Method for Measurement and User Equipment Antenna Selection

Abstract

A method for deriving measurement results for UE antenna selection, beam selection, cell selection, handover, and RRM is proposed. First, the UE determines its mobility state by using at least two of the following metrics: 1) Doppler information (e.g., from the mobility detection gear, MD); 2) beam ping-pong rate, beam change rate, beam change per time period; and 3) motion speed and motion direction from an acceleration sensor, rotation speed from a gyroscope, ambient magnetic field from a magnetic field sensor, and at least one active antenna group. Then, the UE uses an average value adjusted based on its mobility state to derive an average measurement result including one of RSRP, RSRQ, RSSI, IL, SNR, and SINR. Finally, the UE performs antenna selection, beam selection, cell selection, or RRM based on the average measurement result and joint consideration factors.

Description

Technical Field

[0001] Embodiments of the present invention generally relate to wireless communication, and more particularly to methods and apparatuses for reference signal measurement and antenna selection in a new radio (NR) system. Background Art

[0002] For many years, wireless communication networks have grown exponentially. The Long-Term Evolution (LTE) system provides high peak data rates, low latency, improved system capacity, and low operating costs brought by a simple network architecture. The LTE system, also known as the 4th Generation (4G) system, also provides seamless integration with older networks, such as the Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA), and Universal Mobile Telecommunications System (UMTS). In the LTE system, the evolved universal terrestrial radio access network (E-UTRAN) includes multiple evolved Node-Bs (eNodeB or eNB) that communicate with multiple mobile stations called user equipment (UE). The 3rd generation partner project (3GPP) network generally includes a mixture of 2nd Generation (2G) / 3rd Generation (3G) / 4G systems. The Next Generation Mobile Network (NGMN) board has decided to focus future NGMN activities on defining the end-to-end requirements of the 5G new radio (NR) system.

[0003] Reference Signal Received Power (RSRP) and Reference Signal Received Quality (RSRQ) are key measurement criteria for the signal level and quality of LTE and NR networks. In a cellular network, when a UE moves from one cell to another and performs cell selection, reselection, and handover, the UE needs to measure the signal strength and quality of neighboring cells. Although channel quality measurements expressed as Signal to Interference plus Noise Ratio (SINR) are used together with packet scheduling for link adaptation, RSRP and RSRQ are required to make handover decisions. Received Strength Signal Indicator (RSSI) measurements can be used to determine RSRP and RSRQ. RSSI measurements measure the average total received power observed in Orthogonal Frequency Division Multiplexing (OFDM) symbols containing reference symbols in the bandwidth on certain resource blocks. RSSI is measured over the entire bandwidth including noise, serving cell power, and interference power.

[0004] The measurement results are often used for UE antenna selection, beam selection, cell selection, handover, and Radio Resource Management (RRM). Different mechanisms are desired for deriving the measurement results when the UE is in different mobility states. Therefore, it is important to determine the UE mobility state. Metrics for determining the UE mobility state and corresponding mechanisms for deriving the measurement results are desired. Summary of the Invention

[0005] A method for deriving measurement results for UE antenna selection, beam selection, cell selection, handover, and RRM is proposed. First, the UE determines its mobility state by using at least two of the following metrics: 1) Doppler information; 2) beam ping-pong rate, beam change rate, beam change per time period; and 3) motion speed and direction from an accelerometer sensor, rotation speed from a gyroscope, ambient magnetic field from a magnetic field sensor, and at least one active antenna group. Then, the UE uses an average value adjusted based on its mobility state to obtain an average measurement result including one of RSRP, RSRQ, RSSI, Interference Level (IL), Signal to Noise Ratio (SNR), and SINR. Finally, the UE performs antenna selection, beam selection, cell selection, or RRM based on the average measurement result and joint consideration factors.

[0006] The method for measurement and user equipment antenna selection proposed by the present invention helps to reduce the beam ping-pong rate or measurement error.

[0007] Other embodiments and advantages are described in the detailed description below. The summary of the invention is not intended to define the invention. The invention is defined by the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The drawings depict embodiments of the invention, where like numbers represent like components.

[0009] Figure 1 A beamforming wireless communication system using an enhanced method of measurement and UE antenna selection according to a novel aspect is shown.

[0010] Figure 2 A simplified block diagram of a UE and a base station (BS) according to an embodiment of the invention is shown.

[0011] Figure 3 A method for adjusting measurement samples and determining UE antenna selection, beam selection, cell selection, or RRM according to a novel aspect is shown.

[0012] Figure 4 A simplified block diagram of a UE performing measurements and determining antenna selection, beam selection, cell selection, or RRM according to a novel aspect is shown.

[0013] Figure 5 Certain problems and improvement methods of applying Doppler information to the average RSRP measurement result are shown.

[0014] Figure 6Embodiments of beam selection, cell selection, or RRM using MD plus beam ping rate are shown.

[0015] Figure 7 Embodiments of beam selection, cell selection, or RRM using MD plus beam change rate are shown.

[0016] Figure 8 Embodiments of beam selection and cell selection using MD plus antenna selection, speed, and direction of movement are shown.

[0017] Figure 9 A first embodiment of antenna selection using the moving speed and direction of movement of an acceleration sensor, the rotational speed of a gyroscope, the ambient magnetic field of a magnetic field sensor, and the direction of a UE is shown.

[0018] Figure 10 A second embodiment of antenna selection using the moving speed and direction of movement of an acceleration sensor, the rotational speed of a gyroscope, the ambient magnetic field of a magnetic field sensor, and the direction of a UE is shown.

[0019] Figure 11 It is a flowchart of a method for UE beam selection, cell selection, or RRM according to a novel aspect of the present invention.

[0020] Figure 12 It is a flowchart of a method for UE antenna selection according to a novel aspect of the present invention.

[0021] Figure 13 It is a flowchart of a method for UE antenna selection according to a novel aspect of the present invention. Detailed Description of the Invention

[0022] Now, some embodiments of the present invention will be described in detail, and examples thereof are shown in the accompanying drawings.

[0023] Figure 1 A beamforming wireless communication system 100 using an enhanced method of measurement and UE antenna selection according to a novel aspect is shown. The beamforming wireless communication system 100 includes a base station BS 101 and a user equipment UE 102. Directional communication is achieved through digital and / or analog beamforming, wherein different beamforming groups are applied to multiple antenna elements to form different beams. In Figure 1In the example of, BS 101 is directionally configured with multiple cells, and each cell is covered by a set of transmitting (TX) or receiving (RX) beams. For example, cell 110 is covered by a set of five BS beams #1, #2, #3, #4, and #5. The set of BS beams #B1 - #B5 covers the entire service area of cell 110. Similarly, UE 102 can be configured with multiple antenna groups, and beamforming can also be applied to form multiple UE beams, for example, #U1, #U2. For beamforming access, both ends of the link need to know which beamformers to use. For example, a service beam pair link (BPL) 131 needs to be established for communication between BS 101 #B3 and UE 102 #U2. An antenna set refers to a group of antennas.

[0024] The set of BS beams can be configured periodically or occur infinitely and repeatedly in an order known to the UE. Each BS beam broadcasts a minimum amount of cell - specific and beam - specific information similar to the System Information Block (SIB) or Master Information Block (MIB) in the LTE system or the Synchronization Signal Block (SSB) in the NR system. Each BS beam also carries UE - specific control or data traffic. Each BS beam transmits a set of known reference signals for initial time - frequency synchronization, identifying the beam of the transmitted signal, and measuring the radio channel quality of the beam of the transmitted signal. Beam management and beam training mechanisms, including initial beam alignment and subsequent beam tracking, ensure that the base station (BS) beams and user equipment (UE) beams are aligned for data communication.

[0025] RSRP and RSRQ are key measurement criteria for the signal level and quality in LTE and NR networks. In a cellular network, when a UE moves from one cell to another and performs cell selection, reselection, and handover, the UE needs to measure the signal strength and quality of adjacent cells. Although channel quality measurements represented by SINR are used for link adaptation together with packet scheduling, RSRP and RSRQ are required to make handover decisions. RSSI measurements can be used to determine RSRP and RSRQ. RSSI measurements measure the average total received power observed in the OFDM symbols containing reference symbols in the bandwidth on certain resource blocks. RSSI is measured over the entire bandwidth including noise, serving cell power, and interference power.

[0026] According to a novel aspect, methods for deriving measurement results for UE antenna selection, beam selection, cell selection, handover, and RRM are proposed. AsFigure 1 As shown in block 140, first, the UE 102 determines its mobility state by using at least the following two metrics: 1) Doppler information that includes at least one of the following: Doppler shift, Doppler spread, and a mobility rank that combines Doppler shift and Doppler spread (e.g., MD estimated by a channel estimator from a mobility detection bin); 2) beam ping-pong rate, beam change rate, beam changes per time period; and 3) movement speed and direction from an acceleration sensor, rotation speed from a gyroscope, ambient magnetic field from a magnetic field sensor, and at least one active antenna group. The active antenna group refers to the antenna group used for transmission or reception, and the antenna group includes at least one antenna.

[0027] In addition, the movement speed and direction from the acceleration sensor, the rotation speed from the gyroscope, and the ambient magnetic field from the magnetic field sensor can be used to derive the direction of the UE 102 in the east-north-up coordinate system or another local coordinate system. The east-north-up coordinate system can be defined as a direct orthogonal reference, where: X points east and is tangent to the ground, Y points north and is tangent to the ground, and Z points skyward and is perpendicular to the ground. The derivation can be based on the implementation of the rotation vector and orientation functions of the Android SDK. The UE 102 can further consider the direction to determine its mobility state. The UE 102 can receive at least one measurement result including at least one of RSRP, RSRQ, RSSI, IL, SNR, and SINR results from the channel estimator. Then, the UE 102 uses an average value adjusted based on its mobility state to derive an average measurement result including at least one of RSRP, RSRQ, RSSI, IL, SNR, and SINR. The average measurement result may be more suitable for the mobility state of the UE 102. Finally, the UE 102 performs antenna selection, beam selection, cell selection, or RRM based on the average measurement result and joint consideration. In the first example, for a low-mobility UE, the UE averages multiple RSRP or SINR results in a moving window based on the average value to derive an average measurement result for UE antenna selection, beam selection, cell selection, or RRM. The UE can select the antenna group or BS beam with the best average measurement result for transmission or reception. In the second example, for a high-mobility UE, the UE applies a smaller average value or a joint RSRP / SINR method to UE antenna selection. The moving window represents a duration or multiple samples for the moving average. In the third example, for a high-mobility UE, the UE uses at least one active antenna group and a rotation angle in one period to select the UE antenna group for another period.

[0028] Figure 2A simplified block diagram of a wireless device (e.g., UE 201 and BS 202) according to an embodiment of the present invention is shown. BS 202 has an antenna 226 that transmits and receives radio signals. A radio frequency (RF) transceiver 223 is coupled to the antenna 226, receives RF signals from the antenna 226, converts them into baseband signals, and sends them to the processor 222. The RF transceiver 223 also converts the baseband signals received from the processor 222, converts them into RF signals, and sends them to the antenna 226. The processor 222 processes the received baseband signals and invokes different functional modules to perform functions in BS 202. The memory 221 stores program instructions and data 224 to control the operation of BS 202. BS 202 also includes a set of control functional modules and circuits, such as a measurement circuit 281 that performs measurements and a measurement configuration circuit 282 that configures measurement resources for the UE.

[0029] Similarly, UE 201 has an antenna 235 that transmits and receives radio signals. An RF transceiver 234 is coupled to the antenna 235, receives RF signals from the antenna 235, converts them into baseband signals, and sends them to the processor 232. The RF transceiver 234 also converts the baseband signals received from the processor 232, converts them into RF signals, and sends them to the antenna 235. The processor 232 processes the received baseband signals and invokes different functional modules and circuits to perform functions in UE 201. The memory 231 stores program instructions and data 236 to control the operation of UE 201 by the processor. Suitable processors include, for example, special purpose processors, digital signal processors (DSPs), multiple microprocessors, one or more microprocessors associated with a DSP core, controllers, microcontrollers, application specific integrated circuits (ASICs), field programmable gate array (FPGA) circuits, and other types of integrated circuits (ICs) and / or state machines.

[0030] The UE 201 also includes a set of functional modules and circuits that perform functional tasks. These functions can be implemented by software, firmware, and hardware. The processor associated with the software can be used to implement and configure the functional characteristics of the UE 201. For example, the measurement configuration circuit 291 configures the measurement radio resources from the network. The measurement circuit 292 performs Layer 1 (L1) and Layer 3 (L3) measurements based on the measurement configuration. The measurement report circuit 293 sends the measurement report to the NR network for RRM. Additionally, the UE 102 can receive the moving speed, moving direction, rotation information, and ambient magnetic field from sensors (internal or external) including at least one of an accelerometer, a gyroscope, and a magnetic field sensor to achieve better measurement results and better determine antenna selection, beam selection, cell selection, and RRM.

[0031] Figure 3 A method for adjusting measurement samples and determining UE antenna selection, beam selection, cell selection, or RRM according to a novel aspect is shown. The UE has an L1 control unit 301 and a higher layer module 302. The L1 control unit has L1 (physical layer, PHY) design logic that is configured to receive Doppler information from the MD, receive the UE moving speed from an accelerometer sensor, receive rotation information from a gyroscope, receive the ambient magnetic field from a magnetic field sensor, and other sensor reports. Then, the measurement results are operated on, for example, averaged using a suitable average, to derive an average measurement result including at least one of RSRP, SINR, etc. Then, the average measurement result is provided to the physical layer, higher layer, or its serving base station for cell selection, RRM, or handover decision. The average measurement result can also be used to determine BS beam selection, UE antenna selection, and RX beamforming.

[0032] Figure 4A simplified block diagram showing a UE performing measurements and determining antenna selection, beam selection, cell selection, or RRM according to a novel aspect is shown. The UE includes a plurality of antenna groups 410, an OFDM radio signal transceiver 401, an L1 control unit 402, a high layer module 403, a channel estimator 404, and a sensor 405. The channel estimator 404 processes radio signals received through the OFDM transceiver 401 coupled to the plurality of antenna groups. The channel estimator 404 may include MD detection, such as MD bins based on Doppler shift and Doppler spread, and RSRP / SINR estimation. The sensor 405 may include an accelerometer for providing the UE's moving speed and moving direction, a gyroscope for providing the UE's rotation information, a magnetic field sensor for providing the ambient magnetic field, and other sensors. Then, the measurement results from the channel estimator 404 and the sensor reports from the sensor 405 are provided to the L1 control unit 402, and the L1 control unit 402 applies the RSRP / SINR average to BS beam selection, UE antenna selection, and RX beamforming. The average measurement results including at least one of RSRP, SINR, etc. may also be provided to the physical layer, the high layer module 403 for L3-RSRP / SINR screening, or to the serving base station of the UE for cell selection and RRM.

[0033] One basic design concept is to consider MD in channel estimation for beam selection, cell selection, or RRM. To perform channel estimation, the UE uses the Cell Reference Signal (CRS) / primary synchronization signal (PSS) / secondary synchronization signal (SSS) / Channel state information reference signal (CSI-RS) to estimate and track the channel between the UE and the serving base station. The channel estimation may include mobility detection bins (MD) indicating the Doppler shift and the spread level corresponding to different signal paths / carrier frequencies. MD can consider the Doppler spread and shift between the UE and the serving base station and can be used to determine the mobility level. For example, if the UE estimates that the Doppler spread or shift is greater than a threshold, the corresponding MD is a higher mobility level. If the UE estimates that the Doppler spread and shift are less than the threshold, the corresponding MD is a lower mobility level. If the Doppler shift level is below a predefined value X (low mobility level), the UE may average multiple RSRP measurement results from the channel estimator and use the average RSRP measurement results for beam selection, cell selection, or RRM. If the Doppler shift level is equal to or higher than the predefined value X (high mobility level), the UE may average one or several RSRP measurement results.

[0034] Figure 5 illustrates certain problems and improvement methods of applying Doppler frequency shift to the average RSRP measurement result. In Figure 5 the example of, the UE 502 with beamforming is served by its serving base station 501. It can be seen that when the UE 502 moves upward, it may have a higher Doppler frequency shift but a higher ping-pong rate. When the UE 502 moves laterally, it may have a lower Doppler frequency shift but a lower ping-pong rate. As a result, as shown in block 510, the basic design concept is that the averaging of the RSRP or other measurement results can be based on the joint consideration of the Doppler frequency shift level, Doppler spread, ping-pong rate, beam change rate, antenna selection result, UE speed, and moving direction. For example, if the UE estimates that the Doppler spread is less than a threshold and the Doppler frequency shift is less than another threshold, the corresponding MD may be a lower mobility level.

[0035] Figure 6Embodiments of beam selection, cell selection, or RRM using MD plus the beam ping rate are shown. In a novel aspect, in addition to the Doppler shift level, the UE may also consider the beam ping rate as shown in block 610 to average the L1-RSRP for beam selection, cell selection, or RRM. Ping-pong in beam measurement and reporting means that the best beam in the first beam report of the UE becomes another beam over a period of time and then changes back to the best beam in the first report. In the example of block 610, the UE reports 8 L1-RSRP reports in sequence from the Nth RSRP report to the (N + 7)th L1-RSRP report. The Nth RSRP report indicates that beam 1 is the best beam, the (N + 1)th RSRP report indicates that beam 2 is the best beam, and then the (N + 2)th RSRP report indicates that beam 1 is the best beam again. This is the ping-pong of beam management and reporting. The (N + 1), (N + 2), and (N + 3)th RSRP reports represent the same situation. The ping-pong change per second can be defined as the number of ping-pongs divided by the time length, and the ping-pong change rate can be defined as the number of ping-pongs per unit time divided by the number of beam reports. In addition, the ping-pong can further consider one of the signal-to-noise ratio (SNR), SINR, and RSRP. If the differences in SNR, SINR, and RSRP of the (N + 1), (N + 2), and (N + 3)th RSRP reports are greater than a threshold, the ping-pong can be regarded as an exception or a normal beam change. In one example, the UE may estimate the Doppler shift level between the UE and the serving base station and the ping-pong rate of the used BS beam, and then, if the MD is less than X and / or the ping-pong rate is greater than Y%, the UE may average multiple RSRP measurement results from the channel estimator and use the averaged RSRP measurement results for beam selection, cell selection, or RRM. In addition, the ping-pong can be defined as follows: the best beam of the first RSRP / SINR measurement result from the channel estimator changes to another beam and then changes back to the best beam of the first RSRP / SINR measurement result over a period of time.

[0036] Figure 7Embodiments of beam selection, cell selection, or RRM using MD plus the beam change rate are shown. In another novel aspect, in addition to the Doppler shift level, the UE may also consider the beam change rate or the beam change per time period as shown in block 710 to average the RSRP measurements from the channel estimator for beam selection, cell selection, or RRM. In the example of block 710, the beam change per second can be defined as the number of beam changes divided by the time length, and the beam change rate can be defined as the number of beam changes per unit time divided by the number of beam reports. In one example, the UE may estimate the Doppler shift level and the beam change rate between the UE and the serving base station, and then, if the MD is less than X and / or the beam change rate is greater than Y% (and / or the beam change per second is greater than Z), the UE may average multiple RSRP measurements from the channel estimator. Averaging multiple measurements may help reduce the beam ping-pong rate or measurement error.

[0037] Figure 8 Embodiments of beam selection and cell selection using MD plus UE antenna selection, UE speed, and direction of movement are shown. By considering UE antenna selection and direction of movement from the acceleration sensor, the UE can identify that it may be moving towards the serving base station, moving away from the serving base station, or moving around the serving base station. If the MD is less than X and / or the UE is moving towards or away from the serving base station, the UE may average multiple RSRP measurements for beam selection, cell selection, or RRM. For example, as Figure 8 shown, at least one active antenna group is generally oriented towards the serving base station 801. If the direction of movement of the UE 802 is the same as the main lobe direction of at least one active antenna group, the UE 802 can identify that it may be moving towards the serving base station or moving away from the serving base station. The BS beam used may be stable, so the UE802 can use the average of multiple RSRP measurements for beam selection, cell selection, or RRM. If the direction of movement of the UE 802 is different from the main lobe direction of at least one active antenna group, the UE802 can identify that it can move around the serving base station, then the UE 802 can average one or several RSRP measurements. In addition, the UE 802 may be integrated with the acceleration sensor or obtain a UE movement speed report from the acceleration sensor. Based on the UE movement speed report, if the average UE movement speed for one period or the previous UE movement speed is less than X km per hour, indicating low mobility, the UE 802 can average multiple RSRP measurements for beam selection, cell selection, or RRM.

[0038] For antenna selection from multiple antenna groups, the UE can estimate the RSRP / SINR and find at least one best antenna group with at least one best RSRP. If the RSRP difference is less than Z dB, the UE can further use the SINR to select at least one best antenna group for transmission (TX) or reception (RX). The UE can use one of the combined RSRP / SINR methods for UE antenna selection. The combined RSRP / SINR methods include: Proposal 1 (P1): mainly use RSRP > X dBm and SINR > Y dB, for example, find at least one best antenna group where at least one best RSRP > X dBm and SINR > Y dB. Proposal 2 (P2): mainly use RSRP > X dBm. If the RSRP difference between the two best antenna groups with the best RSRP is less than Y dB, further use the SINR to select at least one antenna group, for example, find at least one best antenna group with at least one best RSRP. If the RSRP difference is less than Y dB, further use the SINR to select at least one best antenna group with the best SINR among the two best antenna groups with the best RSRP. Proposal 3 (P3): mainly use SINR > X dB. If the SINR difference between the two best antenna groups with the best SINR is less than Y dB, further use the RSRP to select at least one antenna group, for example, find at least one best antenna group with at least one best SINR. If the SINR difference is less than Y dB, further use the RSRP to select at least one best antenna group with the best RSRP among the two best antenna groups with the best SINR. Proposal 4 (P4): If the rotation speed of the gyroscope is low, use the average SINR or RSRP for antenna selection. The moving direction from the acceleration sensor and the rotation speed from the gyroscope can also be considered to select at least one antenna group and RX beamforming configuration, or to determine whether the UE uses the average SINR or RSRP for low mobility or high mobility.

[0039] Figure 9A first embodiment of antenna selection using the moving speed and direction of a mobile device using an acceleration sensor, the rotational speed of a gyroscope, the ambient magnetic field of a magnetic field sensor, and the direction of a UE is shown. As shown in Table 910, the UE may record at least one active antenna group of the UE TX or RX beamforming configuration and the BS beam with the corresponding UE direction, and when the direction changes, use one of the recorded UE TX or RX beamforming and at least one active antenna group. If the UE moving speed or MD from the acceleration sensor is below a threshold, the UE may use a longer time for RSRP estimation and / or UE TX or RX beamforming configuration update. If the UE moving speed or MD from the acceleration sensor is above a threshold, the UE may use a shorter time for RSRP estimation and / or RX beam update.

[0040] The UE may record multiple BS beams and corresponding information. In one example, the UE may be used for reading, so the UE direction is stable. When the direction changes, the UE may directly use at least one of the recorded UE TX or RX beamforming configurations. In Figure 9 the example, if the latest direction is close to (0,0,0), the UE may set the beam weight setting A for the BS TX or RX beam 1 and set the beam weight setting B for the BS TX or RX beam 2. The beam weight setting is a beamforming configuration for coordinating multiple antenna elements to form an antenna port for TX or RX.

[0041] Figure 10 A second embodiment of antenna selection using the moving speed and direction of a mobile device using an acceleration sensor, the rotational speed of a gyroscope, the ambient magnetic field of a magnetic field sensor, and the direction of a UE is shown. As shown in Table 1010, the UE may predefined the UE RX / TX beamforming configuration and at least one active antenna group with the corresponding direction, and record the UE TX or RX beamforming configuration and at least one active antenna group with the corresponding UE direction for the BS beam. When the direction changes, the UE may use one of the predefined and recorded UE TX or RX beamforming configurations and at least one active antenna group. If the UE moving speed or MD from the acceleration sensor is below a threshold, the UE may use a longer time for RSRP estimation or RX beam update. On the other hand, if the UE moving speed or MD from the acceleration sensor is above a threshold, the UE may use a shorter time for RSRP estimation or RX beam update.

[0042] The reference direction can be defined as a direction in a predefined direction system other than the east-north-up coordinate system. For example, the orientation of the phone's main screen is (0,0,0), and the orientation of the phone's back cover is (0,180,0). The orientation change is defined as the difference between two measured orientations (refer to Section 7.1 Coordinate System of 3GPP TR38.901). A suitable beam pair entry can be found whose reference direction is closest to the previous reference direction plus the orientation change. In one example, the last reference direction is (0,0,0). The last recorded beam pair with the best L1-RSRP or SINR is close to the beam pair entry "Antenna Group 1, Beam Weight Setting A" in Table 910, and the orientation changes from (30,30,30) to (30,120,30). Therefore, the orientation change is (0,90,0), and the UE can use the beam pair entry (Antenna Group 2, Beam Weight Setting B) because "((0,0,0)+(0,90,0)=(0,90,0) (previous reference direction + orientation offset = next reference direction)". In another example, the last reference direction is (0,0,0). The last recorded beam pair with the best L1-RSRP or SINR is close to the beam pair entry "Antenna Group 2, Beam Weight Setting B" in Table 910, and the orientation changes from (30,30,30) to (30,-60,30). Therefore, the orientation change is (0,-90,0), and the UE can use the beam pair entry (Antenna Group 1, Beam Weight Setting A) because "(0,90,0)+(0,-90,0)=(0,0,0)".

[0043] Figure 11A flowchart of a method for UE beam selection, cell selection, or RRM according to a novel aspect of the present invention. In step 1101, the UE receives Doppler information from the UE's channel estimator. In step 1102, the UE receives at least one measurement result from the channel estimator. In step 1103, the UE adjusts an average value based on the Doppler information to derive an average measurement result of at least one measurement result in a moving window. The moving window represents a duration or a plurality of samples, and it can be used for simple moving average, weighted moving average, exponential moving average, and other average methods. In step 1104, the UE sends a measurement report including the average measurement result to the physical layer, higher layers such as layer 2 and layer 3, or to the serving base station of the UE. Layer 1 in the protocol stack (e.g., the NR user plane protocol stack and the NR control plane protocol stack) may include the physical layer. Layer 2 and layer 3 may include the Packet Data Convergence Protocol (PDCP), Radio Link Control (RLC), Medium Access Control (MAC), and Radio Resource Control (RRC) layers.

[0044] Figure 12 A flowchart of a method for UE antenna selection according to a novel aspect of the present invention. In step 1201, the UE performs channel estimation on at least two antenna groups of the measured base station through the UE's channel estimator. In step 1202, the UE receives at least two measurement results from the channel estimator. The at least two measurement results may be selected from at least two of RSRP, RSRQ, RSSI, LI, and SINR, and may include the corresponding values of RSRP, RSRQ, RSSI, LI, SNR, and SINR of at least two antenna groups. In step 1203, the UE adjusts an average value based on the Doppler information from the channel estimator to derive at least two average measurement results among the at least two measurement results in a moving window. In step 1204, the UE selects at least one antenna group for receiving or transmitting radio signals based on a joint consideration of the at least two average measurement results.

[0045] Figure 13A flowchart of a method for UE antenna selection according to a novel aspect of the present invention. In step 1301, channel estimation is performed on at least two antenna groups of the measured base station by a channel estimator of the UE. In step 1302, the UE receives at least one measurement result. In step 1303, the UE receives at least one rotation angle from a gyroscope and calculates at least one rotation angle difference between two reports from the gyroscope. In step 1304, the UE selects at least one antenna group for receiving or transmitting radio signals based on at least one measurement result, the main lobe angles of at least two antenna groups, and at least one rotation angle difference.

[0046] Although the present invention has been described in connection with certain specific embodiments for illustrative purposes, the present invention is not limited thereto. Accordingly, various modifications, adaptations, and combinations of the various features of the described embodiments can be made without departing from the scope of the invention as set forth in the claims.

Claims

1. A method for measurement and user equipment antenna selection, characterized in that, comprising: a channel estimator of the user equipment performs channel estimation on at least two antenna groups of the measured base station; receiving at least one measurement result from the channel estimator; receiving at least one rotation angle from a gyroscope and calculating at least one rotation angle difference between two reports from the gyroscope; and selecting at least one antenna group for receiving or transmitting radio signals based on the at least one measurement result, the main lobe angles of the at least two antenna groups, and the at least one rotation angle difference.

2. The method for measurement and user equipment antenna selection according to claim 1, characterized in that, selecting the at least one measurement result from reference signal received power, reference signal received quality, received signal strength indicator, interference level, signal-to-noise ratio, and signal-to-interference-plus-noise ratio.

3. The method for measurement and user equipment antenna selection according to claim 1, characterized in that, selecting the at least one antenna group based on the main lobe angles of at least one previously selected antenna group, the main lobe angles of the at least two antenna groups, and the at least one rotation angle difference.

4. The method for measurement and user equipment antenna selection according to claim 1, characterized in that, selecting the at least one antenna group based on that at least one of reference signal received power, reference signal received quality, received signal strength indicator, signal-to-noise ratio, and signal-to-interference-plus-noise ratio is higher than a first threshold or at least one of received signal strength indicator and interference level is lower than a second threshold.

5. The method for measurement and user equipment antenna selection according to claim 1, further comprising: receiving moving speed and moving direction from an acceleration sensor.

6. The method for measurement and user equipment antenna selection according to claim 5, characterized in that, when the moving speed is lower than a threshold, the user equipment uses a longer time period to receive at least one rotation angle from the gyroscope or perform channel estimation, and when the moving speed is higher than the threshold, uses a shorter time period to receive or receive at least one rotation angle from the gyroscope or perform channel estimation from a channel.

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