# US 10,484,955 B2 · Beam forming for synchronization signals > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,484,955 B2 - Document ID: US10484955B2 - Status: Granted - Kind: B2 - Application number: 15/569,226 - Filed: 2017-10-12 - Published: 2019-04-18 - Granted: 2019-11-19 - Earliest claimed: 2017-10-12 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget LM Ericsson (publ) - Inventors: Magnus Åström; Andres Reial; Henrik Sahlin; Sven Petersson - Web page: https://patentgrep.com/patent/US10484955B2 ## CPC - H04W 56/001: {Synchronization between nodes} - H04B 7/0608: {Antenna selection according to transmission parameters} - H04B 7/0617: {for beam forming} - H04B 7/10: Polarisation diversity; Directional diversity - H04L 27/2636: {with FFT or DFT modulators, e.g. standard single-carrier frequency-division multiple access [SC-FDMA] transmitter or DFT spread orthogonal frequency division multiplexing [DFT-SOFDM]} - H04B 7/0456: Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting - H04B 7/0691: {using subgroups of transmit antennas} - 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) - H04B: TRANSMISSION - 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 A method is disclosed for a network node configured to transmit wireless communication signals using beam forming and configured to apply any of one or more data carrying beam widths for transmission of data carrying signals dedicated to a specific wireless communication device. The method comprises determining one or more requirement parameters for transmission of synchronization signals, wherein the one or more requirement parameters comprise a desired synchronization signal beam width and a minimum effective power, and wherein the determined desired synchronization signal beam width is larger than a minimum one of the data carrying beam widths. The method also comprises calculating beam forming weights based on the one or more requirement parameters, wherein a beam resulting from the calculated beam forming weights has a beam width larger than, or equal to, the determined desired synchronization signal beam width and an effective power larger than, or equal to, the minimum effective power, and wherein the calculation is performed by assigning non-zero value to a number of beam forming weights which exceeds a minimum number of beam forming weights for the determined desired synchronization signal beam width. The method further comprises generating a synchronization signal for transmission and transmitting the generated synchronization signal using the calculated beam forming weights. Corresponding arrangement, network node and computer program product are also disclosed. ## Claims ### Claim 1 A method for a network node configured to transmit wireless communication signals using beam forming and configured to apply any of one or more data carrying beam widths for transmission of data carrying signals dedicated to a specific wireless communication device, the method comprising: determining one or more requirement parameters for transmission of synchronization signals, wherein the one or more requirement parameters comprise a desired synchronization signal beam width and a minimum effective power, and wherein the determined desired synchronization signal beam width is larger than a minimum one of the data carrying beam widths; calculating beam forming weights based on the one or more requirement parameters by assigning non-zero values to a number of beam forming weights that exceeds a minimum number of beam forming weights for the determined desired synchronization signal beam width, wherein a beam resulting from the calculated beam forming weights has a beam width larger than or equal to the determined desired synchronization signal beam width, and an effective power larger than or equal to the minimum effective power; generating a synchronization signal for transmission; and transmitting the generated synchronization signal using the calculated beam forming weights. ### Claim 2 (depends on 1) The method of claim 1 wherein the determined desired synchronization signal beam width is smaller than an omnidirectional beam width. ### Claim 3 (depends on 1) The method of claim 1 wherein the one or more requirement parameters further comprise one or more of: a beam direction and a beam polarization. ### Claim 4 (depends on 1) The method of claim 1 wherein determining the one or more requirement parameters is performed based on a required coverage for the synchronization signals. ### Claim 5 (depends on 1) The method of claim 1 wherein at least one of the minimum effective power and the minimum number of beam forming weights is associated with a discrete Fourier transform beam having the determined desired synchronization signal beam width. ### Claim 6 (depends on 5) The method of claim 5 wherein the minimum effective power is larger than an effective power achieved by constructing the discrete Fourier transform beam having the determined desired synchronization signal beam width. ### Claim 7 (depends on 5) The method of claim 5 wherein the minimum number of beam forming weights is larger than a number of non-zero beam forming weights achieved by constructing the discrete Fourier transform beam having the determined desired synchronization signal beam width. ### Claim 8 (depends on 5) The method of claim 5 wherein calculating the beam forming weights comprises applying an iterative algorithm using the discrete Fourier transform beam having the determined desired synchronization signal beam width as an input value, and wherein each iteration increases the number of non-zero beam forming weights. ### Claim 9 (depends on 1) The method of claim 1 wherein the one or more requirement parameters further comprise a number of beams to be swept, wherein the method further comprises: calculating beam forming weights for each of the beams to be swept; generating the synchronization signal by adapting, based on a sweeping pattern, the synchronization signal for the beams to be swept; and transmitting the adapted synchronization signal by sweeping the beams. ### Claim 10 (depends on 9) The method of claim 9 wherein sweeping the beams is performed in at least one of: a time dimension and a frequency dimension. ### Claim 11 (depends on 1) A non-transitory, computer readable medium storing program instructions that, when executed by a data processing unit, cause execution of the method of claim 1. ### Claim 12 An arrangement for a network node configured to transmit wireless communication signals using beam forming and configured to apply any of one or more data carrying beam widths for transmission of data carrying signals dedicated to a specific wireless communication device, the arrangement comprising: at least one processor; and at least one memory storing executable program instructions that, when executed by the at least one processor, cause: determination of one or more requirement parameters for transmission of synchronization signals, wherein the one or more requirement parameters comprise a desired synchronization signal beam width and a minimum effective power, and wherein the determined desired synchronization signal beam width is larger than a minimum one of the data carrying beam widths; calculation of beam forming weights based on the one or more requirement parameters by assigning non-zero value to a number of beam forming weights that exceeds a minimum number of beam forming weights for the determined desired synchronization signal beam width, wherein a beam resulting from the calculated beam forming weights has a beam width larger than or equal to the determined desired synchronization signal beam width, and an effective power larger than or equal to the minimum effective power; generation of a synchronization signal for transmission; and transmission of the generated synchronization signal using the calculated beam forming weights. ### Claim 13 (depends on 12) The arrangement of claim 12 wherein at least one of the minimum effective power and the minimum number of beam forming weights is associated with a discrete Fourier transform beam having the determined desired synchronization signal beam width. ### Claim 14 (depends on 13) The arrangement of claim 13 wherein the executed program instructions further cause calculation of the beam forming weights by application of an iterative algorithm that uses the discrete Fourier transform beam having the determined desired synchronization signal beam width as an input value, wherein each iteration increases the number of non-zero beam forming weights. ### Claim 15 (depends on 12) The arrangement of claim 12 wherein the one or more requirement parameters further comprise a number of beams to be swept, and wherein the executed program instructions further cause: calculation of beam forming weights for each of the beams to be swept; generation of the synchronization signal by adaptation, based on a sweeping pattern, of the synchronization signal for the beams to be swept; and transmission of the adapted synchronization signal by sweeping the beams. ### Claim 16 (depends on 12) A network node comprising the arrangement of claim 12.