Joint processing of random access channel communication

Abstract

Techniques and apparatus are described for joint processing for random access channel communication to improve the reliability and / or geographical range of the random access procedure of a user equipment (110). Joint processing, including joint transmission and / or joint reception, performed by a coordinated set of user equipments (108) representing a single user equipment (110) or by an active coordinated set of base stations (120) having a single user equipment (110) can improve the link budget of random access channel communication and assist network access of the user equipment (110) at greater distances from a base station (121) or in the face of challenging channel conditions.

Description

Background Art

[0001] Generally, a base station manages wireless connections with user equipment (UE) connected to a wireless network. The base station determines the configuration of the wireless connection, such as the bandwidth, timing, and protocol for the wireless connection.

[0002] The quality of service between the UE and the base station can degrade due to various factors such as low signal strength, bandwidth limitations, interfering signals, operation on higher (above 6 GHz) frequency bands, etc. This is especially true for UEs operating at the cell edge, which often suffers from weak signal quality that hinders network access. Existing network access technologies do not consider the joint processing (joint transmission, joint reception) capabilities of a user equipment coordination set (UECS) or a base station coordination set (sometimes referred to as an active coordination set (ACS)) to improve the performance of random access channel (RACH) communication for network access. Summary of the Invention

[0003] This summary of the invention is provided to introduce a simplified concept of joint processing for random access channel communication. This simplified concept is further described in the detailed description. This summary of the invention is not intended to identify the essential features of the claimed subject matter, nor is it intended to be used to determine the scope of the claimed subject matter.

[0004] In various aspects, methods, devices, systems, and apparatuses are described for a user equipment in a user equipment coordination set (UECS) to access a wireless communication network using a random access procedure. A first user equipment configured as a coordinating user equipment for the UECS receives a random access channel (RACH) resource group configuration from a base station for random access procedure communication. The coordinating user equipment receives a request to initiate a random access procedure from a second user equipment in the UECS and generates a random access preamble message using a preamble sequence included in the RACH resource group configuration. The coordinating user equipment conveys the random access preamble message to multiple user equipment in the UECS, the random access preamble message instructing the multiple user equipment to transmit the random access preamble message using a first time-frequency resource set indicated in the RACH resource group configuration, and the coordinating user equipment transmits the random access preamble message to the base station using a time-frequency resource.

[0005] In further aspects, methods, apparatuses, systems, and devices are described for providing access to a wireless communication network using a random access procedure by base stations in an active coordination set (ACS). The base stations coordinate with other base stations in the ACS to allocate a set of random access resources for a user equipment to perform a random access procedure with the ACS and to transmit configuration information of the set of random access resources to the user equipment. The base station receives a random access preamble from the user equipment, receives samples of the random access preamble from one or more other base stations in the ACS, and jointly processes the received random access preamble and the received samples. The base station coordinates the joint transmission of a random access response for the random access procedure with other base stations in the ACS and transmits the random access response to enable the user equipment to access the wireless communication network. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Details of one or more aspects of the joint processing of random access channel communications are described below. The same reference numerals are used in different instances in the specification and drawings to indicate like elements:

[0007] Figure 1 An example operating environment is illustrated in which aspects of the joint processing of random access channel communications can be implemented.

[0008] Figure 2 An example block diagram of a user equipment and a serving cell base station is illustrated.

[0009] Figure 3 An air interface resource is illustrated that extends between a user equipment and a base station and by which aspects of the joint processing of random access channel communications can be implemented.

[0010] Figure 4 An example data and control transaction between a user equipment and a base station of a user equipment coordination set for a random access procedure according to aspects of the joint processing of random access channel communications is illustrated.

[0011] Figure 5 An example environment of an ACS is illustrated in which aspects of the joint processing of random access channel communications can be implemented.

[0012] Figure 6 Another example environment of an ACS is illustrated in which aspects of the joint processing of random access channel communications can be implemented.

[0013] Figure 7 An example method of the joint processing of random access channel communications as typically associated with coordinated user equipment of a UECS according to aspects of the techniques described herein is illustrated.

[0014] Figure 8FIG. illustrates an example method of joint processing of random access channel communication, such as typically associated with a base station in an ACS, according to aspects of the techniques described herein. DETAILED DESCRIPTION

[0015] This document describes techniques and apparatus for joint processing of random access channel (RACH) communication to improve the reliability and / or geographical range of the random access process of a user equipment (UE). When operating in a higher frequency band (e.g., a band above 6 GHz) experiencing more severe fading, or facing challenging channel conditions, joint processing including joint transmission and / or joint reception by a user equipment coordination set (UECS) representing a single UE or by an active coordination set (ACS) of a base station with a single UE can improve the link budget of RACH communication and facilitate network access of the UE at a greater distance from the base station.

[0016] In one aspect, a base station allocates a RACH resource group configuration for RACH communication with a UECS during a random access process. The RACH resource group configuration includes preambles specific to RACH transmissions of the UECS and specific time-frequency resources for RACH communication with the UECS. Since joint transmission and / or joint reception by the UECS includes communication among the UEs in the UECS via a local wireless network, the base station can configure longer timing and / or timeouts for communication during the random access process than those expected for a single UE to account for the latency due to coordination of joint transmission and / or joint reception within the UECS. The base station transmits RACH resource group configuration information in a system information block (SIB). The base station may transmit RACH resource group configuration information for the UECS and RACH resource configuration information for individual UEs in the SIB. Any UECS that receives the RACH resource group configuration information in the SIB can initiate a random access process (non-competitive or contention-based) with the base station using the RACH resource group configuration information. The base station monitors the designated time-frequency resources to receive RACH transmissions from any UECS requesting network access using the designated preambles.

[0017] UEs in or not in the UECS can cache / store the RACH resource group configuration information previously received (received individually by the UE or jointly by the UECS) when within the communication range of the base station for later use when an individual UE may only be able to communicate with the network using the joint communication capabilities of the UECS. UEs in the UECS can associate and store location information for the RACH resource group configuration information for later use to determine which one of multiple sets of RACH resource group configuration information may be a candidate for the random access procedure. Optionally or additionally, the serving cell base station can transmit the RACH resource group configuration information of neighboring cells in the system information block (SIB) to further assist the UECS in accessing the network. The neighboring cells can be in the same or different frequency bands as the serving cell base station. For example, a sub-1 GHz serving cell can broadcast the RACH resource group configuration information of its nearby above 6 GHz and millimeter wave base stations to assist the UECS in communicating with higher bandwidth base stations in these higher frequency bands while leveraging the propagation characteristics of the sub-1 GHz frequency band to convey the RACH resource group configuration information.

[0018] On the other hand, the base stations in the ACS coordinate with each other or with the ACS server in the core network to allocate a RACH resource set for RACH communication by the UE for accessing the ACS during the random access procedure. Each RACH resource set configuration includes a preamble sequence specific to the ACS and specific time-frequency resources for RACH communication with the ACS. The RACH resource set configuration for a given ACS can be communicated to the UE via a broadcast message from the base station or the ACS or using dedicated signaling (e.g., in a radio resource control (RRC) message or a non-access stratum (NAS) message). The ACS-specific random access procedure also includes ACS-specific timing advance and ACS identification, which can also be included in the RACH resource set configuration for the ACS. The ACS-specific timing advance depends on the joint processing mechanism at the ACS. For example, the ACS-specific timing advance can be the maximum timing advance required by any base station in the ACS. In another example, the ACS-specific timing advance can be the average of the individual timing advances of each base station in the ACS. In yet another example, the ACS-specific timing advance is determined based on the timing advance values of a subset of the base stations in the ACS (e.g., the subset of base stations that receive the highest signal strength from the UE). The UE can locally store the RACH resource sets of the ACSs with which the UE has communicated in the past. The UE can determine which ACS and associated RACH resource set to use for network access based on its current geographical location compared to the geographical scope associated with the known ACSs, broadcast signals received from the base station or the ACS, etc. The base stations in the ACS monitor the time-frequency resources specified in the RACH resource set of the ACS and coordinate to jointly process the communication received from the UE by the base stations in the ACS. For example, all base stations in the ACS that receive RACH communication using the specified time-frequency resources forward samples of the received signal to the master base station, which jointly processes the samples to receive the RACH communication from the UE. The master base station then coordinates the joint transmission of downlink messages during the random access procedure. Since the joint transmission and / or joint reception via the ACS includes communication among the base stations in the ACS, the master base station can configure longer timings and / or timeouts for the communication during the random access procedure than those expected between a single single base station and the UE to account for the latency caused by the joint transmission and / or joint reception via the ACS. The random access procedure between the UE and the ACS can be contention-free or contention-based.

[0019] In joint transmission, multiple transmitters (of UE 110 or base station 120) coordinate the transmission of signals for the same data set to increase the transmission power compared to a single transmitter and improve the link budget to the receiver. In joint reception, multiple receivers (of UE 110 or base station 120) each receive the transmitted signals of the same data set and accumulate the I / Q samples from each receiver to decode the combined I / Q samples into the data set. By using joint reception, the receiver provides increased receiver sensitivity and improves the link budget for receiving data from the transmitter compared to a single receiver.

[0020] Example Environment

[0021] Figure 1 FIG. illustrates an exemplary environment 100 that includes a plurality of user devices 110 (UE 110), illustrated as UE 111, UE 112, UE 113, and UE 114. Each UE 110 is capable of communicating with one or more base stations 120 (illustrated as base stations 121 and 122) via one or more wireless communication links 130 (wireless links 130) illustrated as wireless links 131, 132, and 133. Each UE 110 in UE coordination set 108 (illustrated as UE 111, UE 112, and UE 113) is capable of communicating with a coordinated UE in the UE coordination set and / or a target UE in the UE coordination set using a local wireless network that includes one or more local wireless network connections such as local wireless network connections 134, 135, and 136 (e.g., WLAN, Bluetooth, NFC, personal area network (PAN), WiFi Direct, IEEE 802.15.4, ZigBee, Thread, millimeter wave communication (millimeter wave), etc.). A single UE (illustrated as UE 114) is capable of joint communication with multiple base stations (illustrated as base stations 121 and 122) in the ACS via multiple wireless links (illustrated as wireless links 132 and 133). Although illustrated as a smart phone, UE 110 may be implemented as any suitable computing or electronic device, such as a mobile communication device, a modem, a cellular phone, a gaming device, a navigation device, a media device, a laptop computer, a desktop computer, a tablet computer, a smart appliance, a vehicle-based communication system, an Internet of Things (IoT) device (e.g., a sensor node, a controller / actuator node, a combination thereof), etc. Base stations 120 (e.g., evolved universal terrestrial radio access network node B, E-UTRAN node B, evolved node B, eNodeB, eNB, next generation node B, gNode B, gNB, etc.) may be implemented in a macro cell, a micro cell, a small cell, a pico cell, etc. or any combination thereof.

[0022] Base station 120 communicates with user equipment 110 using wireless links 131, 132, and 133, which can be implemented as any suitable type of wireless link. Wireless links 131, 132, and 133 can be beamformed or non-beamformed wireless links. Wireless links 131, 132, and 133 include control and data communications, such as downlink of data and control information transmitted from base station 120 to user equipment 110, uplink of other data and control information transmitted from user equipment 110 to base station 120, or both. Wireless link 130 can include one or more wireless links (e.g., radio links) or bearers implemented using any suitable communication protocol or standard, such as 3rd Generation Partnership Project Long Term Evolution (3GPP LTE), 5th Generation New Radio (5G NR), etc., or a combination of communication protocols or standards. Multiple wireless links 130 can be aggregated in carrier aggregation to provide a higher data rate for UE 110. Multiple wireless links 130 from multiple base stations 120 can be configured for coordinated multi-point (CoMP) communication with UE 110.

[0023] Base stations 120 are collectively referred to as radio access network 140 (e.g., RAN, evolved universal terrestrial radio access network, E-UTRAN, 5G NR RAN, or NR RAN). Base stations 121 and 122 in RAN 140 are connected to core network 150. Base stations 121 and 122 are connected to core network 150 at 102 and 104 respectively, when connected to a 5G core network via the NG2 interface for control plane signaling and using the NG3 interface for user plane data communication, or when connected to an evolved packet core (EPC) network using the S1 interface for both control plane signaling and user plane data communication. At 106, base stations 121 and 122 are capable of communicating via the Xn interface using the Xn application protocol (XnAP) or via the X2 interface using the X2 application protocol (X2AP) to exchange user plane and control plane data. User equipment 110 can be connected to a public network, such as the Internet 160, via core network 150 to interact with remote service 170.

[0024] The base station 121 in the cell can specify a set of UEs (e.g., UEs 111, 112, and 113) to form a UE coordination set (e.g., UE coordination set 108) for the joint transmission and joint reception of data for a target UE (e.g., UE 112). The base station 121 can determine whether coordination is beneficial for a particular UE based on information corresponding to the UE (e.g., UE location, signal level, battery level, etc.). The effective transmission power of the target UE 112 can increase significantly (e.g., linearly) with the number of UEs in the UE coordination set, which can greatly improve the link budget of the target UE 112. The base station 121 can determine the UE coordination set based on various factors such as the position of each UE relative to the base station 121, the distance between UEs (such as between each other, between each UE and the target UE, or between each UE and the coordinating UEs in the UE coordination set), or a combination thereof. Alternatively, a group of UEs that are individually outside the communication range of the base station can be configured as a UECS (e.g., by one or more users of the UEs, discovery by other UEs using a local wireless network, etc.) to improve the link budget of the RACH communication of the target UE 112.

[0025] The base station 121 can select UE 111 to act as a coordinating UE because UE 111 is located between UE 112 and UE 113, or because UE 111 can communicate with each of the other UEs 112 and 113 in the UE coordination set 108. Alternatively, a group of UEs can form a UECS without the help of the base station (e.g., initiated by a user of one of the UEs in the UECS). The UEs coordinate on the local wireless network to select a UE as a coordinating UE based on the capabilities of the UEs in the UECS.

[0026] Exemplary apparatus

[0027] Figure 2 FIG. 200 is an example device diagram showing a user equipment and a base station. In various aspects, device diagram 200 depicts a device capable of implementing various aspects of the joint processing of random access channel communication. Figure 2 It includes a plurality of UEs 110 and a base station 120. The plurality of UEs 110 and the base station 120 may include, for clarity, from Figure 2Omitted additional features and interfaces. The UE 110 includes antennas 202, a radio frequency front end 204 (RF front end 204), and radio frequency transceivers (e.g., an LTE transceiver 206 and a 5G NR transceiver 208) for communicating with base stations 120 in the 5G RAN 141 and / or the E-UTRAN 142. The UE 110 includes one or more additional transceivers (e.g., a local wireless network transceiver 210) for communicating with at least the coordinating UE and / or the target UE of the UE coordination set via one or more local wireless networks (e.g., WLAN, Bluetooth, NFC, personal area network (PAN), WiFi Direct, IEEE 802.15.4, ZigBee, Thread, millimeter wave, etc.). The RF front end 204 of the UE 110 is capable of coupling or connecting the LTE transceiver 206, the 5G NR transceiver 208, and the local wireless network transceiver 210 to the antennas 202 to facilitate various types of wireless communication.

[0028] The antennas 202 of the UE 110 may include an array of multiple antennas configured to be similar or different from each other. The antennas 202 and the RF front end 204 can be tuned to and / or are tunable to one or more frequency bands defined by the 3GPP LTE and 5G NR communication standards and implemented by the LTE transceiver 206 and / or the 5G NR transceiver 208. Additionally, the antennas 202, the RF front end 204, the LTE transceiver 206, and / or the 5G NR transceiver 208 can be configured to support beamforming for transmission and reception of communication with the base stations 120. By way of example and not limitation, the antennas 202 and the RF front end 204 can be implemented for operation in sub-gigahertz frequency bands, sub-6 GHz frequency bands, and / or frequency bands above 6 GHz defined by the 3GPP LTE and 5G NR communication standards. Additionally, the RF front end 204 can be tuned to and / or is tunable to one or more frequency bands defined and implemented by the local wireless network transceiver 210 to support transmission and reception of communication with other UEs in the UE coordination set via the local wireless network.

[0029] The UE 110 includes sensors 212 that can be implemented to detect various attributes such as temperature, power supply power, power usage, battery status, etc. Thus, the sensors 212 can include any one or combination of a temperature sensor, a thermistor, a battery sensor, and a power usage sensor.

[0030] UE 110 also includes a processor 214 and a computer-readable storage medium 216 (CRM 216). The processor 214 can be a single-core or multi-core processor composed of various materials such as silicon, polysilicon, high-K dielectrics, copper, etc. The computer-readable storage medium described herein does not include propagated signals. The CRM 216 can include any suitable memory or storage device that can be used to store the device data 218 of the UE 110, such as random access memory (RAM), static RAM (SRAM), dynamic RAM (DRAM), non-volatile RAM (NVRAM), read-only memory (ROM), or flash memory. The device data 218 includes user data, multimedia data, beamforming codebooks, applications, and / or the operating system of the UE 110, which can be executed by the processor 214 to enable user plane communication, control plane signaling, and user interaction with the UE 110.

[0031] The CRM 216 also includes a communication manager 220 (e.g., communication manager application 220). Alternatively or additionally, the communication manager 220 can be implemented as hardware logic or circuitry that is integrated with or separated from other components of the UE 110, in whole or in part. At least in some aspects, the communication manager 220 configures the RF front end 204, the LTE transceiver 206, the 5G NR transceiver 208, and / or the local wireless network transceiver 210 to implement the techniques described herein.

[0032] Figure 2 The device diagram for the base station 120 shown includes a single network node (e.g., gNode B). The functionality of the base station 120 can be distributed across multiple network nodes or devices and can be distributed in any manner suitable for performing the functions described herein. The base station 120 includes an antenna 252 for communicating with the UE 110, a radio frequency front end 254 (RF front end 254), one or more LTE transceivers 256, and / or one or more 5G NR transceivers 258. The RF front end 254 of the base station 120 is capable of coupling or connecting the LTE transceiver 256 and the 5G NR transceiver 258 to the antenna 252 to facilitate various types of wireless communication. The antenna 252 of the base station 120 can include an array of multiple antennas configured to be similar or different from each other. The antenna 252 and the RF front end 254 can be tuned to and / or be tunable to one or more frequency bands defined by the 3GPP LTE and 5G NR communication standards and implemented by the LTE transceiver 256 and / or the 5G NR transceiver 258. Additionally, the antenna 252, the RF front end 254, the LTE transceiver 256, and / or the 5G NR transceiver 258 can be configured to support beamforming, such as massive MIMO, for the transmission and reception of communication with any UE 110 in coordination with the UE.

[0033] Base station 120 also includes a processor 260 and a computer-readable storage medium 262 (CRM 262). The processor 260 can be a single-core or multi-core processor composed of various materials such as silicon, polysilicon, high-K dielectrics, copper, etc. The CRM 262 can include any suitable memory or storage device for storing device data 264 of the base station 120, such as random access memory (RAM), static RAM (SRAM), dynamic RAM (DRAM), non-volatile RAM (NVRAM), read-only memory (ROM), or flash memory. The device data 264 includes network scheduling data, radio resource management data, beamforming codebooks, applications, and / or the operating system of the base station 120, which can be executed by the processor 260 to enable communication with the UE 110.

[0034] The CRM 262 also includes a base station manager 266 (e.g., base station manager application 266). Alternatively or additionally, the base station manager 266 can be implemented in whole or in part as hardware logic or circuitry integrated with or separated from other components of the base station 120. At least in some aspects, the base station manager 266 configures the LTE transceiver 256 and the 5G NR transceiver 258 for communication with the UE 110 and with the core network. The base station 120 includes an inter-base station interface 268, such as an Xn and / or X2 interface, which the base station manager 266 configures to exchange user plane and control plane data between another base station 120 to manage communication between the base station 120 and the UE 110. The base station 120 includes a core network interface 270, which the base station manager 266 configures to exchange user plane and control plane data with core network functions and entities.

[0035] Air interface resources

[0036] Figure 3 Illustrated are various aspects of air interface resources that extend between a user equipment and a base station and enable joint processing for random access channel communication. The air interface resources 302 can be divided into resource units 304, each resource unit occupying some intersection of the spectrum and the elapsed time. A portion of the air interface resources 302 is graphically illustrated as a grid or matrix having a plurality of resource blocks 310, including example resource blocks 311, 312, 313, 314. Thus, an example of a resource unit 304 includes at least one resource block 310. As shown, time is depicted along the horizontal dimension as the x-axis, and frequency is depicted along the vertical dimension as the y-axis. The air interface resources 302, as defined by a given communication protocol or standard, can span any suitable specified frequency range and / or can be divided into intervals of any specified duration. For example, the increment of time can correspond to milliseconds (mSec). For example, the increment of frequency can correspond to megahertz (MHz).

[0037] Typically, in an exemplary operation, the base station 120 allocates portions of the air interface resources 302 (e.g., resource units 304) for uplink and downlink communications. Each resource block 310 for which network access resources can be allocated supports a corresponding wireless communication link 130 of multiple user equipments 110. In the lower left corner of the grid, as defined by a given communication protocol, the resource block 311 can span a specified frequency range 306 and include multiple subcarriers or frequency subbands. The resource block 311 can include any suitable number of subcarriers (e.g., 12), each corresponding to a respective portion (e.g., 15 kHz) of the specified frequency range 306 (e.g., 180 kHz). As defined by a given communication protocol, the resource block 311 can also span a specified time interval 308 or time slot (e.g., lasting approximately half a millisecond or seven orthogonal frequency division multiplexing (OFDM) symbols). The time interval 308 includes subintervals, each of which can correspond to a symbol, such as an OFDM symbol. As Figure 3 shown, each resource block 310 can include subcarriers corresponding to the frequency range 306 and subintervals (or symbols) of the time interval 308 or be defined by a plurality of resource elements 320 (RE). Alternatively, a given resource element 320 can span more than one frequency subcarrier or symbol. Thus, the resource unit 304 can include at least one resource block 310, at least one resource element 320, etc.

[0038] In an exemplary embodiment, multiple user equipments 110 (one of which is shown) are communicating with a base station 120 (one of which is shown) via access provided by a portion of the air interface resources 302. The base station manager 266 (shown in Figure 2 the figure) can determine the corresponding data rate, type of information, or amount of information (e.g., data or control information) to be communicated (e.g., transmitted) to the user equipment 110. For example, the base station manager 266 is capable of determining that each user equipment 110 will transmit at a different corresponding data rate or transmit different corresponding amounts of information. The base station manager 266 then allocates one or more resource blocks 310 to each user equipment 110 based on the determined data rate or amount of information.

[0039] Additionally, or as an alternative to block-level resource grants, the base station manager 266 can allocate resource units at the element level. Thus, the base station manager 266 can allocate one or more resource elements 320 or individual subcarriers to different user equipments 110. By doing so, one resource block 310 can be allocated to facilitate network access for multiple user equipments 110. Thus, the base station manager 266 can allocate one or up to all subcarriers or resource elements 320 of a resource block 310 to one user equipment 110 or divide them among multiple user equipments 110 at various granularities, thereby achieving higher network utilization or increased spectral efficiency.

[0040] Thus, the base station manager 266 can allocate the air interface resources 302 by means of resource units 304, resource blocks 310, frequency carriers, time intervals, resource elements 320, frequency sub-carriers, time sub-intervals, symbols, spreading codes, some combinations thereof, and so on. Based on the corresponding allocation of the resource units 304, the base station manager 266 can transmit corresponding messages to the plurality of user equipments 110, which indicate the corresponding allocation of the resource units 304 to each user equipment 110. Each message can enable the corresponding user equipment 110 to queue information or configure the LTE transceiver 206 and / or the 5G NR transceiver 208 to communicate via the allocated resource units 304 of the air interface resources 302.

[0041] User Equipment-Coordinated Set Random Access Procedure

[0042] The UE Coordinated Set is formed by a plurality of UEs that are assigned as a group to work together, similar to a distributed antenna, to benefit a particular UE. The UE Coordinated Set includes a coordinating UE that coordinates the joint transmission and reception of downlink and / or uplink data for a particular UE (e.g., the target UE) or multiple UEs in the UE Coordinated Set. By combining the antennas and transmitters of the multiple UEs in the UE Coordinated Set, the effective transmission power of a particular UE is significantly increased, and the effective signal quality is greatly improved.

[0043] Each of the multiple UEs in the UECS can receive a downlink data transmission from the base station. Different from traditional relay technologies, these UEs do not decode the downlink transmission into data packets and then forward the data packets to the destination. Instead, the UEs demodulate and sample the downlink transmission to generate I / Q samples. The UEs determine where to forward the I / Q samples of the downlink transmission, such as forwarding them to the coordinating UE or the target UE for decoding. In various aspects, the target UE can be included in a subset of target UEs within the UE Coordinated Set. The coordinating UE (or the target UE) receives the I / Q samples from other UEs in the UE Coordinated Set and stores the I / Q samples in a buffer memory for decoding. Then, the coordinating UE (or the target UE) synchronizes and decodes the stored I / Q samples into data packets for the target UE. Thus, the processing of the I / Q samples occurs at the coordinating UE or the target UE. In this way, the UE Coordinated Set acts as a distributed antenna for the target UE. The target UE can include its own antenna and participate in the reception, demodulation, and sampling of the downlink transmission from the base station.

[0044] Similar to the described downlink scenario, multiple UEs can also form a UE coordination set to transmit messages to the base station at a higher effective transmission power than would be possible for a single UE alone. For example, each of the multiple UEs in the UECS uses their respective antennas and transmitters to transmit uplink data from the target UE on air interface resources as directed by the base station such as the coordinated UECS. In this way, the transmitters and transmit antennas of multiple (including all) UEs in the UECS can be used together to process and transmit the uplink data of the target UE. In an example, the target UE uses its local radio network transceiver 210 to transmit uplink data to the coordinating UE. The coordinating UE uses its local radio network transceiver 210 to distribute the data to the other UEs in the UECS. Then, all the UEs in the UECS process the uplink data and transmit it to the base station. In this way, distributed transmission provides a more effective link budget taking into account the channel impairments encountered by the target UE.

[0045] Figure 4 FIG. 400 illustrates example data and control transactions between a user equipment and a base station for a user equipment coordination set for random access procedures in accordance with aspects of joint processing of random access channel communications. When the target UE 112 desires to request access to the RAN 140, the target UE 112 transmits an indication of the access request to the coordinating UE 111 at 405. The coordinating UE 111 uses the local radio network to distribute a preamble sequence (which is referred to herein as a random access preamble but may also be referred to as message one or Msg1 in the relevant 3GPP standards) as I / Q samples and an indication of time-frequency resources for RACH communications to the UE 112 at 410 and to the UE 113 at 415. At 420, the UEs 111, 112, and 113 jointly transmit the preamble sequence to the base station 121. At 425, the base station 121 receives the jointly transmitted preamble sequence from the UEs 111, 112, and 113 and processes the combined signal to decode the preamble sequence from the UECS 108. At 430, the base station 121 transmits a random access response (message 2, Msg2) received and sampled by the UEs 111, 112, and 113 to the UEs 111, 112, and 113. At 435, the UE 112 transmits I / Q samples corresponding to the received random access response to the coordinating UE 111. At 440, the UE 113 transmits I / Q samples corresponding to the received random access response to the coordinating UE 111. At 445, the coordinating UE 111 jointly processes the I / Q samples received from the UEs 112 and 113, and the I / Q samples of the random access response received by the coordinating UE 111 to jointly receive the random access response. If the random access procedure is a contention-free random access procedure, the random access procedure terminates at 450, where the coordinating UE 111 uses the local radio network to transmit the random access response to the UE 112.

[0046] If the random access procedure is a contention-based random access procedure, the random access procedure continues at 455, where UE 112 transmits a Radio Resource Control (RRC) connection request (Message 3, Msg3) to coordinating UE 111. Coordinating UE 111 uses the local radio network to distribute the RRC connection request as I / Q samples and an indication of time-frequency resources for RACH communication to UE 112 at 460, and distributes it to UE 113 at 465. At 470, UEs 111, 112, and 113 jointly transmit the RRC connection request to base station 121. At 475, base station 121 receives the jointly transmitted RRC connection request from UEs 111, 112, and 113 and processes the combined signals to decode the RRC connection request from UECS 108. At 480, base station 121 transmits an acknowledgement (ACK) and a contention resolution identifier (CRID) (Message 4 or Msg4) received and sampled by UEs 111, 112, and 113 to UEs 111, 112, and 113. At 485, UE 112 transmits I / Q samples corresponding to the received ACK and CRID to coordinating UE 111. At 490, UE 113 transmits I / Q samples corresponding to the received ACK and CRID to coordinating UE 111. At 493, coordinating UE 111 jointly processes the I / Q samples received from UEs 112 and 113, and the I / Q samples of the ACK and CRID received by coordinating UE 111, to jointly receive the ACK and CRID, and at 495, coordinating UE 111 uses the local radio network to transmit the ACK and CRID to UE 112.

[0047] In one aspect, base station 121 allocates a RACH resource group configuration for RACH communication with UECS 108. The RACH resource group configuration includes a preamble sequence for random access preambles specific to RACH transmissions through the UECS and specific time-frequency resources for RACH communication from any UECS. Base station 121 sends the RACH resource group configuration information in a System Information Block (SIB) to the UECS. UECS 108 receives the RACH resource group configuration information included in the SIB and uses the RACH resource group configuration information to initiate a random access procedure (contention-free or contention-based) with base station 121. Base station 121 monitors the designated time-frequency resources using the designated RACH sequence from UECS 108 to receive RACH transmissions.

[0048] UEs within the UECS 108 coordinate with each other to select a preamble sequence for the UECS 108. For example, the coordinating UE 111 can determine the preamble sequence and time-frequency resources and use the local radio network to notify the remaining UEs (112, 113) in the UECS 108. The coordinating UE 111 determines the timing (e.g., time slots and symbols) for the joint transmission for RACH communication (e.g., random access preamble) to the base station 121. The coordinating UE 111 determines the initial transmission power level for each UE in the UECS 108 for RACH transmission. This determination can be based on the number of UEs in the UECS for joint transmission, the maximum transmission power available from each jointly transmitting UE in the UECS, the available battery power of any UE in the UECS, the beam steering ability of any UE in the UECS, and / or various other factors.

[0049] The base station 121 assigns a group RACH radio network temporary identity (RNTI) to the target UE 112 such that the UECS 108 (each UE in the UECS 108) can use this RACH RNTI to receive the random access response (Message Two, Msg2) of the random access process. The coordinating UE 111 is responsible for setting a backoff timer to determine whether the first attempt to initiate the random access process fails (e.g., no random access response is received before the backoff timer expires). Due to the latency of coordination and joint processing within the UECS 108, the coordinating UE 111 can set the time value of the backoff timer to be longer than the time value that a single UE performing the random access process should set. If the first attempt fails (e.g., the random access response is not received by the UECS 108), the coordinating UE 111 also determines the transmission power for each UE in the UECS 108 for further random access attempts.

[0050] The coordinating UE 111 determines for each UE the use of any additional messages (e.g., radio resource control (RRC) connection request, Message 3, Msg3, acknowledgment (ACK), and contention resolution ID (CRID), Message 4, or Msg4) to be sent during the random access process. For example, the coordinating UE 111 can determine that each UE in the UECS 108 will use the same timing advance. In another example, the coordinating UE 111 can command each UE to use a different timing advance (to adjust the uplink timing of each individual UE). In yet another example, the coordinating UE 111 can create a set of timing advance values and a subset of UEs can share the same timing advance value. The coordinating UE 111 also determines the random identity used in the radio resource control (RRC) connection request (Message 3, Msg3) jointly transmitted by the UECS for contention resolution.

[0051] Active Coordinating Set Random Access Process

[0052] Figure 5 Illustrated is an example environment 500 in which user equipment 110 is moving through a radio access network (RAN) that includes a plurality of base stations 120 illustrated as base stations 121 - 127. These base stations may utilize different technologies (e.g., LTE, 5G NR, 6G) at various frequencies (e.g., in the sub - gigahertz, sub - 6 GHz, and above 6 GHz bands and sub - bands). An ACS is a set of base stations determined by the UE to perform coordinated communication with the UE, such as communicating with the UE using joint transmission and / or joint reception by the base stations in the ACS.

[0053] For example, user equipment 110 follows path 502 through RAN 140. User equipment 110 periodically measures link quality (e.g., the link quality of the base stations currently in the ACS and candidate base stations that the UE 110 may add to the ACS). For example, at location 504, the ACS includes base stations 121, 122, and 123 at 506. As UE 110 continues to move, at location 508, UE 110 has removed base stations 121 and 122 from the ACS and added base stations 124, 125, and 126, as shown at 510. Continuing along path 502, UE 110 has removed base stations 123 and 124 and added base station 127 at location 512, as shown in the ACS at 514.

[0054] Figure 6 Illustrated is an example environment 600 in which various aspects of joint processing of random access channel communication can be implemented. User equipment 110 engages in joint transmission and / or reception (joint communication) with three base stations 121, 122, and 123. Although the communication with base stations 121, 122, and 123 is illustrated as beamformed communication, beamforming is not required to implement aspects of the ACS or joint processing of random access channel communication. Base station 121 serves as the primary base station for joint transmission and / or reception. Which base station is the primary base station is transparent to UE 110, and the primary base station can change as base stations are added and / or removed from the ACS. The ACS can be a component of a user - centric cell - free (UCNC) network architecture or be used to implement a user - centric cell - free (UCNC) network architecture. The primary base station coordinates control plane and user plane communication to perform joint communication with UE 110 via Xn interface 106 (or a similar 6G interface) to base stations 122 and 123 and maintains the user plane context between UE 110 and core network 150. Coordination can be performed using proprietary or standards - based messaging, procedures, and / or protocols.

[0055] The master base station schedules air interface resources for the joint communication of UE 110 and base stations 121, 122, and 123 based on the ACS associated with UE 110. The master base station (base station 121) is connected to the user plane function 610 (UPF 610) in the core network 150 via the N3 interface 601 (or the 6G equivalent interface) for the communication of user plane data to and from the user equipment 110. The master base station distributes the user plane data to all base stations in the joint communication via the Xn interface 106. The UPF 610 is further connected to a data network, such as the Internet 160, via the N6 interface 602.

[0056] UE 110 downlink data can be sent from all base stations 120 in the ACS or any subset of the base stations 120 in the ACS. The master base station 121 determines which combination of base stations 120 in the ACS is used to transmit downlink data to UE 110. The selection of the base stations 120 for transmitting downlink data can be based on one or more factors, such as application quality of service (QoS) requirements, the location of UE 110, the speed of UE 110, reference signal received power (RSRP), received signal strength indicator (RSSI), interference, etc. UE 110 uplink data can be received by all base stations 120 in the ACS or any subset of the base stations 120 in the ACS.

[0057] Similar to the downlink data, the master base station 121 determines which combination of base stations 120 in the ACS is used to receive uplink data from UE 110. The selection of the base stations 120 for receiving uplink data can be based on one or more factors, such as application QoS requirements, the location of UE 110, the speed of UE 110, RSRP, RSSI, interference, etc. Generally, the combination of base stations 120 for downlink transmission and uplink reception will be the same, although different combinations of base stations 120 can be used for downlink transmission and uplink reception.

[0058] When the user equipment 110 creates or modifies an ACS, the user equipment 110 conveys the ACS or ACS modification to the ACS server 620, which stores the ACS for each user equipment 110 operating in the RAN 140. Additionally or alternatively, the UE 110 is capable of conveying a RACH resource set for the ACS to the ACS server 620. Although shown in the core network 150, alternatively, the ACS server 620 can be an application server located outside the core network 150. The user equipment 110 conveys the ACS or ACS modification via the primary base station (base station 121), which is connected to the ACS server 620 via the N-ACS interface 603. Optionally or alternatively, the user equipment 110 conveys the ACS or ACS modification to the ACS server 620 via the access and mobility function 630 (AMF 630), which is connected to the primary base station (base station 121) via the N2 interface 604. The AMF 630 relays ACS-related communication to and from the ACS server 620 via the ACS-AMF interface 605. The ACS data between the user equipment 110 and the ACS server 620 can be communicated via radio resource control (RRC) communication, non-access stratum (NAS) communication, or application layer communication.

[0059] In one aspect, the base stations in the ACS coordinate with each other or with the ACS server 620 to allocate a set of RACH resources for RACH communication of the UE during the random access procedure with the ACS. Each RACH resource set includes a preamble sequence specific to the ACS and specific time-frequency resources for RACH communication with the ACS. The RACH resource set for a given ACS can be communicated to the UE 110 via a broadcast message from one or more base stations in the ACS or using dedicated signaling (e.g., in a radio resource control (RRC) message or a non-access stratum (NAS) message). The ACS-specific RACH procedure may also include ACS-specific timing advance and ACS identification. The UE 110 can locally store the RACH resource sets of the ACSs with which the UE 110 has communicated in the past. The UE 110 is able to determine which ACS and the associated RACH resource set are used for network access based on its current geographical location compared to the locations of known ACSs, broadcast signals received from base stations or the ACS, etc. The base stations in the ACS monitor the designated time-frequency resources in the RACH resource set and coordinate to jointly process the communications received using the time-frequency resources in the RACH resource set. For example, all base stations in the ACS that receive random access communications forward samples of the received signals to the master base station, which jointly processes the samples to receive RACH communications from the UE. The master base station then coordinates the joint transmission of downlink messages during the random access procedure. The random access procedure between the UE and the ACS can be contention-free or contention-based. Optionally or additionally, the allocated RACH resource set can depend on whether the RACH procedure is contention-free or contention-based.

[0060] One or more base stations in the ACS jointly transmit the RACH resource set to the user in a broadcast message or using dedicated signaling (e.g., in a radio resource control (RRC) message or a non-access stratum (NAS) message). Each ACS in the RAN 140 transmits a RACH resource set that is unique to the specific ACS or different from neighboring ACSs.

[0061] The UE 110 monitors the downlink signals from the base stations in the ACS to receive the RACH resource set for the ACS. The UE uses the ACS-specific RACH resource set for the random access procedure to access the RAN 140 using the base stations in the ACS.

[0062] When a base station within a particular ACS receives an ACS-specific random access communication (using joint reception), the base station coordinates the joint transmission of the random access response (Message 2, Msg2) of the random access process and jointly conveys any subsequent messages required to complete the random access process (e.g., radio resource control (RRC) connection request, Message 3, Msg3, acknowledgment (ACK) and contention resolution ID (CRID), Message 4 or Msg4). For example, the base stations in the ACS jointly receive the RRC connection request message and jointly transmit Message 4 of the random access process for contention resolution. The ACS random access process also includes ACS-specific timing advance and ACS-specific UE identification. Each UE has a specific identification (ACS_RNTI) associated with each different ACS. For a contention-free random access process, one or more base stations in the ACS can communicate with the UE using the UE's ACS_RNTI.

[0063] Example method

[0064] In accordance with one or more aspects of the joint processing of random access channel communications, reference is made to Figure 7 and Figure 8 Example methods 700 and 800 are described. The order of the method blocks described is not intended to be construed as limiting, and any number of the described method blocks can be skipped, repeated, or combined in any order to implement the method or an alternative method. Generally, any components, modules, methods, and operations described herein can be implemented using software, firmware, hardware (e.g., fixed logic circuitry), manual processing, or any combination thereof. Some operations of the example methods can be described in the general context of executable instructions stored on a computer-readable memory local and / or remote to a computer processing system, and implementations can include software applications, programs, functions, etc. Alternatively or additionally, any functionality described herein can be at least partially performed by one or more hardware logic components, such as, but not limited to, field-programmable gate arrays (FPGA), application-specific integrated circuits (ASIC), application-specific standard products (ASSP), system-on-a-chip (SoC), complex programmable logic devices (CPLD), etc.

[0065] Figure 7 Example method 700 illustrates joint processing of random access channel communications as generally related to coordinated user equipment in a UECS. At 702, the coordinated user equipment receives a random access channel (RACH) resource group configuration from a base station for random access process communications. For example, the coordinated user equipment (e.g., coordinated UE 111) receives an RACH resource group configuration from a base station (e.g., base station 121) for random access process communications. The RACH resource group configuration includes one or more preambles and time-frequency resources for RACH communications.

[0066] At 704, the coordinating user equipment receives a request to initiate a random access procedure from a second user equipment in the UECS. For example, the coordinating user equipment 111 receives a request to initiate a random access procedure from a second user equipment (e.g., UE 112) in the UECS 108 to enable the UE 112 to access the RAN 140. The second user equipment can be the target UE, or in other words, can be the UE that utilizes the UECS to perform the random access procedure.

[0067] At 706, the coordinating user equipment generates a random access preamble message using a preamble sequence included in the RACH resource group configuration. For example, the coordinating UE 111 generates a random access preamble message using a preamble sequence included in the RACH resource group configuration. The coordinating UE 111 can select a preamble sequence from among a plurality of preamble sequences included in the RACH resource group configuration.

[0068] At 708, the coordinating user equipment conveys the random access preamble message to a plurality of user equipments in the UECS, which instructs the plurality of user equipments to convey the random access preamble message using a first time-frequency resource set indicated in the RACH resource group configuration. For example, the coordinating user equipment 111 conveys the random access preamble message to a plurality of user equipments (e.g., UE 112, UE 113) in the UECS 108 using a local wireless network, which instructs the plurality of user equipments to convey the random access preamble message using the first time-frequency resource set indicated in the RACH resource group configuration. The coordinating UE 111 conveys the random access preamble message as a set of I / Q samples for joint transmission by the UE 112 and UE 113. The coordinating UE 111 can also convey the first time-frequency resource set to the plurality of user equipments in the UECS. In this way, the coordinating UE enables other UEs to convey the random access preamble message using the first time-frequency resource set.

[0069] At 710, the coordinating user equipment conveys the random access preamble message to the base station using time-frequency resources. For example, the coordinating user equipment 111 conveys the random access preamble message to the base station 121 using the time-frequency resources indicated in the RACH resource group configuration. The coordinating UE 111 synchronizes the conveyance of the random access preamble message with the conveyance of the UE 112 and UE 113 to jointly convey the random access preamble message using effectively higher transmission power. For example, the coordinating UE 111 and other UEs 112, 113 in the UECS can convey the random access preamble message simultaneously using the same frequency resources, such that constructive interference between the corresponding conveyances results in higher transmission power.

[0070] Figure 8FIG. 800 illustrates an example method of joint processing of random access channel communication typically associated with a base station in an ACS. At 802, the base station coordinates with other base stations in the ACS to allocate a set of random access resources for a user equipment to perform a random access procedure with the ACS. For example, a base station (e.g., base station 121) coordinates with other base stations in the ACS (e.g., base station 122, base station 123) to allocate a set of random access resources for a user equipment (e.g., base station 110) to perform a random access procedure with the ACS. The base station 121 uses the Xn or X2 interface to coordinate with the base stations 122 and 123.

[0071] At 804, the base station transmits configuration information of the set of random access resources to the user equipment. For example, the base station 121 transmits (or multiple base stations in the ACS jointly transmit) the configuration information of the set of random access resources to the user equipment 110. The configuration information of the set of random access resources includes a preamble specific to the ACS and time-frequency resources for RACH communication with the ACS.

[0072] At 806, the base station receives a random access preamble from the user equipment on the set of random access resources using the ACS-specific preamble. If the UE has previously received the ACS-specific timing advance and the ACS identifier, the random access preamble may also reflect the ACS-specific timing advance and incorporate the ACS identifier. At 808, the base station receives samples of the random access preamble from one or more other base stations in the ACS. For example, the base stations 121, 122, and 123 jointly receive the random access preamble from the user equipment 110. The base stations 122 and 123 use the Xn or X2 interface to send the I / Q samples of the received random access preamble to the base station 121.

[0073] At 810, the base station jointly processes the received random access preamble and the received samples. For example, the base station 121 jointly processes the received random access preamble and the samples of the random access preamble received from the base stations 122 and 123 to decode the random access preamble.

[0074] At 812, the base station coordinates with other base stations in the ACS for the joint transmission of a random access response of the random access procedure. For example, the base station 121 generates a random access response and forwards the random access response to be jointly transmitted to the base stations 122 and 123. The base station 121 may also convey timing information for the joint transmission of the random access response.

[0075] At 814, the base station transmits a random access response to enable a user equipment to access a wireless communication network. For example, base station 121 transmits the random access response synchronously with base stations 122 and 123 to jointly transmit the random access response with effectively higher transmission power. For example, the coordinating base station 121 and other base stations 122, 123 in the ACS can use the same frequency resource to transmit the random access response simultaneously, such that constructive interference between the corresponding transmissions results in higher transmission power.

[0076] Methods 700 and 800 can be executed together or can be executed independently of each other. In an example of executing these methods together, the UECS can transmit a random access preamble to the ACS according to method 700. According to method 800, the ACS can receive the random access preamble from the UECS and transmit a random access response to the UECS. By combining methods 700 and 800, both the random access preamble and the random access response can be transmitted with effectively higher transmission power. This can improve the performance of RACH communication when the quality of service between the UE and the base station is degraded, such as when the target UE is at the cell edge.

[0077] Some examples are described below:

[0078] Example 1: A method for a first user equipment UE to access a wireless communication network using a random access procedure, the first user equipment UE being configured as a coordinating user equipment of a user equipment coordination set, UECS, the method comprising, for the coordinating user equipment:

[0079] Receiving a random access channel, RACH, resource group configuration of a random access procedure communication from a base station;

[0080] Receiving a request to initiate the random access procedure from a second UE in the UECS;

[0081] Generating a random access preamble message using a preamble sequence included in the RACH resource group configuration;

[0082] Transmitting the random access preamble message to a plurality of user equipments in the UECS, the random access preamble message instructing the plurality of user equipments to transmit the random access preamble message using a first time-frequency resource set indicated in the RACH resource group configuration; and

[0083] Transmitting the random access preamble message to the base station using the time-frequency resource.

[0084] Example 2: The method according to example 1, wherein receiving the RACH resource group configuration comprises:

[0085] Receiving the RACH resource group configuration in a system information block, SIB, from the base station.

[0086] Example 3: The method according to Example 1 or Example 2, wherein the RACH resource group configuration includes a plurality of preambles, and wherein generating the random access preamble message includes:

[0087] Selecting the preamble from the plurality of preambles to be included in the random access preamble message.

[0088] Example 4: The method according to any one of Examples 1 to 3, wherein the RACH resource group configuration includes a plurality of RACH time-frequency resources, and wherein generating the random access preamble message includes the coordinating user equipment:

[0089] Selecting the time-frequency resource from the plurality of RACH time-frequency resources.

[0090] Example 5: The method according to any one of Examples 1 to 4, wherein communicating the random access preamble message to the plurality of user equipment in the UECS includes the coordinating user equipment:

[0091] Determining a timing for jointly transmitting the random access preamble message to the base station; and

[0092] Communicating the timing for the joint transmission of the random access preamble message to the plurality of user equipment in the UECS.

[0093] Example 6: The method according to any one of Examples 1 to 5, wherein communicating the random access preamble message to the plurality of user equipment in the UECS includes the coordinating user equipment:

[0094] Determining a first transmission power for jointly transmitting the random access preamble message to the base station; and

[0095] Transmitting the first transmission power for the joint transmission of the random access preamble message to the plurality of user equipment in the UECS.

[0096] Example 7: The method according to any one of Examples 1 to 6, including the coordinating user equipment:

[0097] Receiving, from the base station, the group RACH radio network temporary identity, RNTI, of the second user equipment; and

[0098] Jointly receiving a random access response of the random access procedure including the group RACH RNTI.

[0099] Example 8: The method according to Example 7, including the coordinating user equipment:

[0100] Based on receiving the random access response, determine that the random access procedure is successful.

[0101] Example 9: The method according to any one of Examples 1 to 7, including the coordinating user equipment:

[0102] Based on transmitting the random access preamble message, set a backoff timer; and

[0103] In response to the backoff timer expiring before receiving a random access response, direct the plurality of user equipment in the UECS to retransmit the random access preamble message.

[0104] Example 10: The method according to Example 9, wherein setting the backoff timer includes:

[0105] Set the backoff timer to a first time value that is longer than a second time value, the second time value to be set by a separate UE performing the random access procedure.

[0106] Example 11: The method according to Example 9 or Example 10, further including the coordinating user equipment:

[0107] Determine a second transmission power for joint transmission of retransmitting the random access preamble message.

[0108] Example 12: The method according to any one of Examples 1 to 6, wherein the random access procedure is a contention-based random access procedure, the method including the coordinating user equipment:

[0109] Determine a timing advance for joint transmission of a radio resource control, RRC, connection request message;

[0110] Convey the timing advance to the plurality of user equipment in the UECS;

[0111] Convey the RRC connection request message to the plurality of user equipment in the UECS, the RRC connection request message directing the plurality of user equipment to transmit the RRC connection request message; and

[0112] Transmit the RRC connection request message to the base station using the time-frequency resources indicated in the RACH resource group configuration.

[0113] Example 13: A method for a second user equipment, UE, in a user equipment coordination set, UECS, to access a wireless communication network using a random access procedure, the method including the second user equipment:

[0114] Receive a random access channel, RACH, resource group configuration for random access procedure communication from a base station;

[0115] Transmit a request to initiate the random access procedure to a first UE that acts as a coordinating UE in the UECS;

[0116] Receive a random access preamble message from the first UE using a preamble sequence included in the RACH resource group configuration; and

[0117] Transmit the random access preamble message to the base station using a first time-frequency resource set indicated in the RACH resource group configuration.

[0118] Example 14: A user equipment, comprising:

[0119] A wireless transceiver;

[0120] A local wireless network transceiver;

[0121] A processor; and

[0122] Instructions for a communication manager application, the instructions being executable by the processor to configure the user equipment to perform the method according to any one of Examples 1 to 13.

[0123] Example 15: A method for a base station in an active coordination set, ACS, to provide access to a wireless communication network using a random access procedure, the method comprising, for the base station:

[0124] Coordinate with other base stations in the ACS to allocate a random access resource set for a user equipment to perform a random access procedure with the ACS;

[0125] Transmit configuration information of the random access resource set to the user equipment;

[0126] Coordinate with other base stations in the ACS to jointly receive a radio resource control connection request from the user equipment;

[0127] Coordinate the joint transmission of a random access response of the random access procedure with one or more of the other base stations in the ACS; and

[0128] Transmit the random access response to enable the user equipment to access the wireless communication network.

[0129] Example 16: The method according to Example 15, wherein coordinating with other base stations in the ACS to jointly receive the radio resource control connection request comprises:

[0130] Receive a random access preamble from the user equipment;

[0131] Receive samples of the random access preamble from one or more of the other base stations in the ACS;

[0132] Jointly process the received random access preambles and the received samples.

[0133] Example 17: The method according to Example 15 or Example 16, wherein the configuration information for the random access resource set includes a preamble sequence specific to the ACS and time-frequency resources for communicating with a random access channel, RACH, of the ACS.

[0134] Example 18: The method according to any one of Examples 15 to 17, wherein the random access resource set is specific to the ACS.

[0135] Example 19: The method according to any one of Examples 15 to 18, wherein the ACS transmits the configuration information of the random access resource set to the user equipment in a broadcast message, a radio resource control, RRC, message, or a non-access stratum, NAS, message.

[0136] Example 20: The method according to any one of Examples 15 to 19, further comprising:

[0137] Coordinating with other base stations in the ACS to jointly transmit an acknowledgement, ACK, and a contention resolution identifier, CRID, to the user equipment.

[0138] Example 21: The method according to any one of Examples 15 to 20, further comprising, for the base station:

[0139] Assigning an ACS-specific identifier, ACS_RNTI, to the user equipment.

[0140] Example 22: The method according to Example 21, wherein the random access procedure is a contention-free random access procedure; and wherein one or more base stations in the ACS communicate with the user equipment using the ACS_RNTI of the user equipment.

[0141] Example 23: The method according to any one of Examples 15 to 22, comprising, for the base station:

[0142] Determining a timing advance for the joint transmission to the user equipment.

[0143] Example 24: A base station, comprising:

[0144] A wireless transceiver;

[0145] An interface between base stations;

[0146] A processor; and

[0147] Instructions for a base station manager application, the instructions being executable by the processor to configure the base station to perform according to any one of Examples 15 to 23.

[0148] Example 25: A computer-readable medium including instructions that, when executed by a processor, cause an apparatus including the processor to perform the method according to any one of Examples 1 to 13 or 15 to 23.

[0149] Although aspects of the joint processing of random access channel communication have been described in language specific to features and / or methods, the subject matter of the appended claims is not necessarily limited to the specific features or methods described. Instead, the specific features and methods are disclosed as example embodiments of the joint processing of random access channel communication, and other equivalent features and methods are intended to fall within the scope of the appended claims. In addition, various different aspects are described, and it is to be understood that each described aspect can be implemented independently or in combination with one or more other described aspects.

Claims

1. A method for a first user equipment (UE) to access a wireless communication network using a random access procedure, the first UE being configured as a coordinated UE of a user equipment coordination set (UECS), the method being performed by the coordinated UE and comprising: receiving a random access channel (RACH) resource group configuration for random access procedure communication from a base station; receiving a request to initiate the random access procedure from a second UE in the UECS; generating a random access preamble message using a preamble sequence included in the RACH resource group configuration; transmitting the random access preamble message to a plurality of user equipment in the UECS, the random access preamble message instructing the plurality of user equipment to transmit the random access preamble message using a first time-frequency resource set indicated in the RACH resource group configuration; and transmitting the random access preamble message to the base station using the first time-frequency resource set.

2. The method according to claim 1, wherein receiving the RACH resource group configuration includes: receiving the RACH resource group configuration from a system information block (SIB) of the base station.

3. The method according to claim 1, wherein the RACH resource group configuration includes a plurality of preamble sequences, and wherein generating the random access preamble message includes: selecting the preamble sequence from the plurality of preamble sequences to be included in the random access preamble message.

4. The method according to claim 1, wherein the RACH resource group configuration includes a plurality of RACH time-frequency resources, and wherein generating the random access preamble message includes: selecting the time-frequency resource from the plurality of RACH time-frequency resources.

5. The method according to claim 1, wherein transmitting the random access preamble message to the plurality of user equipment in the UECS includes: determining a timing for jointly transmitting the random access preamble message to the base station; and communicating the timing for the joint transmission of the random access preamble message to the plurality of user equipment in the UECS.

6. The method according to claim 1, wherein transmitting the random access preamble message to the plurality of user equipment in the UECS includes: determining a first transmission power for jointly transmitting the random access preamble message to the base station; and transmitting the first transmission power for the joint transmission of the random access preamble message to the plurality of user equipment in the UECS.

7. The method according to claim 1, further comprising: receiving a group RACH radio network temporary identifier (RNTI) of the second UE from the base station; and jointly receiving a random access response of the random access procedure including the group RACH RNTI.

8. The method according to claim 1, further comprising: setting a backoff timer based on transmitting the random access preamble message; and in response to the backoff timer expiring before receiving a random access response, instructing the plurality of user equipment in the UECS to retransmit the random access preamble message.

9. The method according to claim 8, Wherein, Setting the backoff timer includes: Setting the backoff timer to a first time value that is longer than a second time value, the second time value to be set by a separate UE performing the random access procedure.

10. The method according to claim 8, further including: Determining a second transmission power for joint transmission of retransmitting the random access preamble message.

11. The method according to claim 1, wherein, The random access procedure is a contention-based random access procedure, and the method further includes: Determining a timing advance for joint transmission of a radio resource control (RRC) connection request message; Communicating the timing advance to the plurality of user equipments in the UECS; Communicating the RRC connection request message to the plurality of user equipments in the UECS, the RRC connection request message instructing the plurality of user equipments to transmit the RRC connection request message; and Transmitting the RRC connection request message to the base station using the time-frequency resources indicated in the RACH resource group configuration.

12. A user equipment, comprising: A wireless transceiver; A local wireless network transceiver; A processor; and Instructions for a communication manager application, the instructions being executable by the processor to configure the user equipment to perform the method according to any one of claims 1 to 11.

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