Method and system for adapting beamwidth of a beam on a NR physical channel

Abstract

The present disclosure relates to a quasi-fifth generation (5G) or 5G communication system that will be provided to support higher data rates than fourth generation (4G) communication systems such as long term evolution (LTE). A method and system for adapting the beam width of a beam on an NR physical channel is disclosed. Alignment between beams of a UE and a gNB is created by refining a beam codebook. Phase shifters and PA / LNAs of tuned antenna elements are used to refine the beam codebook. Strengths of signals received through different RX beams are determined based on RSRP / SINR associated with different RX beams. A direction in which RSRP / SINR associated with consecutive RX beams is increasing is determined. A pair of RX beams is determined, wherein the RSRP / SINR associated with a first beam is greater than the RSPR / SINR associated with a second beam, wherein the RSRP / SINR associated with the first beam is maximum along the determined direction. A third wide beam or a fourth narrow beam is generated based on the refined beam codebooks of the first beam and the second beam to align the RX beam in the direction of the TX beam.

Description

Technical Field

[0001] Embodiments herein relate to a fifth generation (5G) new radio (NR) communication system, and more particularly, to methods and systems for generating beams with appropriate beam properties on an NR physical channel. Background Art

[0002] In order to meet the growing demand for wireless data traffic since the deployment of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also referred to as "beyond 4G networks" or "post-LTE systems."

[0003] 5G communication systems are considered to be implemented in higher frequency (mmWave) bands, for example, 60 GHz bands, in order to achieve higher data rates. In order to reduce the propagation loss of radio waves and increase the transmission distance, beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antenna technologies are discussed in 5G communication systems.

[0004] In addition, in the 5G communication system, research and development of system network improvements are being carried out based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communications, wireless backhaul, mobile networks, cooperative communications, coordinated multi-point (CoMP), receiving-end interference elimination, etc.

[0005] In 5G systems, hybrid FSK with QAM modulation (FQAM) and sliding window superposition coding (SWSC) as advanced coding modulation (ACM), and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as advanced access technologies have been developed.

[0006] In the beam management process P3, the user equipment (UE) scans all receiver (RX) beams relative to each of the next generation Node B (gNB) transmitter (TX) beams. During the P3 process, there is a possibility that the UE RX beam is not aligned with the gNB TX beam. The initial acquisition may not require a perfect alignment between the gNB TX beam and the UE RX beam. However, for successful reception of random access channel (RACH) signals and unicast data, alignment between the gNB TX beam and the UE RX beam is required. The requirement for beam alignment is particularly necessary if the UE is not stationary. Considering that the same set of beams can be used by the UE for uplink transmission, beam misalignment due to the movement of the UE can affect the uplink transmission. Misalignment between the TX beam and the RX beam can degrade the performance of the UE in different scenarios and can cause link failures in millimeter (mm) wave systems.

[0007] Figure 1 An example scenario is depicted where the UE RX beam and the gNB TX beam are not aligned with each other. There may be three UE RX beams, namely beam “i”, beam “i+1” and beam “i+2”. Figure 1 As depicted in , the RX beam scanning operation at the UE may miss the direction of the TX beam, resulting in misalignment between the UE RX beam and the gNB TX beam. Summary of the invention

[0008] [Technical issues]

[0009] A primary objective of the embodiments herein is to disclose a method and system for creating alignment between a beam of a user equipment (UE) and a beam of a next generation Node B (gNB) by refining a beam codebook of the UE's beam, wherein the refined beam codebook can be used to generate a beam with appropriate beam properties and there is alignment between the generated beam of the UE and the beam of the gNB.

[0010] Another object of embodiments herein is to refine the beam codebook by tuning the phase angle of the phase shifters of the antenna elements of the UE and the gain of the power amplifier or low noise amplifier (PA / LNA) to generate a beam with a wider or narrower beamwidth.

[0011] Another object of the embodiments herein is to refine the beam codebook to generate a wider beam or a narrower beam based on the distance between the UE and the gNB, the channel conditions between the UE and the gNB, and the type of messages sent / received between the UE and the gNB.

[0012] Another object of embodiments herein is to optimize reference signal received power / signal to interference and noise ratio (RSRP / SINR) measurements of transmit (TX) beams received using different receive (RX) beams.

[0013] [Problem Solution]

[0014] Thus, embodiments provide methods and systems for creating alignment between a beam of a user equipment (UE) and a next generation node B (gNB). Embodiments include creating alignment between a beam of a UE and a beam of a gNB by refining a beam codebook for the beam of the UE. Embodiments include determining the strength of a transmitted signal received by different receiver (RX) beams based on a reference signal received power (RSRP) or a signal to interference and noise ratio (SINR) associated with the different RX beams. These embodiments include determining a direction in which RSRP / SINR associated with consecutive RX beams are increasing. Embodiments include determining a pair of RX beams, wherein the RSRP / SINR associated with a first RX beam is greater than the RSPR / SINR associated with a second RX beam, wherein the RSRP / SINR associated with the first RX beam is greatest along the direction in which the RSPR / SINR associated with the consecutive RX beams are increasing. Embodiments include tuning the angles of phase shifters of one or more UE antenna elements and the gains of power amplifiers and low noise amplifiers (PA / LNA) to refine the beam codebook. Embodiments include generating a beam with appropriate beam properties, i.e., a beam with a wider beam width or a beam with a narrower (directional) beam width, based on tuning to align the RX beam in the direction of the transmitter (TX) beam. Embodiments include generating a wider beam or a narrower beam based on the distance between the UE and the gNB, the channel conditions used for communication between the UE and the gNB, and the types of messages exchanged between the UE and the gNB. Embodiments include using measurements of the UE RX beam to optimize the gNB TX beam.

[0015] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and accompanying drawings. However, it should be understood that the following description, although indicating embodiments and many specific details thereof, is provided by way of illustration and not limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit of the exemplary embodiments, and the embodiments herein include all such modifications. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The embodiments of the present invention are shown in the accompanying drawings, and similar reference numerals represent corresponding parts in the various drawings throughout the drawings. The embodiments of the present invention will be better understood from the following description with reference to the accompanying drawings, in which:

[0017] Figure 1Depicted is an example scenario where a user equipment (UE) receiver (RX) beam and a next generation Node B (gNB) transmitter (TX) beam are misaligned with each other;

[0018] Figure 2 Various elements of a system configured to adapt a beamwidth of a beam of a UE on a New Radio (NR) physical channel according to embodiments disclosed herein are depicted;

[0019] Figure 3 is a flow chart depicting a method for adapting the beamwidth of a beam of a UE according to embodiments disclosed herein;

[0020] Figure 4 is an example scenario depicting replacement of an existing RX beam with generation of a new RX beam according to an embodiment disclosed herein, wherein the beamwidth of the generated RX beam is wider than the beamwidth of the existing RX beam;

[0021] Figure 5 An example scenario of generating a new RX beam between two existing RX beams according to an embodiment disclosed herein, wherein the beamwidth of the new RX beam is narrower than the beamwidth of the existing RX beams;

[0022] Figure 6a and Figure 6b depicts the calculation of a phase angle corresponding to a beam angle of an RX beam having a narrow beamwidth according to embodiments disclosed herein;

[0023] Figure 6c Depicted is an array of antenna elements of a UE and power amplifiers and low noise amplifiers (PA / LNA) associated with the antenna elements for managing a UE beam codebook according to embodiments disclosed herein;

[0024] Figure 7 is an example scenario depicting refinement of a UE TX beam codebook for generating a TX beam with a wider beamwidth according to an embodiment disclosed herein;

[0025] Figure 8 is an example scenario depicting refinement of a UE TX beam codebook for generating a TX beam with a narrow beamwidth according to an embodiment disclosed herein;

[0026] Fig. 9 depicts an example replacement of an existing RX beam and generation of a new RX beam, wherein the beamwidth of the generated RX beam is wider than the beamwidth of the replaced RX beam, according to embodiments disclosed herein;

[0027] Fig.10Depicting an example generation of a new RX beam between two existing RX beams, wherein the beamwidth of the new RX beam is narrower than the beamwidth of the existing RX beams, according to embodiments disclosed herein;

[0028] Fig.11 is an example scenario describing receiving a physical downlink control channel (PDCCH) using a wide RX beam according to an embodiment disclosed herein, wherein the RX beam is generated by refining an RX beam codebook; and

[0029] Fig.12 An example scenario is described for receiving a physical downlink scheduling channel (PDSCH) using a narrow RX beam according to an embodiment disclosed herein, wherein the RX beam is generated by refining an RX beam codebook. DETAILED DESCRIPTION

[0030] The embodiments of this invention and their various features and advantageous details are explained more fully with reference to the non-limiting embodiments shown in the drawings and described in detail in the following description. The description of well-known components and processing techniques is omitted so as not to unnecessarily obscure the embodiments of this invention. The examples used herein are merely intended to facilitate understanding of the manner in which the embodiments of this invention may be practiced, and further enable those skilled in the art to practice the embodiments of this invention. Therefore, the examples should not be interpreted as limiting the scope of the embodiments of this invention.

[0031] Embodiments herein disclose methods and systems for adapting the beam width of a beam to create alignment between beams of a user equipment (UE) and a next generation Node B (gNB) in a fifth generation (5G) new radio (NR) communication system. Embodiments include creating alignment between a beam of a gNB and a beam of a UE by refining a beam codebook of a beam of the UE. Embodiments include refining a beam codebook of a beam of the UE by tuning a phase shifter and a low noise amplifier / power amplifier (LNA / PA) of an antenna element of the UE. Embodiments include generating a beam with a wider beam width or a beam with a narrower beam width based on the refinement of the beam codebook of the beam of the UE. The wide beam or the narrow beam is aligned with the gNB beam to improve transmission and reception between the UE and the gNB.

[0032] Referring now to the drawings, and more particularly to Figures 2 to 12 , a preferred embodiment is shown, wherein like reference numerals throughout the drawings denote corresponding features.

[0033] Figure 2 Various elements of a system 200 configured to adapt the beamwidth of a beam of a UE 201 on an NR physical channel according to embodiments disclosed herein are depicted. Figure 2As depicted, system 200 includes at least one UE 201 and at least one gNB 202. UE 201 is capable of communicating with gNB 202 as a transmitter or a receiver. If UE 201 acts as a receiver, gNB 202 acts as a transmitter. Similarly, if UE 201 acts as a transmitter, gNB 202 acts as a receiver. UE 201 also includes a processor 203, a memory 204, and a display 205. Processor 203 may include at least one of an application processor and a communication processor (not shown).

[0034] Processor 203 may determine whether there is alignment between the beam of UE 201 and the beam of gNB 202. If the strength of the signal received through the RX beam is less than a predetermined decoding threshold, UE 201 may infer that there is misalignment between the beam of UE 201 and the beam of gNB 202. UE 201 may create alignment by refining the beam codebook of the beam of UE 201. In an embodiment, consider that UE 201 acts as a receiver and gNB 202 acts as a transmitter. Consider that UE 201 is attempting to receive a signal from gNB 202 in a transmitter (TX) beam. Processor 203 may determine the strength of the signal received through the receiver (RX) beam of UE 201.

[0035] In an embodiment, the strength of a signal received through an RX beam may be determined based on a reference signal received power (RSRP) associated with the RX beam. In an embodiment, the strength of a signal received through an RX beam may be determined based on a signal to interference and noise ratio (SINR) associated with the RX beam.

[0036] Once the strength of the signals received through different RX beams is determined based on the RSRP / SINR associated with different RX beams of UE 201, processor 203 can determine the direction in which the RSRP / SINR associated with consecutive RX beams are increasing. In the example, consider that based on the activated (active) antenna elements in UE 201, four RX beams can receive signals sent by gNB 202 through TX beams. The RX beams can be referred to as beam "A", beam "B", beam "C", and beam "D". Beam AD of UE 201 is an RX beam through which UE 201 can receive signals sent by gNB 202 in TX beams.

[0037] Processor 203 may determine a pair of RX beams, wherein the RSRP / SINR associated with the first RX beam is greater than the RSPR / SINR associated with the second RX beam, and the RSRP / SINR associated with the first RX beam is greatest in the direction in which the RSPR / SINR associated with consecutive RX beams are increasing. Consider the above example, where beam D is consecutive to beam A, beam A is consecutive to beam B, beam B is consecutive to beam C, and beam C is consecutive to beam D. The order in which UE 201 may perform RX beam scanning (scanning across consecutive beams) may be CBAD, ABCD, BADC, etc.

[0038] The processor 203 may determine that the RSRP / SINR associated with beam C is less than the RSRP / SINR associated with beam B. Similarly, the RSRP / SINR associated with beam B is less than the RSRP / SINR associated with beam A. The RSRP / SINR associated with beam A may be greater than the RSRP / SINR associated with beam D. Based on the determined RSRP / SINR values ​​of the RX beams, the processor 203 may determine that CBA is the direction in which the values ​​of RSRP / SINR associated with consecutive RX beams are increasing. The processor 203 may consider beam A as the first RX beam because the RSRP / SINR associated with beam A is the largest in the direction in which the RSRP / SINR associated with consecutive RX beams are increasing. The processor 203 may consider beam D as the second RX beam because the RSRP / SINR associated with beam A is greater than the RSRP / SINR associated with beam D.

[0039] The processor 203 may tune the angle of the phase shifter of one or more antenna elements of the UE 201 and the gain of the power amplifier and the low noise amplifier (PA / LNA). The tuning may result in the refinement of the beam codebook of the RX beam. In an embodiment, the processor 203 may perform the tuning to generate a third RX beam having a wider beam width than the first RX beam and the second RX beam. The generation of the third RX beam may result in the replacement of the first RX beam and the second RX beam. The replacement of the first RX beam and the second RX beam may result in a reduction in the number of activated antenna elements, which may reduce the power consumption of the UE 201.

[0040] In another embodiment, the processor 203 may perform tuning to generate a fourth RX beam, wherein the fourth RX beam has a narrower beam width than the first RX beam and the second RX beam. The fourth RX beam may be a directional beam (with a greater antenna gain). The fourth RX beam may be generated between the first RX beam and the second RX beam. The beam angle of the first RX beam may be Ω 1 The beam angle of the second RX beam may be Ω2 If the antenna elements of the UE 201 are arranged in an array (separated by a predetermined distance) in the horizontal direction, the beam angles of the corresponding beams may be measured with respect to the vertical direction.

[0041] The processor 203 may generate a fourth RX beam between the first RX beam and the second RX beam by tuning the phase angle of the phase shifter of the antenna element involved in generating the first RX beam and the second RX beam. If the phase angle of the phase shifter is "X" degrees, the first RX beam is at a beam angle Ω 1 The phase angle of the first RX beam generated by the phase shifter can be expressed as φ 1 If the phase angle of the phase shifter is (X+θ) degrees, the second RX beam is Ω 2 The phase angle of the second RX beam generated by the phase shifter can be expressed as φ 2 The processor 203 can tune the phase angle of the phase shifter so that the phase angle is (X+θ'), where 0<θ'<θ. The phase angle tuning θ' can result in a beam angle Ω 4 A fourth RX beam angle between the first RX beam and the second RX beam is generated.

[0042] The phase angles of the first RX beam and the second RX beam generated by the phase shifter can be expressed as follows:

[0043]

[0044] In an embodiment, the relationship between the beam angles of the first RX beam and the second RX beam and the beam angle of the fourth RX beam may be expressed as:

[0045]

[0046] The phase angle (X+θ') of the fourth RX beam generated by the phase shifter can be expressed as:

[0047]

[0048] In another embodiment, the relationship between the beam angles of the first RX beam and the second RX beam and the beam angle of the fourth RX beam is expressed as:

[0049]

[0050] The phase angle (X+θ') of the fourth RX beam generated by the phase shifter can be expressed as:

[0051]

[0052] The processor 203 can tune the angle of the phase shifter and the gain of the LNA / PA (to generate a third RX beam or a fourth RX beam) based on the distance between the UE 201 and the gNB 202, the instantaneous conditions of the channel used for communication between the UE 201 and the gNB 202, and the types of messages exchanged between the UE 201 and the gNB 202 (such as the physical random access channel (PRACH), the physical downlink control channel (PDCCH), the physical uplink scheduling channel (PUSCH), the physical downlink scheduling channel (PDSCH), etc.).

[0053] In an embodiment, if the distance between UE 201 and gNB 202 is less than a predetermined distance and the instantaneous channel condition is optimal, the processor 203 may generate a third RX beam having a wide beamwidth compared to beamwidths of the first RX beam and the second RX beam.

[0054] In an embodiment, if the distance between UE 201 and gNB 202 is greater than a predetermined distance and the instantaneous channel condition is not optimal, the processor 203 may generate a fourth RX beam between the first RX beam and the second RX beam, i.e., an RX beam having a narrow beam width.

[0055] If the first RX beam and the second RX beam are not aligned in the direction of the TX beam, the processor 203 may generate a third RX beam or a fourth RX beam so that one of the generated beams is aligned in the direction of the TX beam transmitted by the gNB 202.

[0056] In an embodiment, if UE 201 acts as a transmitter and gNB 202 acts as a receiver, UE 201 may use the same set of RX beams to generate TX beams. Based on RSRP / SINR measurements performed on the RX beams, processor 203 may treat the first RX beam as a first TX beam and the second RX beam as a second TX beam. Processor 203 may refine the beam codebook of the TX beam to generate a third TX beam with a wider beamwidth or a fourth TX beam with a narrower beamwidth. If the first TX beam and the second TX beam are not aligned in the direction of the gNB 202 RX beam, processor 203 may generate at least one TX beam such that at least one generated beam is aligned in the direction of the gNB 202 RX beam.

[0057] Processor 203 may use UE 201 RX beams to optimize measurements of gNB 202 TX beams. Processor 203 may measure gNB 202 TX beams by determining RSRP values ​​associated with beams having a wider beamwidth (third RX beam) and a narrower beamwidth (fourth RX beam). Processor 203 may calculate a difference (given by Δ ) between the RSRP value associated with the third RX beam and the RSRP value associated with the fourth RX beam as follows: RSRP express):

[0058]

[0059] The processor 203 may store the measured values ​​in the memory 204. The processor 203 may choose to measure a particular TX beam at a later stage by determining the RSRP relative to an RX beam with a wider beam width, and using Δ RSRP The measurement value may be scaled to determine the RSRP relative to the RX beam with the narrower beamwidth. This may reduce the power consumption of the UE 201 during the measurement because the number of antenna elements that need to be activated to generate a beam with a wider beamwidth is less than the number of antenna elements required to generate a beam with a narrow beamwidth.

[0060] Figure 2 Exemplary units of UE 200 are shown, but it should be understood that other embodiments are not limited thereto. In other embodiments, UE 200 may include fewer or more units. In addition, the labels or names of the units are only for illustrative purposes, but do not limit the scope of the present invention. One or more units may be combined together to perform the same or substantially similar functions in UE 200.

[0061] Figure 3 is a flow chart 300 depicting a method for adapting a beam width of a beam of a UE 201 according to embodiments disclosed herein. At step 301, the method includes determining a strength of a signal received through a UE 201 RX beam if the strength of the signal received through the RX beam is less than a predetermined beam decoding threshold. The signal is transmitted using a gNB 202 TX beam, wherein the UE 201 (which acts as a receiver) attempts to receive a TX beam from a gNB 202 (which acts as a transmitter). Embodiments include determining whether there is alignment between the RX beam and the TX beam during RX beam scanning. Since the strength of the signal received through the RX beam is less than a predetermined beam decoding threshold, embodiments include determining that there is no alignment between the RX beam and the TX beam. The UE 201 may create alignment by refining a beam codebook for the RX beam. These embodiments include determining the strength of signals received through different RX beams based on RSRP / SINR associated with the different RX beams.

[0062] At step 302, the method includes determining a direction in which RSRP / SINR associated with consecutive RX beams is increasing. In an example, consider receiving signals via four RX beams "i", "i+1", "i+2", and "i+3". Beam "i" is continuous with beam "i+1", beam "i+1" is continuous with beam "i+2", beam "i+2" is continuous with beam "i+3", and beam "i+3" is continuous with beam "i". An embodiment includes determining RSRP i+3 <RSRP i+2 <RSRP i+1 , and RSRP i <RSRP i+1 Therefore, the direction in which the RSRP / SINR associated with consecutive RX beams is increasing is (i+3)-(i+2)-(i+1).

[0063] In step 303, the method includes determining a first RX beam and a second RX beam based on the determined direction and RSRP / SINR associated with consecutive RX beams. An embodiment includes considering beam "i+1" as the first RX beam and considering beam "i" as the second RX beam. This is because the RSRP associated with beam "i+1" is greater than the RSRP associated with beam "i", and the RSRP associated with beam "i+1" is the largest along the direction in which the RSRP associated with consecutive RX beams "i+1", "i+2", and "i+3" are increasing.

[0064] At step 304, the method includes generating at least one RX beam (such as a third RX beam, a fourth RX beam, etc.) by refining an RX beam codebook of the first RX beam and the second RX beam, wherein at least one of the generated RX beams is aligned in the direction of the TX beam transmitted by the gNB 202. Refining the RX beam codebook includes tuning the angles of phase shifters and the gains of the PA / LNA of the antenna elements of the UE 201. In an embodiment, the tuning of the RX beam codebook results in the generation of a third RX beam, the third RX beam having a wider beam width than the first RX beam and the second RX beam. The generation of the third RX beam results in the replacement of the first RX beam and the second RX beam. An embodiment includes reducing the number of activated antenna elements to generate the third RX beam, which in turn can result in reducing the power consumption of the UE 201.

[0065] In another embodiment, tuning of the RX beam codebook results in generation of a fourth RX beam, the fourth RX beam having a narrower beam width than the first RX beam and the second RX beam. The fourth RX beam may be generated between the first RX beam and the second RX beam. An embodiment includes determining a beam angle of the first RX beam and the second RX beam. An embodiment includes determining a beam angle of the fourth RX beam based on the beam angles of the first RX beam and the second RX beam. An embodiment includes determining a phase angle at which a phase shifter needs to be tuned to generate the fourth RX beam.

[0066] An embodiment includes generating an RX beam based on the distance between UE 201 and gNB 202, the instantaneous channel conditions for communication between UE 201 and gNB 202, and the type of messages exchanged between UE 201 and gNB 202.

[0067] The various actions in flowchart 300 may be performed in the order presented, in a different order, or simultaneously. In addition, in some embodiments, the Figure 3 Some of the actions listed in .

[0068] Figure 4 FIG. 1 is an example scenario of replacing an existing RX beam with generation of a new RX beam according to an embodiment disclosed herein, wherein the beamwidth of the generated RX beam is wider than the beamwidth of the existing RX beam. In the current example scenario, consider that UE 201 acts as a receiver and gNB 202 acts as a transmitter. Figure 4 As shown, the RX beam of UE 201 is not aligned in the direction of the TX beam of gNB 202. RX beam “i+1” can be considered as the first RX beam. RX beam “i+2” can be considered as the second RX beam, where the RSRP / SINR associated with RX beam “i+2” is less than the RSRP / SINR associated with RX beam “i+1”. The number of activated antenna elements (required to maintain RX beams “i+1” and “i+2”) is 8.

[0069] An embodiment includes refining the RX beam codebook of the existing RX beams “i+1” and “i+2” to generate a new RX beam “j”. The generation of the new RX beam “j” results in the replacement of the existing RX beams “i+1” and “i+2”. The beam width of the RX beam “j” is wider than the beam width of the existing RX beams “i+1” and “i+2”. The number of activated antenna elements required to generate the RX beam “j” is 4.

[0070] Thus, the number of activated UE 201 antenna elements is reduced by half. The power consumption of UE 201 is reduced by reducing the number of activated UE 201 antenna elements. The reduction in the number of activated UE 201 antenna elements results in the generation of an RX beam "j" with a wider beamwidth, which is aligned with the direction of the gNB 202 TX beam.

[0071] Figure 5 FIG. 2 is a diagram illustrating an example scenario of generating a new RX beam between two existing RX beams according to an embodiment disclosed herein, wherein the beamwidth of the new RX beam is narrower than the beamwidth of the existing RX beams. In the example scenario, consider that UE 201 acts as a receiver and gNB 202 acts as a transmitter. Figure 5 As shown, the RX beam of UE 201 is not aligned in the direction of the TX beam of gNB 202. RX beam "i" can be considered as the first RX beam. RX beam "i+1" can be considered as the second RX beam. The RSRP / SINR associated with RX beam "i" is greater than the RSRP / SINR associated with RX beam "i-1".

[0072] The beam angle of RX beam "i" can be Ω I The beam angle of RX beam “i+1” can be Ω I+1 . Corresponding to the beam angle Ω I The phase angle of the phase shifter (involved in generating RX beam "i") may be 'X' degrees. This corresponds to a beam angle Ω I+1 The phase angle of the phase shifter (involved in generating RX beam “i+1”) may be (X+θ) degrees. An embodiment includes refining the RX beam codebook by tuning the phase angle of the phase shifter to generate a new RX beam “j” between the existing RX beams “i” and “i+1”. The beam angle of RX beam “j” may be Ω J .

[0073] The beam width of RX beam "j" is narrower than the beam widths of RX beams "i" and "i+1". Corresponding to the beam angle Ω J The phase angle of the phase shifter may be (X+θ') degrees. An embodiment includes tuning the phase angle of at least one phase shifter to θ', where 0<θ'<θ. Tuning the phase angle to θ' may result in generating an RX beam "j" with a narrow beamwidth that is aligned with the direction of the TX beam of gNB 202.

[0074] Figure 6a and Figure 6bDepicted is the calculation of a phase angle corresponding to a beam angle of an RX beam having a narrow beamwidth according to an embodiment disclosed herein. Embodiments include calculating a phase angle to tune a phase shifter of an antenna element of a UE 201, wherein the antenna elements are placed in an array. The antenna elements may be spaced apart by a predetermined distance "d". The phase angle may be determined based on a beam angle of a narrow RX beam generated between two RX beams having a wider beamwidth. The beam angle of the narrow RX beam is based on the beam angle of the beam between which the narrow RX beam is generated.

[0075] Consider generating a narrow RX beam between RX beams "i" and "i+1". Figure 6a As shown, the beam angles of RX beams "i" and "i+1" can be expressed as Ω i and Ω i+1 The phase angles corresponding to RX beams "i" and "i+1" can be determined as follows:

[0076]

[0077] like Figure 6b As shown, the narrow RX beam is called beam "j", which is generated between RX beam "i" and RX beam "i+1". The beam angle of RX beam "j" can be expressed as Ω j The phase angle corresponding to RX beam “j” can be determined as:

[0078]

[0079] In an embodiment, the relationship between the beam angle of RX beam "j" and the beam angles of beams "i" and "i+1" may be

[0080] Therefore, the phase angle to which the phase shifter of the antenna element is to be tuned is calculated as:

[0081]

[0082] In an embodiment, the relationship between the beam angle of RX beam "j" and the beam angles of beams "i" and "i+1" may be.

[0083]

[0084] Therefore, the phase angle to which the phase shifter of the antenna element is to be tuned is calculated as:

[0085]

[0086] Figure 6cDepicted is an antenna element array of UE 201 and PAs and LNAs associated with the antenna elements for managing UE beam codebooks according to embodiments disclosed herein. Embodiments may manage the number of antenna elements allowed to be activated at a particular moment. If the number of activated antenna elements is reduced, the beams may be widened and the number of generated beams may be reduced compared to the width and number of current beams.

[0087] If the phase angle of the phase shifter is adjusted, a narrow beam can be generated between two existing beams. The phase angle of the generated beam is larger than the phase angle used to generate one of the existing beams and smaller than the phase angle used to generate the other existing beam.

[0088] Figure 7 FIG. 1 is an example scenario depicting a refinement of a UE 201 TX beam codebook for generating a TX beam with a wider beamwidth according to an embodiment disclosed herein. Figure 7 As shown in the example scenario in , consider that UE 201 initially acts as a receiver and gNB 202 acts as a transmitter. UE 201 can determine that the RX beam is not aligned in the direction of the gNB 202 TX beam because the RX beam with a narrow beamwidth missed the direction of the gNB 202 TX beam during the initial acquisition. UE 201 can measure the RSRP / SINR associated with each of RX beams "i", "i+1", and "i+2". In an embodiment, UE 201 can perform the measurements during the initial acquisition. UE 201 can determine based on the measurements that RX beam "i+1" is the first RX beam and RX beam "i+2" is the second RX beam.

[0089] Embodiments include generating TX beams using RX beams when UE 201 acts as a transmitter and gNB 202 acts as a receiver. Due to a determination that the RX beam of UE 201 is not aligned with the gNB 202 TX beam, UE 201 may refine the TX beam codebook to align the UE 201 TX beam and the gNB 202 RX beam. The TX beam codebook may be refined by tuning the phase shifters and PA / GNA of the antenna elements of UE 201. In an embodiment, the refinement may result in the generation of TX beams 'j' and 'j+1'. The refinement of the UE 201 TX codebook may be performed during a RACH procedure.

[0090] Embodiments include determining that UE 201 is located near gNB 202 based on a distance between UE 201 and gNB 202 (the distance between UE 201 and gNB 202 is less than a predetermined distance). Embodiments also include determining that instantaneous channel conditions are optimal. Based on these determinations, UE 201 can perform refinement to generate TX beams "j" and "j+1". The beam widths of TX beams "j" and "j+1" are wider than RX beams "i", "i+1", and "i+2". Refinement of the TX beam codebook results in alignment between the TX beam of UE 201 and the RX beam of gNB 202. Once alignment is achieved, UE 201 can send messages such as PRACH and PUSCH.

[0091] Figure 8 FIG. 1 is an example scenario depicting refinement of a UE 201 TX beam codebook for generating a TX beam with a narrow beamwidth according to an embodiment disclosed herein. Figure 8 As shown in the example scenario depicted in , consider that UE 201 initially acts as a receiver and gNB 202 acts as a transmitter. UE 201 can determine that the RX beam is not aligned with the gNB 202 TX beam because the RX beam scanning missed the direction of the gNB 202 TX beam during the initial acquisition. UE 201 measures the RSRP / SINR associated with each of RX beams "i", "i+1", and "i+2". RX beam "i+1" is the first RX beam, and RX beam "i+2" is the second RX beam. Since the UE 201 RX beam is not aligned with the gNB 202 TX beam, when UE 201 acts as a transmitter and gNB 202 acts as a receiver, UE 201 can refine the TX beam codebook to align the UE 201 TX beam and the gNB 202 RX beam.

[0092] Embodiments include determining that UE 201 is away from gNB 202 based on the distance between UE 201 and gNB 202 (the distance between UE 201 and gNB 202 is greater than a predetermined distance). Embodiments also include determining that instantaneous channel conditions are not optimal. Based on these determinations, UE 201 can perform refinement of the TX beam codebook so that TX beam "j" is generated between TX beams "i+1" and "i+2" (initially serving as RX beams). The refinement is performed by tuning the phase angles of the phase shifters of the antenna elements of UE 201 used to generate the TX beams.

[0093] The beamwidth of TX beam “j” is narrower than RX beams “i”, “i+1”, and “i+2”. The refinement of the TX beam codebook results in alignment between the TX beam of UE 201 and the RX beam of gNB 202. Once alignment is achieved, UE 201 can send messages such as NPRACH and NPUSCH.

[0094] Fig. 9 An example replacement of an existing RX beam and generation of a new RX beam according to an embodiment disclosed herein is depicted, wherein the beamwidth of the generated RX beam is wider than the beamwidth of the replaced RX beam. Consider that UE 201 acts as a receiver and gNB 202 acts as a transmitter. Fig. 9 As shown, UE 201 can determine that the existing RX beam is not aligned in the direction of the TX beam of gNB 202 because the existing RX beam with a narrow beamwidth missed the direction of the TX beam of gNB 202 during the initial acquisition. RX beam "i+1" is determined to be the first RX beam, where the RSRP / SINR associated with RX beam "i+1" is optimal in the direction where the RSRP / SINR of consecutive RX beams ("i", "i+1", and "i+2") are increasing. RX beam "i+2" can be determined to be the second RX beam, where the RSRP / SINR associated with RX beam "i+2" is less than the RSRP / SINR associated with RX beam "i+1". UE 201 can perform RSRP / SINR measurements during the initial acquisition.

[0095] Embodiments include refining the RX beam codebook by tuning the phase shifters of the antenna elements of the UE 201 and the gains of the PA / LNA. The refinement of the UE 201 RX codebook may be performed during the RACH process. The refinement may result in the generation of new RX beams "j" and "j+1" and the replacement of RX beams "i", "i+1", and "i+2". The beamwidths of the RX beams "j" and "j+1" are wider than the beamwidths of the RX beams "i", "i+1", and "i+2". The refinement of the RX beam codebook results in alignment between the RX beam of the UE 201 and the TX beam of the gNB 202. Once the alignment is achieved, the UE 201 may receive messages such as PRACH and PUSCH.

[0096] Fig.10 An example generation of a new RX beam between two existing RX beams according to an embodiment disclosed herein is depicted, wherein the beamwidth of the new RX beam is narrower than the beamwidth of the existing RX beams. Consider that UE 201 acts as a receiver and gNB 202 acts as a transmitter. Fig.10As shown, UE 201 can determine that the existing RX beam is not aligned in the direction of the TX beam of gNB 202 because the RX beam scanning missed the direction of the TX beam during the initial acquisition. RX beam "i+1" is determined to be the first RX beam. RX beam "i+2" is determined to be the second RX beam. During the initial acquisition, the RSRP / SINR associated with RX beam "i+1" is determined to be greater than the RSRP / SINR associated with RX beam "i+2".

[0097] Embodiments include determining that UE 201 is away from gNB 202 based on a distance between UE 201 and gNB 202 (the distance between UE 201 and gNB 202 is greater than a predetermined distance). Embodiments also include determining that instantaneous channel conditions are not optimal. Based on these determinations, UE 201 can perform refinement of the RX beam codebook so that RX beam "j" is generated between RX beams "i+1" and "i+2". The refinement is performed by tuning the phase angles of the phase shifters of the antenna elements of UE 201.

[0098] The beamwidth of RX beam “j” is narrower than RX beams “i”, “i+1”, and “i+2”. The refinement of the RX beam codebook results in alignment between the RX beam of UE 201 and the TX beam of gNB 202. Once alignment is achieved, UE 201 can send messages such as PRACH and PUSCH.

[0099] Fig.11 The present invention describes an example scenario of receiving a PDCCH using a wide RX beam according to an embodiment disclosed herein, wherein the RX beam is generated by refining the RX beam codebook. Fig.11 As shown, UE 201 may use RX beam "i+1" to receive PDCCH. The PDCCH message for UE 201 may be sent by gNB 202 along with other PDCCH messages on the control resource set (CORESET).

[0100] Since the PDCCH message for UE 201 is shared with other UEs by sending the PDCCH message on the CORESET, it can be inferred that gNB 202 sends the PDCCH message on a beam with a wider beamwidth than the beam used for unicast transmission on the NPDSCH scheduled for UE 201. Therefore, UE 201 can refine the RX beam codebook to generate RX beams "i", "i+1", and "i+2" with narrow beamwidths. The RX beam codebook can be refined by tuning the phase angles of the phase shifters of the antenna elements of UE 201. RX beams "i", "i+1", and "i+2" can improve the success rate of PDCCH reception.

[0101] Fig.12 The present invention describes an example scenario of receiving a PDSCH using a narrow RX beam according to an embodiment disclosed herein, wherein the RX beam is generated by refining the RX beam codebook. Fig.12 As shown, UE 201 may receive PDSCH using RX beam "i". A PDSCH message for UE 201 may be sent by gNB 202 using a TX beam having a narrower beamwidth than the beamwidth of a TX beam used to send PDCCH on the CORESET.

[0102] In scheme 3 of the PDSCH beam indication provided to UE 201 in downlink control information (DCI) in PDCCH, if the scheduling offset between the reception of the DCI and the corresponding PDSCH is greater than or equal to the threshold offset, the gNB 202 may transmit the PDSCH using a different TX beam. The beam width of the beam used to transmit the PDSCH may be narrower than the beam width of the TX beam used to transmit the PDCCH and have focused energy toward UE 201.

[0103] Therefore, UE 201 can refine the RX beam codebook to generate RX beams "i" and "i+1" with wider beamwidths. The RX beam codebook can be refined by tuning the phase shifters and PA / LNA of the antenna elements of UE 201. UE 201 can attempt to receive the unicast PDSCH with a beam with a wider beamwidth to prevent misalignment with the narrower TX beam. Receiving the PDSCH using RX beam "i" can improve the success rate of PDSCH reception. In addition, this can also save power because a beam with a wider beamwidth requires a smaller number of antenna elements to be activated.

[0104] The embodiments disclosed herein may be implemented by at least one software program running on at least one hardware device and performing network management functions to control network elements. Figure 2 The illustrated network elements include blocks, which may be at least one of hardware devices, or a combination of hardware devices and software modules.

[0105] The embodiments disclosed herein describe methods and systems for generating beams with wide or narrow beamwidths in a wireless NR communication network using appropriate beam codebooks so as to achieve successful signal reception / transmission in scenarios where there is misalignment between the beams of the UE and the gNB. Therefore, it should be understood that the scope of protection extends to such a program, and in addition to a computer-readable device having a message therein, such a computer-readable storage device contains program code means for implementing one or more steps of the method when the program is run on a server or a mobile device or any suitable programmable device. In a preferred embodiment, the method is implemented by or together with a software program written in, for example, a very high speed integrated circuit hardware description language (VHDL) or another programming language, or by one or more VHDL or several software modules being executed on at least one hardware device. The hardware device can be any kind of portable device that is programmable. The device can also include a device, which can be, for example, a hardware device, such as an ASIC, or a combination of hardware and software devices, such as an ASIC and an FPGA, or at least one microprocessor and at least one memory with a software module located therein. The method embodiments described herein can be implemented partially in hardware and partially in software. Alternatively, the present invention can be implemented on different hardware devices, for example using multiple CPUs.

[0106] The foregoing description of specific embodiments will so fully reveal the general nature of the embodiments herein that others can easily modify and / or adapt such specific embodiments for various applications without departing from the general concepts by applying current knowledge, and therefore, such adaptations and modifications should and are intended to be understood as being within the meaning and range of equivalents of the disclosed embodiments. It should be understood that the words or terms used herein are for descriptive purposes and not for limitation. Therefore, although the embodiments herein have been described according to preferred embodiments, those skilled in the art will recognize that the embodiments herein can be modified to practice within the scope of the embodiments described herein.

Claims

1. A method for aligning a beam with a beam of a next generation Node B gNB, performed by a user equipment UE, the method comprising: Determining, by the UE, that a strength of a signal received by a plurality of receive RX beams of the UE is less than a threshold strength for decoding the signal, wherein the signal is transmitted using a transmit TX beam of the gNB; determining, by the UE, a direction in which the strength of the signal is increasing; The UE determines, in the determined direction, a first RX beam and a second RX beam among a plurality of RX beams of the UE, wherein the strength of a signal received through the first RX beam is greater than the strength of a signal received through the second RX beam; and The UE generates a wide RX beam by refining the RX beam codebooks of the first RX beam and the second RX beam, or the UE generates a narrow RX beam to have a beam direction between beam directions of the first RX beam and the second RX beam, wherein the narrow RX beam is narrower than the first RX beam or the second RX beam, and the wide RX beam is wider than the first RX beam or the second RX beam, and The RX beam codebook is refined by tuning at least one of a phase angle of a phase shifter of at least one UE antenna element generating the first RX beam and the second RX beam and a gain of a power amplifier and a low noise amplifier PA / LNA.

2. The method according to claim 1, in, The strength of the signal received by the first RX beam is greatest along the determined direction, and The strength of the signals received through the multiple RX beams of the UE is determined based on at least one of a reference signal received power RSRP or a signal to interference and noise ratio SINR.

3. The method according to claim 2, in, The wide RX beam is generated by reducing a number of activated UE antenna elements in the at least one UE antenna element, wherein the narrow RX beam is generated by tuning the phase angle of a phase shifter of the at least one UE antenna element, and Wherein, the phase angle of the phase shifter of the at least one UE antenna element is tuned based on the beam direction of the first RX beam, the beam direction of the second RX beam, the distance between two separated antenna elements of the at least one UE antenna element, and the wavelength of the signal received by at least one of the narrow RX beam, the first RX beam, and the second RX beam.

4. The method according to claim 1, wherein: Generating one of the wide RX beam and the narrow RX beam is based on at least one of a condition of a channel used for communication between the UE and the gNB, a distance between the UE and the gNB, and a type of messages exchanged between the UE and the gNB.

5. The method according to claim 1, further comprising: Measuring, by the UE, a strength of a signal received through the wide RX beam and a strength of a signal received through the narrow RX beam; Calculating, by the UE, a difference between the strength of a signal received through the wide RX beam and the strength of a signal received through the narrow RX beam; and The strength of the signal received through the narrow RX beam is determined by the UE based on the strength of the signal received through the wide RX beam and the calculated difference.

6. A user equipment (UE) for aligning a beam with a beam of a next generation Node B (gNB), the UE comprising: a memory storing one or more computer programs; transceiver; and one or more processors communicatively coupled to the memory and the transceiver, in, The one or more computer programs include computer executable instructions which, when executed by the one or more processors, cause the UE to: determining that a strength of a signal received through a plurality of receive RX beams of the UE is less than a threshold strength for decoding the signal, the signal being transmitted using a transmit TX beam of the gNB, Determine the direction in which the signal strength is increasing, determining a first RX beam and a second RX beam in the determined direction among the plurality of RX beams, wherein the strength of a signal received through the first RX beam is greater than the strength of a signal received through the second RX beam, and A wide RX beam is generated by refining the RX beam codebooks of the first RX beam and the second RX beam, or a narrow RX beam is generated so that it has a beam direction between the beam directions of the first RX beam and the second RX beam, wherein the narrow RX beam is narrower than the first RX beam or the second RX beam, and the wide RX beam is wider than the first RX beam or the second RX beam, and The RX beam codebook is refined by tuning at least one of a phase angle of a phase shifter of at least one UE antenna element generating the first RX beam and the second RX beam and a gain of a power amplifier and a low noise amplifier PA / LNA.

7. The UE according to claim 6, in, The strength of the signal received by the first RX beam is greatest along the determined direction, and The strength of the signals received through the multiple RX beams of the UE is determined based on at least one of the reference signal received power RSRP or the signal to interference and noise ratio SINR.

8. The UE according to claim 7, in, The wide RX beam is generated by reducing a number of activated UE antenna elements in the at least one UE antenna element, wherein the narrow RX beam is generated by tuning the phase angle of a phase shifter of at least one UE antenna element, wherein the narrow RX beam is generated between the first RX beam and the second RX beam, and Wherein, the phase angle of the phase shifter of the at least one UE antenna element is tuned based on the beam direction of the first RX beam, the beam direction of the second RX beam, the distance between two separated antenna elements of the at least one UE antenna element, and the wavelength of the signal received by at least one of the narrow RX beam, the first RX beam, and the second RX beam.

9. The UE according to claim 6, wherein: The one or more computer programs also include computer executable instructions that, when executed by the one or more processors, cause the UE to: Measures the strength of the signal received via a wide RX beam and the strength of the signal received via a narrow RX beam, Calculate the difference between the strength of the signal received via the wide RX beam and the strength of the signal received via the narrow RX beam, and The strength of the signal received through the narrow RX beam is determined based on the strength of the signal received through the wide RX beam and the calculated difference.

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