Beam training for inter-band carrier aggregation

Abstract

Various aspects of this disclosure provide inter-band carrier aggregation (CA) beam training. In some aspects, inter-band CA beam training may include simultaneously performing inter-band CA beam training for a first frequency band and inter-band CA beam training for a second frequency band between one or more base stations and user equipment.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to non-provisional application No. 17 / 225,920 filed with the U.S. Patent and Trademark Office on April 8, 2021, and provisional application No. 63 / 008,568 filed with the U.S. Patent and Trademark Office on April 10, 2020, the entire contents of which are incorporated herein by reference as fully set forth herein and for all applicable purposes.

[0003] background

[0004] field

[0005] The various aspects of this disclosure generally relate to wireless communication, and more particularly to beam training in wireless communication systems. Background Technology

[0006] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, message sending and receiving, broadcasting, and so on. These systems can support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth-generation (4G) systems (such as Long Term Evolution (LTE) systems, LTE-A Advanced (LTE-A) systems, or LTE-A Pro systems) and fifth-generation (5G) systems, which may be referred to as New Radio (NR) systems. These systems can employ various technologies, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), or Discrete Fourier Transform Extended OFDM (DFT-S-OFDM). Wireless multiple access communication systems may include multiple base stations or network access nodes, each supporting communication from multiple communication devices simultaneously, which may also be referred to as User Equipment (UE).

[0007] Wireless communication systems (e.g., 5G systems) can operate in millimeter-wave (mmWave) bands (e.g., above 24.25 GHz), which significantly increases bandwidth and data rates. However, the challenge of operating in the millimeter-wave band is that transmissions in this band can suffer from significant path loss, penetration loss, and barrier loss. To compensate for the high signal attenuation in the millimeter-wave band, the wireless communication system can employ beamforming, which enables signals to be transmitted and received with high directivity.

[0008] Overview

[0009] The following is a simplified overview of one or more implementations to provide a basic understanding of such implementations. This overview is not an exhaustive summary of all conceived implementations, nor is it intended to identify key or decisive elements of all implementations, nor to define the scope of any or all implementations. Its sole purpose is to present some concepts of one or more implementations in a simplified form as a prelude to the more specific explanations that follow.

[0010] The first aspect relates to a method for wireless communication by a base station. The method includes: allocating a first set of reference signal (RS) symbols for beam training in a first frequency band; and allocating a second set of RS symbols for beam training in a second frequency band, wherein the first and second RS symbol sets overlap in time. The method further includes: generating a message indicating the first and second RS symbol sets; and transmitting the message to a user equipment (UE).

[0011] The second aspect relates to a method for wireless communication by a user equipment (UE). The method includes: receiving a message from a base station indicating a first reference signal (RS) symbol set and a second RS symbol set, wherein the first RS symbol set and the second RS symbol set overlap in time. The method further includes: beam sweeping a first received beam set; and for each received beam in the first received beam set, receiving a corresponding RS symbol from the first RS symbol set in a first frequency band, and performing a signal measurement on the corresponding RS symbol received in the first frequency band. The method further includes: beam sweeping a second received beam set; and for each received beam in the second received beam set, receiving a corresponding RS symbol from the second RS symbol set in a second frequency band, and performing a signal measurement on the corresponding RS symbol received in the second frequency band.

[0012] A third aspect relates to a method for wireless communication by a user equipment (UE). The method includes: receiving a message from a base station indicating a first reference signal (RS) symbol set and a second RS symbol set, wherein the first RS symbol set and the second RS symbol set overlap in time. The method further includes: beam sweeping a first transmit beam set; and for each transmit beam in the first transmit beam set, transmitting a corresponding RS symbol from the first RS symbol set in a first frequency band. The method further includes: beam sweeping a second transmit beam set; and for each transmit beam in the second transmit beam set, transmitting a corresponding RS symbol from the second RS symbol set in a second frequency band.

[0013] The fourth aspect relates to a method for wireless communication by a base station. The method includes: beam sweeping a first set of transmit beams over a first time interval; and for each transmit beam in the first set of transmit beams, transmitting a corresponding reference signal (RS) symbol in a first frequency band. The method further includes: beam sweeping a second set of transmit beams over a second time interval, wherein the second time interval overlaps with the first time interval; and for each transmit beam in the second set of transmit beams, transmitting a corresponding RS symbol in a second frequency band.

[0014] A fifth aspect relates to a method for wireless communication by a user equipment (UE). The method includes: beam sweeping a first set of received beams over a first time interval; and for each received beam in the first set of received beams, receiving a corresponding reference signal (RS) symbol in a first frequency band; and performing signal measurement on the corresponding RS symbol received in the first frequency band. The method further includes: beam sweeping a second set of received beams over a second time interval, wherein the second time interval overlaps with the first time interval; and for each received beam in the second set of received beams, receiving a corresponding RS symbol in a second frequency band; and performing signal measurement on the corresponding RS symbol received in the second frequency band.

[0015] A sixth aspect relates to an apparatus for wireless communication. The apparatus includes a processor, a memory coupled to the processor, and instructions stored in the memory. These instructions are executable by the processor to cause the apparatus to: allocate a first set of reference signal (RS) symbols for beam training in a first frequency band; allocate a second set of RS symbols for beam training in a second frequency band, wherein the first and second RS symbol sets overlap in time; generate a message indicating the first and second RS symbol sets; and transmit the message to the user equipment (UE).

[0016] A seventh aspect relates to an apparatus for wireless communication. The apparatus includes a processor, a memory coupled to the processor, and instructions stored in the memory. These instructions are executable by the processor to cause the apparatus to: receive a message from a base station indicating a first set of reference signal (RS) symbols and a second set of RS symbols, wherein the first set of RS symbols and the second set of RS symbols overlap in time. These instructions are also executable by the processor to cause the apparatus to: beam sweep a first set of receiving beams; and for each receiving beam in the first set of receiving beams, receive a corresponding RS symbol from the first set of RS symbols in a first frequency band, and perform a signal measurement on the corresponding RS symbol received in the first frequency band. These instructions are also executable by the processor to cause the apparatus to: beam sweep a second set of receiving beams; and for each receiving beam in the second set of receiving beams, receive a corresponding RS symbol from the second set of RS symbols in a second frequency band, and perform a signal measurement on the corresponding RS symbol received in the second frequency band.

[0017] The eighth aspect relates to an apparatus for wireless communication. The apparatus includes a processor, a memory coupled to the processor, and instructions stored in the memory. These instructions are executable by the processor to cause the apparatus to: receive a message from a base station indicating a first set of reference signal (RS) symbols and a second set of RS symbols, wherein the first set of RS symbols and the second set of RS symbols overlap in time. These instructions are also executable by the processor to cause the apparatus to: beam sweep a first set of transmit beams; and for each transmit beam in the first set of transmit beams, transmit a corresponding RS symbol from the first set of RS symbols in a first frequency band. These instructions are also executable by the processor to cause the apparatus to: beam sweep a second set of transmit beams; and for each transmit beam in the second set of transmit beams, transmit a corresponding RS symbol from the second set of RS symbols in a second frequency band.

[0018] A ninth aspect relates to an apparatus for wireless communication. The apparatus includes a processor, a memory coupled to the processor, and instructions stored in the memory. These instructions are executable by the processor to cause the apparatus to: beam sweep a first set of transmit beams over a first time interval; and transmit a corresponding reference signal (RS) symbol in a first frequency band for each transmit beam in the first set of transmit beams. These instructions are also executable by the processor to cause the apparatus to: beam sweep a second set of transmit beams over a second time interval, wherein the second time interval overlaps with the first time interval; and transmit a corresponding RS symbol in a second frequency band for each transmit beam in the second set of transmit beams.

[0019] A tenth aspect relates to an apparatus for wireless communication. The apparatus includes a processor, a memory coupled to the processor, and instructions stored in the memory. These instructions are executable by the processor to cause the apparatus to: beam sweep a first set of receiving beams over a first time interval; and for each receiving beam in the first set of receiving beams, receive a corresponding reference signal (RS) symbol in a first frequency band; and perform signal measurements on the corresponding RS symbols received in the first frequency band. These instructions are also executable by the processor to cause the apparatus to: beam sweep a second set of receiving beams over a second time interval, wherein the second time interval overlaps with the first time interval; and for each receiving beam in the second set of receiving beams, receive a corresponding RS symbol in a second frequency band; and perform signal measurements on the corresponding RS symbols received in the second frequency band.

[0020] The eleventh aspect relates to an apparatus. The apparatus includes: means for allocating a first set of reference signal (RS) symbols for beam training in a first frequency band; means for allocating a second set of RS symbols for beam training in a second frequency band, wherein the first and second RS symbol sets overlap in time; means for generating a message indicating the first and second RS symbol sets; and means for transmitting the message to a user equipment (UE).

[0021] The twelfth aspect relates to an apparatus. The apparatus includes: means for receiving a message from a base station, the message indicating a first reference signal (RS) symbol set and a second RS symbol set, wherein the first RS symbol set and the second RS symbol set overlap in time. The apparatus further includes: means for beam sweeping a first received beam set; and means for performing the following operations for each received beam in the first received beam set: receiving a corresponding RS symbol from the first RS symbol set in a first frequency band, and performing a signal measurement on the corresponding RS symbol received in the first frequency band. The apparatus further includes: means for beam sweeping a second received beam set; and means for performing the following operations for each received beam in the second received beam set: receiving a corresponding RS symbol from the second RS symbol set in a second frequency band, and performing a signal measurement on the corresponding RS symbol received in the second frequency band.

[0022] The thirteenth aspect relates to an apparatus. The apparatus includes: means for receiving a message from a base station, the message indicating a first reference signal (RS) symbol set and a second RS symbol set, wherein the first RS symbol set and the second RS symbol set overlap in time. The apparatus further includes: means for beam sweeping a first transmit beam set; and means for transmitting a corresponding RS symbol from the first RS symbol set in a first frequency band for each transmit beam in the first transmit beam set. The apparatus further includes: means for beam sweeping a second transmit beam set; and means for transmitting a corresponding RS symbol from a second RS symbol set in a second frequency band for each transmit beam in the second transmit beam set.

[0023] The fourteenth aspect relates to an apparatus. The apparatus includes: means for beam sweeping a first set of transmit beams over a first time interval; and means for transmitting a corresponding reference signal (RS) symbol for each transmit beam in the first set of transmit beams in a first frequency band. The apparatus further includes: means for beam sweeping a second set of transmit beams over a second time interval, wherein the second time interval overlaps with the first time interval; and means for transmitting a corresponding RS symbol for each transmit beam in the second set of transmit beams in a second frequency band.

[0024] The fifteenth aspect relates to an apparatus. The apparatus includes: means for beam sweeping a first set of received beams over a first time interval; and means for performing the following operations for each received beam in the first set of received beams: receiving a corresponding reference signal (RS) symbol in a first frequency band; and performing signal measurement on the corresponding RS symbol received in the first frequency band. The apparatus further includes: means for beam sweeping a second set of received beams over a second time interval, wherein the second time interval overlaps with the first time interval; and means for performing the following operations for each received beam in the second set of received beams: receiving a corresponding RS symbol in the second frequency band; and performing signal measurement on the corresponding RS symbol received in the second frequency band.

[0025] To achieve the foregoing and related objectives, these one or more implementations include the features fully described below and specifically pointed out in the claims. The following description and accompanying illustrations illustrate certain illustrative aspects of these one or more implementations. However, these aspects merely indicate a few of the various ways in which the principles of the various implementations may be employed, and the described implementations are intended to cover all such aspects and their equivalents. Brief description of the attached diagram

[0027] Figure 1 An example of a wireless communication system according to certain aspects of this disclosure is shown.

[0028] Figure 2An example of beamforming for downlink communication between a base station and a UE, according to certain aspects of this disclosure, is explained.

[0029] Figure 3 An example of a UE receiving a signal from a base station via an indirect path, according to certain aspects of this disclosure, is explained.

[0030] Figure 4 An example of beamforming for uplink communication between a base station and a UE, according to certain aspects of this disclosure, is explained.

[0031] Figure 5 An example of a base station receiving a signal from a UE via an indirect path is described according to certain aspects of this disclosure.

[0032] Figure 6 An example of a first procedure for beam selection according to certain aspects of this disclosure is explained.

[0033] Figure 7 An example of a second procedure for improving the transmission beam according to certain aspects of this disclosure is explained.

[0034] Figure 8 An example of a third procedure for improving the received beam, according to certain aspects of this disclosure, is explained.

[0035] Figure 9 An example of a multi-band UE according to certain aspects of this disclosure is shown.

[0036] Figure 10 An example of inter-band carrier aggregation for a single base station scenario is shown, according to certain aspects of this disclosure.

[0037] Figure 11 An example of inter-band carrier aggregation for a multi-base station scenario is shown, according to certain aspects of this disclosure.

[0038] Figure 12 The code allocation for inter-band beam training according to certain aspects of this disclosure is explained.

[0039] Figure 13 A first exemplary method for improving inter-band transmit beams according to certain aspects of this disclosure is explained.

[0040] Figure 14 A second exemplary method for improving inter-band transmit beams according to certain aspects of this disclosure is explained.

[0041] Figure 15 A third exemplary method for improving inter-band transmit beams according to certain aspects of this disclosure is explained.

[0042] Figure 16A fourth exemplary method for improving inter-band transmit beams according to certain aspects of this disclosure is explained.

[0043] Figure 17 A fifth exemplary method for improving inter-band transmit beams according to certain aspects of this disclosure is explained.

[0044] Figure 18 A first exemplary method for improving inter-band receive beam according to certain aspects of this disclosure is explained.

[0045] Figure 19 A second exemplary method for improving inter-band receive beam according to certain aspects of this disclosure is explained.

[0046] Figure 20 A third exemplary method for improving inter-band receive beam according to certain aspects of this disclosure is explained.

[0047] Figure 21 An example device in which aspects of this disclosure may be implemented is shown.

[0048] Figure 22 This is a flowchart illustrating an exemplary method for wireless communication by a base station according to certain aspects of this disclosure.

[0049] Figure 23 This is a flowchart illustrating an exemplary method for wireless communication by a user equipment (UE) according to certain aspects of this disclosure.

[0050] Figure 24 This is a flowchart illustrating another exemplary method for wireless communication by a UE according to certain aspects of this disclosure.

[0051] Figure 25 This is a flowchart illustrating another exemplary method for wireless communication by a base station according to certain aspects of this disclosure.

[0052] Figure 26 This is a flowchart illustrating yet another exemplary method for wireless communication by a UE according to certain aspects of this disclosure.

[0053] Detailed description

[0054] The detailed description that follows, taken in conjunction with the accompanying drawings, is intended as a description of various configurations and is not intended to represent the only configuration in which the concepts described herein can be practiced. This detailed description includes specific details to provide a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form to avoid obscuring such concepts.

[0055] Figure 1 An example of a wireless communication system 100 in which aspects of this disclosure may be performed is shown. The wireless communication system 100 includes a base station 105, a user interface unit (UE) 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE) network, an Advanced LTE (LTE-A) network, an LTE-A Pro network, a New Radio (NR) network, or a combination thereof.

[0056] Base station 105 can wirelessly communicate with UE 115 via one or more base station antennas. Base station 105 described herein may include, or may be referred to by those skilled in the art as, a base transceiver station, radio base station, access point, radio transceiver, B-node, evolved B-node (eNB), next-generation B-node, or gigabit B-node (any of which may be referred to as gNB), home B-node, home evolved B-node, or some other suitable term. Wireless communication system 100 may include different types of base station 105 (e.g., macrocell base station or small cell base station). UE 115 described herein may be able to communicate with various types of base station 105 and network equipment (including macro eNB, small cell eNB, gNB, relay base station, etc.).

[0057] Each base station 105 may be associated with a corresponding geographic coverage area 110, in which communication with various UEs 115 is supported. Each base station 105 may provide communication coverage to the corresponding geographic coverage area 110 via a communication link 125, and the communication link 125 between the base station 105 and the UE 115 may utilize one or more carriers. The communication link 125 shown in the wireless communication system 100 may include uplink transmissions from the UE 115 to the base station 105 and downlink transmissions from the base station 105 to the UE 115. The downlink transmission may also be referred to as a forward link transmission, and the uplink transmission may also be referred to as a reverse link transmission.

[0058] Each base station 105 provides communication coverage to macrocells, small cells, hotspots, or other types of cells, or various combinations thereof. In some examples, base station 105 may be mobile, and thus provide communication coverage to mobile geographic coverage areas 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, and overlapping geographic coverage areas 110 associated with different technologies may be supported by the same base station 105 or different base stations 105. The wireless communication system 100 may include, for example, heterogeneous LTE / LTE-A / LTE-A Pro or NR networks, wherein different types of base stations 105 provide coverage to various geographic coverage areas 110.

[0059] Each UE 115 may be distributed throughout the wireless communication system 100, and each UE 115 may be stationary or mobile. UE 115 may also be referred to as a mobile device, wireless device, remote device, handheld device, or subscriber device, or any other suitable term, wherein "device" may also be referred to as a unit, station, terminal, or client. UE 115 may also be a personal electronic device, such as a cellular phone, personal digital assistant (PDA), tablet computer, laptop computer, or personal computer. In some examples, UE 115 may also refer to a wireless local loop (WLL) station, Internet of Things (IoT) device, Internet of Everything (IoE) device, or MTC device, which may be implemented in various items (such as appliances, vehicles, instruments, etc.).

[0060] Base station 105 can communicate with core network 130 and with each other. For example, base station 105 can interface with core network 130 via backhaul link 132 (e.g., via S1 interface or another interface). Base stations 105 can communicate with each other directly (e.g., directly between base stations 105) or indirectly (e.g., via core network 130) on backhaul link 134 (e.g., via X2 interface or other interfaces).

[0061] Core network 130 provides user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. Core network 130 may be an evolved packet core (EPC), which may include at least one Mobility Management Entity (MME), at least one Serving Gateway (S-GW), and at least one Packet Data Network (PDN) Gateway (P-GW). The MME manages non-access stratum (e.g., control plane) functions, such as mobility, authentication, and bearer management of UE 115 served by base station 105 associated with the EPC. User IP packets can be delivered via the S-GW, which itself can connect to the P-GW. The P-GW provides IP address allocation and other functions. The P-GW can connect to network operator IP services. Operator IP services may include access to the Internet, intranets, IP Multimedia Subsystem (IMS), or packet-switched (PS) streaming services.

[0062] Wireless communication system 100 (e.g., NR system) can operate in millimeter-wave (mmWave) bands (e.g., above 24.25 GHz), which significantly increases bandwidth and data rate. However, the challenge of operating in the millimeter-wave band is that transmission in the millimeter-wave band can suffer from significant path loss, penetration loss, and barrier loss. To compensate for the high signal attenuation in the millimeter-wave band, wireless communication system 100 can employ beamforming that enables signals to be transmitted and received with high directivity.

[0063] Figure 2An example of beamforming being used for downlink communication from base station 205 (e.g., gNB) to UE 215 is explained. UE 215 may correspond to... Figure 1 One of the UEs 115, while base station 205 can correspond to Figure 1 One of the base stations 105 in this example. In this example, base station 205 includes an antenna array that enables base station 205 to transmit signals to UE 215 with high directivity using any of a plurality of transmit beams. Each transmit beam may correspond to a different transmission direction and / or radiation pattern (i.e., beam pattern). Base station 205 may electronically switch between different transmit beams, for example, by adjusting the phase between signals transmitted from antenna elements in the antenna array. Figure 2 An example of one of the transmit beams 230 pointing in the direction of UE 215 is shown.

[0064] UE 215 includes an antenna array that enables UE 215 to receive signals from base station 205 with high directivity using any of a plurality of receive beams. Each receive beam may correspond to a different receiving direction and / or radiation pattern (i.e., beam pattern). UE 215 may electronically switch between different receive beams, for example, by adjusting the phase between signals received via antenna elements in the antenna array. This enables UE 215 to electronically tune its receiving direction. Figure 2 An example of one of the receiving beams 235 is shown.

[0065] The advantage of operating in the millimeter-wave band is that it allows the use of small antenna elements, which significantly reduces the area of ​​the antenna array. This allows the antenna array to be incorporated into a UE 215 (e.g., a handheld device), a small base station (e.g., a client equipment (CPE)), or another wireless device.

[0066] Figure 2The exemplary transmit beam 230 and receive beam 235 shown constitute a beam pair (also referred to as a beam pair link), wherein base station 205 uses transmit beam 230 to transmit a signal to UE 215, and UE 215 uses receive beam 235 to receive a signal. Since base station 205 is capable of using any of a plurality of transmit beams to transmit a signal, and UE 215 is capable of using any of a plurality of receive beams to receive a signal, base station 205 and UE 215 support multiple beam pairs for downlink communication between base station 205 and UE 215. Base station 205 and UE 215 may use a beam training procedure to select one beam pair from these beam pairs for downlink communication between base station 205 and UE 215, as discussed further below. In practice, the relative positions of base station 205 and UE 215 may change over time (e.g., due to movement of UE 215) and / or channel conditions may change over time. In this regard, base station 205 and UE 215 can update beam pairs to adapt to changes.

[0067] exist Figure 2 In the example, the transmit beam 230 is pointed at UE 215, while the receive beam 235 is pointed at base station 205. However, it will be understood that this is not necessarily the case. In this regard, Figure 3 An example is shown in which a transmission from base station 205 is reflected from object 310 (e.g., a building) to UE 215. In this example, transmit beam 330 is pointed at object 310, and receive beam 335 is also pointed at object 310.

[0068] Beamforming can also be used for uplink communication from UE 215 to base station 205 (e.g., gNB). Examples are shown in... Figure 4 The explanation is as follows. In this example, UE 215 includes an antenna array that enables UE 215 to transmit signals to base station 205 with high directivity using any of a plurality of transmit beams. This antenna array can be the same antenna array used by UE 215 to receive signals from base station 205 or different antenna arrays. Each transmit beam may correspond to a different transmission direction and / or radiation mode. UE 215 can electronically switch between different transmit beams, for example, by adjusting the phase between signals transmitted from antenna elements in the antenna array. Figure 4 An example of one of the transmit beams 430 pointing in the direction of base station 205 is shown.

[0069] Base station 205 includes an antenna array that enables base station 205 to receive signals from UE 215 with high directivity using any of a plurality of receive beams. This antenna array can be the same antenna array used by base station 205 to transmit signals to UE 215 or different antenna arrays. Each receive beam may correspond to a different receiving direction and / or radiation mode. Base station 205 can electronically switch between different receive beams, for example, by adjusting the phase between signals received via antenna elements in the antenna array. This allows base station 205 to electronically tune its receiving direction. Figure 4 An example of one of the receiving beams 435 is shown.

[0070] Figure 4 The exemplary transmit beam 430 and receive beam 435 shown constitute a beam pair, wherein UE 215 uses transmit beam 430 to transmit signals to base station 205, and base station 205 uses receive beam 435 to receive signals. Since base station 205 can use any of a plurality of receive beams to receive signals, and UE 215 can use any of a plurality of transmit beams to transmit signals, base station 205 and UE 215 support multiple beam pairs for uplink communication between UE 215 and base station 205. Base station 205 and UE 215 can use a beam training procedure to select one beam pair from these beam pairs for uplink communication between base station 205 and UE 215, as discussed further below.

[0071] exist Figure 4 In the example, the transmit beam 430 is pointed at the base station 205, while the receive beam 435 is pointed at the UE 215. However, it will be understood that this is not necessarily the case. In this regard, Figure 5 An example is shown in which a transmission from base station UE 215 is reflected from object 510 (e.g., a building) to base station 205. In this example, transmit beam 530 is pointed at object 510, and receive beam 535 is pointed at object 510.

[0072] Therefore, beamforming can be used for both the downlink and uplink between base station 205 and UE 215. When there is good reciprocity between the downlink and uplink, the beam direction for the uplink can be determined based on the beam direction used for the downlink.

[0073] As discussed above, beamforming can be used to overcome high path loss in a wireless communication system 100 (e.g., an NR system). On the downlink, base station 205 and UE 215 communicate using a beam pair comprising a transmit beam (e.g., transmit beam 230) at base station 205 and a receive beam (e.g., receive beam 235) at UE 215. This beam pair can be selected from multiple available beam pairs using a beam training procedure. In an NR system, beam training may include a first procedure P1, a second procedure P2, and a third procedure P3 (also referred to as Procedure One, Procedure Two, and Procedure Three). As discussed further below, the first procedure P1 can be used for initial beam selection at both ends, the second procedure P2 can be used to improve the transmit beam, and the third procedure P3 can be used to improve the receive beam.

[0074] Figure 6 An example of the first procedure P1 for the downlink between base station 205 and UE 215 is explained. In this example, base station 205 sweeps the transmit beam set 610. For each transmit beam, base station 205 transmits one or more reference signal (RS) symbols. Base station 205 may sweep transmit beam 610 more than once. It will be understood that transmit beam 610 may be a subset of the transmit beams supported by base station 205.

[0075] UE 215 sweeps the receive beam set 620. For each receive beam 620, UE 215 may receive one or more RS symbols from base station 205. UE 215 may sweep the receive beam 620 more than once. It will be understood that the receive beam 620 may be a subset of the receive beams supported by UE 215.

[0076] In this example, the beam sweep at base station 205 and the beam sweep at UE 215 are coordinated such that for each of the plurality of beam pairs, base station 205 transmits an RS symbol, and UE 215 receives the RS symbol. Each of these beam pairs may correspond to a different combination of one of the transmit beams 610 and one of the receive beams 620.

[0077] For each of multiple beam pairs, UE 215 can perform signal measurements on the RS symbols received by that beam pair. These signal measurements can measure Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Signal-to-Interference-Noise Ratio (SINR), Signal-to-Noise Ratio (SNR), Received Signal Strength Indicator (RSSI), or another parameter indicating signal strength or signal quality. In one example, UE 215 can transmit a report to base station 205 indicating the beam pair with the highest signal measurements (e.g., highest RSRP, highest RSRQ, highest SINR, highest SNR, highest RSSI, etc.).

[0078] Therefore, the first procedure P1 selects a beam pair, and thus selects the transmit beam and receive beam corresponding to the selected beam pair. The first procedure P1 includes beam sweeping at base station 205, beam sweeping at UE 215, beam measurement, and beam reporting. In one example, the selected beam pair can be used for downlink communication between base station 205 and UE 215. In another example, a second procedure P2 can be performed to improve the transmit beam, and / or a third procedure P3 can be performed to improve the receive beam, as discussed further below.

[0079] Figure 7 An example of the second procedure P2 is explained. In this example, base station 205 sweeps the transmit beam set 710, while the receive beam 720 at UE 215 can be fixed. The beamwidth of the transmit beam 710 in the second procedure P2 can be narrower than that of the transmit beam 610 in the first procedure P1, and can cover a narrower range (i.e., a smaller spatial area) than the transmit beam 610 in the first procedure P1. The transmit beam 710 can be spatially close to the transmit beam selected in the first procedure P1. The receive beam 720 used in the second procedure P2 can be based on the receive beam selected in the first procedure P1.

[0080] As discussed above, during the second procedure P2, base station 205 sweeps the transmit beam 710. For each transmit beam in the transmit beam 710, base station 205 transmits an RS symbol, and UE 215 uses receive beam 720 to receive that RS symbol.

[0081] For each transmit beam in transmit beam 710, UE 215 performs signal measurements on the RS symbols received for that transmit beam. These signal measurements may measure RSRP, RSRQ, SINR, SNR, RSSI, or another parameter indicating signal strength or signal quality. In one example, UE 215 may transmit a report to base station 205 indicating the transmit beam corresponding to the highest signal measurement at UE 215 (e.g., highest RSRP, highest RSRQ, highest SINR, highest SNR, highest RSSI, etc.). Upon receiving this report, base station 205 selects the indicated transmit beam for downlink communication with UE 215.

[0082] Since the transmit beam 710 in the second procedure P2 can be narrower than the transmit beam 610 in the first procedure P1, the transmit beam selected in the second procedure P2 can be narrower than the transmit beam selected in the first procedure P1, and is therefore more improved.

[0083] Figure 8An example of the third procedure P3 is explained. In this example, UE 215 sweeps the receive beam set 820, while the transmit beam 810 at base station 205 can be fixed. The beamwidth of the receive beam 820 in the third procedure P3 can be narrower than that of the receive beam 620 in the first procedure P1, and can cover a narrower range (i.e., a smaller spatial area) than the receive beam 620 in the first procedure P1. The receive beam 820 can be spatially close to the receive beam selected in the first procedure P1. The transmit beam 810 used in the third procedure P3 can be based on the transmit beam selected in the second procedure P2.

[0084] During the third procedure, base station 205 uses transmit beam 810 multiple times to transmit RS symbols, while UE 215 sweeps receive beam set 820. For each transmission of RS symbols, UE 215 can use different beams in receive beam 820 to receive the RS symbol.

[0085] For each receive beam in receive beam 820, UE 215 performs signal measurements on the RS symbols received for that receive beam. These signal measurements may measure RSRP, RSRQ, SINR, SNR, RSSI, or another parameter indicating signal strength or signal quality. UE 215 may then select the receive beam with the highest signal measurement (e.g., highest RSRP, highest RSRQ, highest SINR, etc.) for downlink communication with base station 205. In one example, UE 215 may transmit a report to base station 205 indicating the receive beam with the highest signal measurement. In another example, UE 215 may omit transmitting this report to base station 205.

[0086] Since the receiving beam 820 in the third procedure P3 can be narrower than the receiving beam 620 in the first procedure P1, the receiving beam selected in the third procedure P3 can be narrower than the receiving beam selected in the first procedure P1, and is therefore more improved.

[0087] Therefore, procedures P1, P2, and P3 can be used for downlink beam training to determine the beam pair for downlink communication between base station 205 and UE 215. A similar set of procedures (referred to as procedures U1, U2, and U3) can be used for uplink beam training to determine the beam pair for uplink communication between UE 215 and base station 205. Procedures U1, U2, and U3 can be similar to procedures P1, P2, and P3, respectively, where the roles of UE 215 and base station 205 are reversed. More specifically, procedure U1 can be executed to select the transmit beam of UE 215 and the receive beam of base station 205 (e.g., following...). Figure 6 The procedures explained herein (where the roles of UE 215 and base station 205 are reversed) can then be executed to improve the transmit beam at UE 215 (e.g., following...). Figure 7 The procedure explained herein (where the roles of base station 205 and UE 215 are reversed) can then be executed to improve the received beam at base station 205 (e.g., following...). Figure 8 The procedures explained herein involve reversing the roles of base station 205 and UE 215.

[0088] UE 215 may be a multi-band UE capable of communicating with one or more base stations in multiple frequency bands (e.g., to increase bandwidth, improve experience quality, improve reliability, etc.). In one example, UE 215 may support communication in a first frequency band (hereinafter referred to as "first frequency band") and a second frequency band (hereinafter referred to as "second frequency band"). Both the first and second frequency bands may be millimeter-wave bands. In one example, the first frequency band may be within frequency range 2 (FR2), while the second frequency band may be within frequency range 4 (FR4). The frequency range of FR2 is approximately 24.25–52.6 GHz, while the frequency range of FR4 is approximately 52.6–114.25 GHz. However, it will be understood that the first and second frequency bands are not limited to the exemplary frequency ranges above. In some respects, the first and second frequency bands are above 24.25 GHz (i.e., the lowest frequency of each of the first and second frequency bands is above 24.25 GHz). In some respects, the first and second frequency bands do not overlap in frequency. In some respects, the first and second frequency bands are separated in frequency. For example, the first and second frequency bands may be separated by a frequency gap of at least 2 GHz, as a non-limiting example.

[0089] UE 215 may employ carrier aggregation (CA), whereby UE 215 combines two or more carriers (e.g., to increase bandwidth). Carriers may also be referred to as component carriers or subcarriers. For example, UE 215 may combine multiple carriers within the same frequency band (e.g., a first frequency band or a second frequency band) for intra-band carrier aggregation (CA). In this case, the carriers within the frequency band may be contiguous or non-contiguous. UE 215 may also combine multiple carriers from multiple frequency bands (e.g., a first frequency band and a second frequency band) for inter-band carrier aggregation (CA). In this case, inter-band CA may include one or more carriers in the first frequency band and one or more carriers in the second frequency band.

[0090] Figure 9 An example where UE 215 is a multi-band UE is shown. In this example, UE 215 includes a first antenna array 910 for a first frequency band (e.g., FR2) and a second antenna array 920 for a second frequency band (e.g., FR4). Figure 9In this configuration, individual antenna elements of the antenna array (e.g., dual-polarized patch antenna elements) are represented by squares. UE 215 may use a first antenna array 910 to beamform a first frequency band and a second antenna array 920 to beamform a second frequency band. The first antenna array 910 and the second antenna array 920 may have different sizes, different geometries, different numbers of antenna elements, different spacing between antenna elements, etc.

[0091] In some respects, the first antenna array 910 and the second antenna array 920 may share the same aperture of the UE 215 for transmitting and receiving signals. In one example, the first antenna array 910 and the second antenna array 920 may be located on the same antenna module. In this example, the module may include multiple substrate layers (e.g., on a printed circuit board), and the first antenna array 910 and the second antenna array 920 may be integrated on different substrate layers of the module. In another example, the first antenna array 910 and the second antenna array 920 may be located on different modules.

[0092] UE 215 can use inter-band CA to receive data from base station 205 (e.g., gNB), an example of which is shown in Figure 10 Chinese explanation. In Figure 10 In the example, UE 215 uses a first antenna array 910 to receive signals in a first frequency band (e.g., FR2) and a second antenna array 920 to receive signals in a second frequency band (e.g., FR4).

[0093] In this example, base station 205 uses a first transmit beam 1010 to transmit signals in a first frequency band, and UE 215 uses a first receive beam 1015 to receive signals in the first frequency band. Figure 10 In the example, the signal in the first frequency band is reflected from the first object 1012 (e.g., a glass window or metal object in a building). However, it will be understood that this is not necessarily the case. In another example, UE 215 may receive signals from base station 205 in the first frequency band via a direct line-of-sight (LOS) path.

[0094] Base station 205 uses a second transmit beam 1020 to transmit signals in a second frequency band, and UE 215 uses a second receive beam 1025 to receive signals in the second frequency band. Figure 10 In the example, the signal in the second frequency band is reflected from the second object 1022 (e.g., a vehicle). However, it will be understood that this is not necessarily the case. In another example, UE215 may receive a signal from base station 205 in the second frequency band via a direct / LOS path.

[0095] like Figure 10As shown, the first receiving beam 1015 for the first frequency band and the second receiving beam 1025 for the second frequency band can point in different directions (e.g., by independently performing beamforming on the first and second frequency bands using the first antenna array 910 and the second antenna array 920, respectively). The first receiving beam 1015 and the second receiving beam 1025 can also have different beamwidths. The first transmitting beam 1010 and the second transmitting beam 1020 can also have different directions and / or beamwidths. In this regard, the base station 205 can use different antenna arrays at the base station 205 for the first transmitting beam 1010 and the second transmitting beam 1020.

[0096] Thus, different beam pairs can be used for a first frequency band and a second frequency band, wherein the beam pair for the first frequency band includes a first transmit beam 1010 and a first receive beam 1015, while the beam pair for the second frequency band includes a second transmit beam 1020 and a second receive beam 1025. Different beam pairs for the first and second frequency bands may be due to, for example, differences in channel conditions, requirements, or capabilities between the first and second frequency bands, differences in the first antenna array 910 and the second antenna array 920, etc.

[0097] UE 215 can also use inter-band CA to receive data from multiple base stations (e.g., Transmitter Receiver Points (TRPs)), an example of which is shown in [link to example]. Figure 11 The explanation is as follows. In this example, UE 215 uses a first antenna array 910 to receive signals from a first base station 1105 in a first frequency band (e.g., FR2), and uses a second antenna array 920 to receive signals from a second base station 1108 in a second frequency band (e.g., FR4). The first base station 1105 may correspond to... Figure 1 One of the base stations 105, while the second base station 1108 can correspond to Figure 1 The other one of base stations 105.

[0098] In this example, the first base station 1105 uses a first transmit beam 1110 to transmit signals in a first frequency band, and the UE 215 uses a first receive beam 1115 to receive signals in the first frequency band. Figure 11 In the example, the signal in the first frequency band is reflected from the first object 1112 (e.g., a glass window or metal object in a building). However, it will be understood that this is not necessarily the case. In another example, UE215 may receive a signal from the first base station 1105 in the first frequency band via a direct / LOS path.

[0099] The second base station 1108 uses a second transmit beam 1120 to transmit signals in the second frequency band, and the UE 215 uses a second receive beam 1125 to receive signals in the second frequency band. Figure 11In the example, the signal in the second frequency band is reflected from the second object 1122 (e.g., a vehicle). However, it will be understood that this is not necessarily the case. In another example, UE 215 may receive a signal from the second base station 1108 in the second frequency band via a direct / LOS path.

[0100] like Figure 11 As shown, the first receiving beam 1115 for the first frequency band and the second receiving beam 1125 for the second frequency band can point in different directions (e.g., by independently performing beamforming on the first and second frequency bands using the first antenna array 910 and the second antenna array 920, respectively). The first receiving beam 1115 and the second receiving beam 1125 can also have different beamwidths. The first transmitting beam 1110 and the second transmitting beam 1120 can also have different directions and / or beamwidths.

[0101] Thus, different beam pairs can be used for the first frequency band and the second frequency band, wherein the beam pair used for the first frequency band includes a first transmit beam 1110 and a first receive beam 1115, while the beam pair used for the second frequency band includes a second transmit beam 1120 and a second receive beam 1125. Different beam pairs used for the first and second frequency bands may be due to, for example, differences in channel conditions, requirements, or capabilities between the first and second frequency bands, differences in the first antenna array 910 and the second antenna array 920, differences in the positions of the first base station 1105 and the second base station 1108 relative to the UE 215, etc.

[0102] Therefore, inter-band CA can be used to transmit data to UE215 using carriers spanning multiple frequency bands (e.g., the first and second frequency bands), where different beam pairs can be used for each frequency band. Accordingly, the methods for inter-band CA beam training are expected to support inter-band CA.

[0103] Interband CA beamforming will now be described in accordance with various aspects of this disclosure. Interband CA beamforming determines a first beam pair for a first frequency band and a second beam pair for a second frequency band.

[0104] In some respects, UE 215 determines the number of RS symbols used for inter-band CA beam training and sends a message indicating the number of RS symbols to one or more base stations. The number of RS symbols may include a first number of RS symbols used for beam training in a first frequency band and a second number of RS symbols used for beam training in a second frequency band, as discussed further below.

[0105] In one example, UE 215 may determine the number of RS symbols for each frequency band based on the antenna array size or geometry used for each band. For example, UE 215 may determine a larger number of RS symbols for a larger antenna array (e.g., a larger number of antenna elements) compared to a smaller antenna array (e.g., a smaller number of antenna elements). Since the first antenna array 910 (which is used in the first frequency band) and the second antenna array 920 (which is used in the second frequency band) may have different sizes and / or geometries, UE 215 may determine different numbers of RS symbols for the first and second frequency bands.

[0106] In another example, UE 215 may determine the number of RS symbols per frequency band based on the power level of UE 215. For example, if UE 215 operates at a low power level to save power (e.g., due to low battery power), UE 215 may determine a smaller number of RS symbols per frequency band compared to a normal power level.

[0107] In another example, UE 215 may determine the number of RS symbols per frequency band based on the temperature of UE 215, which may be sensed by one or more temperature sensors (also referred to as thermal sensors) in UE 215. In this example, if the sensed temperature is above a thermal threshold, UE 215 may determine a smaller number of RS symbols per frequency band to prevent UE 215 from overheating, while if the sensed temperature is below the thermal threshold, UE 215 may determine a larger number of RS symbols per frequency band.

[0108] In yet another example, UE 215 may determine the number of RS symbols for each frequency band based on UE 215 mobility (e.g., speed). UE 215 mobility can be determined using sensors (e.g., accelerometers) within UE 215. In this example, if the sensed mobility (e.g., rate) is greater than a threshold, UE 215 may determine a smaller number of RS symbols for each frequency band. Compared to the case where mobility is below the threshold, when mobility is above the threshold, a smaller number of symbols can be used to complete beam training more quickly, since channel conditions may change more rapidly for higher mobility scenarios.

[0109] In yet another example, UE 215 may determine the number of RS symbols for each frequency band based on the subcarrier spacing within the band. In this example, UE 215 may determine a larger number of RS symbols for a larger subcarrier spacing compared to a smaller subcarrier spacing. In one example, the first and second frequency bands may have different subcarrier spacings. As a result, in this example, UE 215 may determine different numbers of RS symbols for the first and second frequency bands. For example, the subcarrier spacing of the first frequency band (e.g., FR2) may be 120 kHz, while the subcarrier spacing of the second frequency band (e.g., FR4) may be 240 kHz or greater. In this example, UE 215 may determine a larger number of RS symbols for the second frequency band compared to the first frequency band. Furthermore, in this example, the subcarrier spacing in the second frequency band may be at least twice the subcarrier spacing in the first frequency band.

[0110] UE 215 may determine the number of RS symbols for each frequency band based on any combination of the exemplary parameters discussed above. After determining the number of RS symbols for each frequency band, UE 215 may transmit a request message to one or more base stations (e.g., base station 205) indicating the number of RS symbols for the first frequency band and the number of RS symbols for the second frequency band.

[0111] The base station (e.g., base station 205) receives the request message from UE 215. The base station then allocates RS symbols for beam training in the first frequency band and for beam training in the second frequency band based on the request message. For example, the base station may allocate the same number of RS symbols for the first frequency band as indicated in the request message. Similarly, the base station may allocate the same number of RS symbols for the second frequency band as indicated in the request message.

[0112] In some aspects, a base station may allocate a first set of RS symbols for beam training in a first frequency band within one or more time slots, wherein each of the RS symbols allocated to the first frequency band corresponds to one of the RS symbols in the first set of RS symbols. The first set of RS symbols may be contiguous, in which case the RS symbols in the first frequency band are contiguous. The number of RS symbols in the first set of RS symbols may be equal to the number of RS symbols for the first frequency band indicated in the request message.

[0113] The base station may also allocate a second set of RS symbols for beam training in the second frequency band within one or more time slots, wherein each of the RS symbols allocated to the second frequency band corresponds to one of the RS symbols in the second set of RS symbols. The second set of RS symbols may be contiguous, such that the RS symbols in the second frequency band are contiguous. The number of RS symbols in the second set of RS symbols may be equal to the number of RS symbols for the second frequency band indicated in the request message.

[0114] In some respects, the symbol duration of the second frequency band may differ from that of the first frequency band. In this case, the duration of a symbol in the second frequency band differs from that of a symbol in the first frequency band.

[0115] In some respects, the base station times the first RS symbol set and the second RS symbol set so that the first RS symbol set overlaps with the second RS symbol set in time. In this way, the RS symbols in the first frequency band and the RS symbols in the second frequency band overlap in time, thereby allowing beam training for the first frequency band and beam training for the second frequency band to be performed simultaneously, as discussed further below.

[0116] Figure 12 An example is shown of a first RS symbol set 1210 allocated for beam training in a first frequency band and a second RS symbol set 1220 allocated for beam training in a second frequency band. The first RS symbol set 1210 and the second RS symbol set 1220 overlap for simultaneous RS transmission across the first and second frequency bands. In this example, the base station allocates four RS symbols for beam training in the first frequency band (band 1) and eight RS symbols for beam training in the second frequency band (band 2). Furthermore, in this example, the symbol duration of the second frequency band (e.g., FR4) is half that of the symbol duration of the first frequency band (e.g., FR2). As a result, in this example, the duration of a symbol in the second frequency band is half that of a symbol in the first frequency band. However, it will be appreciated that this disclosure is not limited to this example. In one example, the duration of a symbol in the first RS symbol set is at least twice the duration of a symbol in the second RS symbol set.

[0117] exist Figure 12 In the example, the first RS symbol set 1210 may be located within a time slot of the first frequency band (e.g., time slot 0), with a duration of 125 μs. In this example, the time slot includes 14 symbols, of which four symbols are allocated for RS symbols in the first frequency band. Similarly, the second RS symbol set 1220 may be located within a time slot of the second frequency band (e.g., time slot 0), with a duration of 62.5 μs. In this example, the time slot includes 14 symbols, of which eight symbols are allocated for RS symbols in the second frequency band. Each symbol in the time slot may be identified by a corresponding symbol number (e.g., for the example where the time slot includes 14 symbols, one of symbol numbers 0 to 13). Figure 12 In the example, the four RS symbols allocated for the first frequency band correspond to symbols 3-6 in the time slots of the first frequency band, while the eight RS symbols allocated for the second frequency band correspond to symbols 6-13 in the time slots of the second frequency band.

[0118] After allocating the first RS symbol set for beam training in the first frequency band and the second RS symbol set for beam training in the second frequency band, the base station may transmit a message to the UE 215 indicating the first RS symbol set and the second RS symbol set. In an example where the symbols in the first RS symbol set are indicated by symbol numbers in the time slots of the first frequency band, the message may indicate the first RS symbol set by indicating the corresponding symbol number (e.g., symbol 3-6). Similarly, in an example where the symbols in the second RS symbol set are indicated by symbol numbers in the time slots of the second frequency band, the message may indicate the second RS symbol set by indicating the corresponding symbol number (e.g., symbol 6-13).

[0119] UE 215 receives the message from base station 205. UE 215 uses the message to determine the timing of RS symbols for beam training in the first frequency band and the timing of RS symbols for beam training in the second frequency band. For example, UE 215 may determine a first RS symbol set based on the indication of a first RS symbol set in the message, and determine a second RS symbol set based on the indication of a second RS symbol set in the message.

[0120] Beam training can then be performed simultaneously for both the first and second frequency bands. Simultaneous beam training for both the first and second frequency bands and the effect of transmission in the first frequency band on reception in the second frequency band, and vice versa, are also possible.

[0121] Beam training for the first frequency band can be performed using RS symbols allocated for the first frequency band. Beam training for the first frequency band can be similar to the first procedure P1 discussed above. In this example, the base station (e.g., base station 205) sweeps a first transmit beam set. Each transmit beam in the first transmit beam set can point in a different direction. For each of these transmit beams, the base station can transmit a corresponding RS symbol from the first RS symbol set allocated for the first frequency band. In other words, the base station uses the first transmit beam in the first transmit beam set to transmit the first RS symbol from the first RS symbol set, uses the second transmit beam in the first transmit beam set to transmit the second RS symbol from the first RS symbol set, and so on.

[0122] UE 215 sweeps a first set of receive beams. Each receive beam in the first set of receive beams may point in a different direction. For each of these receive beams, UE 215 may receive a corresponding RS symbol from the first set of RS symbols and perform received signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) on the received RS symbol. In other words, UE 215 uses the first receive beam in the first set of receive beams to receive the first RS symbol in the first set of RS symbols, uses the second receive beam in the first set of receive beams to receive the second RS symbol in the first set of RS symbols, and so on.

[0123] The beam sweep at the base station and the beam sweep at the UE 215 are coordinated such that for each of the multiple beam pairs used for the first frequency band, the base station transmits one of the RS symbols assigned to the first frequency band, and the UE 215 receives the RS symbol.

[0124] For each of a plurality of beam pairs, UE 215 may perform signal measurements on the RS symbols received by that beam pair. These signal measurements may measure RSRP, RSRQ, SINR, SNR, RSSI, or another parameter indicating signal strength or signal quality. In one example, UE 215 may transmit a report to the base station indicating received signal measurements for at least one RS symbol in a first set of RS symbols. Since the base station 205 knows which transmit beam it transmitted for each RS symbol, it can identify the transmit beam corresponding to the received signal measurement in the report based on the RS symbols used for signal measurement in the report. In one example, the base station 205 may select, based on the report, the transmit beam corresponding to the RS symbol with the highest signal measurement (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) from the first set of transmit beams. Furthermore, UE 215 may select the receive beam corresponding to the RS symbol with the highest received signal measurement. In this example, the selected transmit beam and the selected receive beam constitute a selected beam pair for a first frequency band. Therefore, beam training in the first frequency band determines the beam pairs used in the first frequency band.

[0125] Beam training for the second frequency band can be performed using RS symbols allocated for the second frequency band. Beam training for the second frequency band can be similar to the first procedure P1 discussed above. Since the RS symbols for the second frequency band overlap with those for the first frequency band in time, beam training for the second frequency band is performed simultaneously with the beam training for the first frequency band discussed above. In this example, the base station (e.g., base station 205) sweeps a second transmit beam set. Each transmit beam in the second transmit beam set can point in a different direction. For each of these transmit beams, the base station can transmit a corresponding RS symbol from the second RS symbol set. In other words, the base station uses the first transmit beam in the second transmit beam set to transmit the first RS symbol in the second RS symbol set, uses the second transmit beam in the second transmit beam set to transmit the second RS symbol in the second RS symbol set, and so on.

[0126] UE 215 sweeps a second set of receive beams. Each of these receive beams can point in a different direction. For each of these receive beams, UE 215 can receive a corresponding RS symbol from the second RS symbol set and perform signal measurements on the received RS symbol. In other words, UE 215 uses the first receive beam in the second set of receive beams to receive the first RS symbol in the second RS symbol set, uses the second receive beam in the second set of receive beams to receive the second RS symbol in the second RS symbol set, and so on.

[0127] The second transmit beam set may differ from the first transmit beam set, and the second receive beam set may differ from the first receive beam set (e.g., due to differences in the antenna arrays used for the first and second frequency bands). For example, the transmit beams in the second transmit beam set may have a narrower beamwidth than the transmit beams in the first transmit beam set (e.g., in cases where a larger antenna array is used for the second frequency band than for the first frequency band). Furthermore, the receive beams in the second receive beam set may have a narrower beamwidth than the receive beams in the first receive beam set (e.g., in cases where the second antenna array 920 has a larger number of antenna elements than the first antenna array 910).

[0128] The beam sweep at the base station and the beam sweep at the UE 215 are coordinated such that for each of the multiple beam pairs used for the second frequency band, the base station transmits one of the RS symbols allocated for the second frequency band, and the UE 215 receives that RS symbol.

[0129] For each of a plurality of beam pairs, UE 215 may perform signal measurements on the RS symbols received by that beam pair. These signal measurements may measure RSRP, RSRQ, SINR, SNR, RSSI, or another parameter indicating signal strength or signal quality. In one example, UE 215 may transmit a report to the base station indicating received signal measurements for at least one RS symbol in a second set of RS symbols. Since base station 205 knows which transmit beam it transmitted for each symbol, base station 205 may identify the transmit beam corresponding to the received signal measurement in the report based on the RS symbols used for signal measurement in the report. In one example, base station 205 may select, based on the report, the transmit beam corresponding to the RS symbol with the highest signal measurement (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) from the second set of transmit beams. Furthermore, UE 215 may select the receive beam corresponding to the RS symbol with the highest received signal measurement in the second set of RS symbols. In this example, the selected transmit beam and the selected receive beam constitute a selected beam pair for the second frequency band. Thus, beam training in the second frequency band determines the beam pair used for the second frequency band.

[0130] Therefore, in this example, inter-band CA beam training includes beam training for a first frequency band to determine beam pairs for a first frequency band and beam training for a second frequency band to determine beam pairs for a second frequency band, wherein the beam training for the first frequency band and the beam training for the second frequency band can be performed simultaneously. The beam pairs for the first frequency band may be referred to as the first beam pair, and the beam pairs for the second frequency band may be referred to as the second beam pair.

[0131] After completing the inter-band CA beam training discussed above, inter-band CA transmit beam enhancement can be performed according to various aspects of this disclosure to improve the transmit beam for the first frequency band and improve the transmit beam for the second frequency band. Any of the following methods discussed below can be used for inter-band CA transmit beam enhancement.

[0132] Figure 13 A first approach for inter-band CA transmit beam improvement, based on certain aspects, has been explained. In this example, a base station (e.g., base station 205) sweeps a set of K transmit beams M times in a first frequency band and a set of M transmit beams in a second frequency band. Note that this set of K transmit beams differs from the first set of transmit beams used in the beam training discussed above. For example, the transmit beams in this set of K transmit beams may have a narrower beamwidth and cover a narrower area (i.e., a smaller spatial region) compared to the transmit beams in the first set of transmit beams. The transmit beams in this set of K transmit beams may spatially approximate the transmit beams selected for the first frequency band during the inter-band CA beam training discussed above.

[0133] The set of M transmit beams used for transmit beam improvement targeting the second frequency band differs from the second transmit beam set used in the beam training discussed above. For example, the transmit beams in this set of M transmit beams may have narrower beamwidths and cover a narrower area (i.e., a smaller spatial region) compared to the transmit beams in the second transmit beam set. The transmit beams in this set of M transmit beams may spatially approximate the transmit beams selected for the second frequency band during the inter-band beam CA training discussed above.

[0134] During inter-band CA transmit beam improvement, the UE uses a first receive beam for a first frequency band and a second receive beam for a second frequency band. The first receive beam may correspond to the receive beam selected for the first frequency band during the inter-band beam CA training discussed above, while the second receive beam may correspond to the receive beam selected for the second frequency band.

[0135] exist Figure 13 In this diagram, the subscript T indicates the transmit beam, and the subscript R indicates the receive beam. Furthermore, the first subscript number is the beam index indicating one of the beams in the beam set, while the number in parentheses indicates the frequency band. For example, B... T1(1) Indicates the first transmit beam in a set of K transmit beams for the first frequency band, while B T2(1) This indicates the second transmit beam in the group of K transmit beams used for the first frequency band, and so on. B R(1) Indicates the fixed receiving beam used for the first frequency band, while B R(1) Indicates the fixed receiving beam used for the second frequency band.

[0136] Now, based on certain aspects, Figure 13 This describes the inter-band CA transmit beam improvement based on the first method.

[0137] During the first cycle 1310-1, the base station (e.g., base station 205) sweeps a set of K transmit beams for the first frequency band, while the receive beam for the first frequency band (i.e., the first receive beam) is fixed. For each of the K transmit beams, the base station may transmit an RS symbol, and the UE 215 may use the fixed receive beam (i.e., the first receive beam) for the first frequency band to receive the RS symbol and perform signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) on the received RS symbol. Furthermore, during the first cycle 1310-1, the base station may use the first transmit beam (i.e., B) of the M transmit beams for the second frequency band. T1(2)The UE 215 transmits RS symbols multiple times. For each of these transmissions, the UE 215 can use a fixed receive beam for the second frequency band (i.e., the second receive beam) to receive the corresponding RS symbol and perform signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) on the received symbol.

[0138] During the second cycle 1310-2, the base station switches to the second transmit beam for the second frequency band (i.e., B). T2(2) ) and replace the first transmit beam for the second frequency band in the first cycle 1310-1 with the second transmit beam for the second frequency band (i.e., B). T1(2) Repeat the above process.

[0139] For each subsequent cycle, the transmit beam used for the second frequency band is switched to the next transmit beam from a set of M transmit beams used for the second frequency band, and the above process is repeated. For example... Figure 13 As shown, since there are M transmit beams in the set of M transmit beams used for the second frequency band, there are M cycles 1310-1 to 1310-M.

[0140] After cycle M 1310-M, UE 215 may transmit to the base station (e.g., base station 205) a report indicating signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) for the group of K transmit beams and for the group of M transmit beams. This report may include received signal measurements for at least one transmit beam in the group of K transmit beams and received signal measurements for at least one transmit beam in the group of M transmit beams. Upon receiving this report, base station 205 may select, based on the report, the transmit beam with the highest signal measurement (e.g., highest RSRP, highest RSRQ, highest SINR, highest SNR, highest RSSI, etc.) for a first frequency band from the group of K transmit beams for a second frequency band. Base station 205 may also select, based on the report, the transmit beam with the highest signal measurement (e.g., highest RSRP, highest RSRQ, highest SINR, highest SNR, highest RSSI, etc.) for a second frequency band from the group of M transmit beams for a third frequency band.

[0141] The transmit beams selected for the first frequency band and the transmit beams selected for the second frequency band can be used for inter-band CA communication between the base station and UE215.

[0142] Figure 14 A second approach for improving inter-band CA transmit beamforming, based on certain aspects, is explained. This second approach is similar to the first, except that the roles of the first and second frequency bands are reversed.

[0143] During the first cycle 1410-1, the base station (e.g., base station 205) sweeps a set of M transmit beams for the second frequency band, while the receive beam for the second frequency band (i.e., the second receive beam) is fixed. For each of the M transmit beams, the base station may transmit an RS symbol, and the UE 215 may use the fixed receive beam for the second frequency band to receive the RS symbol and perform signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) on the received RS symbol. Furthermore, during the first cycle 1410-1, the base station may use the first transmit beam (i.e., B) from the K transmit beams for the first frequency band. T1(1) The UE 215 transmits RS symbols multiple times. For each of these transmissions, the UE 215 can use a fixed receive beam for the first frequency band to receive the corresponding RS symbol and perform signal measurements on the received symbol (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.).

[0144] During the second cycle 1410-2, the base station switches to the second transmit beam (i.e., B) for the first frequency band. T2(1) ) and replace the first transmit beam for the first frequency band in the first cycle 1410-1 with the second transmit beam for the first frequency band (i.e., B). T1(1) Repeat the above process.

[0145] For each subsequent cycle, the transmit beam used for the first frequency band is switched to the next transmit beam from a set of K transmit beams used for the first frequency band, and the above process is repeated. For example... Figure 14 As shown, since there are K transmit beams in the group of K transmit beams used for the first frequency band, there are K cycles 1410-1 to 1410-K.

[0146] After cycle K 1410-K, UE 215 may transmit to the base station (e.g., base station 205) a report indicating signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) for the group of K transmit beams and for the group of M transmit beams. This report may include received signal measurements for at least one transmit beam in the group of K transmit beams and received signal measurements for at least one transmit beam in the group of M transmit beams. Upon receiving this report, base station 205 may select, based on the report, the transmit beam with the highest signal measurement (e.g., highest RSRP, highest RSRQ, highest SINR, SNR, RSSI, etc.) for a first frequency band from the group of K transmit beams for a second frequency band. Base station 205 may also select, based on the report, the transmit beam with the highest signal measurement (e.g., highest RSRP, highest RSRQ, highest SINR, highest SNR, highest RSSI, etc.) for a second frequency band from the group of M transmit beams for a third frequency band.

[0147] The transmit beams selected for the first frequency band and the transmit beams selected for the second frequency band can be used for inter-band CA communication between the base station and UE215.

[0148] Figure 15 A third method for improving inter-band CA transmit beams, based on certain aspects, has been explained. This third method determines the transmit beam for a first frequency band, and then uses the determined transmit beam for the first frequency band to determine the transmit beam for a second frequency band, as discussed further below.

[0149] During the first cycle 1510-1, the base station (e.g., base station 205) sweeps a set of K transmit beams for the first frequency band, while the receive beam for the first frequency band (i.e., the first receive beam) is fixed. For each of the K transmit beams, the base station may transmit an RS symbol, and the UE 215 may use the fixed receive beam for the first frequency band to receive the RS symbol and perform signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) on the received RS symbol. Furthermore, during the first cycle 1510-1, the base station may use one of the M transmit beams for the second frequency band (e.g., B...). T1(2) The UE 215 transmits RS symbols multiple times. For each of these transmissions, the UE 215 can use a fixed receive beam for the second frequency band (i.e., the second receive beam) to receive the corresponding RS symbol and perform signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) on the received symbol.

[0150] After the first cycle 1510-1, UE 215 may transmit a report to the base station (e.g., base station 205) indicating signal measurements (e.g., RSRP, RSRQ, SINR, SNT, RSSI, etc.) for at least one of the K transmit beams in the group. Upon receiving this report, the base station may select, based on the report, the transmit beam with the highest signal measurements (e.g., highest RSRP, highest RSRQ, highest SINR, highest SNR, highest RSSI, etc.) for the first frequency band from the group of K transmit beams for the first frequency band. The transmit beam selected for the first frequency band... Figure 15 The middle is marked as "B" T(1) *”.

[0151] During the second cycle 1510-2, the base station (e.g., base station 205) sweeps a set of M transmit beams for the second frequency band, while the receive beam for the second frequency band (i.e., the second receive beam) is fixed. For each of the M transmit beams, the base station may transmit an RS symbol, and the UE 215 may use the fixed receive beam for the second frequency band to receive the RS symbol and perform signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) on the received RS symbol. Furthermore, during the second cycle 1510-2, the base station may use the transmit beam (i.e., B) determined for the first frequency band in the first cycle 1510-1. T(1) *) to transmit RS symbols multiple times.

[0152] Following the second cycle 1510-2, UE 215 may transmit a report to the base station (e.g., base station 205) indicating signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) for at least one of the M transmit beams in the group. Upon receiving this report, the base station may select, based on the report, the transmit beam with the highest measurement (e.g., highest RSRP, highest RSRQ, highest SINR, NSR, RSSI, etc.) for the second frequency band from the group of M transmit beams for the purpose of selection.

[0153] The transmit beams selected for the first frequency band and the transmit beams selected for the second frequency band can be used for inter-band CA communication between the base station and UE215.

[0154] Figure 16 A fourth method for improving inter-band CA transmit beamforming, based on certain aspects, is explained. This fourth method is similar to the third method, except that the roles of the first and second frequency bands are reversed.

[0155] During the first cycle 1610-1, the base station (e.g., base station 205) sweeps a set of M transmit beams for the second frequency band, while the receive beam for the second frequency band (i.e., the second receive beam) is fixed. For each of the M transmit beams, the base station may transmit an RS symbol, and the UE 215 may use the fixed receive beam for the second frequency band to receive the RS symbol and perform signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) on the received RS symbol. Furthermore, during the first cycle 1610-1, the base station may use one of the K transmit beams for the first frequency band (e.g., B...). T1(1) The UE 215 transmits RS symbols multiple times. For each of these transmissions, the UE 215 may use a fixed receive beam for the first frequency band (i.e., the first receive beam) to receive the corresponding RS symbol and perform signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) on the received symbol.

[0156] Following the first cycle 1610-1, UE 215 may transmit a report to the base station (e.g., base station 205) indicating signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) for at least one of the M transmit beams in the group. Upon receiving this report, the base station may select, based on the report, the transmit beam with the highest signal measurements (e.g., highest RSRP, highest RSRQ, highest SINR, etc.) for the second frequency band from the group of M transmit beams. The transmit beam selected for the second frequency band... Figure 16 The middle is marked as "B" T(2) *.

[0157] During the second cycle 1610-2, the base station (e.g., base station 205) sweeps a set of K transmit beams for the first frequency band, while the receive beam for the first frequency band (i.e., the second receive beam) is fixed. For each of the K transmit beams, the base station may transmit an RS symbol, and the UE 215 may use the fixed receive beam for the first frequency band to receive the RS symbol and perform signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) on the received RS symbol. Furthermore, during the second cycle 1610-2, the base station may use the transmit beam (i.e., B) determined for the second frequency band in the first cycle 1610-1. T(2) *) to transmit RS symbols multiple times.

[0158] Following the second cycle 1610-2, UE 215 may transmit a report to the base station (e.g., base station 205) indicating signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) for at least one of the group of K transmit beams. Upon receiving this report, the base station may select, based on the report, the transmit beam with the highest signal measurement (e.g., highest RSRP, highest RSRQ, highest SINR, highest SNR, highest RSSI, etc.) for the first frequency band from the group of K transmit beams for the first frequency band.

[0159] The transmit beams selected for the first frequency band and the transmit beams selected for the second frequency band can be used for inter-band CA communication between the base station and UE215.

[0160] Figure 17 The fifth method for improving inter-band CA transmit beams, based on certain aspects, was explained.

[0161] During the first cycle 1710-1, the base station (e.g., base station 205) sweeps the transmit beams for the first frequency band in a first beam order for the first frequency band, while the receive beams for the first frequency band are fixed. For each of these transmit beams, the base station may transmit an RS symbol, and the UE 215 may use the fixed receive beam for the first frequency band to receive the RS symbol and perform signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) on the received RS symbol. The first beam order for the first frequency band may be predetermined, random, etc.

[0162] Furthermore, during the first cycle 1710-1, the base station (e.g., base station 205) sweeps the transmit beams for the second frequency band in a first beam order for the second frequency band, while the receive beams for the second frequency band are fixed. For each of these transmit beams, the base station may transmit RS symbols, and the UE 215 may use the fixed receive beams for the second frequency band to receive the RS symbols and perform signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) on the received RS symbols. The first beam order for the second frequency band may be predetermined, random, etc. Note that the first beam order for the second frequency band is not necessarily the same as the first beam order for the first frequency band.

[0163] During the second cycle 1710-2, the base station repeats the above process using a second beam sequence for the first frequency band and a second beam sequence for the second frequency band. The second beam sequence for the first frequency band may be the same as or different from the first beam sequence for the first frequency band. The second beam sequence for the second frequency band may be the same as or different from the first beam sequence for the second frequency band.

[0164] The base station can repeat the above process for each cycle from 1710-3 to 1710-N, wherein the beam order for the first frequency band and the beam order for the second frequency band can be the same in each cycle, or can be changed with each cycle.

[0165] After cycle N 1710-N, UE 215 may transmit a report to the base station (e.g., base station 205) indicating signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) for at least one of the transmit beams in the first frequency band and for at least one of the transmit beams in the second frequency band. Upon receiving this report, the base station may select, based on the report, the transmit beam with the highest signal measurement (e.g., highest RSRP, highest RSRQ, highest SINR, highest SNR, highest RSSI, etc.) for the first frequency band from among the transmit beams used for the first frequency band. The base station may also select, based on the report, the transmit beam with the highest signal measurement (e.g., highest RSRP, highest RSRQ, highest SINR, highest SNR, highest RSSI, etc.) for the second frequency band from among the transmit beams used for the second frequency band.

[0166] The transmit beams selected for the first frequency band and the transmit beams selected for the second frequency band can be used for inter-band CA communication between the base station and UE215.

[0167] In the example above, the report can indicate the received signal measurement for the transmit beam by using a time index (e.g., a symbol) that indicates the received signal measurement. Since the base station knows when a particular transmit beam is used, it can identify the transmit beam corresponding to the received signal measurement in the report based on the time index.

[0168] After inter-band transmit beam enhancement is completed, inter-band CA receive beam enhancement can be performed according to various aspects of this disclosure to improve the receive beam for the first frequency band and improve the receive beam for the second frequency band. Any of the following methods discussed below can be used for inter-band CA receive beam enhancement.

[0169] Figure 18 The first method for improving the receive beam for inter-band CA (Cross-band Receiver) is explained based on certain aspects. The first method determines the receive beam for a first frequency band and subsequently determines the receive beam for a second frequency band, as discussed further below.

[0170] During the first cycle 1810-1, UE 215 sweeps a set of P receive beams for the first frequency band, while the transmit beams for the first frequency band are fixed. The receive beams in this set of P receive beams may have a narrower beamwidth than the first receive beam set used in the beam training discussed above. The transmit beams for the first frequency band may be the transmit beams selected for the first frequency band during the transmit beam improvement discussed above (i.e., B...). T(1)*). In this example, the base station can use a fixed transmit beam for the first frequency band to transmit RS symbols multiple times. For each transmission, the UE 215 can use different beams from the set of P receive beams to receive the corresponding RS symbols and perform signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) on the received RS symbols. Furthermore, during the first cycle 1810-1, the base station can use a fixed transmit beam for the second frequency band to transmit RS symbols multiple times. The transmit beam for the second frequency band can be the transmit beam selected for the second frequency band during the transmit beam improvement discussed above (i.e., B). T(2) *).

[0171] After the first cycle 1810-1, UE 215 can select the receiving beam with the highest signal measurement (e.g., highest RSRP, highest RSRQ, highest SINR, highest SNR, highest RSSI, etc.) from the group of P receiving beams for the first frequency band. The receiving beam selected for the first frequency band is... Figure 18 The middle is marked as "B" R(1) *". UE 215 can also transmit to the base station a report indicating signal measurements for at least one of the received beams.

[0172] During the second cycle 1810-2, UE 215 sweeps a set of Q receive beams for the second frequency band, while the transmit beams for the second frequency band (e.g., B) T(2) *) is fixed. The receive beams in this set of Q receive beams may have a narrower beamwidth than the second set of receive beams used in the beam training discussed above. In this example, the base station can use the fixed transmit beam for the second frequency band to transmit RS symbols multiple times. For each transmission, the UE 215 can use different beams from this set of Q receive beams to receive the corresponding RS symbols and perform signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) on the received RS symbols. Furthermore, during the second cycle 1820-1, the base station can use the fixed transmit beam for the first frequency band to transmit RS symbols multiple times and use the receive beam selected for the first frequency band (i.e., B) R(1) *) to receive these RS symbols.

[0173] After the second cycle 1810-2, UE 215 can select the receiving beam with the highest signal measurement (e.g., highest RSRP, highest RSRQ, highest SINR, SNR, RSSI, etc.) from the receiving beams in the group of Q receiving beams for the second frequency band. UE 215 can also transmit a report to the base station indicating the signal measurement for at least one of the receiving beams.

[0174] UE 215 may use a receive beam selected for a first frequency band and a receive beam selected for a second frequency band in inter-band CA communication between the base station and UE 215, as discussed further below.

[0175] Figure 19 A second approach for improving inter-band CA receiver beamforming, based on certain aspects, has been explained. This second approach is similar to the first, except that the roles of the first and second frequency bands are reversed, as discussed further below.

[0176] During the first cycle 1910-1, UE 215 sweeps a set of Q receive beams for the second frequency band, while the transmit beam for the second frequency band is fixed. As discussed above, the transmit beam for the second frequency band can be the transmit beam selected for the second frequency band during the transmit beam improvement period discussed above (i.e., B). T(2) *). In this example, the base station can use a fixed transmit beam for the second frequency band to transmit RS symbols multiple times. For each transmission, the UE 215 can use different beams from the set of Q receive beams to receive the corresponding RS symbols and perform signal measurements on the received RS symbols (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.). Furthermore, during the first cycle 1910-1, the base station can use a fixed transmit beam for the first frequency band (e.g., B...). T(1) *) to transmit RS symbols multiple times.

[0177] After the first cycle 1910-1, UE 215 can select the receiving beam with the highest signal measurement (e.g., highest RSRP, highest RSRQ, highest SINR, highest SNR, highest RSSI, etc.) from the group of Q receiving beams for the second frequency band. The receiving beam selected for the second frequency band is... Figure 19 The middle is marked as "B" R(2) *". UE 215 can also transmit to the base station a report indicating signal measurements for at least one of the received beams.

[0178] During the second cycle 1910-2, UE 215 sweeps a set of P receive beams for the first frequency band, while the transmit beams for the first frequency band (e.g., B) T(1)*) is fixed. In this example, the base station can use a fixed transmit beam for the first frequency band to transmit RS symbols multiple times. For each transmission, the UE 215 can use different beams from the set of P receive beams to receive the corresponding RS symbols and perform signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) on the received RS symbols. Furthermore, during the second cycle 1920-1, the base station can use a fixed transmit beam for the second frequency band to transmit RS symbols multiple times and use the receive beam selected for the second frequency band (i.e., B) R(2) *) to receive these RS symbols.

[0179] After the second cycle 1910-2, UE 215 can select the receiving beam with the highest signal measurement (e.g., highest RSRP, highest RSRQ, highest SINR, etc.) from the receiving beams in the group of P receiving beams for the first frequency band. UE 215 can also transmit a report to the base station indicating the signal measurement for at least one of the receiving beams.

[0180] UE 215 can use the receive beam selected for the first frequency band and the receive beam selected for the second frequency band in inter-band CA communication between the base station and UE 215.

[0181] Figure 20 The third approach to improving the receiving beam of inter-band CA is explained based on certain aspects.

[0182] During the first cycle 2010-1, the base station used the transmit beam selected for the first frequency band (i.e., B) during the transmit beam improvement period. T(1) The UE 215 transmits RS symbols multiple times, and sweeps the receive beams for the first frequency band with a first beam order for the first frequency band. For each transmission of RS symbols, the UE 215 can use one of the receive beams for the first frequency band to receive the RS symbol and perform signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) on the received RS symbol. The first beam order for the first frequency band can be predetermined, random, etc.

[0183] Furthermore, during the first cycle 2010-1, the base station used the transmit beam selected for the second frequency band (i.e., B) during the transmit beam improvement period. T(2)The UE 215 transmits RS symbols multiple times, and sweeps the receive beams for the second frequency band with the first beam order for the second frequency band. For each transmission of RS symbols, the UE 215 can use one of the receive beams for the second frequency band to receive the RS symbol and perform signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) on the received RS symbol. The first beam order for the second frequency band can be predetermined, random, etc. Note that the first beam order for the second frequency band is not necessarily the same as the first beam order for the first frequency band.

[0184] During the second cycle 2010-2, UE 215 repeats the above process using a second beam sequence for the first frequency band and a second beam sequence for the second frequency band. The second beam sequence for the first frequency band may be the same as or different from the first beam sequence for the first frequency band. The second beam sequence for the second frequency band may be the same as or different from the first beam sequence for the second frequency band.

[0185] The base station can repeat the above process for each cycle from 2010-3 to 2010-N, wherein the beam order for the first frequency band and the beam order for the second frequency band can be the same in each cycle, or can be changed with each cycle.

[0186] After the Nth cycle 2010-N, UE 215 can select the receiving beam with the highest measurement (e.g., highest RSRP, highest RSRQ, highest SINR, highest SNR, highest RSSI, etc.) for the first frequency band from the receiving beams used for the first frequency band, and select the receiving beam with the highest signal measurement (e.g., highest RSRP, highest RSRQ, highest SINR, highest SNR, highest RSSI, etc.) for the second frequency band from the receiving beams used for the second frequency band.

[0187] UE 215 can use a receive beam for the first frequency band and a receive beam selected for the second frequency band in inter-band CA communication between the base station and UE 215.

[0188] After transmit beam enhancement and receive beam enhancement, the base station and UE 215 can communicate using transmit beams selected for the first and second frequency bands, and receive beams selected for the first and second frequency bands. For example, the base station can use inter-band carrier aggregation in the first and second frequency bands to transmit data signals to UE 215, wherein using inter-band carrier aggregation to transmit data signals includes: transmitting a first portion of the data signal using a transmit beam selected for the first frequency band on one or more carriers (e.g., subcarriers) in the first frequency band; and transmitting a second portion of the data signal using a transmit beam selected for the second frequency band on one or more carriers (e.g., subcarriers) in the second frequency band. The one or more carriers in the first frequency band may be contiguous or non-contiguous, and the one or more carriers in the second frequency band may be contiguous or non-contiguous.

[0189] UE 215 may use inter-band carrier aggregation in a first frequency band and a second frequency band to receive data signals from a base station, wherein using inter-band carrier aggregation to receive data signals includes: using a receive beam selected for the first frequency band on one or more carriers in the first frequency band to receive a first portion of the data signal; and using a receive beam selected for the second frequency band on one or more carriers in the second frequency band to receive a second portion of the data signal.

[0190] The foregoing has discussed exemplary inter-band CA beamforming training according to various aspects of this disclosure, using the downlink as an example. Exemplary inter-band beamforming training can also be used for the uplink, where the roles of the base station and UE 215 are reversed, as discussed further below.

[0191] After receiving a message from the base station indicating the first RS symbol set and the second RS symbol set, UE 215 can perform beam training for the first frequency band using the RS symbols allocated for the first frequency band. In this example, UE 215 sweeps the first transmit beam set. Each transmit beam in the first transmit beam set can point in a different direction. For each of these transmit beams, UE 215 can transmit a corresponding RS symbol from the first RS symbol set allocated for the first frequency band. In other words, UE 215 uses the first transmit beam in the first transmit beam set to transmit the first RS symbol in the first RS symbol set, uses the second transmit beam in the first transmit beam set to transmit the second RS symbol in the first RS symbol set, and so on.

[0192] The base station sweeps a first set of receive beams. Each receive beam in the first set of receive beams may point in a different direction. For each of the receive beams, the base station may receive a corresponding RS symbol from the first set of RS symbols and perform received signal measurements (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) on the received RS symbol. In other words, the base station uses the first receive beam in the first set of receive beams to receive the first RS symbol in the first set of RS symbols, uses the second receive beam in the first set of receive beams to receive the second RS symbol in the first set of RS symbols, and so on.

[0193] The beam sweep at the base station and the beam sweep at the UE 215 are coordinated such that for each of the multiple beam pairs used in the first frequency band, the UE 215 transmits one of the RS symbols assigned to the first frequency band, and the base station receives the RS symbol.

[0194] For each of a plurality of beam pairs, the base station may perform signal measurements on the RS symbols received by that beam pair. These signal measurements may measure RSRP, RSRQ, SINR, SNR, RSSI, or another parameter indicating signal strength or signal quality. In one example, the base station may transmit a report to UE 215 indicating received signal measurements for at least one symbol in a first set of RS symbols. Since UE 215 knows which transmit beam it transmitted for each RS symbol, UE 215 can identify the transmit beam corresponding to the received signal measurements in the report. In one example, UE 215 may select, based on the report, the transmit beam corresponding to the RS symbol with the highest signal measurement (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) from the first set of transmit beams. Furthermore, the base station may select the receive beam corresponding to the RS symbol with the highest received signal measurement in the first set of RS symbols. In this example, the selected transmit beam and the selected receive beam constitute a selected beam pair for a first frequency band. Therefore, beam training in the first frequency band determines the beam pairs used in the first frequency band.

[0195] Beam training for the second frequency band can be performed using RS symbols allocated for the second frequency band. Since the RS symbols for the second frequency band overlap with those for the first frequency band in time, beam training for the second frequency band is performed simultaneously with the beam training for the first frequency band discussed above. In this example, UE 215 sweeps the second transmit beam set. Each transmit beam in the second transmit beam set can point in a different direction. For each of these transmit beams, UE 215 can transmit a corresponding RS symbol from the second RS symbol set. In other words, UE 215 uses the first transmit beam in the second transmit beam set to transmit the first RS symbol in the second RS symbol set, uses the second transmit beam in the second transmit beam set to transmit the second RS symbol in the second RS symbol set, and so on.

[0196] The base station sweeps a second set of receive beams. Each of these receive beams can point in a different direction. For each of these receive beams, the base station can receive a corresponding RS symbol from the second RS symbol set and perform signal measurements on the received RS symbol. In other words, the base station uses a first receive beam from the second set of receive beams to receive a first RS symbol from the second RS symbol set, uses a second receive beam from the second set of receive beams to receive a second RS symbol from the second RS symbol set, and so on.

[0197] The second transmit beamset may differ from the first transmit beamset, and the second receive beamset may differ from the first receive beamset (e.g., due to differences in the antenna arrays used for the first and second frequency bands). For example, the transmit beams in the second transmit beamset may have a narrower beamwidth than the transmit beams in the first transmit beamset. Similarly, the receive beams in the second receive beamset may have a narrower beamwidth than the receive beams in the first receive beamset.

[0198] The beam sweep at the base station and the beam sweep at the UE 215 are coordinated such that for each of the multiple beam pairs used for the second frequency band, the UE 215 transmits one of the RS symbols allocated for the second frequency band, and the base station receives that RS symbol.

[0199] For each of a plurality of beam pairs, the base station may perform signal measurements on the RS symbols received by that beam pair. These signal measurements may measure RSRP, RSRQ, SINR, SNR, RSSI, or another parameter indicating signal strength or signal quality. In one example, the base station may transmit a report to UE 215 indicating received signal measurements for at least one symbol in a second set of RS symbols. Since UE 215 knows which transmit beam it transmitted for each RS symbol, UE 215 can identify the transmit beam corresponding to the received signal measurements in the report. In one example, UE 215 may select, based on this report, the transmit beam corresponding to the RS symbol with the highest signal measurement (e.g., RSRP, RSRQ, SINR, SNR, RSSI, etc.) from the second set of transmit beams. Furthermore, the base station may select the receive beam corresponding to the RS symbol with the highest received signal measurement in the second set of RS symbols. In this example, the selected transmit beam and the selected receive beam constitute a selected beam pair for a second frequency band. Therefore, beam training in the second frequency band determines the beam pairs used in the second frequency band.

[0200] After completing the inter-band beamforming training discussed above, inter-band transmit beamforming enhancement can be performed to improve the transmit beam at UE 215 for the first frequency band and to improve the transmit beam at UE 215 for the second frequency band. This can be achieved using... Figure 13-17 Any of the methods described herein is used to perform inter-band CA transmit beam improvement, in which the roles of the base station and UE 215 are reversed.

[0201] Following inter-band CA transmit beamforming improvement, inter-band CA receive beamforming improvement can be performed to improve the receive beam at the base station for the first frequency band and to improve the receive beam at the base station for the second frequency band. This can be used... Figure 18-20 Any of the methods described herein can be used to perform inter-band receive beam improvement, in which the roles of the base station and UE215 are reversed.

[0202] After transmit beam enhancement and receive beam enhancement, the base station and UE 215 can communicate on the uplink using transmit beams selected for the first and second frequency bands, and receive beams selected for the first and second frequency bands. For example, UE 215 can transmit data signals to the base station using inter-band carrier aggregation in the first and second frequency bands, wherein using inter-band carrier aggregation to transmit data signals includes:

[0203] A first portion of the data signal is transmitted using a transmit beam selected for the first frequency band on one or more carriers in a first frequency band; and a second portion of the data signal is transmitted using a transmit beam selected for the second frequency band on one or more carriers in a second frequency band. The one or more carriers in the first frequency band may be adjacent or non-adjacent, and the one or more carriers in the second frequency band may be adjacent or non-adjacent.

[0204] The base station may use inter-band carrier aggregation in a first frequency band and a second frequency band to receive data signals from UE 215, wherein using inter-band carrier aggregation to receive data signals includes: using a receiving beam selected for the first frequency band on one or more carriers in the first frequency band to receive a first portion of the data signal; and using a receiving beam selected for the second frequency band on one or more carriers in the second frequency band to receive a second portion of the data signal.

[0205] As referenced above Figure 11 As discussed, UE 215 can use inter-band CA to receive data from or transmit data to multiple base stations. In this example, inter-band CA beamtraining can be coordinated across multiple base stations. For example, beamtraining for a first frequency band can be performed by a first base station (e.g., base station 1105), and beamtraining for a second frequency band can be performed by a second base station (e.g., base station 1108). In this example, the first and second base stations can communicate with each other (e.g., on an X2 interface between the two base stations) to align the timing of beamtraining for the first frequency band with the timing of beamtraining for the second frequency band, such that beamtraining for the first frequency band and beamtraining for the second frequency band are performed simultaneously by the respective base stations.

[0206] Figure 21 Example device 2100 according to certain aspects of this disclosure is described. Device 2100 may be configured to operate in a base station (e.g., base station 205) or UE (e.g., UE 215) and may be configured to perform one or more operations described herein. Device 2100 may include processor 2120, memory 2110, transceiver 2130, first antenna array 2160, second antenna array 2165, one or more antennas 2170, and user interface 2140. These components may be in electronic communication via one or more buses 2145.

[0207] Memory 2110 may store instructions 2115 that can be executed by controller 2120 to cause device 2100 to perform one or more operations described herein. Processor 2120 may include a general-purpose processor, digital signal processor (DSP), central processing unit (CPU), microcontroller, application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), programmable logic device, discrete gate or transistor logic component, discrete hardware component, or any combination thereof. As an example, memory 2110 may include random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), register, disk, optical disk, hard disk drive, or any other suitable storage medium, or any combination thereof.

[0208] Transceiver 2130 is coupled to a first antenna array 2160 and a second antenna array 2165. The first antenna array 2160 can be configured to transmit and / or receive signals in a first frequency band, and the second antenna array 2165 can be configured to transmit and / or receive signals in a second frequency band. In the case of a UE (e.g., UE 215), the first antenna array 2160 may correspond to a first antenna array 910, and the second antenna array 2165 may correspond to a second antenna array 920. Each of antenna arrays 2160 and 2165 includes an array of antenna elements (…). Figure 21 (Not shown in the image). The first antenna array 2160 and the second antenna array 2165 may have different sizes, different geometries, different numbers of antenna elements, different spacing between antenna elements, etc.

[0209] The first antenna array 2160 allows device 2100 to transmit signals with high directivity using any of a plurality of transmit beams (e.g., a first set of transmit beams) in a first frequency band. In this regard, transceiver 2130 may be configured to perform beamforming, wherein transceiver 2130 electronically switches the first antenna array 2160 between different transmit beams, for example, by adjusting the phase between the transmit signals output to individual antenna elements of the first antenna array 2160. The first antenna array 2160 also allows device 2100 to receive signals with high directivity using any of a plurality of receive beams (e.g., a first set of receive beams) in the first frequency band. In this regard, transceiver 2130 may be configured to perform beamforming, wherein transceiver 2130 electronically switches the first antenna array 2160 between different receive beams, for example, by adjusting the phase between the signals received from individual antenna elements of the first antenna array 2160.

[0210] The second antenna array 2165 allows device 2100 to transmit signals with high directivity using any of a plurality of transmit beams (e.g., a second set of transmit beams) in a second frequency band. In this regard, transceiver 2130 may be configured to perform beamforming, wherein transceiver 2130 electronically switches the second antenna array 2165 between different transmit beams, for example, by adjusting the phase between the transmit signals of the individual antenna elements output to the second antenna array 2165. The second antenna array 2165 also allows device 2100 to receive signals with high directivity using any of a plurality of receive beams (e.g., a second set of receive beams) in a second frequency band. In this regard, transceiver 2130 may be configured to perform beamforming, wherein transceiver 2130 electronically switches the second antenna array 2165 between different receive beams, for example, by adjusting the phase between the signals received from the individual antenna elements of the second antenna array 2165.

[0211] Processor 2120 can control transceiver 2130 to perform beamforming on the first antenna array 2160 and the second antenna array 2165 via bus 2145. For example, processor 2120 can instruct transceiver 2130 to sweep a first transmit beamset or receive beamset on the first antenna array 2160 and sweep a second transmit beamset or receive beamset on the second antenna array 2165. Processor 2120 can also control the timing of beam sweeping on the first antenna array 2160 and the second antenna array 2165 (e.g., performing beam training on the first and second frequency bands simultaneously).

[0212] It will be understood that device 2100 may include additional antenna arrays (e.g., for other frequency bands).

[0213] Transceiver 2130 may also be coupled to one or more antennas 2170 and may be configured to transmit and / or receive signals (e.g., in a first frequency band, a second frequency band, or another frequency band) via one or more antennas 2170. In some aspects, transceiver 2130 may transmit and / or receive signals in a sub-6 GHz frequency band (e.g., for LTE communications) via one or more antennas 2170 and in a millimeter-wave frequency band (e.g., for NR communications) via antenna arrays 2160 and 2165. In some aspects, transceiver 2130 may transmit messages or reports via one or more antennas 2170, the first antenna array 2160, or the second antenna array 2165. Similarly, transceiver 2130 may receive messages or reports via one or more antennas 2170, the first antenna array 2160, or the second antenna array 2165. In addition, transceiver 2130 can be configured to perform signal measurements on signals received via first antenna array 2160, second antenna array 2165, or one or more antennas 2170, and transmit the signal measurements to processor 2120 via bus 2145.

[0214] In the case of a UE (e.g., UE 215), device 2100 may include a user interface 2140 coupled to processor 2120. User interface 2140 may be configured to receive data from a user (e.g., via a keyboard, mouse, etc.) and provide that data to processor 2120. User interface 2140 may also be configured to output data from processor 2120 to the user (e.g., via a display, speaker, etc.). In this case, the data may undergo additional processing before being output to the user. In the case of a base station (e.g., base station 205), user interface 2140 may be omitted.

[0215] Figure 22 A method 2200 for wireless communication by a base station has been described according to certain aspects. Method 2200 can be performed by an exemplary device 2100 configured to operate in a base station (e.g., base station 205).

[0216] In block 2210, a first reference signal (RS) symbol set is assigned for beam training in the first frequency band. The first RS symbol set may be assigned by processor 2120 (e.g., based on a request message indicating the number of RS symbols for the first frequency band).

[0217] In block 2220, a second RS symbol set is allocated for beam training in the second frequency band, wherein the first RS symbol set and the second RS symbol set overlap in time. The second RS symbol set may be allocated by processor 2120 (e.g., based on a request message indicating the number of RS symbols for the second frequency band).

[0218] In box 2230, a message is generated indicating the first RS symbol set and the second RS symbol set. This message can be generated by processor 2120.

[0219] In box 2240, the message is transmitted to user equipment (UE). This UE may correspond to UE 215. The message may be transmitted by transceiver 2130 via a first antenna array 2160, a second antenna array 2165, or one or more antennas 2170.

[0220] Figure 23 A method 2300 for wireless communication by a user equipment, according to certain aspects, has been described. Method 2300 can be performed by an exemplary device 2100 configured to operate in a UE (e.g., UE 215).

[0221] In block 2310, a message is received from the base station indicating a first reference signal (RS) symbol set and a second RS symbol set, wherein the first RS symbol set and the second RS symbol set overlap in time. For example, the message may be received by transceiver 2130 via a first antenna array 2160, a second antenna array 2165, or one or more antennas 2170.

[0222] In block 2320, the beam sweeps the first receive beam set. For example, the receive beam may be swept by transceiver 2130 and first antenna array 2160, wherein transceiver 2130 performs beamforming.

[0223] In block 2330, for each receive beam in the first receive beam set, a corresponding RS symbol from the first RS symbol set is received in the first frequency band, and a signal measurement is performed on the corresponding RS symbol received in the first frequency band. The RS symbols of each receive beam can be received by transceiver 2130 via the first antenna array 2160, and the signal measurement can be performed by transceiver 2130.

[0224] In block 2340, the beam sweeps a second set of receive beams. For example, the receive beams may be swept by transceiver 2130 and a second antenna array 2165, wherein transceiver 2130 performs beamforming.

[0225] In block 2350, for each receive beam in the second receive beam set, a corresponding RS symbol from the second RS symbol set is received in the second frequency band, and a signal measurement is performed on the corresponding RS symbol received in the second frequency band. The RS symbols of each receive beam can be received by transceiver 2130 via the second antenna array 2165, and the signal measurement can be performed by transceiver 2130.

[0226] Figure 24A method 2400 for wireless communication by a user equipment is described according to certain aspects. Method 2400 can be performed by an exemplary device 2100 configured to operate in a UE (e.g., UE 215).

[0227] In block 2410, a message is received from the base station indicating a first reference signal (RS) symbol set and a second RS symbol set, wherein the first RS symbol set and the second RS symbol set overlap in time. For example, the message may be received by transceiver 2130 via a first antenna array 2160, a second antenna array 2165, or one or more antennas 2170.

[0228] In block 2420, the beam sweeps the first transmit beam set. For example, the transmit beam may be swept by transceiver 2130 and first antenna array 2160, wherein transceiver 2130 performs beamforming.

[0229] In block 2430, for each transmit beam in the first transmit beam set, a corresponding RS symbol from the first RS symbol set is transmitted in the first frequency band. For example, the RS symbol of each transmit beam may be transmitted by transceiver 2130 via the first antenna array 2160.

[0230] In block 2440, the beam sweeps a second transmit beam set. For example, the transmit beam may be swept by transceiver 2130 and a second antenna array 2165, wherein transceiver 2130 performs beamforming.

[0231] In block 2450, for each transmit beam in the second transmit beam set, a corresponding RS symbol from the second RS symbol set is transmitted in the second frequency band. For example, the RS symbol of each transmit beam may be transmitted by transceiver 2130 via the second RS array 2165.

[0232] Figure 25 A method 2500 for wireless communication by a base station has been described in some respects. Method 2500 can be performed by an exemplary device 2100 configured to operate in a base station (e.g., base station 205).

[0233] In block 2510, a beam sweeps across a first transmit beam set over a first time interval. For example, the transmit beam may be swept by transceiver 2130 and a first antenna array 2160, wherein transceiver 2130 performs beamforming. For example, the first time interval may span... Figure 13-17 One or more cycles are shown. The first transmit beam set may correspond to an exemplary set of K transmit beams in the first frequency band discussed above.

[0234] In block 2520, for each transmit beam in the first transmit beam set, a corresponding reference signal (RS) symbol is transmitted in the first frequency band. The RS symbol of each transmit beam can be transmitted by transceiver 2130 via the first antenna array 2160.

[0235] In box 2530, a second transmit beamset is swept over a second time interval, wherein the first and second time intervals overlap in time. For example, the transmit beam can be swept by transceiver 2130 and a second antenna array 2165, wherein transceiver 2130 performs beamforming. For example, the second time interval can span... Figure 13-17 One or more cycles are shown. The second transmit beam set may correspond to an exemplary set of M transmit beams in the second frequency band discussed above.

[0236] In block 2540, for each transmit beam in the second transmit beam set, a corresponding reference signal (RS) symbol is transmitted in the second frequency band. The RS symbol of each transmit beam can be transmitted by transceiver 2130 via the second linear array 2165.

[0237] Figure 26 A method 2600 for wireless communication by a user equipment is described according to certain aspects. Method 2600 can be performed by an exemplary device 2100 configured to operate in a UE (e.g., UE 215).

[0238] In block 2610, a beam sweeps a first set of received beams over a first time interval. For example, the received beams may be swept by transceiver 2130 and a first antenna array 2160, wherein transceiver 2130 performs beamforming. For example, the first time interval may span... Figure 18-20 One or more cycles are shown. The first receive beam set may correspond to an exemplary set of P receive beams in the first frequency band discussed above.

[0239] In block 2620, for each receive beam in the first receive beam set, a corresponding reference signal (RS) symbol is received in the first frequency band; and signal measurements are performed on the corresponding RS symbols received in the first frequency band. The RS symbols of each receive beam can be received by transceiver 2130 via the first antenna array 2160, and the signal measurements can be performed by transceiver 2130.

[0240] In box 2630, a second receive beamset is swept over a second time interval, wherein the second time interval overlaps with the first time interval. For example, the receive beam can be swept by transceiver 2130 and a second antenna array 2165, wherein transceiver 2130 performs beamforming. For example, the second time interval can span... Figure 18-20One or more cycles are shown. The second receive beam set may correspond to an exemplary set of Q receive beams in the second frequency band discussed above.

[0241] In block 2640, for each receive beam in the second receive beam set, a corresponding reference signal (RS) symbol is received in the second frequency band; and signal measurements are performed on the corresponding RS symbols received in the second frequency band. The RS symbols of each receive beam can be received by transceiver 2130 via the second antenna array 2165, and the signal measurements can be performed by transceiver 2130.

[0242] RS symbols can be Channel State Information RS (CSI-RS) symbols (e.g., for downlink), Probe Reference Signal (SRS) (e.g., for uplink), or other types of symbols that can be used for beam training.

[0243] Examples of implementations are described in the following numbered clauses.

[0244] 1. A method for wireless communication via a base station, comprising:

[0245] Assign a first reference signal (RS) symbol set for beam training in the first frequency band;

[0246] A second RS symbol set is assigned for beam training in the second frequency band, wherein the first RS symbol set and the second RS symbol set overlap in time.

[0247] Generate a message indicating the first RS symbol set and the second RS symbol set; and

[0248] Send the message to the user equipment (UE).

[0249] 2. The method of Clause 1, wherein the first and second frequency bands are above the frequency of 24.25 GHz.

[0250] 3. The method of Clause 1 or 2, wherein the duration of an RS symbol in the first RS symbol set is greater than the duration of an RS symbol in the second RS symbol set.

[0251] 4. The method of any of Clauses 1 to 3, wherein the first frequency band and the second frequency band are separated in frequency.

[0252] 5. The method of any of clauses 1 to 4, wherein:

[0253] The first RS symbol set is indicated by the symbol number of the first time slot; and

[0254] The second RS symbol set is indicated by the symbol number of the second time slot.

[0255] 6. The method of any of Clauses 1 to 5 further includes:

[0256] Beam sweep of the first transmitted beam set;

[0257] For each transmit beam in the first transmit beam set, transmit a corresponding RS symbol from the first RS symbol set in the first frequency band;

[0258] Beam sweeping second transmit beam set; and

[0259] For each transmit beam in the second transmit beam set, a corresponding RS symbol from the second RS symbol set is transmitted in the second frequency band.

[0260] 7. As in Clause 6, wherein:

[0261] Each transmitted beam in the first transmitted beam set points in a different direction, or each transmitted beam in the first transmitted beam set has a different beam pattern; and

[0262] Each transmit beam in the second transmit beam set points in a different direction, or each transmit beam in the second transmit beam set has a different beam pattern.

[0263] 8. The method of Clause 6 or 7, wherein at least one transmit beam in the second transmit beam set has a beamwidth narrower than each transmit beam in the first transmit beam set.

[0264] 9. The method of any of Clauses 1 to 5 further includes:

[0265] Beam sweep of the first receiving beam set;

[0266] For each receive beam in the first receive beam set

[0267] Receive a corresponding RS symbol from the first RS symbol set in the first frequency band; and

[0268] Perform signal measurement on the corresponding RS symbol received in the first frequency band;

[0269] Beam sweeping second receiving beam set; and

[0270] For each receive beam in the second receive beam set

[0271] Receive a corresponding RS symbol from the second RS symbol set in the second frequency band; and

[0272] Perform signal measurement on the corresponding RS symbol received in the second frequency band.

[0273] 10. As in Clause 9, wherein:

[0274] Each receiving beam in the first receiving beam set points in a different direction, or each receiving beam in the first receiving beam set has a different beam pattern; and

[0275] Each receiving beam in the second receiving beam set points in a different direction, or each receiving beam in the second receiving beam set has a different beam pattern.

[0276] 11. The methods described in Clause 9 or 10 further include:

[0277] Generate a report indicating signal measurements for at least one RS symbol in a first RS symbol set and signal measurements for at least one RS symbol in a second RS symbol set; and

[0278] The report is transmitted to the UE.

[0279] 12. The method of any of Clauses 9 to 11, wherein each signal measurement includes a reference signal received power (RSRP) measurement, a reference signal received quality (RSRQ) measurement, a signal-to-interference plus-noise ratio (SINR) measurement, a signal-to-noise ratio (SNR) measurement, or a received signal strength indicator (RSSI) measurement.

[0280] 13. The method of any of clauses 1 to 12 further includes:

[0281] Receive a message from the UE, wherein the message from the UE indicates the number of first RS symbols and the number of second RS symbols;

[0282] The allocation of the first RS symbol set includes: allocating the first RS symbol set based on the number of first RS symbols; and

[0283] The allocation of the second RS symbol set includes: allocating the second RS symbol set based on the number of second RS symbols.

[0284] 14. The method as described in Clause 13, wherein:

[0285] The number of RS symbols in the first RS symbol set is equal to the number of RS symbols in the first RS symbol set; and

[0286] The number of RS symbols in the second RS symbol set is equal to the number of RS symbols in the second RS symbol set.

[0287] 15. A method for wireless communication by a user equipment (UE), comprising:

[0288] A message is received from the base station indicating a first reference signal (RS) symbol set and a second RS symbol set, wherein the first RS symbol set and the second RS symbol set overlap in time;

[0289] Beam sweep of the first receiving beam set;

[0290] For each receive beam in the first receive beam set

[0291] Receive a corresponding RS symbol from the first RS symbol set in the first frequency band; and

[0292] Perform signal measurement on a corresponding RS symbol received in the first frequency band; and

[0293] Beam sweeping second receiving beam set; and

[0294] For each receive beam in the second receive beam set

[0295] Receive a corresponding RS symbol from the second RS symbol set in the second frequency band; and

[0296] Perform signal measurement on the corresponding RS symbol received in the second frequency band.

[0297] 16. The method as described in Clause 15 further includes:

[0298] Generate a report indicating signal measurements for at least one RS symbol in a first RS symbol set and signal measurements for at least one RS symbol in a second RS symbol set; and

[0299] The report was transmitted to the base station.

[0300] 17. The method as described in Clause 15 or 16, wherein the first and second frequency bands are above the frequency of 24.25 GHz.

[0301] 18. The method of any of clauses 15 to 17, wherein the duration of an RS symbol in the first RS symbol set is greater than the duration of an RS symbol in the second RS symbol set.

[0302] 19. The method of any of Clauses 15 to 18, wherein the first frequency band and the second frequency band are separated in frequency.

[0303] 20. The method of any of clauses 15 to 19 further includes:

[0304] Determine the number of the first RS symbols;

[0305] Determine the number of second RS symbols;

[0306] Generate a request message indicating the number of the first RS symbols and the number of the second RS symbols; and

[0307] The request message is sent to the base station.

[0308] 21. The method of Clause 20, wherein determining the number of first RS symbols comprises: determining the number of first RS symbols based on at least one of the size or geometry of the first antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the subcarrier spacing in the first frequency band.

[0309] 22. The method of Clause 21, wherein determining the number of second RS symbols comprises: determining the number of second RS symbols based on at least one of the size or geometry of the second antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the subcarrier spacing in the second frequency band.

[0310] 23. A method for wireless communication by a user equipment (UE), comprising:

[0311] A message is received from the base station indicating a first reference signal (RS) symbol set and a second RS symbol set, wherein the first RS symbol set and the second RS symbol set overlap in time;

[0312] Beam sweep of the first transmitted beam set;

[0313] For each transmit beam in the first transmit beam set, a corresponding RS symbol from the first RS symbol set is transmitted in the first frequency band;

[0314] Beam sweeping second transmit beam set; and

[0315] For each transmit beam in the second transmit beam set, a corresponding RS symbol from the second RS symbol set is transmitted in the second frequency band.

[0316] 24. The method of Clause 23, wherein the first and second frequency bands are above the frequency of 24.25 GHz.

[0317] 25. The method of Clause 23 or 24, wherein the duration of an RS symbol in the first RS symbol set is greater than the duration of an RS symbol in the second RS symbol set.

[0318] 26. The method of any of clauses 23 to 25, wherein the first frequency band and the second frequency band are separated in frequency.

[0319] 27. The method of any of clauses 23 to 26 further includes:

[0320] Determine the number of the first RS symbols;

[0321] Determine the number of second RS symbols;

[0322] Generate a request message indicating the number of the first RS symbols and the number of the second RS symbols; and

[0323] The request message is sent to the base station.

[0324] 28. The method of Clause 27, wherein determining the number of first RS symbols comprises: determining the number of first RS symbols based on at least one of the size or geometry of the first antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the subcarrier spacing in the first frequency band.

[0325] 29. The method of Clause 28, wherein determining the number of second RS symbols comprises: determining the number of second RS symbols based on at least one of the size or geometry of the second antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the subcarrier spacing in the second frequency band.

[0326] 30. A method for wireless communication by a base station, comprising:

[0327] The beam sweeps across the first transmitted beam set in the first time interval;

[0328] For each transmit beam in the first transmit beam set, a corresponding reference signal (RS) symbol is transmitted in the first frequency band;

[0329] The beam sweeps across the second transmitted beam set in the second time interval, wherein the second time interval overlaps with the first time interval; and

[0330] For each transmit beam in the second transmit beam set, the corresponding RS symbol is transmitted in the second frequency band.

[0331] 31. The method as described in Clause 30 further includes:

[0332] Receive one or more reports from the user equipment (UE) indicating one or more signal measurements at the UE related to a first transmit beam set and one or more signal measurements at the UE related to a second transmit beam set;

[0333] Selecting a transmit beam from the first transmit beam set based on one or more signal measurements associated with the first transmit beam set; and

[0334] A transmit beam is selected from the second transmit beam set based on one or more signal measurements associated with the second transmit beam set.

[0335] 32. The method as described in Clause 31 further includes:

[0336] Using inter-band carrier aggregation in the first and second frequency bands to transmit data signals to the UE, wherein using inter-band carrier aggregation to transmit the data signals includes:

[0337] The first portion of the data signal is transmitted using a transmit beam selected from the first transmit beam set on one or more carriers in the first frequency band; and

[0338] The second portion of the data signal is transmitted using a transmit beam selected from the second transmit beam set on one or more carriers in the second frequency band.

[0339] 33. The method of any of clauses 30 to 32, wherein the first and second frequency bands are above the frequency of 24.25 GHz.

[0340] 34. The method of any of clauses 30 to 33, wherein the duration of each RS symbol in the first frequency band is greater than the duration of each RS symbol in the second frequency band.

[0341] 35. The method of any of clauses 30 to 34, wherein the first frequency band and the second frequency band are separated in frequency.

[0342] 36. A method for wireless communication by a user equipment (UE), comprising:

[0343] The beam sweeps across the first receiving beam set in the first time interval;

[0344] For each receive beam in the first receive beam set

[0345] Receive the corresponding reference signal (RS) symbols in the first frequency band; and

[0346] Perform signal measurement on the corresponding RS symbols received in the first frequency band;

[0347] The beam sweeps across the second receiving beam set in the second time interval, wherein the second time interval overlaps with the first time interval; and

[0348] For each receive beam in the second receive beam set

[0349] Receive the corresponding RS symbols in the second frequency band; and

[0350] Signal measurements are performed on the corresponding RS symbols received in the second frequency band.

[0351] 37. The method as described in Clause 36 further includes:

[0352] Selecting a receiving beam from the first receiving beam set based on signal measurements of the first receiving beam set; and

[0353] A receive beam is selected from the second receive beam set based on signal measurements for the second receive beam set.

[0354] 38. The method as described in Clause 37 further includes:

[0355] Using inter-band carrier aggregation in the first and second frequency bands to receive data signals from a base station, wherein using inter-band carrier aggregation to receive the data signals includes:

[0356] The first portion of the data signal is received using a receive beam selected from a first receive beam set on one or more carriers in the first frequency band; and

[0357] The second portion of the data signal is received using a receive beam selected from the second receive beam set on one or more carriers in the second frequency band.

[0358] 39. The method of any of clauses 36 to 38, wherein the first and second frequency bands are above the frequency of 24.25 GHz.

[0359] 40. The method of any of clauses 36 to 39, wherein the duration of each RS symbol in the first frequency band is greater than the duration of each RS symbol in the second frequency band.

[0360] 41. The method of any of clauses 36 to 40, wherein the first frequency band and the second frequency band are separated in frequency.

[0361] 42. An apparatus for wireless communication, comprising:

[0362] processor;

[0363] The memory coupled to the processor; and

[0364] Instructions, which are stored in the memory and can be executed by the processor, to cause the device to:

[0365] Assign a first reference signal (RS) symbol set for beam training in the first frequency band;

[0366] A second RS symbol set is assigned for beam training in the second frequency band, wherein the first RS symbol set and the second RS symbol set overlap in time.

[0367] Generate a message indicating the first RS symbol set and the second RS symbol set; and

[0368] The message is transmitted to the user equipment (UE).

[0369] 43. The apparatus of Clause 42, wherein the first and second frequency bands are above the frequency of 24.25 GHz.

[0370] 44. The apparatus of clause 42 or 43, wherein the duration of an RS symbol in the first RS symbol set is greater than the duration of an RS symbol in the second RS symbol set.

[0371] 45. An apparatus of any of clauses 42 to 44, wherein the first frequency band and the second frequency band are separated in frequency.

[0372] 46. ​​An apparatus as described in any of clauses 42 to 45, wherein:

[0373] The first RS symbol set is indicated by the symbol number of the first time slot; and

[0374] The second RS symbol set is indicated by the symbol number of the second time slot.

[0375] 47. An apparatus as described in any of clauses 42 to 46, wherein these instructions cause the apparatus to:

[0376] Beam sweep of the first transmitted beam set;

[0377] For each transmit beam in the first transmit beam set, a corresponding RS symbol from the first RS symbol set is transmitted in the first frequency band;

[0378] Beam sweeping second transmit beam set; and

[0379] For each transmit beam in the second transmit beam set, a corresponding RS symbol from the second RS symbol set is transmitted in the second frequency band.

[0380] 48. The device as described in Clause 47, wherein

[0381] Each transmitted beam in the first transmitted beam set points in a different direction, or each transmitted beam in the first transmitted beam set has a different beam pattern; and

[0382] Each transmit beam in the second transmit beam set points in a different direction, or each transmit beam in the second transmit beam set has a different beam pattern.

[0383] 49. The apparatus of clause 47 or 48, wherein at least one transmit beam in the second transmit beam set has a beamwidth narrower than each transmit beam in the first transmit beam set.

[0384] 50. An apparatus as described in any of clauses 42 to 46, wherein these instructions cause the apparatus to:

[0385] Beam sweep of the first receiving beam set;

[0386] For each receive beam in the first receive beam set

[0387] Receive a corresponding RS symbol from the first RS symbol set in the first frequency band; and

[0388] Perform signal measurement on the corresponding RS symbol received in the first frequency band;

[0389] Beam sweeping second receiving beam set; and

[0390] For each receive beam in the second receive beam set

[0391] Receive a corresponding RS symbol from the second RS symbol set in the second frequency band; and

[0392] Perform signal measurement on the corresponding RS symbol received in the second frequency band.

[0393] 51. The device as described in Clause 50, wherein

[0394] Each receiving beam in the first receiving beam set points in a different direction, or each receiving beam in the first receiving beam set has a different beam pattern; and

[0395] Each receiving beam in the second receiving beam set points in a different direction, or each receiving beam in the second receiving beam set has a different beam pattern.

[0396] 52. A device as described in Clause 50 or 51, wherein these instructions cause the device to:

[0397] Generate a report indicating signal measurements for at least one RS symbol in a first RS symbol set and signal measurements for at least one RS symbol in a second RS symbol set; and

[0398] The report is transmitted to the UE.

[0399] 53. An apparatus as described in any of Clauses 50 to 52, wherein each signal measurement includes a reference signal received power (RSRP) measurement, a reference signal received quality (RSRQ) measurement, a signal-to-interference plus-noise ratio (SINR) measurement, a signal-to-noise ratio (SNR) measurement, or a received signal strength indicator (RSSI) measurement.

[0400] 54. An apparatus as described in any of clauses 42 to 53, wherein these instructions cause the apparatus to:

[0401] Receive a message from the UE, wherein the message from the UE indicates the number of first RS symbols and the number of second RS symbols;

[0402] The first RS symbol set is allocated based on the number of first RS symbols; and

[0403] The second RS symbol set is allocated based on the number of second RS symbols.

[0404] 55. The device as described in Clause 54, wherein

[0405] The number of RS symbols in the first RS symbol set is equal to the number of RS symbols in the first RS symbol set; and

[0406] The number of RS symbols in the second RS symbol set is equal to the number of RS symbols in the second RS symbol set.

[0407] 56. An apparatus for wireless communication, comprising:

[0408] processor;

[0409] The memory coupled to the processor; and

[0410] Instructions, which are stored in the memory and can be executed by the processor, to cause the device to:

[0411] A message is received from the base station indicating a first reference signal (RS) symbol set and a second RS symbol set, wherein the first RS symbol set and the second RS symbol set overlap in time;

[0412] Beam sweep of the first receiving beam set;

[0413] For each receive beam in the first receive beam set

[0414] Receive a corresponding RS symbol from the first RS symbol set in the first frequency band; and

[0415] Perform signal measurement on a corresponding RS symbol received in the first frequency band; and

[0416] Beam sweeping second receiving beam set; and

[0417] For each receive beam in the second receive beam set

[0418] Receive a corresponding RS symbol from the second RS symbol set in the second frequency band; and

[0419] Perform signal measurement on the corresponding RS symbol received in the second frequency band.

[0420] 57. An apparatus as described in Clause 56, wherein these instructions cause the apparatus to:

[0421] Generate a report indicating signal measurements for at least one RS symbol in a first RS symbol set and signal measurements for at least one RS symbol in a second RS symbol set; and

[0422] The report was transmitted to the base station.

[0423] 58. The apparatus of clauses 56 or 57, wherein the first and second frequency bands are above the frequency of 24.25 GHz.

[0424] 59. An apparatus of any of clauses 56 to 58, wherein the duration of an RS symbol in the first RS symbol set is greater than the duration of an RS symbol in the second RS symbol set.

[0425] 60. An apparatus of any of clauses 56 to 59, wherein the first frequency band and the second frequency band are separated in frequency.

[0426] 61. An apparatus as described in any of clauses 56 to 60, wherein these instructions cause the apparatus to:

[0427] Determine the number of the first RS symbols;

[0428] Determine the number of second RS symbols;

[0429] Generate a request message indicating the number of the first RS symbols and the number of the second RS symbols; and

[0430] The request message is sent to the base station.

[0431] 62. An apparatus as described in Clause 61, wherein these instructions cause the apparatus to:

[0432] The number of first RS symbols is determined based on at least one of the following: the size or geometry of the first antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the subcarrier spacing in the first frequency band.

[0433] 63. An apparatus as described in Clause 62, wherein these instructions cause the apparatus to:

[0434] The number of second RS symbols is determined based on at least one of the following: the size or geometry of the second antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the subcarrier spacing in the second frequency band.

[0435] 64. An apparatus for wireless communication, comprising:

[0436] processor;

[0437] The memory coupled to the processor; and

[0438] Instructions, which are stored in the memory and can be executed by the processor, to cause the device to:

[0439] A message is received from the base station indicating a first reference signal (RS) symbol set and a second RS symbol set, wherein the first RS symbol set and the second RS symbol set overlap in time;

[0440] Beam sweep of the first transmitted beam set;

[0441] For each transmit beam in the first transmit beam set, a corresponding RS symbol from the first RS symbol set is transmitted in the first frequency band; and

[0442] Beam sweeping second transmit beam set; and

[0443] For each transmit beam in the second transmit beam set, a corresponding RS symbol from the second RS symbol set is transmitted in the second frequency band.

[0444] 65. The apparatus of Clause 64, wherein the first and second frequency bands are above the frequency of 24.25 GHz.

[0445] 66. The apparatus of clause 64 or 65, wherein the duration of an RS symbol in the first RS symbol set is greater than the duration of an RS symbol in the second RS symbol set.

[0446] 67. An apparatus of any of clauses 64 to 66, wherein the first frequency band and the second frequency band are separated in frequency.

[0447] 68. An apparatus as described in any of clauses 64 to 67, wherein these instructions cause the apparatus to:

[0448] Determine the number of the first RS symbols;

[0449] Determine the number of second RS symbols;

[0450] Generate a request message indicating the number of the first RS symbols and the number of the second RS symbols; and

[0451] The request message is sent to the base station.

[0452] 69. An apparatus as described in Clause 68, wherein these instructions cause the apparatus to:

[0453] The number of first RS symbols is determined based on at least one of the following: the size or geometry of the first antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the subcarrier spacing in the first frequency band.

[0454] 70. An apparatus as described in Clause 69, wherein these instructions cause the apparatus to:

[0455] The number of second RS symbols is determined based on at least one of the following: the size or geometry of the second antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the subcarrier spacing in the second frequency band.

[0456] 71. An apparatus for wireless communication, comprising:

[0457] processor;

[0458] The memory coupled to the processor; and

[0459] Instructions, which are stored in the memory and can be executed by the processor, to cause the device to:

[0460] The beam sweeps across the first transmitted beam set in the first time interval;

[0461] For each transmit beam in the first transmit beam set, a corresponding reference signal (RS) symbol is transmitted in the first frequency band;

[0462] The beam sweeps across the second transmitted beam set in the second time interval, wherein the second time interval overlaps with the first time interval; and

[0463] For each transmit beam in the second transmit beam set, the corresponding RS symbol is transmitted in the second frequency band.

[0464] 72. An apparatus as described in Clause 71, wherein these instructions cause the apparatus to:

[0465] Receive one or more reports from the user equipment (UE) indicating one or more signal measurements at the UE related to a first transmit beam set and one or more signal measurements at the UE related to a second transmit beam set;

[0466] Selecting a transmit beam from the first transmit beam set based on one or more signal measurements associated with the first transmit beam set; and

[0467] A transmit beam is selected from the second transmit beam set based on one or more signal measurements associated with the second transmit beam set.

[0468] 73. An apparatus as described in Clause 72, wherein these instructions cause the apparatus to:

[0469] Using inter-band carrier aggregation in the first and second frequency bands to transmit data signals to the UE, wherein using inter-band carrier aggregation to transmit the data signals includes:

[0470] A first portion of a data signal is transmitted using a transmit beam selected from a first transmit beam set on one or more carriers in a first frequency band; and

[0471] The second portion of the data signal is transmitted using a transmit beam selected from the second transmit beam set on one or more carriers in the second frequency band.

[0472] 74. An apparatus of any of clauses 71 to 73, wherein the first and second frequency bands are above the frequency of 24.25 GHz.

[0473] 75. An apparatus of any of clauses 71 to 74, wherein the duration of each RS symbol in the first frequency band is greater than the duration of each RS symbol in the second frequency band.

[0474] 76. An apparatus of any of clauses 71 to 75, wherein the first frequency band and the second frequency band are separated in frequency.

[0475] 77. An apparatus for wireless communication, comprising:

[0476] processor;

[0477] The memory coupled to the processor; and

[0478] Instructions, which are stored in the memory and can be executed by the processor, to cause the device to:

[0479] The beam sweeps across the first receiving beam set in the first time interval;

[0480] For each receive beam in the first receive beam set

[0481] Receive the corresponding reference signal (RS) symbols in the first frequency band; and

[0482] Perform signal measurement on the corresponding RS symbols received in the first frequency band;

[0483] The beam sweeps across the second receiving beam set in the second time interval, wherein the second time interval overlaps with the first time interval; and

[0484] For each receive beam in the second receive beam set

[0485] Receive the corresponding RS symbols in the second frequency band; and

[0486] Signal measurements are performed on the corresponding RS symbols received in the second frequency band.

[0487] 78. An apparatus as described in Clause 77, wherein these instructions cause the apparatus to:

[0488] Selecting a receiving beam from the first receiving beam set based on signal measurements of the first receiving beam set; and

[0489] A receive beam is selected from the second receive beam set based on signal measurements for the second receive beam set.

[0490] 79. An apparatus as described in Clause 78, wherein these instructions cause the apparatus to:

[0491] Using inter-band carrier aggregation in the first and second frequency bands to receive data signals from a base station, wherein using inter-band carrier aggregation to receive the data signals includes:

[0492] The first portion of the data signal is received using a receive beam selected from a first receive beam set on one or more carriers in the first frequency band; and

[0493] The second portion of the data signal is received using a receive beam selected from the second receive beam set on one or more carriers in the second frequency band.

[0494] 80. An apparatus of any of the provisions 77 to 79, wherein the first and second frequency bands are above the frequency of 24.25 GHz.

[0495] 81. An apparatus of any of the provisions 77 to 80, wherein the duration of each RS symbol in the first frequency band is greater than the duration of each RS symbol in the second frequency band.

[0496] 82. An apparatus of any of the provisions 77 to 81, wherein the first frequency band and the second frequency band are separated in frequency.

[0497] 83. A device for wireless communication, comprising:

[0498] A means for allocating a first set of reference signal (RS) symbols for beam training in a first frequency band;

[0499] A means for allocating a second RS symbol set for beam training in a second frequency band, wherein the first RS symbol set and the second RS symbol set overlap in time;

[0500] A means for generating a message indicating a first RS symbol set and a second RS symbol set; and

[0501] A means for transmitting the message to user equipment (UE).

[0502] 84. The device as described in Clause 83, wherein the first and second frequency bands are above the frequency of 24.25 GHz.

[0503] 85. The device as described in Clause 83 or 84, wherein the duration of an RS symbol in the first RS symbol set is greater than the duration of an RS symbol in the second RS symbol set.

[0504] 86. The equipment of any of clauses 83 to 85, wherein the first frequency band and the second frequency band are separated in frequency.

[0505] 87. Equipment as specified in any of Clauses 83 to 86, wherein:

[0506] The first RS symbol set is indicated by the symbol number of the first time slot; and

[0507] The second RS symbol set is indicated by the symbol number of the second time slot.

[0508] 88. Equipment as described in any of clauses 83 to 87, further comprising:

[0509] Device for beam sweeping the first transmitted beam set;

[0510] A means for transmitting a corresponding RS symbol from a first RS symbol set in a first frequency band for each of the first transmit beams in the first transmit beam set.

[0511] Device for beam sweeping a second transmit beam set; and

[0512] A means for transmitting a corresponding RS symbol from a second RS symbol set in a second frequency band for each transmit beam in a second transmit beam set.

[0513] 89. Equipment as described in Clause 88, wherein

[0514] Each transmitted beam in the first transmitted beam set points in a different direction, or each transmitted beam in the first transmitted beam set has a different beam pattern; and

[0515] Each transmit beam in the second transmit beam set points in a different direction, or each transmit beam in the second transmit beam set has a different beam pattern.

[0516] 90. The apparatus of clause 88 or 89, wherein at least one transmit beam in the second transmit beam set has a beamwidth narrower than each transmit beam in the first transmit beam set.

[0517] 91. The equipment of any of clauses 83 to 87 further includes:

[0518] Device for beam sweeping of the first receiving beam set;

[0519] A means for performing the following operations for each receive beam in a first receive beam set:

[0520] Receive a corresponding RS symbol from the first RS symbol set in the first frequency band; and

[0521] Perform signal measurement on the corresponding RS symbol received in the first frequency band;

[0522] A device for beam sweeping a second receiving beam set; and

[0523] A means for performing the following operations for each receive beam in the second receive beam set:

[0524] Receive a corresponding RS symbol from the second RS symbol set in the second frequency band; and

[0525] Perform signal measurement on the corresponding RS symbol received in the second frequency band.

[0526] 92. Equipment as described in Clause 91, wherein

[0527] Each receiving beam in the first receiving beam set points in a different direction, or each receiving beam in the first receiving beam set has a different beam pattern; and

[0528] Each receiving beam in the second receiving beam set points in a different direction, or each receiving beam in the second receiving beam set has a different beam pattern.

[0529] 93. Equipment as described in Clauses 91 or 92, further comprising:

[0530] A means for generating a report indicating signal measurements for at least one RS symbol in a first RS symbol set and signal measurements for at least one RS symbol in a second RS symbol set; and

[0531] A device used to transmit the report to the UE.

[0532] 94. The equipment of any of Clauses 91 to 93, wherein each signal measurement includes a reference signal received power (RSRP) measurement, a reference signal received quality (RSRQ) measurement, a signal-to-interference plus-noise ratio (SINR) measurement, a signal-to-noise ratio (SNR) measurement, or a received signal strength indicator (RSSI) measurement.

[0533] 95. The equipment of any of clauses 83 to 94 further includes:

[0534] A means for receiving messages from the UE, wherein the message from the UE indicates a first RS symbol number and a second RS symbol number;

[0535] The means for allocating the first RS symbol set includes: means for allocating the first RS symbol set based on the number of first RS symbols; and

[0536] The means for allocating the second RS symbol set includes: means for allocating the second RS symbol set based on the number of second RS symbols.

[0537] 96. Equipment as described in Clause 95, wherein

[0538] The number of RS symbols in the first RS symbol set is equal to the number of RS symbols in the first RS symbol set; and

[0539] The number of RS symbols in the second RS symbol set is equal to the number of RS symbols in the second RS symbol set.

[0540] 97. A device for wireless communication, comprising:

[0541] A means for receiving a message from a base station, the message indicating a first reference signal (RS) symbol set and a second RS symbol set, wherein the first RS symbol set and the second RS symbol set overlap in time;

[0542] Device for beam sweeping of the first receiving beam set;

[0543] A means for performing the following operations for each receive beam in a first receive beam set:

[0544] Receive a corresponding RS symbol from the first RS symbol set in the first frequency band; and

[0545] Perform signal measurement on a corresponding RS symbol received in the first frequency band; and

[0546] A device for beam sweeping a second receiving beam set; and

[0547] A means for performing the following operations for each receive beam in the second receive beam set:

[0548] Receive a corresponding RS symbol from the second RS symbol set in the second frequency band; and

[0549] Perform signal measurement on the corresponding RS symbol received in the second frequency band.

[0550] 98. Equipment as described in Clause 97, further comprising:

[0551] A means for generating a report indicating signal measurements for at least one RS symbol in a first RS symbol set and signal measurements for at least one RS symbol in a second RS symbol set; and

[0552] A device for transmitting the report to the base station.

[0553] 99. Equipment as described in Clauses 97 or 98, wherein the first and second frequency bands are above the frequency of 24.25 GHz.

[0554] 100. The device of any of the provisions 97 to 99, wherein the duration of an RS symbol in the first RS symbol set is greater than the duration of an RS symbol in the second RS symbol set.

[0555] 101. The apparatus of any of the provisions 97 to 100, wherein the first frequency band and the second frequency band are separated in frequency.

[0556] 102. The equipment of any of the provisions 97 to 101 further includes:

[0557] A means for determining the number of first RS symbols;

[0558] A means for determining the number of second RS symbols;

[0559] A means for generating a request message indicating the number of first RS symbols and the number of second RS symbols; and

[0560] A device for transmitting the request message to a base station.

[0561] 103. The apparatus of Clause 102, wherein the means for determining the first number of RS symbols includes: means for determining the first number of RS symbols based on at least one of the size or geometry of the first antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the subcarrier spacing in the first frequency band.

[0562] 104. The apparatus of Clause 103, wherein the means for determining the number of second RS symbols comprises: means for determining the number of second RS symbols based on at least one of the size or geometry of the second antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the subcarrier spacing in the second frequency band.

[0563] 105. A device for wireless communication, comprising:

[0564] A means for receiving a message from a base station, the message indicating a first reference signal (RS) symbol set and a second RS symbol set, wherein the first RS symbol set and the second RS symbol set overlap in time;

[0565] Device for beam sweeping the first transmitted beam set;

[0566] A means for transmitting a corresponding RS symbol from a first RS symbol set in a first frequency band for each of the first transmit beams in the first transmit beam set.

[0567] Device for beam sweeping a second transmit beam set; and

[0568] A means for transmitting a corresponding RS symbol from a second RS symbol set in a second frequency band for each transmit beam in a second transmit beam set.

[0569] 106. The device as described in Clause 105, wherein the first and second frequency bands are above the frequency of 24.25 GHz.

[0570] 107. The device as described in Clause 105 or 106, wherein the duration of an RS symbol in the first RS symbol set is greater than the duration of an RS symbol in the second RS symbol set.

[0571] 108. The equipment of any of clauses 105 to 107, wherein the first frequency band and the second frequency band are separated in frequency.

[0572] 109. The equipment of any of clauses 105 to 108 further includes:

[0573] A means for determining the number of first RS symbols;

[0574] A means for determining the number of second RS symbols;

[0575] A means for generating a request message indicating the number of first RS symbols and the number of second RS symbols; and

[0576] A device for transmitting the request message to a base station.

[0577] 110. The apparatus of Clause 109, wherein the means for determining the first number of RS symbols includes: means for determining the first number of RS symbols based on at least one of the size or geometry of the first antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the subcarrier spacing in the first frequency band.

[0578] 111. The apparatus of Clause 110, wherein the means for determining the number of second RS symbols comprises: means for determining the number of second RS symbols based on at least one of the size or geometry of the second antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the subcarrier spacing in the second frequency band.

[0579] 112. A device for wireless communication, comprising:

[0580] A device for beam sweeping a first transmitted beam set in a first time interval;

[0581] A means for transmitting a corresponding reference signal (RS) symbol in a first frequency band for each transmit beam in a first transmit beam set;

[0582] A means for beam sweeping a second transmitted beam set over a second time interval, wherein the second time interval overlaps with a first time interval; and

[0583] A means for transmitting the corresponding RS symbol in a second frequency band for each transmit beam in a second transmit beam set.

[0584] 113. The equipment as described in Clause 112 further includes:

[0585] A means for receiving one or more reports from a user equipment (UE), the one or more reports indicating one or more signal measurements at the UE in relation to a first transmit beam set and one or more signal measurements at the UE in relation to a second transmit beam set;

[0586] A means for selecting a transmit beam from a first transmit beam set based on one or more signal measurements associated with the first transmit beam set; and

[0587] A means for selecting a transmission beam from a second transmission beam set based on one or more signal measurements associated with the second transmission beam set.

[0588] 114. The equipment as described in Clause 113 further includes:

[0589] An apparatus for transmitting data signals to a UE using inter-band carrier aggregation in a first frequency band and a second frequency band, wherein the apparatus for transmitting the data signals using inter-band carrier aggregation includes:

[0590] A means for transmitting a first portion of a data signal using a transmit beam selected from a first transmit beam set on one or more carriers in a first frequency band; and

[0591] A means for transmitting a second portion of the data signal using a transmit beam selected from a second transmit beam set on one or more carriers in a second frequency band.

[0592] 115. The device of any of the provisions 112 to 114, wherein the first and second frequency bands are above the frequency of 24.25 GHz.

[0593] 116. The device of any of clauses 112 to 115, wherein the duration of each RS symbol in the first frequency band is greater than the duration of each RS symbol in the second frequency band.

[0594] 117. The apparatus of any of clauses 112 to 116, wherein the first frequency band and the second frequency band are separated in frequency.

[0595] 118. A device for wireless communication, comprising:

[0596] A device for beam sweeping a first receiving beam set in a first time interval;

[0597] A means for performing the following operations for each receive beam in a first receive beam set:

[0598] Receive the corresponding reference signal (RS) symbols in the first frequency band; and

[0599] Perform signal measurement on the corresponding RS symbols received in the first frequency band;

[0600] A means for beam-scanning a second receiving beam set in a second time interval, wherein the second time interval overlaps with a first time interval; and

[0601] A means for performing the following operations for each receive beam in the second receive beam set:

[0602] Receive the corresponding RS symbols in the second frequency band; and

[0603] Signal measurements are performed on the corresponding RS symbols received in the second frequency band.

[0604] 119. The equipment as described in Clause 118 further includes:

[0605] A means for selecting a receiving beam from a first receiving beam set based on signal measurements for that first receiving beam set; and

[0606] A means for selecting a receiving beam from a second receiving beam set based on signal measurements for that second receiving beam set.

[0607] 120. The equipment as described in Clause 119 further includes:

[0608] An apparatus for receiving a data signal from a base station using inter-band carrier aggregation in a first frequency band and a second frequency band, wherein the apparatus for receiving the data signal using the inter-band carrier aggregation includes:

[0609] A means for receiving a first portion of a data signal using a receive beam selected from a first receive beam set on one or more carriers in a first frequency band; and

[0610] A means for receiving a second portion of a data signal using a receive beam selected from a second set of receive beams on one or more carriers in a second frequency band.

[0611] 121. The device of any of the provisions 118 to 120, wherein the first and second frequency bands are above the frequency of 24.25 GHz.

[0612] 122. The device of any of the provisions 118 to 121, wherein the duration of each RS symbol in the first frequency band is greater than the duration of each RS symbol in the second frequency band.

[0613] 123. The equipment of any of the provisions 118 to 122, wherein the first frequency band and the second frequency band are separated in frequency.

[0614] 124. The method of any of Articles 15 to 22, wherein:

[0615] Each receiving beam in the first receiving beam set points in a different direction, or each receiving beam in the first receiving beam set has a different beam pattern; and

[0616] Each receiving beam in the second receiving beam set points in a different direction, or each receiving beam in the second receiving beam set has a different beam pattern.

[0617] 125. The method of any of Articles 23 to 29, wherein:

[0618] Each transmitted beam in the first transmitted beam set points in a different direction, or each transmitted beam in the first transmitted beam set has a different beam pattern; and

[0619] Each transmit beam in the second transmit beam set points in a different direction, or each transmit beam in the second transmit beam set has a different beam pattern.

[0620] 126. The method of any of Articles 30 to 35, wherein:

[0621] Each transmitted beam in the first transmitted beam set points in a different direction, or each transmitted beam in the first transmitted beam set has a different beam pattern; and

[0622] Each transmit beam in the second transmit beam set points in a different direction, or each transmit beam in the second transmit beam set has a different beam pattern.

[0623] 127. The method of any of Articles 36 to 41, wherein:

[0624] Each receiving beam in the first receiving beam set points in a different direction, or each receiving beam in the first receiving beam set has a different beam pattern; and

[0625] Each receiving beam in the second receiving beam set points in a different direction, or each receiving beam in the second receiving beam set has a different beam pattern.

[0626] 128. An apparatus as described in any of clauses 56 to 63, wherein:

[0627] Each receiving beam in the first receiving beam set points in a different direction, or each receiving beam in the first receiving beam set has a different beam pattern; and

[0628] Each receiving beam in the second receiving beam set points in a different direction, or each receiving beam in the second receiving beam set has a different beam pattern.

[0629] 129. An apparatus as described in any of clauses 64 to 70, wherein:

[0630] Each transmitted beam in the first transmitted beam set points in a different direction, or each transmitted beam in the first transmitted beam set has a different beam pattern; and

[0631] Each transmit beam in the second transmit beam set points in a different direction, or each transmit beam in the second transmit beam set has a different beam pattern.

[0632] 130. An apparatus as described in any of clauses 71 to 76, wherein:

[0633] Each transmitted beam in the first transmitted beam set points in a different direction, or each transmitted beam in the first transmitted beam set has a different beam pattern; and

[0634] Each transmit beam in the second transmit beam set points in a different direction, or each transmit beam in the second transmit beam set has a different beam pattern.

[0635] 131. An apparatus as described in any of clauses 77 to 82, wherein:

[0636] Each receiving beam in the first receiving beam set points in a different direction, or each receiving beam in the first receiving beam set has a different beam pattern; and

[0637] Each receiving beam in the second receiving beam set points in a different direction, or each receiving beam in the second receiving beam set has a different beam pattern.

[0638] 132. Equipment of any of the provisions 97 to 104, wherein:

[0639] Each receiving beam in the first receiving beam set points in a different direction, or each receiving beam in the first receiving beam set has a different beam pattern; and

[0640] Each receiving beam in the second receiving beam set points in a different direction, or each receiving beam in the second receiving beam set has a different beam pattern.

[0641] 133. Equipment of any of the provisions 105 to 111, wherein:

[0642] Each transmitted beam in the first transmitted beam set points in a different direction, or each transmitted beam in the first transmitted beam set has a different beam pattern; and

[0643] Each transmit beam in the second transmit beam set points in a different direction, or each transmit beam in the second transmit beam set has a different beam pattern.

[0644] 134. Equipment of any of the provisions 112 to 117, wherein:

[0645] Each transmitted beam in the first transmitted beam set points in a different direction, or each transmitted beam in the first transmitted beam set has a different beam pattern; and

[0646] Each transmit beam in the second transmit beam set points in a different direction, or each transmit beam in the second transmit beam set has a different beam pattern.

[0647] 135. Equipment of any of the provisions 118 to 123, wherein:

[0648] Each receiving beam in the first receiving beam set points in a different direction, or each receiving beam in the first receiving beam set has a different beam pattern; and

[0649] Each receiving beam in the second receiving beam set points in a different direction, or each receiving beam in the second receiving beam set has a different beam pattern.

[0650] It will be understood that this disclosure is not limited to the exemplary terms used to describe various aspects of this disclosure. For example, beam sweeping may also be referred to as beam scanning or another term. Device 2100 may also be referred to as an apparatus or another term.

[0651] It will be understood that, unless otherwise stated, sweeping a set of beams does not require sweeping the beams in that set in a particular order or direction.

[0652] The use of designations such as "first" and "second" to refer to elements in this document generally does not restrict the number or order of those elements. Rather, these designations are used as a convenient way to distinguish two or more elements or instances of elements. Thus, a reference to the first element and the second element does not imply that only two elements can be used, or that the first element must precede the second element.

[0653] Within this disclosure, the term “exemplary” is used to mean “serving as an example, instance, or illustration.” Any implementation or aspect described herein as “exemplary” is not necessarily to be construed as superior to or better than other aspects of this disclosure. Similarly, the term “aspect” does not require that all aspects of this disclosure include the features, advantages, or modes of operation discussed. The term “coupling” is used herein to refer to direct or indirect electrical coupling between two structures. As used herein (including in the claims), the word “or” used in an enumeration of items (e.g., an enumeration of items accompanied by phrases such as “at least one of” or “one or more of”) indicates an inclusive enumeration such that an enumeration of, for example, at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Likewise, as used herein, the phrase “based on” should not be construed as referencing a closed set of conditions. For example, an exemplary step described as “based on condition A” may be based on both condition A and condition B without departing from the scope of this disclosure. In other words, as used herein, the phrase “based on” should be interpreted in the same manner as the phrase “at least partially based on.”

[0654] The prior description of this disclosure is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other variations without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not intended to be limited to the examples described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication by a user equipment (UE), comprising: Receive a message from the access point, the message indicating a first reference signal (RS) symbol set and a second RS symbol set, wherein the first RS symbol set and the second RS symbol set overlap in time; The first antenna array of the UE is used to beam sweep the first receive beam set; For each receive beam in the first receive beam set Receive a corresponding RS symbol from the first RS symbol set in the first frequency band; and Perform signal measurement on a corresponding RS symbol received in the first frequency band; And using the second antenna array of the UE to beam sweep the second receive beam set; as well as For each receive beam in the second receive beam set Receive a corresponding RS symbol from the second RS symbol set in the second frequency band; and Perform signal measurement on a corresponding RS symbol received in the second frequency band.

2. The method of claim 1, further comprising: Generate a report indicating signal measurements for at least one RS symbol in the first RS symbol set and for at least one RS symbol in the second RS symbol set; as well as The report is transmitted to the access point.

3. The method of claim 1, wherein the first frequency band and the second frequency band are higher than 24.25 GHz.

4. The method as described in claim 1, wherein the duration of an RS symbol in the first RS symbol set is greater than the duration of an RS symbol in the second RS symbol set.

5. The method of claim 1, wherein the first frequency band and the second frequency band are separated in frequency.

6. The method of claim 1, further comprising: Determine the number of the first RS symbols; Determine the number of second RS symbols; Generate a request message indicating the number of the first RS symbols and the number of the second RS symbols; as well as The request message is transmitted to the access point.

7. The method of claim 6, wherein determining the number of the first RS symbols comprises: The number of the first RS symbols is determined based on at least one of the following: the size or geometry of the first antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the subcarrier spacing in the first frequency band.

8. The method of claim 7, wherein determining the number of the second RS symbols comprises: The number of the second RS symbols is determined based on at least one of the following: the size or geometry of the second antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the subcarrier spacing in the second frequency band.

9. A method for wireless communication by a user equipment (UE), comprising: Receive a message from the access point, the message indicating a first reference signal (RS) symbol set and a second RS symbol set, wherein the first RS symbol set and the second RS symbol set overlap in time; The first antenna array of the UE is used to beam sweep the first transmit beam set; For each transmit beam in the first transmit beam set, transmit a corresponding RS symbol from the first RS symbol set in the first frequency band; The second antenna array of the UE is used to beam sweep the second transmit beam set; as well as For each transmit beam in the second transmit beam set, a corresponding RS symbol from the second RS symbol set is transmitted in the second frequency band.

10. The method of claim 9, wherein the first frequency band and the second frequency band are higher than 24.25 GHz.

11. The method of claim 9, wherein the duration of an RS symbol in the first RS symbol set is greater than the duration of an RS symbol in the second RS symbol set.

12. The method of claim 9, wherein the first frequency band and the second frequency band are frequency-separated.

13. The method of claim 9, further comprising: Determine the number of the first RS symbols; Determine the number of second RS symbols; Generate a request message indicating the number of the first RS symbols and the number of the second RS symbols; as well as The request message is transmitted to the access point.

14. The method of claim 13, wherein determining the number of the first RS symbols comprises: The number of the first RS symbols is determined based on at least one of the following: the size or geometry of the first antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the subcarrier spacing in the first frequency band.

15. The method of claim 14, wherein determining the number of the second RS symbols comprises: The number of the second RS symbols is determined based on at least one of the following: the size or geometry of the second antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the carrier spacing in the second frequency band.

16. A method for wireless communication by a user equipment (UE), comprising: The first antenna array of the UE is used to beam sweep the first received beam set during the first time interval; For each receive beam in the first receive beam set Receive the corresponding reference signal (RS) symbols in the first frequency band; as well as Perform signal measurement on the corresponding RS symbols received in the first frequency band; The second antenna array of the UE is used to beam sweep a second received beam set in a second time interval, wherein the second time interval overlaps with the first time interval; as well as For each receive beam in the second receive beam set Receive the corresponding RS symbols in the second frequency band; and Signal measurements are performed on the corresponding RS symbols received in the second frequency band.

17. The method of claim 16, further comprising: A receiving beam is selected from the first receiving beam set based on signal measurements for the first receiving beam set; as well as A receive beam is selected from the second receive beam set based on signal measurements for the second receive beam set.

18. The method of claim 17, further comprising: Using inter-band carrier aggregation to receive data signals from an access point in the first and second frequency bands, wherein using the inter-band carrier aggregation to receive the data signals includes: A first portion of the data signal is received using a receive beam selected from the first receive beam set on one or more carriers in the first frequency band; and The second portion of the data signal is received using a receive beam selected from the second receive beam set on one or more carriers in the second frequency band.

19. The method of claim 16, wherein the first frequency band and the second frequency band are higher than 24.25 GHz.

20. The method of claim 16, wherein the duration of each RS symbol in the first frequency band is greater than the duration of each RS symbol in the second frequency band.

21. The method of claim 16, wherein the first frequency band and the second frequency band are frequency-separated.

22. A user equipment (UE) for wireless communication, comprising: Memory; as well as One or more processors are coupled to the memory and configured to: Receive a message from the access point, the message indicating a first reference signal (RS) symbol set and a second RS symbol set, wherein the first RS symbol set and the second RS symbol set overlap in time; The first antenna array of the UE is used to beam sweep the first receive beam set; For each receive beam in the first receive beam set Receive a corresponding RS symbol from the first RS symbol set in the first frequency band; And perform signal measurement on the corresponding RS symbol received in the first frequency band; as well as The second antenna array of the UE is used to beam sweep the second receive beam set; as well as For each receive beam in the second receive beam set The corresponding RS symbol in the second RS symbol set is received in the second frequency band; and a signal measurement is performed on the corresponding RS symbol received in the second frequency band.

23. The UE of claim 22, wherein the one or more processors are further configured to: Generate a report indicating signal measurements for at least one RS symbol in the first RS symbol set and signal measurements for at least one RS symbol in the second RS symbol set; and The report is transmitted to the access point.

24. The UE of claim 22, wherein the first frequency band and the second frequency band are higher than the frequency 24.25 GHz.

25. The UE of claim 22, wherein the duration of an RS symbol in the first RS symbol set is greater than the duration of an RS symbol in the second RS symbol set.

26. The UE of claim 22, wherein the first frequency band and the second frequency band are frequency-separated.

27. The UE of claim 22, wherein the one or more processors are further configured to: Determine the number of the first RS symbols; Determine the number of second RS symbols; Generate a request message indicating the number of the first RS symbols and the number of the second RS symbols; and The request message is transmitted to the access point.

28. The UE of claim 27, wherein, in order to determine the first RS symbol number, the one or more processors are configured to determine the first RS symbol number based on at least one of the size or geometry of the first antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the subcarrier spacing in the first frequency band.

29. The UE of claim 28, wherein, in order to determine the second RS symbol number, the one or more processors are configured to determine the second RS symbol number based on at least one of the size or geometry of the second antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the subcarrier spacing in the second frequency band.

30. A user equipment (UE) for wireless communication, comprising: Memory; as well as One or more processors are coupled to the memory and configured to: Receive a message from the access point, the message indicating a first reference signal (RS) symbol set and a second RS symbol set, wherein the first RS symbol set and the second RS symbol set overlap in time; The first antenna array of the UE is used to beam sweep the first transmit beam set; For each transmit beam in the first transmit beam set, transmit a corresponding RS symbol from the first RS symbol set in the first frequency band; The second antenna array of the UE is used to beam sweep the second transmit beam set; as well as For each transmit beam in the second transmit beam set, a corresponding RS symbol from the second RS symbol set is transmitted in the second frequency band.

31. The UE of claim 30, wherein the first frequency band and the second frequency band are above 24.25 GHz.

32. The UE of claim 30, wherein the duration of an RS symbol in the first RS symbol set is greater than the duration of an RS symbol in the second RS symbol set.

33. The UE of claim 30, wherein the first frequency band and the second frequency band are frequency-separated.

34. The UE of claim 30, wherein the one or more processors are further configured to: Determine the number of the first RS symbols; Determine the number of second RS symbols; Generate a request message indicating the number of the first RS symbols and the number of the second RS symbols; and The request message is transmitted to the access point.

35. The UE of claim 34, wherein, in order to determine the first RS symbol number, the one or more processors are configured to determine the first RS symbol number based on at least one of the size or geometry of the first antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the subcarrier spacing in the first frequency band.

36. The UE of claim 35, wherein, in order to determine the second RS symbol number, the one or more processors are configured to determine the second RS symbol number based on at least one of the size or geometry of the second antenna array of the UE, the power level of the UE, the temperature of the UE, the mobility of the UE, or the carrier spacing in the second frequency band.

37. A user equipment (UE) for wireless communication, comprising: Memory; as well as One or more processors are coupled to the memory and configured to: The first antenna array of the UE is used to beam sweep the first received beam set during the first time interval; For each receive beam in the first receive beam set Receive the corresponding reference signal (RS) symbols in the first frequency band; as well as Perform signal measurement on the corresponding RS symbols received in the first frequency band; The second antenna array of the UE is used to beam sweep a second received beam set in a second time interval, wherein the second time interval overlaps with the first time interval; as well as For each receive beam in the second receive beam set Receive the corresponding RS symbols in the second frequency band; and Signal measurements are performed on the corresponding RS symbols received in the second frequency band.

38. The UE of claim 37, wherein the one or more processors are further configured to: Selecting a receiving beam from the first receiving beam set based on signal measurements of the first receiving beam set; and A receive beam is selected from the second receive beam set based on signal measurements for the second receive beam set.

39. The UE of claim 38, wherein the one or more processors are further configured to: Using inter-band carrier aggregation to receive data signals from an access point in the first and second frequency bands, wherein using the inter-band carrier aggregation to receive the data signals includes: The first portion of the data signal is received using a receive beam selected from the first receive beam set on one or more carriers in the first frequency band; as well as The second portion of the data signal is received using a receive beam selected from the second receive beam set on one or more carriers in the second frequency band.

40. The UE of claim 37, wherein the first frequency band and the second frequency band are above a frequency of 24.25 GHz.

41. The UE of claim 37, wherein the duration of each RS symbol in the first frequency band is greater than the duration of each RS symbol in the second frequency band.

42. The UE of claim 37, wherein the first frequency band and the second frequency band are frequency-separated.

43. A user equipment (UE) for wireless communication, comprising: A means for performing the method as described in any one of claims 1-21.

44. A computer-readable medium storing instructions for wireless communication, the instructions causing the one or more processors of a user equipment (UE) to perform the method as described in any one of claims 1-21 when executed by the processors.

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