Method and apparatus for RACH communication of DL synchronization beam information for various DL-UL correspondence states

Abstract

Methods, systems, and apparatus for wireless communications are described. A user equipment (UE) may receive a downlink (DL) signal from a base station on one or more DL beams. The UE may identify a selected DL beam of the one or more DL beams for communication from the base station to the UE. The UE may transmit a scheduling request message to the base station using at least one of a resource or a waveform selected at least in part based on the selected DL beam.

Description

[0001] This application is a divisional application of an application with an application date of August 11, 2017, application number 201780047372.1 (international application number PCT / US2017 / 046430), and name “RACH transmission of DL synchronization beam information for various DL-UL correspondence states”.

[0002] Cross-references

[0003] This patent application claims the benefit of U.S. Patent Application No. 15 / 674,264, filed on August 10, 2017, by Islam et al., entitled “RACH Conveyance of DL Synchronization Beam Information For Various DL-UL Correspondence States,” and U.S. Provisional Patent Application No. 62 / 374,735, filed on August 12, 2016, entitled “RACH Conveyance of DL Synchronization Beam Information For Various DL-UL Reciprocity States,” and U.S. Provisional Patent Application No. 62 / 374,735, filed on August 12, 2016, entitled “RACH Conveyance of DL Synchronization Beam Information For Various DL-UL Reciprocity States,” and U.S. Provisional Patent Application No. 62 / 374,735, filed on August 24, 2016, entitled “RACH Conveyance of DL Synchronization Beam Information For Various DL-UL Reciprocity States,” and U.S. Provisional Patent Application No. 62 / 374,735, filed on August 12, 2016, entitled “RACH Conveyance of DL Synchronization Beam Information For Various DL-UL Reciprocity States,” and U.S. Provisional Patent Application No. 62 / 374,735, filed on August 24, 2016, entitled “RACH Conveyance of DL Synchronization Beam Information For Various DL-UL U.S. Provisional Patent Application No. 62 / 379,209, entitled “RACH Conveyance of DL Synchronization Beam Information For Various DL-UL Reciprocity States,” filed by Islam et al. on October 10, 2016, and U.S. Provisional Patent Application No. 62 / 406,377, entitled “RACH Conveyance of DL Synchronization Beam Information For Various DL-UL Reciprocity States,” filed by Islam et al. on October 12, 2016, and U.S. Provisional Patent Application No.62 / 407,423, and priority to U.S. Provisional Patent Application No. 62 / 418,072, filed on November 4, 2016 by Islam et al., entitled “RACH Conveyance of DL Synchronization Beam Information For Various DL-UL Reciprocity States,” each of which is assigned to the assignee of the present application. Technical Field

[0004] The following relates generally to wireless communications and, more particularly, to random access channel (RACH) communication of downlink (DL) synchronization beam information for various downlink-uplink (DL-UL) correspondence states. Background Art

[0005] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, and the like. These systems may be capable of supporting communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems (e.g., long term evolution (LTE) systems). A wireless multiple-access communication system may include several base stations, each of which simultaneously supports communication for multiple communication devices, which may be further referred to as user equipment (UE).

[0006] Wireless communication systems may operate in the millimeter wave (mmW) frequency range (e.g., 28 GHz, 40 GHz, 60 GHz, etc.). Wireless communication at these frequencies may be associated with increased signal attenuation (e.g., path loss), which may be affected by various factors (such as temperature, air pressure, diffraction, etc.). As a result, signal processing techniques (such as beamforming) may be used to coherently combine energy and overcome path loss at these frequencies. Due to the increased amount of path loss in mmW communication systems, transmissions from base stations and / or UEs may be beamformed.

[0007] Wireless communication between two wireless nodes (e.g., between a base station and a UE) may use beams or beamformed signals for transmission and / or reception. A base station may transmit a beamformed synchronization signal on a downlink (DL) synchronization beam. The UE may receive a synchronization signal on one or more of the DL synchronization beams and may therefore be able to initiate a RACH procedure with the base station. In some instances, the UE may send a message to the base station as part of a RACH procedure, and the base station may assume that the uplink (UL) beam on which the RACH message is received represents the DL beam that the base station should use in communicating with the UE. In other words, the base station assumes a DL-UL correspondence. However, for various reasons, the correspondence between the DL channel and the UL channel may be lost. Therefore, the base station assumption may be incorrect, which means that the DL beam selected by the base station may not be the most appropriate beam for communicating with the UE. Summary of the invention

[0008] The described technology relates to an improved method, system, device, or apparatus (equipment) for RACH communication of DL beam information supporting various DL-UL correspondence states. In general, the described technology provides for a base station to transmit a DL signal to a UE. A DL signal may be transmitted on (several) DL beams. The UE may use a DL beam from (several) DL beams that may be used to communicate with a base station (e.g., DL communication). The UE may select resources and / or a random access channel (RACH) waveform for transmitting a RACH message (e.g., a RACH message 1 (msg1) to a base station). In some aspects, the UE may select resources and / or a RACH waveform based on the DL beam. The UE may transmit the RACH message to the base station on the selected resources and / or RACH waveform. The base station may receive the RACH message on the resources and / or RACH waveform, and identify the DL beam selected by the UE based on the resources and / or RACH waveform. The base station may use the selected DL beam for subsequent communications with the UE.

[0009] A wireless communication method is described. The method may include receiving a DL signal from a base station on one or more DL beams, identifying a selected DL beam of the one or more DL beams for communication from the base station to a UE, and transmitting a RACH message / scheduling request message / beam recovery or beam tracking message to the base station using at least one of a resource or a waveform selected at least in part based on the selected DL beam.

[0010] An apparatus for wireless communication is described. The apparatus may include: means for receiving a DL signal from a base station on one or more DL beams, means for identifying a selected DL beam of the one or more DL beams for communication from the base station to a UE, and means for transmitting a RACH message / scheduling request message / beam recovery or beam tracking message to the base station using at least one of a resource or a waveform selected at least in part based on the selected DL beam.

[0011] Another apparatus for wireless communication is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions are operable to cause the processor to: receive a DL signal from a base station on one or more DL beams, identify a selected DL beam of the one or more DL beams for communication from the base station to a UE, and transmit a RACH message / scheduling request message / beam recovery or beam tracking message to the base station using at least one of a resource or a waveform selected at least in part based on the selected DL beam.

[0012] A non-transitory computer-readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to: receive a DL signal from a base station on one or more DL beams, identify a selected DL beam of the one or more DL beams for communication from the base station to a UE, and transmit a RACH message / scheduling request message / beam recovery or beam tracking message to the base station using at least one of a resource or a waveform selected at least in part based on the selected DL beam.

[0013] In some examples of the methods, apparatuses, and non-transitory computer-readable media described above, the waveform includes one of a scheduling request or a RACH waveform.

[0014] In some examples of the methods, apparatuses, and non-transitory computer-readable media described above, the DL signal includes a synchronization signal or a reference signal.

[0015] In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, the selected resource or waveform includes: selecting the resource or the waveform based at least in part on an index of the selected DL beam. In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, the selected resource or waveform includes: selecting the resource or the waveform based at least in part on a symbol of a subframe of a DL signal of the selected DL beam.

[0016] In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, transmitting the RACH message / scheduling request message / beam recovery or beam tracking message includes: transmitting the RACH message / scheduling request message / beam recovery or beam tracking message during the entire duration of the corresponding random access subframe. In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, identifying the selected DL beam includes: identifying the preferred DL beam based at least in part on the signal strength of the DL signal on one or more DL beams, the signal quality of the DL signal on one or more DL beams, or a combination thereof.

[0017] In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, identifying the selected DL beam includes: identifying the DL beam based at least in part on the DL signal on the one or more DL beams satisfying the transmit power condition. Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include a process, feature, device, or instruction for selecting a resource or RACH waveform for transmitting the RACH message / scheduling request message / beam recovery or beam tracking message to the base station, wherein the resource and / or RACH waveform is selected at least in part based on the selected DL beam.

[0018] In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, selecting the RACH waveform includes: selecting a RACH preamble, a cyclic shift, or a combination thereof based at least in part on an index of the selected DL beam. In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, a correspondence between one or more DL transmit beams from the base station and one or more UL receive beams at the base station may be missing. The missing correspondence may be associated with one or more DL transmit beams having a different beam direction than one or more UL receive beams.

[0019] Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include processes, features, devices, or instructions for identifying that the correspondence is missing by receiving information from the base station in a master information block (MIB) or a system information block (SIB).

[0020] Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include a process, feature, device, or instruction for selecting the resource or waveform based at least in part on the identification of the missing correspondence, and transmitting the RACH message / scheduling request message / beam recovery or beam tracking message to the base station during the entire duration of the RACH subframe based at least in part on the indication of the missing correspondence. Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include a process, feature, device, or instruction for selecting the resource or RACH waveform based at least in part on the indication of the missing correspondence.

[0021] Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include a process, feature, device, or instruction for receiving an indication of the missing correspondence in a master information block (MIB) or a system information block (SIB). Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include a process, feature, device, or instruction for transmitting an indication that the correspondence between one or more DL beams from the base station and one or more UL beams from the UE is missing. Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include a process, feature, device, or instruction for transmitting the RACH message / scheduling request message / beam recovery or beam tracking message to the base station during the first codeword of the first random access subframe and the second codeword of the second random access subframe. Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include a process, feature, device, or instruction for transmitting an indication of the missing correspondence in a RACH message 3, a physical uplink control channel (PUCCH), or a physical uplink shared channel (PUSCH).

[0022] Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include a process, feature, device, or instruction for receiving an indication of a characteristic of a correspondence between one or more DL beams from the base station and one or more UL beams from the UE. In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, the characteristic of the correspondence corresponds to at least one of the following: a complete correspondence, a partial correspondence, or no correspondence.

[0023] Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include a process, feature, device, or instruction for determining that a corresponding relationship exists based on an indication of a characteristic of the corresponding relationship, and selecting a transmission time for transmitting the RACH message / scheduling request message / beam recovery or beam tracking message to the base station based on the existing corresponding relationship. In some examples, the transmission time includes a code element of the corresponding random access subframe. Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include a process, feature, device, or instruction for determining that a partial correspondence exists based on an indication of a characteristic of the corresponding relationship, and selecting a transmission time for transmitting the RACH message / scheduling request message / beam recovery or beam tracking message to the base station based on the partial correspondence. In some examples, the transmission time includes multiple code elements of the corresponding random access subframe.

[0024] Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include a process, feature, device, or instruction for selecting a transmission time, frequency range, and RACH preamble for transmitting the RACH message / scheduling request message / beam recovery or beam tracking message based on the characteristics of the corresponding relationship. Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include a process, feature, device, or instruction for selecting the resource or waveform based at least in part on a symbol associated with the DL signal and an indication of the characteristics of the corresponding relationship. Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include a process, feature, device, or instruction for receiving an indication of the characteristics of the corresponding relationship on a physical broadcast channel (PBCH) or an extended PBCH (ePBCH). Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include a process, feature, device, or instruction for receiving an indication of the characteristics of the corresponding relationship in a MIB or SIB.

[0025] In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, the selected DL beam from the base station may be different from the selected UL beam from the UE. In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, the one or more DL beams may be within a single symbol of a synchronization subframe, wherein selecting a resource or waveform for transmitting a scheduling request message includes: selecting the resource or waveform based at least in part on the symbol of the selected DL beam.

[0026] In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, resources may be associated with one or more frequency tones in a component carrier. In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, resources may be associated with a component carrier. Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include a process, feature, device, or instruction for selecting a combination of resources and a RACH waveform to transmit the RACH message / scheduling request message / beam recovery or beam tracking message to the base station.

[0027] A wireless communication method is described. The method may include transmitting a DL signal on one or more DL beams, receiving a RACH message / scheduling request message / beam recovery or beam tracking message from a UE on at least one of a resource or a waveform, identifying a selected DL beam of the one or more DL beams for communication from a base station to the UE based at least in part on the resource or the waveform, and transmitting one or more subsequent messages to the UE using the selected DL beam.

[0028] An apparatus for wireless communication is described. The apparatus may include: means for transmitting a DL signal on one or more DL beams, means for receiving a RACH message / scheduling request message / beam recovery or beam tracking message from a UE on at least one of a resource or a waveform, means for identifying a selected DL beam of the one or more DL beams for communication from a base station to a UE based at least in part on the resource or the waveform, and means for transmitting one or more subsequent messages to the UE using the selected DL beam.

[0029] Another apparatus for wireless communication is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions are operable to cause the processor to: transmit a DL signal on one or more DL beams, receive a RACH message / scheduling request message / beam recovery or beam tracking message from a UE on at least one of a resource or a waveform, identify a selected DL beam of the one or more DL beams for communication from a base station to a UE based at least in part on the resource or the waveform, and transmit one or more subsequent messages to the UE using the selected DL beam.

[0030] A non-transitory computer-readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to: transmit a DL signal on one or more DL beams, receive a RACH message / scheduling request message / beam recovery or beam tracking message from a UE on at least one of a resource or a waveform, identify a selected DL beam of the one or more DL beams for communication from a base station to a UE based at least in part on the resource or the waveform, and transmit one or more subsequent messages to the UE using the selected DL beam.

[0031] In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, identifying the selected DL beam includes associating the resource or waveform with an index of the selected DL beam. In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, identifying the selected DL beam includes associating the resource or waveform with a codeword of a subframe of a DL signal of the selected DL beam.

[0032] In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, receiving the message / scheduling request message / beam recovery or beam tracking message includes: receiving the message / scheduling request message / beam recovery or beam tracking message during the entire duration of the corresponding random access subframe. In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, receiving the RACH message / scheduling request message / beam recovery or beam tracking message includes: receiving the RACH message / scheduling request message / beam recovery or beam tracking message on multiple UL beams.

[0033] Some examples of the methods, equipment (devices), or non-transitory computer-readable media described above may further include a process, feature, device, or instruction for measuring the quality of the RACH message / scheduling request message / beam recovery or beam tracking message received on the multiple UL beams. Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include a process, feature, device, or instruction for determining a selected UL beam for communication from the UE to the base station based at least in part on the quality.

[0034] In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, measuring the quality of the RACH message / scheduling request message / beam recovery or beam tracking message includes: measuring one or more of reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), signal-to-noise ratio (SNR), or signal to interference plus noise ratio (SINR). In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, identifying the selected DL beam further includes: identifying the selected DL beam based at least in part on a resource or waveform of the RACH message / scheduling request message / beam recovery or beam tracking message.

[0035] In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, identifying the selected DL beam includes: identifying the selected DL beam based at least in part on a RACH preamble of the RACH message, a cyclic shift of the RACH message, or a combination thereof. In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, a correspondence between one or more DL beams from the base station and one or more uplink (UL) beams at the base station is missing, wherein the missing correspondence is associated with the one or more DL beams having a different beam direction than the one or more UL beams.

[0036] Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include processes, features, devices, or instructions for identifying that a correspondence between one or more DL beams from the base station and one or more uplink (UL) beams at the base station is missing.

[0037] Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include a process, feature, device, or instruction for receiving an indication that a correspondence between one or more DL beams from the base station and one or more UL beams from the UE is missing, and mapping a DL beam used to transmit a channel state information reference signal (CSI-RS) to a UL beam used to transmit a sounding reference signal (SRS) or mapping a UL beam used to transmit a sounding reference signal (SRS) to a DL beam used to transmit a channel state information reference signal (CSI-RS). Some examples of the methods, equipment (devices), and non-transitory computer-readable media described above may further include a process, feature, device, or instruction for receiving an indication that a correspondence between one or more DL beams from the base station and one or more UL beams from the UE is missing, and mapping a DL beam used in DL beam training to a UL beam used in UL beam training or mapping a UL beam used in UL beam training to a DL beam used in DL beam training.

[0038] In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, the selected DL beam from the base station may be different from the selected UL beam from the UE. In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, resources may be associated with one or more frequency tones in a component carrier. In some examples of the methods, equipment (devices), and non-transitory computer-readable media described above, resources may be associated with a component carrier. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 An example of a system for wireless communication supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states in accordance with aspects of the present disclosure is illustrated;

[0040] Figure 2 An example of a process flow supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states in accordance with aspects of the present disclosure is illustrated;

[0041] Figure 3 An example of a system for wireless communication supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states in accordance with aspects of the present disclosure is illustrated;

[0042] Figure 4A and 4B An example of various aspects of a beam subframe mapping configuration supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states in accordance with various aspects of the present disclosure is illustrated;

[0043] Figure 5A and 5B An example of a beam subframe mapping configuration for RACH communication supporting DL synchronization beam information for various DL-UL correspondence states according to various aspects of the present disclosure is illustrated;

[0044] Fig. 6A and 6B An example of a beam subframe mapping configuration for RACH communication supporting DL synchronization beam information for various DL-UL correspondence states according to various aspects of the present disclosure is illustrated;

[0045] Fig. 7A and 7B An example of a beam subframe mapping configuration for RACH communication supporting DL synchronization beam information for various DL-UL correspondence states according to various aspects of the present disclosure is illustrated;

[0046] Figures 8 to 10 A block diagram illustrating an apparatus supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states according to various aspects of the present disclosure;

[0047] Fig.11 A block diagram illustrating a system including a UE supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states in accordance with aspects of the present disclosure;

[0048] Figures 12 to 14 A block diagram illustrating an apparatus supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states according to various aspects of the present disclosure;

[0049] Fig.15 A block diagram illustrating a system including a base station supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states in accordance with aspects of the present disclosure; and

[0050] Figures 16 to 19 Methods for RACH communication of DL synchronization beam information for various DL-UL correspondence states according to various aspects of the present disclosure are explained. DETAILED DESCRIPTION

[0051] Free space path loss may increase with carrier frequency. Transmissions in millimeter wave (mmW) systems may also be affected by additional non-line-of-sight losses (e.g., diffraction loss, penetration loss, oxygen absorption loss, foliage loss, etc.). During initial access, base stations and user equipment (UE) may attempt to overcome these high path losses to discover or detect each other. Aspects of the present disclosure provide improved initial access in mmW systems.

[0052] Various aspects of the present disclosure are initially described in the context of a wireless communication system. In general, the described techniques enable a UE to communicate an indication of a selected downlink (DL) beam to a base station by selecting corresponding resources and / or random access channel (RACH) waveforms for transmitting RACH messages / scheduling request messages / beam recovery or beam tracking messages. For example, a base station may transmit (all) DL signals on (all) DL beams. A UE may select a DL beam from (all) DL signals that may be used for DL ​​communication (e.g., from a base station to a UE). A UE may select resources and / or waveforms (e.g., RACH waveforms or scheduling request waveforms) for transmitting RACH messages / scheduling request messages / beam recovery or beam tracking messages to a base station, wherein the selection is based on the selected DL beam. Subsequently, the UE may use the selected resources and / or RACH waveforms to transmit RACH messages / scheduling request messages / beam recovery or beam tracking messages to a base station. The base station receives the RACH message / scheduling request message / beam recovery or beam tracking message on the selected resources and / or RACH waveforms, and identifies the selected DL beam using the resources and / or RACH waveforms. In one non-limiting example, the UE may select resources (e.g., channels) corresponding to the timing characteristics (e.g., symbols) of the DL signal(s). The base station may then use the selected DL beam for communication from the base station to the UE (e.g., for subsequent DL communications). In some aspects, resources may refer to time resources, frequency resources, time-frequency resources, etc.

[0053] Aspects of the present disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flow diagrams related to RACH communication of DL synchronization beam information for various DL-UL correspondence states.In some aspects, the term "correspondence" may refer to reciprocity.

[0054] Figure 1 An example of a wireless communication system 100 is illustrated in accordance with various aspects of the present disclosure. The wireless communication system 100 includes a base station 105, a UE 115, and a core network 130. In some examples, the wireless communication system 100 may be an LTE (or LTE-Advanced) network.

[0055] The base stations 105 may communicate wirelessly with the UEs 115 via one or more base station antennas. Each base station 105 may provide communication coverage for a respective geographic coverage area 110. The communication links 125 shown in the wireless communication system 100 may include UL transmissions from the UE 115 to the base stations 105, or DL ​​transmissions from the base stations 105 to the UEs 115. The UEs 115 may be dispersed throughout the wireless communication system 100, and each UE 115 may be stationary or mobile. The UEs 115 may also be referred to as mobile stations, subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless terminals, remote terminals, handsets, user agents, mobile clients, clients, or some other suitable terminology. UE 115 may also be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a personal electronic device, a handheld device, a personal computer, a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, a machine type communication (MTC) device, an appliance, an automobile, and the like.

[0056] Each base station 105 can communicate with the core network 130 and with each other. For example, the base station 105 can be connected to the core network 130 via a backhaul link 132 (e.g., S1, etc.). The base station 105 can communicate with each other directly or indirectly (e.g., through the core network 130) on a backhaul link 134 (e.g., X2, etc.). The base station 105 can perform radio configuration and scheduling for communication with the UE 115, or can operate under the control of a base station controller (not shown). In some examples, the base station 105 can be a macro cell, a small cell, a hotspot, etc. The base station 105 may also be referred to as an evolved B node (eNB) 105.

[0057] During the initial access procedure (also referred to as the RACH procedure), the UE 115 may transmit a RACH preamble to the base station 105. This may be referred to as a RACH message 1. For example, the RACH preamble may be randomly selected from a set of 64 predetermined sequences. This may enable the base station 105 to distinguish between multiple UEs 115 attempting to access the system at the same time. The base station 105 may respond with a random access response (RAR) or RACH message 2 that provides a UL resource grant, a timing advance, and a temporary cell radio network temporary identity (C-RNTI). The UE 115 may then transmit a radio resource control (RRC) connection request or RACH message 3, as well as a temporary mobile subscriber identity (TMSI) (if the UE 115 has previously been connected to the same wireless network) or a random identifier. The radio resource control (RRC) connection request may also indicate the reason why the UE 115 is connecting to the network (e.g., emergency, signaling notification, data exchange, etc.). The base station 105 may respond to the connection request with a contention resolution message or a RACH message 4 addressed to the UE 115, which may provide a new C-RNTI. If the UE 115 receives the contention resolution message with the correct identity, the UE 115 may continue with the RRC setup. If the UE 115 does not receive the contention resolution message (e.g., if there is a collision with another UE 115), the UE 115 may repeat the RACH process by transmitting a new RACH preamble.

[0058] The wireless communication system 100 may operate using a frequency band from 700 MHz to 2600 MHz (2.6 GHz) in the ultra-high frequency (UHF) frequency region, but in some cases WLAN networks may use frequencies up to 4 GHz. Since the wavelength is in the range from about 1 decimeter to 1 meter long, this region may also be referred to as the decimeter band. UHF waves may be propagated primarily by line of sight and may be blocked by buildings and environmental features. However, these waves may fully penetrate walls to provide services to UEs 115 located indoors. Compared to transmissions using lower frequencies (and longer waves) in the high frequency (HF) or very high frequency (VHF) portions of the spectrum, transmissions of UHF waves are characterized by smaller antennas and shorter ranges (e.g., less than 100 km). In some cases, the wireless communication system 100 may also utilize the extremely high frequency (EHF) portion of the spectrum (e.g., from 30 GHz to 300 GHz). Since the wavelength is in the range from about 1 millimeter to 1 centimeter long, this region may also be referred to as the millimeter band. Therefore, EHF antennas may be even smaller and more closely spaced than UHF antennas. In some cases, this may facilitate the use of antenna arrays (eg, for directional beamforming) within UE 115. However, EHF transmissions may be subject to even greater atmospheric attenuation and shorter range than UHF transmissions.

[0059] Specifically, the wireless communication system 100 may operate in the mmW frequency range (e.g., 28 GHz, 40 GHz, 60 GHz, etc.). Wireless communication at these frequencies may be associated with increased signal attenuation (e.g., path loss), which may be affected by various factors (such as temperature, air pressure, diffraction, etc.). As a result, signal processing techniques such as beamforming (i.e., directional transmission) may be used to coherently combine signal energy and overcome path loss in a specific beam direction. In some cases, a device (such as a UE 115) may select a beam direction for communicating with the network by selecting the strongest beam from among several signals transmitted by a base station. In one example, the signal may be a DL synchronization signal (e.g., a primary or secondary synchronization signal) or a DL reference signal (e.g., a channel state information reference signal (CSI-RS)) transmitted from a base station 105 during discovery. The discovery procedure may be cell-specific, for example, it may be directed in incremental directions around a coverage area 110 of a base station 105. In at least some aspects, a discovery procedure may be used to identify and select beam(s) to be used for beamformed transmissions between base station 105 and UE 115.

[0060] In some cases, the base station antennas may be located within one or more antenna arrays. One or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some cases, the antennas or antenna arrays associated with the base station 105 may be located at different geographic locations. The base station 105 may use multiple antennas or antenna arrays to perform beamforming operations for directional communication with the UE 115.

[0061] The wireless communication system 100 may be or may include a multi-carrier mmW wireless communication system. Broadly, aspects of the wireless communication system 100 may include a UE 115 and a base station 105, which are configured to support RACH communication of DL synchronization beam information for various DL-UL correspondence states. For example, the base station 105 may transmit (all) DL signals on (all) DL beams. The UE 115 may select a DL beam from (all) DL signals that may be used for DL ​​communication (e.g., from the base station 105 to the UE 115). The UE 115 may select resources and / or RACH waveforms for transmitting RACH messages to the base station 105, wherein the selection is based on the selected DL beam. Subsequently, the UE 115 may use the selected resources and / or RACH waveforms to transmit RACH messages to the base station 105. The base station 105 receives the RACH message on the selected resources and / or RACH waveforms, and uses these resources and / or RACH waveforms to identify the selected DL beam. In one non-limiting example, UE 115 may select resources (e.g., channels) corresponding to the timing characteristics (e.g., symbols) of the DL synchronization signal(s). Base station 105 may then use the selected DL beam for communications from base station 105 to UE 115 (e.g., for subsequent DL communications).

[0062] Figure 2 An example of a process flow 200 for RACH communication of DL synchronization beam information for various DL-UL correspondence states is illustrated. The process flow 200 may implement Figure 1 The process flow 200 may include a UE 115-a and a base station 105-a, which may be Figure 1 Base station 105-a may be a mmW base station and a serving base station for UE 115-a.

[0063] At 205, the base station 105-a may transmit an indication of a correspondence associated with the DL beam at the base station side. In some aspects, the base station 105-a may explicitly indicate the correspondence to the UE 115-a. For example, one bit may be dedicated to conveying the correspondence indication. In other aspects, the base station 105-a may implicitly indicate the correspondence. For example, the UE 115-a may infer whether the correspondence at the base station 105-a is present or absent from a mapping of the DL beam to the RACH resource or waveform. In one example, if time division duplexing (TDD) is used to configure the DL beam and RACH resources, this may indicate that the base station 105-a may have a correspondence.

[0064] In some cases, the base station 105-a may include an indication of the correspondence in a master information block (MIB) (e.g., a bit reserved for indicating the correspondence) or a system information block (SIB) (e.g., a bit reserved for indicating the correspondence) transmitted to the UE 115-a. In some examples, the base station may transmit the MIB on a physical broadcast channel (PBCH), and the base station may transmit the SIB on an extended PBCH. In some examples, the indication may be based on a preamble format, wherein one preamble format may convey an indication of no correspondence, a second preamble format may convey an indication of a partial correspondence, and a third preamble format may convey an indication of a complete correspondence. Based on the indication of the correspondence, the UE 115-a may determine whether there is a complete correspondence, no correspondence, or a partial correspondence (e.g., with an uncertainty region of 2×N+1, where N represents the number of subarrays at the UE 115-a or with an uncertainty of 2×M+1, where M represents the number of beams transmitted by the base station 105-a). If UE 115-a determines that the correspondence is missing, UE 115-a may select a UL beam that is different from the DL beam used by base station 105-a (e.g., for communication with base station 105-a).

[0065] Additionally or alternatively, at 205, the UE 115-a may transmit an indication of a correspondence associated with a UL beam at the UE side. For example, the UE 115-a may transmit characteristics of a correspondence between one or more receive DL synchronization beams at the UE and one or more transmit uplink (UL) beams at the UE, an indication of a correspondence in a RACH message (e.g., RACH message 1 (msg1) or RACH message 3 (msg3)) or on a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH). The base station 105-a may receive an indication of a correspondence at the UE side, and based on the indication, the base station 105-a may determine to map a beam used to transmit a channel state information reference signal (CSI-RS) to a beam used to transmit a sounding reference signal (SRS), or vice versa. Additionally, the base station 105-a may determine to map a beam used in DL beam training to a beam used in UL beam training, or vice versa, based on the indication.

[0066] At 210, the base station 105-a may transmit (and the UE 115-a may receive) a DL synchronization signal to the UE 115-a. The DL synchronization signal may be a beamformed signal transmitted from the base station 105-a on the DL synchronization beam(s). The DL synchronization signal may be associated with an index and / or symbol of a subframe. The DL synchronization signal may be associated with a transmit power condition.

[0067] In some aspects, the base station 105-a transmits multiple DL synchronization signals during a synchronization subframe. Each DL synchronization signal can be transmitted in a codeword of the synchronization subframe (e.g., DL synchronization signal 1 can be transmitted during codeword 1, DL synchronization signal 2 can be transmitted during codeword 2, etc.).

[0068] At 215, the UE 115-a may identify a selected DL beam among the DL synchronization beams for communication from the base station 105-a to the UE 115-a. The UE 115-a may identify the selected DL beam by identifying a preferred DL beam based on a signal strength and / or a signal quality (e.g., a high received signal strength and / or a low interference level) of the DL synchronization signal. In some aspects, the UE 115-a may identify the selected DL beam by identifying a transmit power condition (e.g., a transmit power above a threshold level) of the DL synchronization signal on the DL synchronization beam.

[0069] At 220, the UE 115-a may select resources and / or a RACH waveform for transmitting a RACH message to the base station 105-a. At least in some aspects, the resources and / or the RACH waveform may be selected based on the selected DL beam (e.g., based on an index of the selected DL beam, based on a symbol of a subframe of a DL synchronization signal of the selected DL beam, etc.). The resources and / or the RACH waveform may be associated with a tone(s) in a component carrier and / or associated with a component carrier.

[0070] At 225, the UE 115-a may transmit a RACH message to the base station 105-a. The RACH message may be transmitted on a selected RACH resource and / or RACH waveform. The RACH message may be transmitted during the entire duration of the corresponding random access subframe (e.g., during each symbol of the random access subframe). In some aspects, the RACH message may be transmitted during the entire duration of the corresponding random access slot, subframe, opportunity, burst, burst set, etc. In general, these terms may refer to the time duration when the gNB sweeps some or all of its receive beams to receive (all) RACH messages. In some aspects, the UE 115-a may select a RACH waveform for transmitting the RACH message. The RACH waveform may be selected based on the selected DL beam, and the RACH waveform may include a RACH preamble, a cyclic shift, etc. In some aspects, the UE 115-a may transmit the RACH message on multiple UL beams.

[0071] At 230, the base station 105-a may identify the selected DL beam. The base station 105-a may identify the selected DL beam based on the resources and / or RACH waveform used for RACH message transmission. In some aspects, the base station 105-a may identify the selected DL beam by associating the resources and / or RACH waveform with an index of the selected DL beam. In some aspects, the base station 105-a may identify the selected DL beam by associating the resources and / or RACH waveform with a symbol of a subframe of a DL synchronization signal for the selected DL beam.

[0072] In some aspects, the base station 105-a may identify the selected DL beam based on a RACH waveform of the RACH message. For example, the base station 105-a may identify the selected DL beam based on a RACH preamble of the RACH message, a cyclic shift of the RACH message, etc.

[0073] At 235, the base station 105-a may use the selected DL beam to transmit subsequent messages to the UE 115-a. In some cases, the selected DL beam is a preferred DL beam. In addition, in some aspects, the base station 105-a may use the RACH message received from the UE 115-a to determine the selected UL beam for communication from the UE 115-a to the base station 105-a. For example, the base station 105-a may measure the quality of the RACH message received on multiple UL beams and determine the selected UL beam based on the measured quality. Measuring the quality of the RACH message may include measuring a reference signal received power (RSRP), a received signal strength indicator (RSSI), a reference signal received quality (RSRQ), a signal-to-noise ratio (SNR), a signal-to-interference and noise ratio (SINR), and the like.

[0074] In some cases, UE 115-a may measure the RSRP of a received signal transmitted on a synchronization signal block (e.g., a combination of one or more synchronization signals transmitted together in a certain direction) to identify the best signal. In a case where UE 115-a cannot determine the strongest port associated with a particular symbol, UE 115-a may use different spreading codes (e.g., orthogonal cover codes (OCC)) to indicate or communicate the best SS block index or preferred DL beam to base station 105-a. In some examples, base station 105-a may transmit one or more additional reference signals (e.g., beam reference signal (BRS), mobility reference signal (MRS), etc.) within the symbol used for synchronization signal 205, and UE 115-a may identify the best transmission port (e.g., best downlink transmission beam ID). As a result, UE 115-a may feedback the best downlink transmission beam ID by using different spreading codes.

[0075] If the base station 105-a does not have a beam correspondence, the base station 105-a may request the UE 115-a to transmit RACH in all symbols of the RACH time slot. Subsequently, the base station 105-a may find the best uplink receive beam based on the quality of the received RACH signal. In some examples, when the base station 105-a does not have a transmit / receive beam correspondence, the base station 105-a may configure an association between a downlink signal or a downlink channel and a subset of RACH resources and / or a subset of preamble indices (e.g., RACH preamble indices), which may be used to determine a downlink transmission beam (e.g., for sending message 2 (Msg2)). Based on the downlink measurement of the received signal and the corresponding association, the UE 115-a may select a subset of RACH resources and / or a subset of RACH preamble indices. In such a case, the preamble index may include a preamble sequence index and an OCC index, such as in a case where OCC is supported. In some examples, a subset of preambles may be indicated by an OCC index.

[0076] In some aspects, there may be a missing correspondence between the DL synchronization beam from the base station 105-a and the UL beam from the UE 115-a. Therefore, in some examples, the selected DL beam may be different from the selected UL beam. Various aspects of the present disclosure may support partial beam correspondence or no beam correspondence between DL transmission beams and UL reception beams. In the case of partial correspondence, the RACH message transmitted at 225 may be transmitted at the transmission time with a center symbol corresponding to the best (e.g., strongest received signal strength) DL synchronization beam or with a center symbol corresponding to a symbol associated with the best DL synchronization beam. Similarly, the UE 115-a may determine the RACH preamble of the RACH message at 225 based on the best DL synchronization beam, and the UE 115-a may determine the subcarrier region for the RACH message transmission at 225 based on the best DL synchronization beam. This may be applicable to frequency division duplex (FDD) systems in which there may not be a complete beam correspondence between DL and UL. The amount of partial beam correspondence may vary from scene to scene. In some examples, the missing correspondence may be associated with different channel propagation characteristics of the DL and UL beams (eg, different transmit power levels, different departure and / or arrival angles, etc.).

[0077] In some cases, the correspondence may exist at the base station 105-a. In this case, the base station 105-a may transmit different DL synchronization signals at different times, and the base station 105-a may simultaneously receive the corresponding RACH resources from the UE 115-a through the digital receiver subsystem, which may not be affected by the analog beam constraints. In this case, the base station 105-a may request the UE 115-a to map the DL synchronization signal to the RACH resource or waveform. Subsequently, the base station 105-a may analyze each receive beam path with a RACH detector.

[0078] Aspects of the present disclosure may also support beam correspondence between DL transmission beams and UL reception beams. In the case of a correspondence, the RACH message transmitted at 225 may be transmitted at a transmission time corresponding to the best DL synchronization beam or a symbol corresponding to the best DL synchronization beam.

[0079] Figure 3 An example of a system 300 for wireless communication supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states is illustrated. The system 300 may be Figure 1 1. The system 300 may be an example of aspects of a wireless communication system 100. The system 300 may be a mmW wireless communication system. The system 300 may include a UE 115-b and a base station 105-b, which may be Figure 1 and 2 Broadly, system 300 illustrates aspects of a discovery procedure in which a UE 115-b discovers a base station 105-b based on a DL synchronization signal transmitted on a DL synchronization beam.

[0080] In some examples, base station 105-b may be a mmW base station that transmits beamformed transmissions on an active beam to UE 115-b. Transmissions from base station 105-b may be beamformed transmissions or directional transmissions directed toward UE 115-a.

[0081] For example, the base station 105-b may transmit a DL synchronization signal on a DL synchronization beam 305. The base station 105-b may transmit the DL synchronization signal in a beamformed manner (e.g., for random access) and sweep through an angular coverage area (e.g., in azimuth and / or elevation). Each DL synchronization beam 305 may be transmitted in a beam sweeping operation in different directions to cover the coverage area of ​​the base station 105-b. For example, the DL synchronization beam 305-a may be transmitted in a first direction, the DL synchronization beam 305-b may be transmitted in a second direction, the DL synchronization beam 305-c may be transmitted in a third direction, and the DL synchronization beam 305-d may be transmitted in a fourth direction. Although the system 300 shows four DL synchronization beams 305, it should be understood that fewer and / or more DL synchronization beams 305 may be transmitted. In addition, the DL synchronization beams 305 may be transmitted with different beam widths, at different elevation angles, and the like. In some aspects, the DL synchronization beam 305 may be associated with a beam index (eg, an indicator identifying the beam).

[0082] In some aspects, the DL synchronization beam 305 may also be transmitted during different symbol periods of the synchronization subframe. For example, the DL synchronization beam 305-a may be transmitted during a first symbol period (e.g., symbol 0), the DL synchronization beam 305-b may be transmitted during a second symbol period (e.g., symbol 1), the DL synchronization beam 305-c may be transmitted during a third symbol period (e.g., symbol 2), and the DL synchronization beam 305-d may be transmitted during a fourth symbol period (e.g., symbol 3). Additional DL synchronization beams 305 may be transmitted during other symbol periods of the synchronization subframe.

[0083] In general, performing a beam sweeping operation supports the base station 105-b in determining in which direction the UE 115-b is located (e.g., after receiving a response message from the UE 115-b). This supports the transmission of a RACH message 2 from the base station 105-b. In addition, the beam sweeping operation improves communication when a correspondence is not maintained between the DL and UL channels, and the UE 115-b can select a frequency region and / or waveform configuration (e.g., resources and / or RACH waveform) for transmitting a random access signal (e.g., a RACH message, RACH message 1, or RACH message 3) based on an index of a best or preferred DL synchronization signal on the DL synchronization beam 305. In some cases, the UE 115-a can use an index or identifier in the RACH message 1 to convey the best or preferred DL beam. During the random access period, the base station 105-a can find a suitable UL beam by receiving the random access signal in a sweeping manner. The base station 105-b can identify the DL beam selected by the UE 115-a from the used resources and / or the RACH waveform (e.g., the used frequency region and / or waveform configuration) of the RACH message (e.g., RACH message 1 or RACH message 3) containing the random access signal.

[0084] Thus, each UE within the coverage area of ​​the base station 105-b can receive a DL synchronization signal on the DL synchronization beam 305. The UE 115-b can identify which DL synchronization signal is the best (e.g., the strongest received signal strength, the best channel quality, etc.) and identify it as the selected DL beam. Subsequently, the UE 115-b can select resources and / or RACH waveforms for transmitting RACH messages based on the selected DL beam (e.g., the preferred DL beam). In one example, the resources and / or RACH waveforms for transmitting the RACH message may correspond to the codewords of the selected DL beam. In another example, the RACH message may include an identifier or index of the preferred DL beam.

[0085] As a non-limiting example, there may be 16 different available DL beams. Thus, UE 115-b may use 4 bits to communicate DL beam information to base station 105-b. There may be 4 subcarrier regions (e.g., resources) and 4 different RACH waveforms available for UE 115-b to use. Accordingly, UE 115-b may transmit the 4 bits by selecting a RACH waveform from the 4 different RACH waveforms and selecting a subcarrier from the four subcarriers. Thus, UE 115-b may select a combination of resources and RACH waveforms to transmit a RACH message to base station 105-a.

[0086] Thus, in certain aspects, the system 300 may enable a UE 115-b to select a combination of RACH waveforms and / or resources for its RACH message transmission based on one or more combinations of indices of DL synchronization beams or indices of symbols of a DL synchronization subframe. The UE 115-b may transmit a random access signal (e.g., a RACH message, RACH message 1, or RACH message 3) during the entire duration of a random access subframe and / or during a portion of a random access subframe.

[0087] In some aspects, the base station 105-b may determine the selected DL beam for the UE 115-b from the used frequency region and / or RACH waveform of the message 1 containing the random access signal. The base station 105-b may determine the best UL receive beam by measuring the quality of the received signal at different uplink receiver beams. The signal quality may represent one or more combinations of RSRP, RSSI, RSRQ, SNR, SINR, etc.

[0088] In some aspects, the UE 115-b may select the best DL synchronization signal and the frequency region and / or RACH waveform of the RACH based on the index of the best DL synchronization signal. The UE 115-b may select the DL synchronization beam 305 that satisfies the transmit power condition. The UE 115-b may select the RACH preamble and cyclic shift based in part on the index of the DL synchronization beam 305.

[0089] The lack of correspondence may indicate that the best DL beam is not the same as the best UL beam.

[0090] In some aspects, if base station 105-b uses multiple antenna ports in each codeword of the synchronization subframe to transmit multiple beams, UE 115-b can select a combination of RACH and resources for transmission of RACH based on the codeword of the DL synchronization subframe. In some aspects, the resources can represent frequency tones and / or component carriers in a component carrier.

[0091] Although the reference Figure 3The described example involves transmitting a RACH message in a RACH subframe, but the example is also applicable to transmitting a scheduling request message, a beam recovery message, or a beam tracking message in a RACH subframe. In some cases, UE 115 may find that the best synchronization beam is transmitted during a specific codeword, and UE 115 may transmit the scheduling request message, the beam recovery message, or the beam tracking message in the frequency region corresponding to the specific codeword. The frequency region may be in different resources (or resource blocks) in the RACH subframe. That is, a first portion of the resources in the RACH subframe may be allocated for RACH message transmission, a second portion of the resources in the RACH subframe may be allocated for scheduling request message transmission, and a third portion of the resources in the RACH subframe may be allocated for beam recovery or beam tracking message transmission.

[0092] UE 115-b may receive an indication of a subcarrier region for scheduling request message transmission, or beam recovery or beam tracking message transmission via RRC signaling. In some cases, there may be eight (8) possible subcarrier regions. UE 115-b may also receive a desired cyclic shift for scheduling request message transmission, or beam recovery or beam tracking message transmission via RRC signaling. In some examples, UE 115-b may use twelve (12) different cyclic shifts to generate a sequence for scheduling request message transmission, or beam recovery or beam tracking message transmission. The number of available cyclic shifts for scheduling request message transmission, or beam recovery or beam tracking message transmission may be greater than the number of available cyclic shifts for RACH message transmission because timing errors may be corrected before UE 115-b transmits a scheduling request message transmission, or beam recovery or beam tracking message. Additionally, a scheduling request message transmission, or a beam restoration or beam tracking message transmission may span two (2) symbols, which may provide additional degrees of freedom (eg, 192 degrees of freedom in each symbol pair).

[0093] Figure 4A and 4B An example of a beam subframe mapping configuration 400 for RACH communication of DL synchronization beam information for various DL-UL correspondence states is illustrated. Configuration 400 may implement Figures 1 to 3 In some aspects, aspects of the wireless communication system 100, process flow 200, and / or system 300 of the present invention may be described in detail with reference to FIG. Figures 1 to 3 The described base station 105 and / or UE 115 are implemented.

[0094] Reference Figure 4A, the beam-subframe mapping configuration 400 may include a plurality of DL synchronization signals transmitted on a DL synchronization beam 405. The base station 105 may transmit the DL synchronization signal in a beamformed manner (e.g., for random access) and sweep through an angular coverage area (e.g., in azimuth and / or elevation). Each DL synchronization beam 405 may be transmitted in a beam sweeping operation in different directions to cover the coverage area of ​​the base station 105. For example, a DL synchronization beam 405-a may be transmitted in a first direction, a DL synchronization beam 405-b may be transmitted in a second direction, and so on. In some aspects, the DL synchronization beam 405 may be associated with a beam index (e.g., an indicator identifying the beam).

[0095] In some aspects, the DL synchronization beam 405 may also be transmitted during different symbol periods of the synchronization subframe 410. The synchronization subframe 410 may be associated with a time characteristic (e.g., symbol) along a horizontal axis and a frequency characteristic (e.g., frequency or tone) along a vertical axis. For example, the DL synchronization beam 405-a may be transmitted during a first symbol period (e.g., symbol 0), the DL synchronization beam 405-b may be transmitted during a second symbol period (e.g., symbol 1), and so on until the DL synchronization beam 405-h is transmitted during an eighth symbol period (e.g., symbol 7).

[0096] In some aspects, each DL synchronization signal transmitted on the DL synchronization beam 405 may be transmitted on some or all frequencies during a symbol. For example, the DL synchronization beam 405-a may be transmitted on frequencies or tones 0-7 during symbol 0, the DL synchronization beam 405-b may be transmitted on frequencies or tones 0-7 during symbol 1, and so on.

[0097] Thus, the base station 105 may sweep the DL synchronization beam 405 in eight directions during the eight symbols of the synchronization subframe 410 .

[0098] Reference Figure 4B , each UE 115 within the coverage area of ​​the base station 105 can receive a DL synchronization signal on the DL synchronization beam 405. The UE 115 can identify which DL synchronization signal is the best (e.g., strongest received signal strength, best channel quality, etc.) and identify it as the selected DL beam. Figure 4B , UE 115 has identified the DL synchronization signal transmitted on DL synchronization beam 405-b as the selected DL beam. As indicated, DL synchronization beam 405-b is transmitted during the second codeword.

[0099] In some aspects, the UE 115 may then select resources for transmitting the RACH message based on the selected DL beam and during the RACH subframe 415. In one example, the resources for transmitting the RACH message may correspond to the codeword of the selected DL beam. Therefore, the UE 115 may select the second resource 420 (e.g., frequency or frequency tone 1) as the resource for transmitting the RACH message. That is, the UE 115 may select the second resource 420 to convey an indication of the DL synchronization beam to be transmitted during the second codeword as the selected DL beam. As discussed above, the UE 115 may also select a RACH waveform to transmit the RACH message.

[0100] Therefore, UE 115 can find that the best synchronization beam is transmitted during the second codeword period. UE 115 can transmit RACH messages in the second frequency region in all time slots (e.g., during all codewords of RACH subframe 415). Base station 105 can find the best DL transmit beam from the used frequency region (e.g., second resource 420) of the random access signal (e.g., RACH message). In some examples, for example, due to DL-UL power differences, the RACH message transmission time unit may be larger than the synchronization subframe time unit.

[0101] In some aspects, the base station 105 may sweep the same eight directions during the same eight symbols during the RACH subframe 415. For example, the base station 105 may configure one or more antenna arrays to receive RACH messages according to the same sweep pattern used to transmit DL synchronization signals on the DL synchronization beam 405 during the RACH subframe 415.

[0102] Reference above Figure 4A and 4B The described example may be applicable to a situation where there is no correspondence for the selected DL beam at the base station 105. Additionally, the example may be applicable to a situation where there is no correspondence at both the base station 105 and the UE 115. In such a situation, the UE 115 may identify a method for transmitting using the selected DL beam based on a link gain associated with a transmission from the UE 115. In some cases, the UE 115 may determine its link gain based on a synchronization signal received from the base station 105. If the UE 115 has sufficient link gain to satisfy the link budget, the UE 115 may transmit a RACH message in a single RACH subframe. However, if the UE 115 does not have sufficient link gain to satisfy the link budget, the UE 115 may transmit a RACH message in multiple RACH subframes.

[0103] Although the reference Figure 4A and 4BThe described example involves transmitting a RACH message in a RACH subframe 415, but the example is also applicable to transmitting a scheduling request message, a beam recovery message, or a beam tracking message in a RACH subframe 415. In some cases, the UE 115 may find that the best synchronization beam is transmitted during the second symbol, and the UE 115 may transmit the scheduling request message, the beam recovery message, or the beam tracking message in the second frequency region in all time slots. The second frequency region may be in different resources (or resource blocks) in the RACH subframe 415. That is, a first portion of the resources in the RACH subframe 415 may be allocated for RACH message transmission, a second portion of the resources in the RACH subframe 415 may be allocated for scheduling request message transmission, and a third portion of the resources in the RACH subframe 415 may be allocated for beam recovery or beam tracking message transmission.

[0104] Figure 5A and 5B An example of a beam subframe mapping configuration 500 for RACH communication of DL synchronization beam information for various DL-UL correspondence states is illustrated. Configuration 500 may implement Figures 1 to 3 In some aspects, aspects of the configuration 500 may be implemented as described with reference to Figures 1 to 3 The described base station 105 and / or UE 115 are implemented.

[0105] Reference Figure 5A , the beam-subframe mapping configuration 500 may include multiple DL synchronization signals transmitted on a DL synchronization beam 505. The base station 105 may transmit the DL synchronization signal in a beamformed manner (e.g., for random access) and sweep through an angular coverage area (e.g., in azimuth and / or elevation). Each DL synchronization beam 505 may be transmitted in a beam sweeping operation in different directions to cover the coverage area of ​​the base station 105. For example, the DL synchronization beam 505-a may be transmitted in a first direction, the DL synchronization beam 505-b may be transmitted in a second direction, and so on. In some aspects, the DL synchronization beam 505 may be associated with a beam index (e.g., an indicator identifying the beam).

[0106] In some aspects, the DL synchronization beam 505 may also be transmitted during different symbol periods of the synchronization subframe 510. The synchronization subframe 510 may be associated with a time characteristic (e.g., symbol) along a horizontal axis and a frequency characteristic (e.g., frequency or tone) along a vertical axis. Figure 5A, the base station 105 can be configured with four antenna arrays, where the base station 105 sweeps four directions in each symbol. For example, antenna ports 0-3 can be grouped into subgroup 510 and used to transmit DL synchronization beams 505-a to 505-d during the first symbol (e.g., symbol 0) of the synchronization subframe 510. Moreover, antenna ports 0-3 can be grouped into subgroup 515 and used to transmit DL synchronization beams 505-e to 505-h during the second symbol (e.g., symbol 1) of the synchronization subframe 510. Therefore, the base station 105 can sweep eight directions during two symbols of the synchronization subframe 510.

[0107] In some aspects, each DL synchronization signal transmitted on the DL synchronization beam 505 may be transmitted on some or all frequencies during a symbol. For example, the DL synchronization beam 505-a may be transmitted on any of the frequencies or tones 0-7 during symbol 0, the DL synchronization beam 505-b may be transmitted on any of the frequencies or tones 0-7 during symbol 1, and so on. In some aspects, the DL synchronization beams 505 transmitted during a symbol may not be transmitted on overlapping frequencies.

[0108] Therefore, the base station 105 can sweep the DL synchronization beam 505 in eight directions during the eight code elements of the synchronization subframe 510.

[0109] Reference Figure 5B , each UE 115 within the coverage area of ​​the base station 105 can receive a DL synchronization signal on the DL synchronization beam 505. The UE 115 can identify which DL synchronization signal is the best (e.g., the strongest received signal strength, the best channel quality, etc.) and identify it as the selected DL beam. Figure 5B , UE 115 has identified the DL synchronization signal transmitted on DL synchronization beam 505-a as the selected DL beam. As indicated, DL synchronization beam 505-a is transmitted during the first code element (e.g., code element 0).

[0110] In some aspects, the UE 115 may then select resources for transmitting a RACH message based on the selected DL beam and during the RACH subframe 515. In one example, the resources for transmitting the RACH message may correspond to the symbols of the selected DL beam. Thus, the UE 115 may select the first resource 520 (e.g., frequency or tone 0) as the resource for transmitting the RACH message. That is, the UE 115 may select the first resource 520 to convey an indication of the DL synchronization beam to be transmitted during the first symbol as the selected DL beam.

[0111] Thus, the UE 115 may find that the best synchronization beam is transmitted during the first symbol. The UE 115 may transmit RACH messages in the first frequency region in all time slots (e.g., during all symbols of the RACH subframe 515). The base station 105 may find the best UL received beam by measuring the quality of the received signal during different time slots (e.g., during different symbols). In some aspects, the base station 105 may find the best route DL beam from the used frequency region (e.g., the first resource 520) of the random access signal (e.g., the RACH message).

[0112] In some aspects, the base station 105 may sweep the same eight directions during the same eight symbols during the RACH subframe 515. For example, the base station 105 may configure one or more antenna arrays to receive RACH messages according to the same sweep pattern used to transmit the DL synchronization signal on the DL synchronization beam 505 during the synchronization subframe 510.

[0113] Fig. 6A and 6B An example of a beam subframe mapping configuration 600 for RACH communication of DL synchronization beam information for various DL-UL correspondence states is illustrated. Configuration 600 may implement Figures 1 to 3 In some aspects, aspects of the wireless communication system 100, process flow 200, and / or system 300 in the embodiment of the present invention may be described in detail with reference to FIG. Figures 1 to 3 The described base station 105 and / or UE 115 are implemented.

[0114] Reference Fig. 6A , the beam subframe mapping configuration 600 may include multiple DL synchronization signals transmitted on a DL synchronization beam 605. The base station 105 may transmit the DL synchronization signal in a beamformed manner (e.g., for random access) and sweep through an angular coverage area (e.g., in azimuth and / or elevation). Each DL synchronization beam 605 may be transmitted in a beam sweeping operation in different directions to cover the coverage area of ​​the base station 105. For example, the DL synchronization beam 605-a may be transmitted in a first direction, the DL synchronization beam 605-b may be transmitted in a second direction, and so on. In some aspects, the DL synchronization beam 605 may be associated with a beam index (e.g., an indicator identifying the beam).

[0115] In some aspects, the DL synchronization beam 605 may also be transmitted during different symbol periods of the synchronization subframe 610. The synchronization subframe 610 may be associated with a time characteristic (e.g., symbol) along a horizontal axis and a frequency characteristic (e.g., frequency or tone) along a vertical axis. For example, the DL synchronization beam 605-a may be transmitted during a first symbol period (e.g., symbol 0), the DL synchronization beam 605-b may be transmitted during a second symbol period (e.g., symbol 1), and so on until the DL synchronization beam 605-h is transmitted during an eighth symbol period (e.g., symbol 7).

[0116] In some aspects, each DL synchronization signal transmitted on the DL synchronization beam 605 may be transmitted on some or all frequencies during a symbol. For example, the DL synchronization beam 605-a may be transmitted on frequencies or tones 0-7 during symbol 0, the DL synchronization beam 605-b may be transmitted on frequencies or tones 0-7 during symbol 1, and so on.

[0117] Therefore, the base station 105 can sweep the DL synchronization beam 605 in eight directions during the eight code elements of the synchronization subframe 610.

[0118] Reference Figure 6B , each UE 115 within the coverage area of ​​the base station 105 can receive a DL synchronization signal on the DL synchronization beam 605. The UE 115 can identify which DL synchronization signal is the best (e.g., the strongest received signal strength, the best channel quality, etc.) and identify it as the selected DL beam. Figure 6B , UE 115 has identified the DL synchronization signal transmitted on DL synchronization beam 605-b as the selected DL beam. As indicated, DL synchronization beam 605-b is transmitted during the second codeword.

[0119] In some aspects, the DL synchronization beam 605-b may have a complete correspondence at the base station 105 and the UE 115. That is, the DL synchronization beam 605-b may be used for transmission and reception at both the base station 105 and the UE 115. Thus, the UE 115 may select the DL synchronization beam 605-b to transmit a RACH message to the base station 105. In some cases, the UE 115 may randomly select a subcarrier region for transmitting a RACH message to provide diversity when there are multiple UEs. In the example Figure 6B , UE 115 has selected subcarrier 3 for transmitting the RACH message.

[0120] In other aspects, the DL synchronization beam 605-b may have a complete correspondence at the base station 105 and no correspondence at the UE 115. That is, the DL synchronization beam 605-b may be used for transmission and reception at the base station 105, but the transmission from the UE 115 on the DL synchronization beam 605-b may be noisy. In such a case, the UE 115 may identify a method for transmitting using the selected DL beam based on the link gain associated with the transmission from the UE 115. In some cases, the UE 115 may determine its link gain based on the synchronization signal received from the base station 105. If the UE 115 has sufficient link gain to meet the link budget, the UE 115 may transmit the RACH message in a single RACH subframe. However, if the UE 115 does not have sufficient link gain to meet the link budget, the UE 115 may transmit the RACH message in multiple RACH subframes.

[0121] Although the reference Fig. 6A and 6B The described example involves transmitting a RACH message in a RACH subframe 615, but the example is also applicable to transmitting a scheduling request message, a beam recovery message, or a beam tracking message in a RACH subframe 615. In some cases, the UE 115 may find that the best synchronization beam is transmitted during the second codeword, and the UE 115 may transmit the scheduling request message, the beam recovery message, or the beam tracking message in the second frequency region in all time slots. The second frequency region may be in different resources (or resource blocks) in the second codeword. That is, a first portion of the resources in the RACH subframe 615 may be allocated for RACH message transmission, a second portion of the resources in the RACH subframe 615 may be allocated for scheduling request message transmission, and / or a third portion of the resources in the RACH subframe 615 may be allocated for beam recovery or beam tracking message transmission.

[0122] Fig. 7A and 7B An example of a beam subframe mapping configuration 700 for RACH communication of DL synchronization beam information for various DL-UL correspondence states is illustrated. Configuration 700 may implement Figures 1 to 3 In some aspects, aspects of the wireless communication system 100, process flow 200, and / or system 300 in the embodiment of the present invention may be described in detail with reference to FIG. Figures 1 to 3 The described base station 105 and / or UE 115 are implemented.

[0123] Reference Fig. 7A, the beam-subframe mapping configuration 700 may include multiple DL synchronization signals transmitted on a DL synchronization beam 705. The base station 105 may transmit the DL synchronization signal in a beamformed manner (e.g., for random access) and sweep through an angular coverage area (e.g., in azimuth and / or elevation). Each DL synchronization beam 705 may be transmitted in a beam sweeping operation in different directions to cover the coverage area of ​​the base station 105. For example, the DL synchronization beam 705-a may be transmitted in a first direction, the DL synchronization beam 705-b may be transmitted in a second direction, and so on. In some aspects, the DL synchronization beam 705 may be associated with a beam index (e.g., an indicator identifying the beam).

[0124] In some aspects, the DL synchronization beam 705 may also be transmitted during different symbol periods of the synchronization subframe 710. The synchronization subframe 710 may be associated with a time characteristic (e.g., symbol) along a horizontal axis and a frequency characteristic (e.g., frequency or tone) along a vertical axis. For example, the DL synchronization beam 705-a may be transmitted during a first symbol period (e.g., symbol 0), the DL synchronization beam 705-b may be transmitted during a second symbol period (e.g., symbol 1), and so on until the DL synchronization beam 705-h is transmitted during an eighth symbol period (e.g., symbol 7).

[0125] In some aspects, each DL synchronization signal transmitted on the DL synchronization beam 705 may be transmitted on some or all frequencies during a symbol. For example, the DL synchronization beam 705-a may be transmitted on frequencies or tones 0-7 during symbol 0, the DL synchronization beam 705-b may be transmitted on frequencies or tones 0-7 during symbol 1, and so on.

[0126] Therefore, the base station 105 can sweep the DL synchronization beam 705 in eight directions during the eight code elements of the synchronization subframe 710.

[0127] Reference Figure 7B , each UE 115 within the coverage area of ​​the base station 105 can receive the DL synchronization signal on the DL synchronization beam 705. The UE 115 can identify which DL synchronization signal is the best (e.g., the strongest received signal strength, the best channel quality, etc.) and identify it as the selected DL beam. Figure 7B , UE 115 has identified the DL synchronization signal transmitted on DL synchronization beam 705-b as the selected DL beam. As indicated, DL synchronization beam 705-b is transmitted during the second codeword.

[0128] In some aspects, the DL synchronization beam 705-b can have a partial correspondence at the base station 105 and the UE 115. That is, the DL synchronization beam 705-b can be used for transmission and reception with less noise at both the base station 105 and the UE 115. However, it may be desirable for the UE 115 to identify a better beam (e.g., a stronger signal strength) for uplink transmission. Therefore, the UE 115 can transmit a RACH message on the codeword of the selected DL beam and the codeword of each adjacent DL beam (e.g., DL synchronization beams 705-a and 705-c). In order to receive uplink transmissions, the base station 105 can sweep a portion of the eight directions during codewords 0, 1, and 2 in the RACH subframe 715.

[0129] The UE 115 may then select a resource for transmitting the RACH message based on the selected DL beam and during the RACH subframe 415. In one example, the resource for transmitting the RACH message may correspond to the symbol of the selected DL beam. Thus, the UE 115 may select the second resource 720 (e.g., frequency or tone 1) as the resource for transmitting the RACH message. That is, the UE 115 may select the second resource 720 to convey an indication of the DL synchronization beam to be transmitted during the second symbol as the selected DL beam. As discussed above, the UE 115 may also select a RACH waveform to transmit the RACH message.

[0130] Therefore, UE 115 can find that the best synchronization beam is transmitted during the second codeword period. UE 115 can transmit RACH messages in the second frequency region in a portion of all time slots (e.g., during a portion of each codeword of RACH subframe 715). Base station 105 can find the best DL transmit beam from the used frequency region (e.g., second resource 720) of the random access signal (e.g., RACH message). In some examples, for example, due to DL-UL power differences, the RACH message transmission time unit may be larger than the synchronization subframe time unit.

[0131] Although the reference Fig. 7A and 7BThe described example involves transmitting a RACH message in a RACH subframe 715, but the example is also applicable to transmitting a scheduling request message, a beam recovery message, or a beam tracking message in a RACH subframe 715. In some cases, the UE 115 may find that the best synchronization beam is transmitted during the second symbol, and the UE 115 may transmit the scheduling request message, the beam recovery message, or the beam tracking message in a second frequency region in a portion of each symbol. The second frequency region may be in different resources (or resource blocks) in the RACH subframe 715. That is, a first portion of the resources in the RACH subframe 715 may be allocated for RACH message transmission, a second portion of the resources in the RACH subframe 715 may be allocated for scheduling request message transmission, and / or a third portion of the resources in the RACH subframe 715 may be allocated for beam recovery or beam tracking message transmission.

[0132] Figure 8 A block diagram 800 of a wireless device 805 supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states according to various aspects of the present disclosure is shown. The wireless device 805 may be as described with reference to Figure 1 Examples of various aspects of the UE 115 are described. The wireless device 805 may include a receiver 810, a UE synchronization manager 815, and a transmitter 820. The wireless device 805 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0133] The receiver 810 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to RACH communication of DL synchronization beam information for various DL-UL correspondence states, etc.). The information may be delivered to other components of the device. The receiver 810 may be a reference Fig.11 Examples of various aspects of transceiver 1135 are described.

[0134] UE synchronization manager 815 may be a reference Fig.11 Examples of various aspects of the UE synchronization manager 1115 are described. The UE synchronization manager 815 may receive a DL synchronization signal from a base station on one or more DL synchronization beams and identify a selected DL beam of the one or more DL synchronization beams for communication from the base station to the UE.

[0135] The transmitter 820 may transmit signals generated by other components of the device. In some examples, the transmitter 820 may be co-located with the receiver 810 in a transceiver module. For example, the transmitter 820 may be a reference Fig.11Examples of various aspects of the transceiver 1135 described herein. The transmitter 820 may include a single antenna, or it may include a set of antennas. The transmitter 820 may also transmit a RACH message / scheduling request message / beam recovery or beam tracking message to a base station using at least one of a resource or a RACH waveform selected based at least in part on the selected DL beam. In some cases, transmitting the RACH message / scheduling request message / beam recovery or beam tracking message includes transmitting the RACH message / scheduling request message / beam recovery or beam tracking message during the entire duration of the corresponding random access subframe.

[0136] Fig. 9 A block diagram 900 of a wireless device 905 supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states according to various aspects of the present disclosure is shown. The wireless device 905 may be as described with reference to Figure 1 and 8 Examples of various aspects of the wireless device 805 or UE 115 are described. The wireless device 905 may include a receiver 910, a UE synchronization manager 915, and a transmitter 920. The wireless device 905 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0137] The receiver 910 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to RACH communication of DL synchronization beam information for various DL-UL correspondence states, etc.). The information may be delivered to other components of the device. The receiver 910 may be a reference Fig.11 Examples of various aspects of transceiver 1135 are described.

[0138] UE synchronization manager 915 may be a reference Fig.11 Examples of various aspects of the UE synchronization manager 1115 are described. The UE synchronization manager 915 may also include a synchronization signal component 925, a beam selection component 930, and a resource selection component 935.

[0139] The synchronization signal component 925 can receive a DL synchronization signal from a base station on one or more DL synchronization beams. In some cases, the correspondence between the one or more DL synchronization beams from the base station and the one or more UL receive beams at the base station is missing. In some cases, the one or more DL synchronization beams are within a single symbol of a synchronization subframe, wherein selecting resources and / or RACH waveforms for transmitting RACH messages / scheduling request messages / beam recovery or beam tracking messages includes: selecting resources and / or RACH waveforms based on the symbols of the selected DL beams.

[0140] The beam selection component 930 may identify a selected DL beam from one or more DL synchronization beams for communication from the base station to the UE. In some cases, identifying the selected DL beam includes identifying the DL beam based on a DL synchronization signal on the one or more DL synchronization beams satisfying a transmit power condition. In some cases, the selected DL beam from the base station is different from the selected UL beam from the UE. In some cases, the base station may identify the preferred UL beam based on the quality of a received RACH message. The base station may also transmit one or more subsequent messages to the UE, the one or more subsequent messages conveying an indication of the preferred UL beam.

[0141] The resource selection component 935 can select resources and / or RACH waveforms for transmitting RACH messages / scheduling request messages / beam recovery or beam tracking messages to the base station, and the resources and / or RACH waveforms are selected based on the selected DL beam. In some cases, selecting resources and / or RACH waveforms includes: selecting resources and / or RACH waveforms based on the index of the selected DL beam. In some cases, selecting resources and / or RACH waveforms includes: selecting resources and / or RACH waveforms based on the code elements of the subframe of the DL synchronization signal of the selected DL beam. In some cases, resources are associated with one or more frequency tones in a component carrier. In some cases, resources are associated with a component carrier.

[0142] The transmitter 920 may transmit signals generated by other components of the device. In some examples, the transmitter 920 may be co-located with the receiver 910 in a transceiver module. For example, the transmitter 920 may be a reference Fig.11 Examples of various aspects of the transceiver 1135 are described. Transmitter 920 may include a single antenna, or it may include a collection of antennas.

[0143] Fig.10 A block diagram 1000 of a UE synchronization manager 1015 supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states in accordance with various aspects of the present disclosure is shown. The UE synchronization manager 1015 may be a reference Figure 8 , 9 11 and 12. The UE synchronization manager 815, UE synchronization manager 915, or UE synchronization manager 1115 described in detail are examples of various aspects. The UE synchronization manager 1015 may include a synchronization signal component 1020, a beam selection component 1025, a resource selection component 1030, a preferred beam component 1035, a RACH waveform component 1040, and a correspondence management component 1045. Each of these modules can communicate with each other directly or indirectly (e.g., via one or more buses).

[0144] The synchronization signal component 1020 can receive a DL synchronization signal from a base station on one or more DL synchronization beams. The beam selection component 1025 can identify a selected DL beam from one or more DL synchronization beams for communication from the base station to the UE. The resource selection component 1030 can select resources and / or RACH waveforms for transmitting RACH messages / scheduling request messages / beam recovery or beam tracking messages to the base station, and the resources and / or RACH waveforms are selected based on the selected DL beams. In some cases, the resource selection component 1030 can select resources and / or RACH waveforms for transmitting RACH messages / scheduling request messages / beam recovery or beam tracking messages to the base station based on an indication that the correspondence between one or more DL synchronization beams from the base station and one or more UL receive beams at the base station is missing.

[0145] The preferred beam component 1035 can identify a preferred beam from a plurality of beams transmitted by the base station. In some cases, identifying the selected DL beam includes identifying the preferred DL beam based on a signal strength of a DL synchronization signal on one or more DL synchronization beams, a signal quality of a DL synchronization signal on one or more DL synchronization beams, or a combination thereof. The RACH waveform component 1040 can select a RACH waveform for transmitting a RACH message / scheduling request message / beam recovery or beam tracking message to the base station, the RACH waveform being selected based on the selected DL beam. In some cases, selecting the RACH waveform includes selecting a RACH preamble, a cyclic shift, or a combination thereof based on an index of the selected DL beam.

[0146] The correspondence management component 1045 may receive an indication of a missing correspondence between one or more DL synchronization beams from a base station and one or more UL receive beams at the base station. In some cases, the correspondence management component 1045 may transmit a RACH message / scheduling request message / beam recovery or beam tracking message to the base station during the entire duration of the RACH subframe based at least in part on the indication of the missing correspondence. In some cases, the correspondence management component 1045 may receive the indication in the MIB or SIB. In some cases, the correspondence management component 1045 may transmit an indication of a missing correspondence between one or more DL synchronization beams from a base station and one or more UL receive beams at the base station. In some cases, the correspondence management component 1045 may transmit a RACH message / scheduling request message / beam recovery or beam tracking message to the base station during the first symbol of the first random access subframe and the second symbol of the second random access subframe. In some cases, the correspondence management component 1045 may transmit an indication of the missing correspondence to the UE in RACH message 3, PUCCH, or PUSCH.

[0147] In some cases, the correspondence management component 1045 may receive an indication of the characteristics of the correspondence between one or more DL synchronization beams from the base station and one or more UL beams from the UE. In some cases, the characteristics of the correspondence correspond to one of the following: a complete correspondence, a partial correspondence, or no correspondence. In some cases, the correspondence management component 1045 may determine that the correspondence exists, and select the transmission time for transmitting a RACH message / scheduling request message / beam recovery or beam tracking message to the base station based on the existence of the correspondence. In some cases, the transmission time includes the codeword of the corresponding random access subframe. In some cases, the correspondence management component 1045 may determine that there is a partial correspondence, and select the transmission time for transmitting a RACH message / scheduling request message / beam recovery or beam tracking message to the base station based on the partial correspondence. In some cases, the transmission time includes multiple codewords of the corresponding random access subframe. In some cases, if there is no beam correspondence at the UE, the UE can transmit multiple RACH messages.

[0148] In some cases, the correspondence management component 1045 can select a transmission time, a frequency range, and a RACH preamble for transmitting a RACH message based on the characteristics of the correspondence. In some cases, the correspondence management component 1045 can select a resource or a RACH waveform based at least in part on a symbol associated with a DL synchronization signal and an indication of the characteristics of the correspondence. In some cases, the correspondence management component 1045 can receive an indication of the characteristics of the correspondence on a PBCH or an ePBCH. In some cases, the correspondence management component 1045 can receive an indication of the characteristics of the correspondence in a MIB or a SIB.

[0149] Fig.11 A diagram of a system 1000 including a device 1105 supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states according to various aspects of the present disclosure is shown. The device 1105 may be, for example, a device 1105 of the type described in the accompanying drawings. Figure 1 , 8 1105 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a UE synchronization manager 1115, a processor 1120, a memory 1125, software 1130, a transceiver 1135, an antenna 1140, and an I / O controller 1145. These components may be in electronic communication via one or more buses (e.g., bus 1110). The device 1105 may communicate wirelessly with one or more base stations 105.

[0150] The processor 1120 may include an intelligent hardware device (e.g., a general-purpose processor, a digital signal processor (DSP), a central processing unit (CPU), a microcontroller, an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor 1120 may be configured to operate the memory array using a memory controller. In other cases, the memory controller may be integrated into the processor 1120. The processor 1120 may be configured to execute computer-readable instructions stored in the memory to perform various functions (e.g., various functions or tasks supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states).

[0151] The memory 1125 may include random access memory (RAM) and read-only memory (ROM). The memory 1125 may store computer-readable, computer-executable software 1130 including instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, the memory 1125 may include, among other things, a basic input / output system (BIOS) that may control basic hardware and / or software operations, such as interaction with peripheral components or devices.

[0152] The software 1130 may include code for implementing various aspects of the present disclosure, including code for supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states. The software 1130 may be stored in a non-transitory computer-readable medium such as a system memory or other memory. In some cases, the software 1130 may not be directly executable by a processor, but may (e.g., when compiled and executed) cause a computer to perform the functions described herein.

[0153] The transceiver 1135 may communicate bidirectionally via one or more antennas, wired or wireless links, as described above. For example, the transceiver 1135 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 1135 may also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, and demodulate packets received from an antenna.

[0154] In some cases, a wireless device may include a single antenna 1140. However, in some cases, the device may have more than one antenna 1140, which may be capable of transmitting or receiving multiple wireless transmissions concurrently.

[0155] I / O controller 1145 can manage input and output signals for device 1105. I / O controller 1145 can also manage peripheral devices that are not integrated into device 1105. In some cases, I / O controller 1145 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 1145 can utilize an operating system, such as or another known operating system.

[0156] Fig.12 A block diagram 1200 of a wireless device 1205 supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states according to various aspects of the present disclosure is shown. The wireless device 1205 may be as described with reference to Figure 1 Examples of various aspects of the base station 105 are described. The wireless device 1205 may include a receiver 1210, a base station synchronization manager 1215, and a transmitter 1220. The wireless device 1205 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0157] The receiver 1210 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to RACH communication of DL synchronization beam information for various DL-UL correspondence states, etc.). The information may be delivered to other components of the device. The receiver 1210 may be a reference Fig.15 Examples of various aspects of transceiver 1535 are described.

[0158] The base station synchronization manager 1215 may be a reference Fig.15 Examples of various aspects of the described base station synchronization manager 1515. The base station synchronization manager 1215 can transmit a DL synchronization signal on one or more DL synchronization beams, receive a RACH message / scheduling request message / beam recovery or beam tracking message from a UE on at least one of a resource or a RACH waveform, and identify a selected DL beam of the one or more DL synchronization beams for communication from the base station to the UE based on the resource and / or the RACH waveform.

[0159] Transmitter 1220 may transmit signals generated by other components of the device. In some examples, transmitter 1220 may be co-located with receiver 1210 in a transceiver module. For example, transmitter 1220 may be a reference Fig.15 Examples of aspects of the transceiver 1535 are described. The transmitter 1220 may include a single antenna, or it may include a set of antennas. The transmitter 1220 may also use the selected DL beam to transmit one or more subsequent messages to the UE.

[0160] Fig.13 A block diagram 1305 of a wireless device 1300 supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states according to various aspects of the present disclosure is shown. The wireless device 1305 may be as described with reference to Figure 1 and 12 Examples of various aspects of the wireless device 1205 or base station 105 are described. The wireless device 1305 may include a receiver 1310, a base station synchronization manager 1315, and a transmitter 1320. The wireless device 1305 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0161] The receiver 1310 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to RACH communication of DL synchronization beam information for various DL-UL correspondence states, etc.). The information may be delivered to other components of the device. The receiver 1310 may be a reference Fig.15 Examples of various aspects of transceiver 1535 are described.

[0162] The base station synchronization manager 1315 may be a reference Fig.15 Examples of various aspects of the base station synchronization manager 1515 are described. The base station synchronization manager 1315 may also include a synchronization signal component 1325, a RACH component 1330, and a selected beam component 1335.

[0163] The synchronization signal component 1325 can transmit a DL synchronization signal on one or more DL synchronization beams. In some cases, the correspondence between one or more DL synchronization beams from a base station and one or more UL receive beams at the base station is missing.

[0164] The RACH component 1330 can receive a RACH message / scheduling request message / beam recovery or beam tracking message from the UE on the resource and / or RACH waveform. In some cases, receiving the RACH message / scheduling request message / beam recovery or beam tracking message includes: receiving the RACH message / scheduling request message / beam recovery or beam tracking message during the entire duration of the corresponding random access subframe. In some cases, receiving the RACH message / scheduling request message / beam recovery or beam tracking message includes: receiving the RACH message / scheduling request message / beam recovery or beam tracking message on a set of UL beams. In some cases, the resources are associated with one or more frequency tones in the component carrier. In some cases, the resources are associated with the component carrier.

[0165] The selected beam component 1335 can identify a selected DL beam of the one or more DL synchronization beams for communication from the base station to the UE based on resources and / or RACH waveforms. In some cases, identifying the selected DL beam includes associating resources and / or RACH waveforms with an index of the selected DL beam. In some cases, identifying the selected DL beam includes associating resources and / or RACH waveforms with symbols of a subframe of a DL synchronization signal of the selected DL beam. In some cases, identifying the selected DL beam further includes identifying the selected DL beam based on a RACH waveform of a RACH message / scheduling request message / beam recovery or beam tracking message. In some cases, identifying the selected DL beam includes identifying the selected DL beam based on a RACH preamble of a RACH message, a cyclic shift of a RACH message, or a combination thereof. In some cases, the selected DL beam from the base station is different from the selected UL beam from the UE.

[0166] Transmitter 1320 may transmit signals generated by other components of the device. In some examples, transmitter 1320 may be co-located with receiver 1310 in a transceiver module. For example, transmitter 1320 may be a reference Fig.15 Examples of various aspects of the described transceiver 1535. The transmitter 1320 may include a single antenna, or it may include a collection of antennas.

[0167] Fig.14 A block diagram 1400 of a base station synchronization manager 1415 supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states in accordance with various aspects of the present disclosure is shown. The base station synchronization manager 1415 may be a reference Fig.12 , 13 15 and 15. The base station synchronization manager 1415 may include a synchronization signal component 1420, a RACH component 1425, a selected beam component 1430, a quality measurement component 1435, a UL beam component 1440, and a correspondence management component 1445. Each of these modules can communicate with each other directly or indirectly (e.g., via one or more buses).

[0168] The synchronization signal component 1420 can transmit a DL synchronization signal on one or more DL synchronization beams. The RACH component 1425 can receive a RACH message / scheduling request message / beam recovery or beam tracking message from the UE on at least one of the resources or the RACH waveform. The selected beam component 1430 can identify a selected DL beam of the one or more DL synchronization beams for communication from the base station to the UE based on the resources and / or the RACH waveform.

[0169] The quality measurement component 1435 can measure the quality of the RACH message / scheduling request message / beam restoration or beam tracking message received on a set of UL beams. In some cases, measuring the quality of the RACH message / scheduling request message / beam restoration or beam tracking message includes: measuring one or more of reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), signal to noise ratio (signal to noise ratio (SNR)), or signal to interference plus noise ratio (SINR). The UL beam component 1440 can determine the selected UL beam for communication from the UE to the base station based on the quality.

[0170] The correspondence management component 1445 may transmit an indication of a lack of correspondence between one or more DL synchronization beams from a base station and one or more UL receive beams at the base station. In some cases, the correspondence management component 1445 may transmit the indication in a MIB or SIB. In some cases, the correspondence management component 1445 may receive an indication of a lack of correspondence between one or more DL synchronization beams from a base station and one or more UL receive beams at the base station, and map a DL beam for transmitting a CSI-RS to a UL beam for transmitting an SRS or map a UL beam for transmitting an SRS to a DL beam for transmitting a CSI-RS. In some cases, the correspondence management component 1445 may receive an indication of a lack of correspondence between one or more DL synchronization beams from a base station and one or more UL receive beams at the base station, and map a DL beam used in DL beam training to a UL beam used in UL beam training or map a UL beam used in UL beam training to a DL beam used in DL beam training.

[0171] Fig.15 A diagram of a system 1500 including a device 1505 supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states according to various aspects of the present disclosure is shown. The device 1505 may be, for example, a device 1505 of the type described in the accompanying drawings. Figure 1 Examples of the components of the base station 105 described above may include these components. The device 1505 may include components for two-way voice and data communication, including components for transmitting and receiving communications, including a base station synchronization manager 1515, a processor 1520, a memory 1525, software 1530, a transceiver 1535, an antenna 1540, a network communication manager 1545, and a base station communication manager 1550. These components may be in electronic communication via one or more buses (e.g., bus 1510). The device 1505 may communicate wirelessly with one or more UEs 115.

[0172] The processor 1520 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor 1520 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into the processor 1520. The processor 1520 may be configured to execute computer-readable instructions stored in the memory to perform various functions (e.g., various functions or tasks supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states).

[0173] The memory 1525 may include RAM and ROM. The memory 1525 may store computer-readable, computer-executable software 1530 including instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, the memory 1525 may include, among other things, a BIOS that may control basic hardware and / or software operations, such as interaction with peripheral components or devices.

[0174] The software 1530 may include code for implementing various aspects of the present disclosure, including code for supporting RACH communication of DL synchronization beam information for various DL-UL correspondence states. The software 1530 may be stored in a non-transitory computer-readable medium such as a system memory or other memory. In some cases, the software 1530 may not be directly executable by a processor, but may (e.g., when compiled and executed) cause a computer to perform the functions described herein.

[0175] The transceiver 1535 may communicate bidirectionally via one or more antennas, wired or wireless links, as described above. For example, the transceiver 1535 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 1535 may also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, and demodulate packets received from an antenna.

[0176] In some cases, a wireless device may include a single antenna 1540. However, in some cases, the device may have more than one antenna 1540, which may be capable of transmitting or receiving multiple wireless transmissions concurrently.

[0177] The network communications manager 1545 may manage communications with the core network (eg, via one or more wired backhaul links). For example, the network communications manager 1545 may manage the transmission of data communications for client devices, such as one or more UEs 115.

[0178] Base station communication manager 1550 may manage communications with other base stations 105 and may include a controller or scheduler for controlling communications with UE 115 in coordination with other base stations 105. For example, base station communication manager 1550 may coordinate scheduling of transmissions to UE 115 for various interference mitigation techniques, such as beamforming or joint transmissions. In some examples, base station communication manager 1550 may provide an X2 interface within a long term evolution (LTE) / LTE-A wireless communication network technology to provide communications between base stations 105.

[0179] Fig.16 A flow chart illustrating a method 1600 for RACH communication of DL synchronization beam information for various DL-UL correspondence states according to various aspects of the present disclosure is shown. The operations of the method 1600 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 1600 may be implemented by a UE 115 or components thereof as described herein. Figures 8 to 11 In some examples, the UE 115 may execute a set of codes for controlling the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may use dedicated hardware to perform various aspects of the functions described below.

[0180] At block 1605, UE 115 may receive a DL synchronization signal from a base station on one or more DL synchronization beams. The operations of block 1605 may be based on reference Figure 1-Figure 3 , Figure 4A and Figure 4B , Figure 5A and Figure 5B In some examples, various aspects of the operation of block 1605 may be performed as described with reference to Figures 8 to 11 The described synchronization signal components are implemented.

[0181] At block 1610, the UE 115 may identify a selected DL beam from among the one or more DL synchronization beams for communication from the base station to the UE. The operations of block 1610 may be performed according to the reference Figure 1-Figure 3 , Figure 4A and Figure 4B , Figure 5A and Figure 5B In some examples, various aspects of the operation of block 1610 may be performed as described with reference to Figures 8 to 11 The beam selection component described is performed.

[0182] At block 1615, the UE 115 may transmit a RACH message / scheduling request message / beam restoration or beam tracking message to the base station using at least one of the resources or RACH waveform selected based at least in part on the selected DL beam. The operation of block 1615 may be based on reference Figure 1-Figure 3 , Figure 4A and Figure 4B , Figure 5A and Figure 5B In some examples, various aspects of the operation of block 1615 may be performed as described with reference to Figures 8 to 11 The transmitter described is performed.

[0183] Fig.17 A flow chart illustrating a method 1700 for RACH communication of DL synchronization beam information for various DL-UL correspondence states according to various aspects of the present disclosure is shown. The operations of the method 1700 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 1700 may be implemented by a UE 115 or components thereof as described herein. Figures 8 to 11 In some examples, the UE 115 may execute a set of codes for controlling the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may use dedicated hardware to perform various aspects of the functions described below.

[0184] At block 1705, UE 115 may receive a DL synchronization signal from a base station on one or more DL synchronization beams. The operations of block 1705 may be performed according to reference Figure 1-Figure 3 , Figure 4A and Figure 4B , Figure 5A and Figure 5B In some examples, various aspects of the operation of block 1705 may be performed as described with reference to Figures 8 to 11 The described synchronization signal components are implemented.

[0185] At block 1710, the UE 115 may identify a selected DL beam from among the one or more DL synchronization beams for communication from the base station to the UE. The operations of block 1710 may be based on reference Figure 1-Figure 3 , Figure 4A and Figure 4B , Figure 5A and Figure 5B In some examples, various aspects of the operation of block 1710 may be performed as described with reference to Figures 8 to 11 The beam selection component described is performed.

[0186] At block 1715, the UE 115 may transmit a RACH message / scheduling request message / beam recovery or beam tracking message to the base station using at least one of a resource or a RACH waveform selected based at least in part on the selected DL beam, which may also be selected based on the index of the selected DL beam. The operation of block 1715 may be performed according to reference Figure 1-Figure 3 , Figure 4A and Figure 4B , Figure 5A and Figure 5B In some examples, various aspects of the operation of block 1715 may be performed as described with reference to Figures 8 to 11 The transmitter described is performed.

[0187] Fig.18 A flow chart illustrating a method 1800 for RACH communication of DL synchronization beam information for various DL-UL correspondence states according to various aspects of the present disclosure is shown. The operations of the method 1800 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of the method 1800 may be implemented by a base station 105 or components thereof as described herein. Figures 12 to 15 In some examples, the base station 105 may execute a set of codes for controlling the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station 105 may use dedicated hardware to perform various aspects of the functions described below.

[0188] At block 1805, the base station 105 may transmit a DL synchronization signal on one or more DL synchronization beams. The operations of block 1805 may be performed according to the reference Figure 1-Figure 3 , Figure 4A and Figure 4B , Figure 5A and Figure 5B In some examples, various aspects of the operation of block 1805 may be performed as described with reference to Figures 12 to 15 The described synchronization signal components are implemented.

[0189] At block 1810, the base station 105 may receive a RACH message / scheduling request message / beam recovery or beam tracking message from a UE on at least one of a resource or a RACH waveform. The operation of block 1810 may be performed according to the reference Figure 1-Figure 3 , Figure 4A and Figure 4B , Figure 5A and Figure 5B In some examples, various aspects of the operation of block 1810 may be performed as described with reference to Figures 12 to 15 The described RACH components are performed.

[0190] At block 1815, the base station 105 may identify a selected DL beam of the one or more DL synchronization beams for communication from the base station to the UE based at least in part on the resource or the RACH waveform. The operation of block 1815 may be performed according to the reference Figure 1-Figure 3 , Figure 4A and Figure 4B , Figure 5A and Figure 5B In some examples, various aspects of the operation of block 1815 may be performed as described with reference to Figures 12 to 15 The selected beam components described are performed.

[0191] At block 1820, the base station 105 may use the selected DL beam to transmit one or more subsequent messages to the UE. The operations of block 1820 may be performed according to the reference Figure 1-Figure 3 , Figure 4A and Figure 4B , Figure 5A and Figure 5B In some examples, various aspects of the operation of block 1820 may be performed as described with reference to Figures 12 to 15 The transmitter described is performed.

[0192] Fig.19 A flow chart illustrating a method 1900 for RACH communication of DL synchronization beam information for various DL-UL correspondence states according to various aspects of the present disclosure is shown. The operations of the method 1900 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of the method 1900 may be implemented by a base station 105 or components thereof as described herein. Figures 12 to 15 In some examples, the base station 105 may execute a set of codes for controlling the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station 105 may use dedicated hardware to perform various aspects of the functions described below.

[0193] At block 1905, the base station 105 may receive a RACH message / scheduling request message / beam restoration or beam tracking message from the UE on multiple UL beams on at least one of a resource or a RACH waveform. The operation of block 1905 may be performed according to the reference Figure 1-Figure 3 , Figure 4A and Figure 4B , Figure 5A and Figure 5B In some examples, various aspects of the operation of block 1905 may be performed as described with reference to Figures 12 to 15 The described RACH components are performed.

[0194] At block 1910, the base station 105 may measure the quality of RACH messages / scheduling request messages / beam restoration or beam tracking messages received on multiple UL beams. The operation of block 1910 may be based on reference Figure 1-Figure 3 , Figure 4A and Figure 4B , Figure 5A and Figure 5B In some examples, various aspects of the operation of block 1910 may be performed as described with reference to Figures 12 to 15 Describes the quality measurement components to perform.

[0195] At block 1915, the base station 105 may determine or identify a selected UL beam (e.g., a preferred UL beam) for communication from the UE to the base station based at least in part on the measured quality of the RACH message. The base station may also transmit one or more subsequent messages to the UE, for example in RACH message 2, that convey an indication of the preferred UL beam. The one or more subsequent messages to the UE may include an identification or index (e.g., an OCC index) of the preferred UL beam. The operation of block 1915 may be performed according to reference Figure 1-Figure 3 , Figure 4A and Figure 4B , Figure 5A and Figure 5B In some examples, various aspects of the operation of block 1915 may be performed as described with reference to Figures 12 to 15 The UL beam component described is used to perform.

[0196] In some cases, receiving a RACH message / scheduling request message / beam restoration or beam tracking message includes receiving the RACH message / scheduling request message / beam restoration or beam tracking message on multiple UL beams.

[0197] It should be noted that the above methods describe possible implementations, and that the operations and steps may be rearranged or otherwise modified and other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0198] The technology described herein can be used for various wireless communication systems, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA) and other systems. The terms "system" and "network" are often used interchangeably. Code division multiple access (CDMA) systems can implement radio technologies such as CDMA2000, Universal Terrestrial Radio Access (UTRA). CDMA2000 covers IS2000, IS-95 and IS-856 standards. IS-2000 versions are often referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is often referred to as CDMA20001xEV-DO, high rate packet data (HRPD), etc. UTRA includes wideband CDMA (WCDMA) and other CDMA variants. Time division multiple access (TDMA) systems can implement radio technologies such as global system for mobile communications (GSM).

[0199] Orthogonal Frequency Division Multiple Access (OFDMA) systems enable technologies such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (WiFi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM TM Radio technologies such as UTRA and E-UTRA are parts of the Universal Mobile Telecommunications System (UMTS). 3GPP Long Term Evolution (LTE) and Advanced LTE (LTE-A) are new Universal Mobile Telecommunications System (UMTS) versions that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and Global System for Mobile Communications (GSM) are described in documents from an organization called "3rd Generation Partnership Project" (3GPP). CDMA2000 and UMB are described in documents from an organization called "3rd Generation Partnership Project 2" (3GPP2). The technology described herein can be used for both the systems and radio technologies mentioned above and for other systems and radio technologies. Although various aspects of the LTE system can be described for example purposes, and LTE terminology is used in most of the above descriptions, the technology described herein can also be applied to applications other than LTE applications.

[0200] In LTE / LTE-A networks (including such networks described herein), the term evolved Node B (eNB) may be generally used to describe a base station. One or more wireless communication systems described herein may include heterogeneous LTE / LTE-A networks in which different types of eNBs provide coverage for various geographic regions. For example, each eNB or base station may provide communication coverage for a macro cell, a small cell, or other types of cells. Depending on the context, the term "cell" may be used to describe a base station, a carrier or component carrier associated with a base station, or a coverage area (e.g., a sector, etc.) of a carrier or base station.

[0201] A base station may include or may be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a Node B, an evolved Node B (eNB), a Home Node B, a Home Evolved Node B, or some other suitable term. The geographic coverage area of ​​a base station may be divided into sectors that constitute only a portion of the coverage area. One or more wireless communication systems described herein may include different types of base stations (e.g., macro or small cell base stations). The UE described herein may be able to communicate with various types of base stations and network equipment (including macro eNBs, small cell eNBs, relay base stations, etc.). There may be overlapping geographic coverage areas of different technologies.

[0202] A macro cell generally covers a relatively large geographic area (e.g., a radius of several kilometers) and may allow unrestricted access by UEs with service subscriptions to a network provider. Compared to a macro cell, a small cell is a low-power base station that may operate in the same or different (e.g., licensed, unlicensed, etc.) frequency band as a macro cell. According to various examples, a small cell may include a pico cell, a femto cell, and a micro cell. A pico cell, for example, may cover a smaller geographic area and may allow unrestricted access by UEs with service subscriptions to a network provider. A femto cell may also cover a smaller geographic area (e.g., a residence) and may provide restricted access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs of users in the residence, etc.). An eNB for a macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An eNB may support one or more (e.g., two, three, four, etc.) cells (e.g., component carriers). A UE may be able to communicate with various types of base stations and network equipment including macro eNBs, small cell eNBs, relay base stations, etc.

[0203] One or more wireless communication systems described herein may support synchronous or asynchronous operation. For synchronous operation, each base station may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, each base station may have different frame timing, and transmissions from different base stations may not be aligned in time. The techniques described herein may be used for synchronous or asynchronous operation.

[0204] Downlink transmissions described herein may also be referred to as forward link transmissions, and uplink transmissions may also be referred to as reverse link transmissions. Each communication link described herein, such as including Figure 1 and 2 The wireless communication systems 100 and 200 may include one or more carriers, where each carrier may be a signal composed of multiple subcarriers (eg, waveform signals of different frequencies).

[0205] The descriptions set forth herein in conjunction with the accompanying drawings describe example configurations and do not represent all examples that may be implemented or that fall within the scope of the claims. The term "exemplary" as used herein means "used as an example, instance, or illustration" and does not mean "better than" or "better than other examples." This detailed description includes specific details to provide an understanding of the described techniques. However, these techniques may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0206] In the accompanying drawings, similar components or features may have the same reference number. In addition, various components of the same type may be distinguished by following the reference number with a dash and a second reference number that distinguishes between the similar components. If only the first reference number is used in the specification, the description may apply to any of the similar components having the same first reference number regardless of the second reference number.

[0207] The information and signals described herein may be represented using any of a variety of different techniques and technologies. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be mentioned throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0208] The various illustrative blocks and modules described in conjunction with the disclosure herein may be implemented or executed with a general purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in an alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0209] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, each function may be stored on a computer-readable medium or transmitted therefrom as one or more instructions or codes. Other examples and implementations fall within the scope of the present disclosure and the appended claims. For example, due to the nature of software, the above functions may be implemented using software executed by a processor, hardware, firmware, hard wiring, or any combination thereof. The features that implement the functions may also be physically located in various locations, including being distributed so that the various parts of the functions are implemented at different physical locations. In addition, as used herein (including in the claims), the "or" used in the enumeration of items (e.g., enumeration of items with phrases such as "at least one of" or "one or more of") indicates an inclusive enumeration, so that, for example, the enumeration of 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). Similarly, as used herein, the phrase "based on" should not be interpreted as citing 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 the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0210] Computer readable medium includes both non-transient computer storage medium and communication medium, and it includes any medium that facilitates computer program to transfer from one place to another place.Non-transient storage medium can be any available medium that can be accessed by general or special-purpose computer.As an example and not limitation, non-transient computer readable medium can include RAM, ROM, electrically erasable programmable read-only memory (EEPROM), compact disk (CD) ROM or other optical disk storage, disk storage or other magnetic storage device, or can be used to carry or store instruction or data structure form of desired program code means and can be accessed by general or special-purpose computer or general or special-purpose processor any other non-transient medium.Any connection is also properly referred to as computer readable medium.For example, if software is transmitted from website, server or other remote source using coaxial cable, optical fiber cable, twisted pair, digital subscriber line (DSL) or wireless technology such as infrared, radio and microwave, then the coaxial cable, optical fiber cable, twisted pair, digital subscriber line (DSL) or wireless technology such as infrared, radio and microwave are just included in the definition of medium. Disk and disc as used herein include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, where disks usually reproduce data magnetically and discs reproduce data optically with lasers. Combinations of the above media are also included in the scope of computer-readable media.

[0211] The description herein is provided to enable those skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to those skilled in the art, and the universal principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a user equipment UE, comprising: receiving a DL signal from a network node on one or more downlink DL beams; selecting a DL beam of the one or more DL beams for communication from the network node to the UE; transmitting an indication of a characteristic of a beam correspondence between one or more DL beams at the UE and one or more uplink (UL) beams at the UE, wherein the characteristic of the beam correspondence corresponds to one of: a full beam correspondence, a partial beam correspondence, or no beam correspondence; selecting a resource or a waveform for uplink transmission, the resource or the waveform corresponding to a selected DL beam of the one or more DL beams and selected based at least in part on characteristics of a beam correspondence between the selected DL beam and one or more uplink beams at the UE; as well as A scheduling request message is transmitted to the network node using at least one of the resources or the waveform selected based at least in part on the selected DL beam.

2. The method of claim 1, wherein the resource or the waveform is selected based at least in part on the indication of a characteristic of the beam correspondence.

3. The method of claim 1, further comprising: determining that there is a beam correspondence based on the indication; as well as A transmission time for transmitting the scheduling request message to the network node is selected based on the existing beam correspondence, wherein the transmission time corresponds to a symbol of a corresponding random access subframe.

4. The method of claim 1, further comprising: determining that a partial beam correspondence exists based on the indication; as well as A transmission time for transmitting the scheduling request message to the network node is selected based on the partial beam correspondence, wherein the transmission time includes a plurality of symbols of a corresponding random access subframe.

5. The method of claim 1, further comprising: The resource or the waveform is selected based at least in part on symbols associated with the DL signal and the indication.

6. The method of claim 1, wherein the waveform comprises one of a scheduling request or a random access channel (RACH) waveform. The method of claim 1 , wherein the DL signal comprises a synchronization signal or a reference signal.

8. The method of claim 1 , wherein selecting the resource or the waveform comprises: The resource or the waveform is selected based at least in part on an index of a selected DL beam or a symbol of a subframe of a DL signal of a selected DL waveform.

9. The method of claim 1 , wherein transmitting the scheduling request message comprises: The scheduling request message is transmitted during the entire duration of the corresponding random access subframe.

10. The method of claim 1, wherein selecting the DL beam comprises: A preferred DL beam is identified based at least in part on a signal strength of the DL signals on the one or more DL beams, a signal quality of the DL signals on the one or more DL beams, or a combination thereof.

11. The method of claim 1 , wherein selecting the DL beam comprises: The DL beams are identified based at least in part on the DL signals on the one or more DL beams satisfying a transmit power condition.

12. The method of claim 1, further comprising: At least one of the resource or the waveform is selected for use in transmitting the scheduling request message to the network node, the resource or the waveform being selected based at least in part on the selected DL beam.

13. The method of claim 1, wherein a beam correspondence between the one or more DL beams and one or more uplink UL beams at the UE is missing.

14. The method of claim 13, wherein the missing beam correspondence is associated with the one or more DL beams having a different beam direction than the one or more UL beams.

15. The method of claim 1, further comprising: The beam correspondence is missing by receiving information from the network node in a master information block MIB or a system information block SIB.

16. The method of claim 15, further comprising: selecting the resource or the waveform based at least in part on the indication of the missing correspondence; as well as The scheduling request message is transmitted to the network node during an entire duration of a RACH subframe based at least in part on the indication of the missing correspondence.

17. The method of claim 1, further comprising: An indication is transmitted that a correspondence between the one or more DL beams at the UE and one or more uplink UL beams at the UE is missing.

18. The method of claim 1, wherein the selected DL beam from the network node is different from the selected uplink UL beam from the UE.

19. The method of claim 1, wherein the one or more DL beams are within a single symbol of a synchronous subframe, wherein selecting the resource or the waveform for transmitting the scheduling request message comprises: The resource or the waveform is selected based at least in part on the single symbol of the selected DL beam.

20. The method of claim 1, further comprising: selecting a random access channel (RACH) preamble based at least in part on an index of the selected DL beam, the RACH preamble corresponding to the selected DL beam of the one or more DL beams; as well as A RACH message is transmitted to the network node using the RACH preamble selected based at least in part on the selected DL beam.

21. A method for wireless communication at a network node, comprising: transmitting a DL signal on one or more downlink DL beams; Receiving an indication of a characteristic of a beam correspondence between one or more DL beams at a user equipment (UE) and one or more uplink (UL) beams at the UE, wherein the characteristic of the beam correspondence corresponds to one of: a full beam correspondence, a partial beam correspondence, or no beam correspondence; receiving a scheduling request message from the UE on at least one of a resource or a waveform; identifying a selected DL beam of the one or more DL beams for communication from the network node to the UE based at least in part on the resource or the waveform and further based at least in part on a characteristic of the beam correspondence, the selected DL beam being associated with one or more uplink beams at the network node by the beam correspondence; as well as One or more subsequent messages are transmitted to the UE using the selected DL beam.

22. The method of claim 21 , wherein identifying the selected DL beam comprises: The resource or the waveform is associated with an index of the selected DL beam or a symbol of a subframe of a DL signal of the selected DL beam.

23. The method of claim 21 , wherein receiving the scheduling request message comprises: The scheduling request message is received during the entire duration of the corresponding random access subframe.

24. The method of claim 21, wherein receiving the scheduling request message comprises: The scheduling request message is received on multiple uplink (UL) beams.

25. The method of claim 21, wherein the characteristic of the beam correspondence corresponds to an absence of beam correspondence, wherein the missing correspondence is associated with the one or more DL beams having a different beam direction than the one or more UL beams.

26. The method of claim 21, further comprising: Identifies that a correspondence between the one or more DL beams at the UE and one or more uplink UL beams at the UE is missing.

27. The method of claim 21, further comprising: receiving a random access channel (RACH) message, wherein the RACH message is transmitted using a RACH preamble; A selected one of the one or more DL beams is identified for communication from the network node to the UE based at least in part on the RACH preamble, the RACH preamble corresponding to an index of the selected DL beam.

28. An apparatus for wireless communication at a user equipment (UE), comprising: processor; a memory coupled to the processor; as well as instructions stored in the memory and executable by the processor to cause the apparatus to: receiving a DL signal from a network node on one or more downlink DL beams; selecting a DL beam of the one or more DL beams for communication from the network node to the UE; transmitting an indication of a characteristic of a beam correspondence between one or more DL beams at the UE and one or more uplink (UL) beams at the UE, wherein the characteristic of the beam correspondence corresponds to one of: a full beam correspondence, a partial beam correspondence, or no beam correspondence; selecting a resource or a waveform for uplink transmission, the resource or the waveform corresponding to a selected DL beam of the one or more DL beams and selected based at least in part on characteristics of a beam correspondence between the selected DL beam and one or more uplink beams at the UE; as well as A scheduling request message is transmitted to the network node using at least one of the resources or the waveform selected based at least in part on the selected DL beam.

29. The apparatus of claim 28, wherein the resource or the waveform is selected based at least in part on the indication of a characteristic of the beam correspondence.

30. The apparatus of claim 28, wherein the instructions are further executable by the processor to cause the apparatus to: Determining that there is a beam correspondence based on the indication; and A transmission time for transmitting the scheduling request message to the network node is selected based on the existing beam correspondence, wherein the transmission time corresponds to a symbol of a corresponding random access subframe.

31. The apparatus of claim 28, wherein the instructions are further executable by the processor to cause the apparatus to: Determining that a partial beam correspondence exists based on the indication; and A transmission time for transmitting the scheduling request message to the network node is selected based on the partial beam correspondence, wherein the transmission time includes a plurality of symbols of a corresponding random access subframe.

32. The apparatus of claim 28, wherein the instructions are further executable by the processor to cause the apparatus to: The resource or the waveform is selected based at least in part on symbols associated with the DL signal and the indication.

33. The apparatus of claim 28, wherein the waveform comprises one of a scheduling request or a random access channel (RACH) waveform.

34. The apparatus of claim 28, wherein the DL signal comprises a synchronization signal or a reference signal.

35. The apparatus of claim 28, wherein selecting the resource or the waveform comprises: The resource or the waveform is selected based at least in part on an index of a selected DL beam or a symbol of a subframe of a DL signal of a selected DL waveform.

36. The apparatus of claim 28, wherein transmitting the scheduling request message comprises: The scheduling request message is transmitted during the entire duration of the corresponding random access subframe.

37. The apparatus of claim 28, wherein selecting the DL beam comprises: A preferred DL beam is identified based at least in part on a signal strength of the DL signals on the one or more DL beams, a signal quality of the DL signals on the one or more DL beams, or a combination thereof.

38. The apparatus of claim 28, wherein selecting the DL beam comprises: The DL beams are identified based at least in part on the DL signals on the one or more DL beams satisfying a transmit power condition.

39. The apparatus of claim 28, wherein the instructions are further executable by the processor to cause the apparatus to: At least one of the resource or the waveform is selected for use in transmitting the scheduling request message to the network node, the resource or the waveform being selected based at least in part on the selected DL beam.

40. The apparatus of claim 28, wherein a beam correspondence between the one or more DL beams and one or more uplink (UL) beams at the UE is missing.

41. The apparatus of claim 40, wherein the missing beam correspondence is associated with the one or more DL beams having a different beam direction than the one or more UL beams.

42. The apparatus of claim 28, wherein the instructions are further executable by the processor to cause the apparatus to: The beam correspondence is missing by receiving information from the network node in a master information block MIB or a system information block SIB.

43. The apparatus of claim 42, wherein the instructions are further executable by the processor to cause the apparatus to: selecting the resource or the waveform based at least in part on the indication of the missing correspondence; and The scheduling request message is transmitted to the network node during an entire duration of a RACH subframe based at least in part on the indication of the missing correspondence.

44. The apparatus of claim 28, wherein the instructions are further executable by the processor to cause the apparatus to: An indication is transmitted that a correspondence between the one or more DL beams at the UE and one or more uplink UL beams at the UE is missing.

45. The apparatus of claim 28, wherein the selected DL beam from the network node is different from the selected uplink UL beam from the UE.

46. ​​The apparatus of claim 28, wherein the one or more DL beams are within a single symbol of a synchronous subframe, wherein selecting the resource or the waveform for transmitting the scheduling request message comprises: The resource or the waveform is selected based at least in part on the single symbol of the selected DL beam.

47. The apparatus of claim 28, wherein the instructions are further executable by the processor to cause the apparatus to: selecting a random access channel (RACH) preamble based at least in part on an index of the selected DL beam, the RACH preamble corresponding to the selected DL beam of the one or more DL beams; and A RACH message is transmitted to the network node using the RACH preamble selected based at least in part on the selected DL beam.

48. An apparatus for wireless communication at a network node, comprising: processor; a memory coupled to the processor; as well as instructions stored in the memory and executable by the processor to cause the apparatus to: transmitting a DL signal on one or more downlink DL beams; Receiving an indication of a characteristic of a beam correspondence between one or more DL beams at a user equipment (UE) and one or more uplink (UL) beams at the UE, wherein the characteristic of the beam correspondence corresponds to one of: a full beam correspondence, a partial beam correspondence, or no beam correspondence; receiving a scheduling request message from the UE on at least one of a resource or a waveform; identifying a selected DL beam of the one or more DL beams for communication from the network node to the UE based at least in part on the resource or the waveform and further based at least in part on a characteristic of the beam correspondence, the selected DL beam being associated with one or more uplink beams at the network node by the beam correspondence; as well as One or more subsequent messages are transmitted to the UE using the selected DL beam.

49. The apparatus of claim 48, wherein identifying the selected DL beam comprises: The resource or the waveform is associated with an index of the selected DL beam or a symbol of a subframe of a DL signal of the selected DL beam.

50. The apparatus of claim 48, wherein receiving the scheduling request message comprises: The scheduling request message is received during the entire duration of the corresponding random access subframe.

51. The apparatus of claim 48, wherein receiving the scheduling request message comprises: The scheduling request message is received on multiple uplink (UL) beams.

52. The apparatus of claim 48, wherein the characteristic of the beam correspondence corresponds to an absence of beam correspondence, wherein the missing correspondence is associated with the one or more DL beams having a different beam direction than the one or more UL beams.

53. The apparatus of claim 48, wherein the instructions are further executable by the processor to cause the apparatus to: Identifies that a correspondence between the one or more DL beams at the UE and one or more uplink UL beams at the UE is missing.

54. The apparatus of claim 48, wherein the instructions are further executable by the processor to cause the apparatus to: receiving a random access channel (RACH) message, wherein the RACH message is transmitted using a RACH preamble; A selected one of the one or more DL beams is identified for communication from the network node to the UE based at least in part on the RACH preamble, the RACH preamble corresponding to an index of the selected DL beam.

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