein the narrowband signal comprise a Narrowband Internet of Things (NB-IoT) signal and wherein the wideband resources comprise Long Term Evolution (LTE) resources. ### Claim 4 (depends on 1) The method of claim 1, wherein the method further comprises: generating a first symbol of the narrowband signal in a frequency domain; multiplying the first symbol of the narrowband signal by a first determined phase offset; and multiplexing the first symbol of the narrowband signal, multiplied by the first determined phase offset, within a wideband symbol of a wideband signal in the frequency domain, wherein transmitting the narrowband signal comprises transmitting a multiplexed signal comprising the first symbol of the narrowband signal multiplexed within the wideband signal. ### Claim 5 (depends on 1) The method of claim 1, wherein the phase offset is based on a frequency separation between a first frequency center of the narrowband signal and a second frequency center of a wideband signal and a symbol index indicating a number of symbols from the reference point in time. ### Claim 6 (depends on 5) The method of claim 5, wherein the reference point in time is comprised in an even numbered subframe. ### Claim 7 (depends on 6) The method of claim 6, wherein the reference point in time is a start of a last even-numbered subframe. ### Claim 8 An apparatus for wireless communication at a base station comprising: means for determining a phase offset for a narrowband signal for transmission using wideband resources, the phase offset having a relationship to a reference point in time; and means for transmitting the narrowband signal using the determined phase offset. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein the reference point comprises a reference symbol in the wideband resources, and the relationship corresponds to an index relative to the reference symbol. ### Claim 10 (depends on 8) The apparatus of claim 8, wherein the narrowband signal comprise a Narrowband Internet of Things (NB-IoT) signal and wherein the wideband resources comprise Long Term Evolution (LTE) resources. ### Claim 11 (depends on 8) The apparatus of claim 8, further comprising: means for generating a first symbol of the narrowband signal in a frequency domain; means for multiplying the first symbol of the narrowband signal by a first determined phase offset; and means for multiplexing the first symbol of the narrowband signal, multiplied by the first determined phase offset, within a wideband symbol of a wideband signal in the frequency domain, wherein transmitting the narrowband signal comprises transmitting a multiplexed signal comprising the first symbol of the narrowband signal multiplexed within the wideband signal. ### Claim 12 (depends on 8) The apparatus of claim 8, wherein the phase offset is based on a frequency separation between a first frequency center of the narrowband signal and a second frequency center of a wideband signal and a symbol index indicating a number of symbols from the reference point in time. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein the reference point in time is comprised in an even numbered subframe. ### Claim 14 (depends on 13) The apparatus of claim 13, wherein the reference point in time is a start of a last even-numbered subframe. ### Claim 15 An apparatus for wireless communication at a base station comprising: a memory; and at least one processor coupled to the memory and configured to: determine a phase offset for a narrowband signal for transmission using wideband resources, the phase offset having a relationship to a reference point in time; and transmit the narrowband signal using the determined phase offset. ### Claim 16 (depends on 15) The apparatus of claim 15, wherein the reference point comprises a reference symbol in the wideband resources, and the relationship corresponds to an index relative to the reference symbol. ### Claim 17 (depends on 16) The apparatus of claim 16, wherein the narrowband signal comprise a Narrowband Internet of Things (NB-IoT) signal and wherein the wideband resources comprise Long Term Evolution (LTE) resources. ### Claim 18 (depends on 15) The apparatus of claim 15, wherein the at least one processor is further configured to: generate a first symbol of the narrowband signal in a frequency domain; multiply the first symbol of the narrowband signal by a first determined phase offset; and multiplex the first symbol of the narrowband signal, multiplied by the first determined phase offset, within a wideband symbol of a wideband signal in the frequency domain, wherein transmitting the narrowband signal comprises transmitting a multiplexed signal comprising the first symbol of the narrowband signal multiplexed within the wideband signal. ### Claim 19 (depends on 15) The apparatus of claim 15, wherein the phase offset is based on a frequency separation between a first frequency center of the narrowband signal and a second frequency center of a wideband signal and a symbol index indicating a number of symbols from the reference point in time. ### Claim 20 (depends on 19) The apparatus of claim 19, wherein the reference point in time is comprised in an even numbered subframe. ### Claim 21 (depends on 20) The apparatus of claim 20, wherein the reference point in time is a start of a last even-numbered subframe. ### Claim 22 A non-transitory computer-readable medium storing computer executable code for wireless communication at a base station comprising code to: determine a phase offset for a narrowband signal for transmission using wideband resources, the phase offset having a relationship to a reference point in time; and transmit the narrowband signal using the determined phase offset. ### Claim 23 (depends on 22) The non-transitory computer-readable medium of claim 22, wherein the reference point comprises a reference symbol in the wideband resources, and the relationship corresponds to an index relative to the reference symbol. ### Claim 24 (depends on 22) The non-transitory computer-readable medium of claim 22, wherein the narrowband signal comprise a Narrowband Internet of Things (NB-IoT) signal and wherein the wideband resources comprise Long Term Evolution (LTE) resources. ### Claim 25 (depends on 22) The non-transitory computer-readable medium of claim 22, further comprising code to: generate a first symbol of the narrowband signal in a frequency domain; multiply the first symbol of the narrowband signal by a first determined phase offset; and multiplex the first symbol of the narrowband signal, multiplied by the first determined phase offset, within a wideband symbol of a wideband signal in the frequency domain, wherein transmitting the narrowband signal comprises a multiplexed signal comprising the first symbol of the narrowband signal multiplexed within the wideband signal. ### Claim 26 (depends on 22) The non-transitory computer-readable medium of claim 22, wherein the phase offset is based on a frequency separation between a first frequency center of the narrowband signal and a second frequency center of a wideband signal and a symbol index indicating a number of symbols from the reference point in time. ### Claim 27 (depends on 26) The non-transitory computer-readable medium of claim 26, wherein the reference point in time is comprised in an even numbered subframe. ### Claim 28 (depends on 27) The non-transitory computer-readable medium of claim 27, wherein the reference point in time is a start of a last even-numbered subframe. ### Claim 29 A method for wireless communications at a user equipment (UE), comprising: receiving a narrowband signal having a frequency location within a wideband signal; and rotating a symbol of the wideband signal by a per symbol phase offset having a relationship to a reference point in time. ### Claim 30 (depends on 29) The method of claim 29, wherein the reference point comprises a reference symbol in the wideband signal, and the relationship corresponds to an index relative to the reference symbol. ### Claim 31 (depends on 29) The method of claim 29, wherein the reference point is comprised in an even numbered subframe. ### Claim 32 (depends on 31) The method of claim 31, wherein the reference point is a start of a last even-numbered subframe. ### Claim 33 (depends on 29) The method of claim 29, wherein the narrowband signal comprise a Narrowband Internet of Things (NB-IoT) signal and wherein the wideband signal comprises a Long Term Evolution (LTE) signal. ### Claim 34 (depends on 29) The method of claim 29, further comprising: determining an operation mode for narrowband signal reception, wherein the symbol of the wideband signal comprises a wideband reference signal that is rotated relative to a corresponding narrowband reference signal. ### Claim 35 (depends on 34) The method of claim 34, wherein a relative rotation of the wideband reference signal corresponds to a frequency separation between a first frequency center of the narrowband signal and a second frequency center of the wideband signal and a symbol index. ### Claim 36 (depends on 35) The method of claim 35, further comprising: determining a phase difference by comparing a first phase of a first set of resource elements and a second phase of a second set of resource elements, wherein the relative rotation of the symbol of the wideband signal is based at least on the determined phase difference. ### Claim 37 (depends on 36) The method of claim 36, wherein the first set of resource elements comprise a cell-specific reference signal (CRS), and the second set of resource elements comprise a narrowband reference signal (NRS). ### Claim 38 (depends on 34) The method of claim 34, wherein the wideband reference signal comprises a cell-specific reference signal (CRS). ### Claim 39 (depends on 38) The method of claim 38, wherein the receiving further comprises: combining a first channel estimation based on the CRS with a second channel estimation based on an narrowband reference signal (NRS); and demodulating the narrowband signal with a combined channel estimation. ### Claim 40 (depends on 39) The method of claim 39, wherein determining the first channel estimation based on the CRS and determining the second channel estimation based on the NRS comprise descrambling at least a portion of the CRS and the NRS after performing a symbol rotation for a corresponding reference signal. ### Claim 41 An apparatus for wireless communication at a User Equipment (UE), comprising: means for receiving a narrowband signal having a frequency location within a wideband signal; and means for rotating a symbol of the wideband signal by a per symbol phase offset having a relationship to a reference point in time. ### Claim 42 (depends on 41) The apparatus of claim 41, wherein the reference point comprises a reference symbol in the wideband signal, and the relationship corresponds to an index relative to the reference symbol. ### Claim 43 (depends on 41) The apparatus of claim 41, wherein the reference point is comprised in an even numbered subframe. ### Claim 44 (depends on 43) The apparatus of claim 43, wherein the reference point is a start of a last even-numbered subframe. ### Claim 45 (depends on 41) The apparatus of claim 41, wherein the narrowband signal comprises a Narrowband Internet of Things (NB-IoT) signal and wherein the wideband signal comprises a Long Term Evolution (LTE) signal. ### Claim 46 (depends on 41) The apparatus of claim 41, further comprising: means for determining an operation mode for narrowband signal reception, wherein the symbol of the wideband signal comprises a wideband reference signal that is rotated relative to a corresponding narrowband reference signal. ### Claim 47 (depends on 46) The apparatus of claim 46, wherein a relative rotation of the wideband reference signal corresponds to a frequency separation between a first frequency center of the narrowband signal and a second frequency center of the wideband signal and a symbol index. ### Claim 48 (depends on 47) The apparatus of claim 47, further comprising: means for determining a phase difference by comparing a first phase of a first set of resource elements and a second phase of a second set of resource elements, wherein the relative rotation of the symbol of the wideband signal is based at least on the determined phase difference. ### Claim 49 (depends on 48) The apparatus of claim 48, wherein the first set of resource elements comprise a cell-specific reference signal (CRS), and the second set of resource elements comprise a narrowband reference signal (NRS). ### Claim 50 (depends on 46) The apparatus of claim 46, wherein the wideband reference signal comprises a cell-specific reference signal (CRS). ### Claim 51 (depends on 50) The apparatus of claim 50, wherein the means for receiving: combine a first channel estimation based on the CRS with a second channel estimation based on an narrowband reference signal (NRS); and demodulate the narrowband signal with a combined channel estimation. ### Claim 52 (depends on 51) The apparatus of claim 51, wherein determining the first channel estimation based on the CRS and determining the second channel estimation based on the NRS comprise descrambling at least a portion of the CRS and the NRS after performing a signal rotation for a corresponding reference signal. ### Claim 53 An apparatus for wireless communication at a User Equipment (UE), comprising: a memory; and at least one processor coupled to the memory and configured to: receive a narrowband signal having a frequency location within a wideband signal; and rotate a symbol of the wideband signal by a per symbol phase offset having a relationship to a reference point in time. ### Claim 54 (depends on 53) The apparatus of claim 53, wherein the reference point comprises a reference symbol in the wideband signal, and the relationship corresponds to an index relative to the reference symbol. ### Claim 55 (depends on 53) The apparatus of claim 53, wherein the reference point is comprised in an even numbered subframe. ### Claim 56 (depends on 55) The apparatus of claim 55, wherein the reference point is a start of a last even-numbered subframe. ### Claim 57 (depends on 53) The apparatus of claim 53, wherein the narrowband signal comprises a Narrowband Internet of Things (NB-IoT) signal and wherein the wideband signal comprises a Long Term Evolution (LTE) signal. ### Claim 58 (depends on 53) The apparatus of claim 53, wherein the at least one processor is further configured to: determine an operation mode for narrowband signal reception, wherein the symbol of the wideband signal comprises a wideband reference signal that is rotated relative to a corresponding narrowband reference signal. ### Claim 59 (depends on 58) The apparatus of claim 58, wherein a relative rotation of the wideband reference signal corresponds to a frequency separation between a first frequency center of the narrowband signal and a second frequency center of the wideband signal and a symbol index. ### Claim 60 (depends on 59) The apparatus of claim 59, wherein the at least one processor is further configured to: determine a phase difference by comparing a first phase of a first set of resource elements and a second phase of a second set of resource elements, wherein the relative rotation of the symbol of the wideband signal is based at least on the determined phase difference. ### Claim 61 (depends on 60) The apparatus of claim 60, wherein the first set of resource elements comprise a cell-specific reference signal (CRS), and the second set of resource elements comprise a narrowband reference signal (NRS). ### Claim 62 (depends on 58) The apparatus of claim 58, wherein the wideband reference signal comprises a cell-specific reference signal (CRS). ### Claim 63 (depends on 62) The apparatus of claim 62, wherein the at least one processor is further configured to: combine a first channel estimation based on the CRS with a second channel estimation based on an narrowband reference signal (NRS); and demodulate the narrowband signal with a combined channel estimation. ### Claim 64 (depends on 63) The apparatus of claim 63, wherein determining the first channel estimation based on the CRS and determining the second channel estimation based on the NRS comprise descrambling at least a portion of the CRS and the NRS after performing a signal rotation for a corresponding reference signal. ### Claim 65 A non-transitory computer-readable medium storing computer executable code for wireless communication at a User Equipment (UE), comprising code to: receive a narrowband signal having a frequency location within a wideband signal; and rotate a symbol of the wideband signal by a per symbol phase offset having a relationship to a reference point in time. ### Claim 66 (depends on 65) The non-transitory computer-readable medium of claim 65, wherein the reference point comprises a reference symbol in the wideband signal, and the relationship corresponds to an index relative to the reference symbol. ### Claim 67 (depends on 65) The non-transitory computer-readable medium of claim 65, wherein the reference point is comprised in an even numbered subframe. ### Claim 68 (depends on 67) The non-transitory computer-readable medium of claim 67, wherein the reference point is a start of a last even-numbered subframe. ### Claim 69 (depends on 65) The non-transitory computer-readable medium of claim 65, wherein the narrowband signal comprises a Narrowband Internet of Things (NB-IoT) signal and wherein the wideband signal comprises a Long Term Evolution (LTE) signal. ### Claim 70 (depends on 65) The non-transitory computer-readable medium of claim 65, further comprising code to: determine an operation mode for narrowband signal reception, wherein the symbol of the wideband signal comprises a wideband reference signal that is rotated relative to a corresponding narrowband reference signal. ### Claim 71 (depends on 70) The non-transitory computer-readable medium of claim 70, wherein a relative rotation of the wideband reference signal corresponds to a frequency separation between a first frequency center of the narrowband signal and a second frequency center of the wideband signal and a symbol index. ### Claim 72 (depends on 71) The non-transitory computer-readable medium of claim 71, further comprising code to: determine a phase difference by comparing a first phase of a first set of resource elements and a second phase of a second set of resource elements, wherein the relative rotation of the symbol of the wideband signal is based at least on the determined phase difference. ### Claim 73 (depends on 72) The non-transitory computer-readable medium of claim 72, wherein the first set of resource elements comprise a cell-specific reference signal (CRS), and the second set of resource elements comprise a narrowband reference signal (NRS). ### Claim 74 (depends on 70) The non-transitory computer-readable medium of claim 70, wherein the wideband reference signal comprises a cell-specific reference signal (CRS). ### Claim 75 (depends on 74) The non-transitory computer-readable medium of claim 74, further comprising code to: combine a first channel estimation based on the CRS with a second channel estimation based on an narrowband reference signal (NRS); and demodulate the narrowband signal with a combined channel estimation. ### Claim 76 (depends on 75) The non-transitory computer-readable medium of claim 75, wherein determining the first channel estimation based on the CRS and determining the second channel estimation based on the NRS comprise descrambling at least a portion of the CRS and the NRS after performing a signal rotation for a corresponding reference signal.