Patent Description:
In some deployments, network access nodes, such as base stations, may have functionality that is split among multiple units. For example, a base station may include a central unit (CU), one or more distributed units (DUs) and one or more radio heads or radio units (RUs), which may allow for enhanced network functionality such as efficient coordinated multipoint (CoMP) communications techniques, multiple-input-multiple-output (MIMO) techniques, and the like. Such differences in functionality for components within a network may result in a relatively large number of different hardware configurations for a network equipment manufacturer, as well as the network operator. Thus, efficient management of different network components that have different functionality is desirable in order to achieve lower cost of network elements development and enhance network management and deployments.

European patent application <CIT> discloses configuring resource of a radio access network (RAN) including a radio unit and supporting flexible RAN functional splits. To support dynamic RAN functional splits, support for a number of different capabilities is required.

3GPP Draft "NGMN Overview on <NUM> RAN Functional Decomposition" by NGMN Alliance provides an overview of various RAN functional split options. International patent application <CIT> discloses a cloud-based radio access network where the baseband unit (BBU) is split into two parts: centralized unit (CU) and distributed unit (DU). The PHY split can be asymmetric. European patent application <CIT> discloses an adaptive fronthaul protocol for communication between a remote radio unit and a baseband unit.

The described techniques relate to improved methods, systems, devices, and apparatuses that support flexible configuration of fronthaul split radio units. Various aspects of the disclosure provide for radio units (RUs), distributed units (DUs), or combinations thereof, in which a single hardware configuration may be configured to implement different functions for radio frequency (RF) and baseband processing at a base station. In some cases, functionality for a RU or DU may be identified, and the RU or DU may be configured to implement the functionality through run-time configuration or boot image options to implement a particular set of functions that may be needed for a particular cell or deployment. In some cases, a RU may be configured to perform RF functions only, RF functions and at least one baseband function, or RF and all baseband functions. In some cases, a DU may be coupled between a RU and a central unit of a base station, and may perform medium access control (MAC) functions only, MAC functions and at least one baseband function, or MAC functions and all baseband functions. In some cases, a RU or DU may be reconfigured following an initial configuration to perform different functions following the reconfiguration.

The present disclosure provides a method for wireless communication at a radio unit according to claim <NUM>, a method for wireless communication at a distributed unit according to claim <NUM>, an apparatus for wireless communication at a radio unit according to claim <NUM>, and an apparatus for wireless communication at a distributed unit according to claim <NUM>. Specific embodiments are subject of the dependent claims.

Aspects of the present disclosure provide for flexible configurations of network components in a radio access network (RAN), such as a centralized or cloud RAN (C-RAN). In some deployments, network access nodes, such as base stations (e.g., gNBs in <NUM> networks), may have functionality that is split among multiple units. For example, a base station may include a central unit (CU) and one or more radio heads or radio units (RUs), which may allow for enhanced network functionality such as efficient coordinated multipoint (CoMP) communications techniques, multiple-input-multiple-output (MIMO) techniques, and the like. In some cases, functionality of a base station may be divided among a CU, one or more distributed units (DUs), and one or more RUs, where communications between a CU and a DU may be referred to as midhaul communications and communications between a DU and a RU may be referred to as fronthaul communications. In different types of deployments, it may be beneficial to have certain functionality implemented differently between DUs and RUs.

For example, some network operators may deploy RANs that use a disaggregated RAN infrastructure architecture. In a disaggregated architecture, the RAN may be split into three areas of functionality corresponding to CU functions, DU functions, and RU functions. The split of functionality between the CU, DU and RU is flexible and as such gives rise to numerous permutations of different functionalities depending upon which functions (e.g., medium access control (MAC) functions, baseband functions, radio frequency (RF) functions, and any combinations thereof) are performed at the CU, DU, and RU. In traditional deployments that use different hardware configurations for different functionalities, such differences in functionality for components within a network may result in a relatively large number of different hardware configurations for a network operator. Such different hardware configurations require significant overhead to develop, manufacture, deploy and maintain, and also provide very little flexibility to an communication equipment developer/manufacturer or a network operator after deployment.

Various techniques as discussed herein provide for flexible configuration of fronthaul split RUs and DUs. Various aspects of the disclosure provide for RUs, DUs, or combinations thereof, in which a single hardware configuration may be configured to implement different functions for RF and baseband processing. In some cases, functionality for a RU or DU may be identified, and the RU or DU may be configured through run-time configuration or a boot image option to implement a particular set of functions that may be needed for a particular cell or deployment. In some cases, a RU may be configured to perform RF functions only, RF functions and at least one baseband function, or RF and all baseband functions. In some cases, a DU may be coupled between a RU and a CU, and may perform MAC functions only, MAC functions and at least one baseband function, or MAC functions and all baseband functions. In some cases, a RU or DU may be reconfigured following an initial configuration to perform different functions following the reconfiguration.

Such techniques may allow a communication equipment developer/manufacturer or network operator to efficiently deploy and configure portions of a RAN that may use disaggregated infrastructure. Further, common hardware components may allow for more efficient development, manufacturing and maintenance and scaling of a network, and thus allow for efficient and economical development of communication network elements (such as RU and DU), network deployments and operations. Further, reconfigurability of RUs and DUs may allow an operator to adjust a network deployment or move equipment within a network in an efficient and cost effective manner.

Aspects of the disclosure are initially described in the context of wireless communications systems. Examples of functionality splits and RU/DU implementations for different functionality are then described. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to methods and apparatus for flexible configuration of fronthaul split radio units.

<FIG> illustrates an example of a wireless communications system <NUM> that supports methods and apparatus for flexible configuration of fronthaul split radio units in accordance with aspects of the present disclosure. The wireless communications system <NUM> may include one or more base stations <NUM>, one or more UEs <NUM>, and a core network <NUM>. In some examples, the wireless communications system <NUM> may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or <NUM> New Radio (5GNR) network. In some examples, the wireless communications system <NUM> may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, communications with low-cost and low-complexity devices, or any combination thereof. In some examples, the wireless communications system <NUM> may be a public network or private network, such as enterprise, office building, or Industrial IOT (IIOT) networks.

The base stations <NUM> may communicate with the core network <NUM> (e.g., a <NUM> core network (5GC)), or with one another, or both. For example, the base stations <NUM> may interface with the core network <NUM> through one or more backhaul links <NUM> (e.g., via an S1, N2, N3, or other interface). The base stations <NUM> may communicate with one another over the backhaul links <NUM> (e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations <NUM>), or indirectly (e.g., via core network <NUM>), or both. In some examples, the backhaul links <NUM> may be or include one or more wireless links.

A carrier may be associated with a frequency channel (e.g., an evolved universal mobile telecommunication system terrestrial radio access (E-UTRA) absolute radio frequency channel number (EARFCN)) and may be positioned according to a channel raster for discovery by the UEs <NUM>. A carrier may be operated in a standalone mode where initial acquisition and connection may be conducted by the UEs <NUM> via the carrier, or the carrier may be operated in a non-standalone mode where a connection is anchored using a different carrier (e.g., of the same or a different radio access technology).

The communication links <NUM> shown in the wireless communications system <NUM> may include uplink transmissions from a UE <NUM> to a base station <NUM>, or downlink transmissions from a base station <NUM> to a UE <NUM>. Carriers may carry downlink or uplink communications (e.g., in an FDD mode) or may be configured to carry downlink and uplink communications (e.g., in a TDD mode).

For example, the carrier bandwidth may be one of a number of determined bandwidths for carriers of a particular radio access technology (e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> megahertz (MHz)). Devices of the wireless communications system <NUM> (e.g., the base stations <NUM>, the UEs <NUM>, or both) may have hardware configurations that support communications over a particular carrier bandwidth or may be configurable to support communications over one of a set of carrier bandwidths. In some examples, the wireless communications system <NUM> may include base stations <NUM> or UEs <NUM> that support simultaneous communications via carriers associated with multiple carrier bandwidths. In some examples, each served UE <NUM> may be configured for operating over portions (e.g., a sub-band, a BWP) or all of a carrier bandwidth.

One or more numerologies for a carrier may be supported, where a numerology may include a subcarrier spacing (Δf) and a cyclic prefix. A carrier may be divided into one or more BWPs having the same or different numerologies. In some examples, a UE <NUM> may be configured with multiple BWPs. In some examples, a single BWP for a carrier may be active at a given time and communications for the UE <NUM> may be restricted to one or more active BWPs.

The time intervals for the base stations <NUM> or the UEs <NUM> may be expressed in multiples of a basic time unit which may, for example, refer to a sampling period of Ts = <NUM>/(Δfmax · Nf) seconds, where Δfmax may represent the maximum supported subcarrier spacing, and Nf may represent the maximum supported discrete Fourier transform (DFT) size. Time intervals of a communications resource may be organized according to radio frames each having a specified duration (e.g., <NUM> milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from <NUM> to <NUM>).

Each base station <NUM> may provide communication coverage via one or more cells, for example a macro cell, a small cell, a hot spot, or other types of cells, or any combination thereof. The term "cell" may refer to a logical communication entity used for communication with a base station <NUM> (e.g., over a carrier) and may be associated with an identifier for distinguishing neighboring cells (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID), or others). In some examples, a cell may also refer to a geographic coverage area <NUM> or a portion of a geographic coverage area <NUM> (e.g., a sector) over which the logical communication entity operates. Such cells may range from smaller areas (e.g., a structure, a subset of structure) to larger areas depending on various factors such as the capabilities of the base station <NUM>. For example, a cell may be or include a building, a subset of a building, or exterior spaces between or overlapping with geographic coverage areas <NUM>, among other examples.

A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by the UEs <NUM> with service subscriptions with the network provider supporting the macro cell. A small cell may be associated with a lower-powered base station <NUM>, as compared with a macro cell, and a small cell may operate in the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells may provide unrestricted access to the UEs <NUM> with service subscriptions with the network provider or may provide restricted access to the UEs <NUM> having an association with the small cell (e.g., the UEs <NUM> in a closed subscriber group (CSG), the UEs <NUM> associated with users in a home or office). A base station <NUM> may support one or multiple cells and may also support communications over the one or more cells using one or multiple component carriers.

Some UEs <NUM>, such as MTC or IoT devices, may be low cost or low complexity devices and may provide for automated communication between machines (e.g., via Machine-to-Machine (M2M) communication). In some examples, M2M communication or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay such information to a central server or application program that makes use of the information or presents the information to humans interacting with the application program. Some UEs <NUM> may be designed to collect information or enable automated behavior of machines or other devices.

The core network <NUM> may be an evolved packet core (EPC) or <NUM> core (5GC), which may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW), a Packet Data Network (PDN) gateway (P-GW), or a user plane function (UPF)). The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for the UEs <NUM> served by the base stations <NUM> associated with the core network <NUM>. User IP packets may be transferred through the user plane entity, which may provide IP address allocation as well as other functions. The user plane entity may be connected to the network operators IP services <NUM>. The operators IP services <NUM> may include access to the Internet, Intranet(s), an IP Multimedia Subsystem (IMS), or a Packet-Switched Streaming Service.

Some of the network devices, such as a base station <NUM>, may include subcomponents such as one or multiple CUs or access network entity <NUM>, which may be an example of an access node controller (ANC). Each CU may communicate with the UEs <NUM> through one or more other access network transmission entities <NUM>, such as a DU and RU (which may be referred to as radio heads, smart radio heads, or transmission/reception points (TRPs)). In some configurations, various functions of each access network entity <NUM> or base station <NUM> may be distributed across various network devices (e.g., CUs, DUs, RUs) or consolidated into a single network device (e.g., a base station <NUM>).

The wireless communications system <NUM> may operate using one or more frequency bands, typically in the range of <NUM> megahertz (MHz) to <NUM> gigahertz (GHz). Generally, the region from <NUM> to <NUM> is known as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from approximately one decimeter to one meter in length. The UHF waves may be blocked or redirected by buildings and environmental features, but the waves may penetrate structures sufficiently for a macro cell to provide service to the UEs <NUM> located indoors. The transmission of UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than <NUM> kilometers) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below <NUM>.

The wireless communications system <NUM> may also operate in a super high frequency (SHF) region using frequency bands from <NUM> to <NUM>, also known as the centimeter band, or in an extremely high frequency (EHF) region of the spectrum (e.g., from <NUM> to <NUM>), also known as the millimeter band. In some examples, the wireless communications system <NUM> may support millimeter wave (mmW) communications between the UEs <NUM> and the base stations <NUM>, and EHF antennas of the respective devices may be smaller and more closely spaced than UHF antennas. In some examples, this may facilitate use of antenna arrays within a device. The propagation of EHF transmissions, however, may be subject to even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions that use one or more different frequency regions, and designated use of bands across these frequency regions may differ by country or regulating body.

A base station <NUM> or a UE <NUM> may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of a base station <NUM> or a UE <NUM> may be located within one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming. In some examples, antennas or antenna arrays associated with a base station <NUM> may be located in diverse geographic locations. Additionally or alternatively, an antenna panel may support radio frequency beamforming for a signal transmitted via an antenna port.

The base stations <NUM> or the UEs <NUM> may use MIMO communications to exploit multipath signal propagation and increase the spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such techniques may be referred to as spatial multiplexing. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). MIMO techniques include single-user MIMO (SU-MIMO), where multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO), where multiple spatial layers are transmitted to multiple devices.

The wireless communications system <NUM> may be a packet-based network that operates according to a layered protocol stack. The MAC layer may also use error detection techniques, error correction techniques, or both to support retransmissions at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer may provide establishment, configuration, and maintenance of an RRC connection between a UE <NUM> and a base station <NUM> or a core network <NUM> supporting radio bearers for user plane data. At the physical layer, transport channels may be mapped to physical channels in baseband processing, and transmitted through an RF front end.

In various aspects, one or more base stations <NUM> may include one or more CUs, DU, and RUs, which may be used for communications with one or more UEs <NUM>. In some cases, RUs may be implemented using a hardware configuration that may be configured to implement different functions for RF and baseband processing. Similarly, DUs may be implemented using a hardware configuration that may be configured to implement different functions for MAC and baseband processing. In some cases, functionality for a RU or DU may be identified, and the RU or DU may be configured to implement the functionality through run-time configuration or boot image options to implement a particular set of functions that are needed for a particular cell or deployment. In some cases, a RU may be configured to perform RF functions only, RF functions and at least one baseband function, or RF and all baseband functions. In some cases, a DU may be coupled between a RU and a central unit of a base station, and may perform MAC functions only, MAC functions and at least one baseband function, or MAC functions and all baseband functions. In some cases, a RU or DU may be reconfigured following an initial configuration to perform different functions following the reconfiguration.

<FIG> illustrates exemplary functionality splits <NUM> that support methods and apparatus for flexible configuration of fronthaul split radio units in accordance with aspects of the present disclosure. In some examples, exemplary functionality splits <NUM> may implement aspects of wireless communication system <NUM>. In the examples of <FIG>, different components of a base station or gNB may perform different functions for wireless communications with UEs <NUM>.

The particular functionality performed by different components may depend upon the deployment. For example, a small cell deployment <NUM> may be implemented with a CU <NUM> coupled between a 5GC <NUM>-a and one or more RUs <NUM>-a, where the CU <NUM> performs radio resource control (RRC) and packet data convergence protocol (PDCP) functions. In such deployments, RU(s) <NUM>-a may perform MAC, baseband (BB), and RF functionality. The RU(s) <NUM>-a may communicate with UE <NUM>-a (and other UEs), and may exchange PDCP protocol data units (PDUs) with the CU <NUM>. In some cases, the RU(s) <NUM>-a may include hardware that allows for performance of the MAC, BB, and RF functionality, and may be configured to perform such functions(e.g., through a run-time configuration or through a boot image option that is selected when starting up the RU <NUM>-a).

In other cases, a relatively simple C-RAN deployment <NUM> may be implemented with a CU <NUM> coupled between 5GC <NUM>-b and one or more RUs <NUM>-b. In this deployment, the CU <NUM> may perform RRC, PDCP, and MAC functions, and the RU(s) <NUM>-b may perform BB and RF functions. The RU(s) <NUM>-b may communicate with UE <NUM>-b, and may exchange transport blocks (TBs) with the CU <NUM>. In some cases, the RU(s) <NUM>-b may include the same hardware as RU <NUM>-a, that allows for performance of the BB and RF functionality, and may be configured to perform such functions (e.g., through a run-time configuration or through a boot image option that is selected when starting up the RU <NUM>-b).

In further cases, a more advanced C-RAN deployment <NUM> may be implemented with a CU <NUM> coupled between 5GC <NUM>-c and one or more DUs <NUM>. In this deployment, the CU <NUM> may perform RRC and PDCP functions, and DU(s) <NUM> may perform MAC and BB functions. The DU(s) <NUM> may be coupled between CU <NUM> and one or more RUs <NUM>-c, where the RU(s) <NUM>-c may perform RF functions. The RU(s) <NUM>-c may communicate with UE <NUM>-c using, in some cases, CoMP or M-MIMO techniques. In some cases, the RU(s) <NUM>-c may exchange in-phase/quadrature (I/Q) digital samples with DU(s) <NUM>, and the DU(s) <NUM> may exchange PDCP PDUs with CU <NUM>. In some cases, the RU(s) <NUM>-c may include the same hardware as RU <NUM>-a and RU <NUM>-b, that allows for performance of the RF functionality, and may be configured to perform such functions (e.g., through a run-time configuration or through a boot image option that is selected when starting up the RU(s) <NUM>-c). In some cases, the DU(s) <NUM> may have a hardware configuration that can accommodate multiple different fronthaul splits, and may also be configured to perform particular functions as desired for a deployment (e.g., through a run-time configuration or through a boot image that is selected when starting up the DU(s) <NUM>).

In some cases a RU <NUM> may be configured for functionality that includes, for example, RF only; RF and fast Fourier transform (FFT); RF, FFT, and precoding; or RF, FFT, precoding, demodulation, and decoding. In a similar manner, the DU <NUM> may be configured for functionality that includes, for example, decoding only; decoding and demodulation; decoding, demodulation, and FFT; or decoding, demodulation, FFT, and precoding. Thus, various aspects provide a common and flexible RU and DU architecture that may address several different deployment scenarios and accommodate multiple functionality splits. Various different functionality splits may include, for example, different combinations of baseband processing splits, such as illustrated in <FIG>.

<FIG> illustrates an example of a RU/DU functionality split <NUM> that supports methods and apparatus for flexible configuration of fronthaul split radio units in accordance with aspects of the present disclosure. In some examples, RU/DU functionality split <NUM> may implement aspects of wireless communication systems <NUM>.

In this example, a RU <NUM>-d may implement RF functions, and a DU <NUM>-a may implement baseband and MAC functions. The DU <NUM>-a may, in this example, receive downlink data <NUM> to be transmitted (e.g., PDCP PDUs), and may perform MAC processing, coding, rate-matching, scrambling, modulation, layer mapping, precoding, resource element (RE) mapping, and IFFT/CP addition. The DU <NUM>-a may output digital I/Q samples <NUM> to the RU <NUM>-d, which may perform RF processing of digital-to-analog conversion and analog beamforming, to output analog signals <NUM> to an RF front end (e.g., one or more RF transmit chains) and one or more antennas.

For uplink communications, the RU <NUM>-d may receive uplink signals <NUM> and perform analog beamforming and analog-to-digital conversion of received signals. The RU <NUM>-d may provide digital I/Q samples <NUM> to the DU <NUM>-a, which may perform FFT/CP removal, RE de-mapping, channel estimation and equalization, inverse discrete Fourier transform (IDFT), demodulation, de-scrambling, rate de-matching, decoding, and MAC processing, to provide PDCP PDUs <NUM> to a CU or 5GC.

<FIG> illustrates an example of a RU/DU functionality split <NUM> that supports methods and apparatus for flexible configuration of fronthaul split radio units in accordance with aspects of the present disclosure. In some examples, RU/DU functionality split <NUM> may implement aspects of wireless communication system <NUM>.

In this example, a RU <NUM>-e may implement RF functions and some baseband functions, and a DU <NUM>-b may implement remaining baseband and MAC functions. The DU <NUM>-b may, in this example, receive downlink data <NUM> to be transmitted (e.g., PDCP PDUs), and may perform MAC processing, coding, rate-matching, scrambling, modulation, layer mapping, precoding, and RE mapping. The DU <NUM>-b may output pre-coded tones <NUM> to the RU <NUM>-e, which may perform IFFT/CP addition, and RF processing of digital-to-analog conversion and analog beamforming, to output analog signals <NUM> to an RF front end (e.g., one or more RF transmit chains) and one or more antennas.

For uplink communications, the RU <NUM>-e may receive uplink signals <NUM> and perform analog beamforming, analog-to-digital conversion of received signals, and FFT/CP removal. The RU <NUM>-e may provide pre-coded tones <NUM> to the DU <NUM>-b, which may perform RE de-mapping, channel estimation and equalization, IDFT, demodulation, de-scrambling, rate de-matching, decoding, and MAC processing, to provide PDCP PDUs <NUM> to a CU or 5GC.

In this example, a RU <NUM>-f may implement RF functions and some baseband functions, and a DU <NUM>-c may implement remaining baseband and MAC functions. The DU <NUM>-c may, in this example, receive downlink data <NUM> to be transmitted (e.g., PDCP PDUs), and may perform MAC processing, coding, rate-matching, scrambling, modulation, and layer mapping. The DU <NUM>-c may output non-precoded tones (layers) <NUM> to the RU <NUM>-f, which may perform baseband processing of precoding, RE mapping, and IFFT/CP addition, and RF processing of digital-to-analog conversion and analog beamforming, to output analog signals <NUM> to an RF front end (e.g., one or more RF transmit chains) and one or more antennas.

For uplink communications, the RU <NUM>-f may receive uplink signals <NUM> and perform analog beamforming, analog-to-digital conversion of received signals, and baseband functions of FFT/CP removal and RE de-mapping. The RU <NUM>-f may provide non-pre-coded tones <NUM> to the DU <NUM>-c, which may perform channel estimation and equalization, IDFT, demodulation, de-scrambling, rate de-matching, decoding, and MAC processing, to provide PDCP PDUs <NUM> to a CU or 5GC.

In this example, a RU <NUM>-g may implement RF functions and some baseband functions, and a DU <NUM>-d may implement remaining baseband and MAC functions. The DU <NUM>-d may, in this example, receive downlink data <NUM> to be transmitted (e.g., PDCP PDUs), and may perform MAC processing, coding, rate-matching, and scrambling. The DU <NUM>-d may output encoded bits <NUM> to the RU <NUM>-g, which may perform baseband processing of modulation, layer mapping, precoding, RE mapping, and IFFT/CP addition, and RF processing of digital-to-analog conversion and analog beamforming, to output analog signals <NUM> to an RF front end (e.g., one or more RF transmit chains) and one or more antennas.

For uplink communications, the RU <NUM>-g may receive uplink signals <NUM> and perform analog beamforming, analog-to-digital conversion of received signals, and baseband functions of FFT/CP removal, RE de-mapping, channel estimation and equalization, IDFT, and demodulation. The RU <NUM>-g may provide LLR metrics <NUM> to the DU <NUM>-d, which may perform de-scrambling, rate de-matching, decoding, and MAC processing, to provide PDCP PDUs <NUM> to a CU or 5GC.

In this example, a RU <NUM>-h may implement all RF functions and baseband functions, and a DU <NUM>-e may implement MAC functions. The DU <NUM>-e may, in this example, receive downlink data <NUM> to be transmitted (e.g., PDCP PDUs), and may perform MAC processing and may output information bits (e.g., transport blocks (TBs)) <NUM> to the RU <NUM>-h, which may perform baseband processing of coding, rate-matching, scrambling, modulation, layer mapping, precoding, RE mapping, and IFFT/CP addition, and RF processing of digital-to-analog conversion and analog beamforming, to output analog signals <NUM> to an RF front end (e.g., one or more RF transmit chains) and one or more antennas.

For uplink communications, the RU <NUM>-h may receive uplink signals <NUM> and perform analog beamforming, analog-to-digital conversion of received signals, and baseband functions of FFT/CP removal, RE de-mapping, channel estimation and equalization, IDFT, demodulation, de-scrambling, rate de-matching, and decoding. The RU <NUM>-h may provide information bits <NUM> (e.g., TBs) to the DU <NUM>-e, which may perform MAC processing and provide PDCP PDUs <NUM> to a CU or 5GC.

While the examples of <FIG> illustrate various different functional splits between RUs <NUM>, CUs, and DUs <NUM>, other functional splits may be implemented. As discussed herein, various aspects provide that RUs <NUM> and DUs <NUM> may be configured to perform different functional splits based on a particular deployment or functionality that is desired for a network. In some cases, a runtime configuration or boot image may be used to configure or reconfigure a RU <NUM> or DU <NUM>. RUs <NUM> and DUs <NUM> that are configured for different functional splits may be implemented in different deployments, some examples of which are illustrated in <FIG>.

<FIG> illustrates an example of a small cell functionality split <NUM> that supports methods and apparatus for flexible configuration of fronthaul split radio units not claimed in the appended claims. In some examples, small cell functionality split <NUM> may implement aspects of wireless communication system <NUM>. In this example, a CU <NUM> may be coupled with a 5GC <NUM>-d and a number of RUs <NUM>-i, in a small cell deployment.

In such a deployment, the multiple RUs <NUM>-i may receive PDCP PDUs <NUM> from CU <NUM> and RLC, MAC, and baseband functions may be collocated with RF functions at the RUs <NUM>-i. Each of the multiple RUs <NUM>-i in such cases may serve UEs in a relatively small geographic area, and provide PDCP PDUs <NUM> to CU <NUM>. In this example, RUs <NUM>-i may include a neural processing unit (NPU) <NUM> for RLC and MAC processing, a baseband digital front end <NUM> (e.g., a Qualcomm FSM100-based digital front end) for baseband processing, and an RF front end <NUM> (e.g., a Qualcomm Snapdragon <NUM>-based RF front end). In this example, DU functionality may be collocated with the RU <NUM>-i with RLC and MAC functions performed on an embedded NPU. The CU <NUM> in such examples may host RRC and PDCP functions (e.g., based on a Linux server).

<FIG> illustrates an example of a centralized RAN functionality split <NUM> that supports methods and apparatus for flexible configuration of fronthaul split radio units not claimed in the appended claims. In some examples, centralized RAN functionality split <NUM> may implement aspects of wireless communication system <NUM>. In this example, a CU <NUM> may be coupled with a 5GC <NUM>-e and a number of RUs <NUM>-j, in a C-RAN deployment with baseband processing collocated with RF processing at RUs <NUM>-j.

In such a deployment, the multiple RUs <NUM>-j may receive TBs <NUM> from CU <NUM> which may perform RRC, PDCP, RLC, and MAC functions. The RUs <NUM>-j may perform baseband functions and RF functions. Each of the multiple RUs <NUM>-j in such cases may serve UEs and may provide CoMP with non-coherent precoding of downlink transmissions, and provide received TBs <NUM> to CU <NUM>. In this example, RUs <NUM>-j may include an optional NPU <NUM> for baseband processing (e.g., for decoding), a baseband digital front end <NUM> for baseband processing, and an RF front end <NUM>. In this example, DU functionality may be split between the RUs <NUM>-j and CU <NUM>. The CU <NUM> in such examples may host RRC, PDCP, RLC, and MAC functions (e.g., based on a Linux server). In such examples, for downlink communications, multiple RUs <NUM>-j may transmit the same bits/TBs over the air, and receiving UEs may benefit from increased receive power and diversity. For uplink transmissions, the multiple RUs <NUM>-j may independently decode uplink communications from the same UE to enhance the likelihood of successful decoding of UE communications.

<FIG> illustrates an example of an advanced C-RAN functionality split supporting CoMP <NUM> that supports methods and apparatus for flexible configuration of fronthaul split radio units in accordance with aspects of the present disclosure. In some examples, advanced c-RAN functionality split supporting CoMP <NUM> may implement aspects of wireless communication system <NUM>. In this example, a CU <NUM> may be coupled with a 5GC <NUM>-f and a DU <NUM>-f. The DU <NUM>-f may be coupled with a number of RUs <NUM>-k, in a C-RAN deployment that may provide CoMP techniques in communications with UEs.

In such a deployment, the DU <NUM>-f may receive PDCP PDUs <NUM> from the CU <NUM>, and perform RLC, MAC, and baseband functions. The DU <NUM>-f may provide I/Q samples to the multiple RUs <NUM>-k. The RUs <NUM>-k may perform baseband functions and RF functions. Each of the multiple RUs <NUM>-k in such cases may serve UEs and may provide CoMP with non-coherent precoding of downlink transmissions, and provide received PDCP PDUs <NUM> to CU <NUM>. In this example, DU <NUM>-f may include a NPU <NUM> for performing RLC and MAC processing, a baseband processor <NUM> for performing baseband functions, and a precoder processor <NUM> that may provide processing capabilities for coherent precoding to provide CoMP communications via the RUs <NUM>-k.

In this example, RUs <NUM>-k may include an optional NPU <NUM> and digital front end <NUM> (e.g., which may not be used for baseband processing based on the configuration of the RUs <NUM>-k), and an RF front end <NUM>. In this example, DU <NUM>-f may host baseband and coherent precoding for CoMP on a Linux server (e.g., as a PCI-e card) or on an custom embedded printed circuit board with an NPU. The CU <NUM> in such examples may host RRC, and PDCP functions (e.g., based on a Linux server). In some cases, such a deployment may provide CoMP without local oscillator (LO)/phase synchronization by providing non coherent precoding and combining, or with LO/phase synchronization with coherent precoding and combining.

<FIG> illustrates an example of an advanced C-RAN functionality split supporting M-MIMO <NUM> that supports methods and apparatus for flexible configuration of fronthaul split radio units in accordance with aspects of the present disclosure. In some examples, advanced c-RAN functionality split supporting M-MIMO <NUM> may implement aspects of wireless communication system <NUM>. In this example, a CU <NUM> may be coupled with a 5GC <NUM>-g and a DU <NUM>-g. The DU <NUM>-g may be coupled with one or more RUs <NUM>-l, in a C-RAN deployment that may provide M-MIMO capability in communications with UEs.

In such a deployment, the DU <NUM>-g may receive PDCP PDUs <NUM> from the CU <NUM>, and perform RLC, MAC, and baseband functions. The DU <NUM>-g may provide I/Q samples <NUM> to the RU <NUM>-l. The RU <NUM>-l may perform precoding baseband functions and RF functions. In this example, the RU <NUM>-l may include multiple baseband digital front ends <NUM> and multiple RF front ends <NUM> and may support M-MIMO. In this example, DU <NUM>-g may include a NPU <NUM> for performing RLC and MAC processing, and a baseband processor <NUM>.

In this example, RUs <NUM>-l may include a precoder processor <NUM> that may provide precoding/combining processing capabilities for M-MIMO via the multiple baseband digital front ends <NUM> and RF front ends <NUM>. In this example, DU <NUM>-g may host baseband processing on a Linux server (e.g., as a PCIe card) or on an custom embedded printed circuit board with an NPU. The CU <NUM> in such examples may host RRC, and PDCP functions (e.g., based on a Linux server). In some cases, such a deployment may provide M-MIMO capabilities for a number of different antenna ports.

<FIG> illustrates an example of a RU hardware <NUM> implementation that supports methods and apparatus for flexible configuration of fronthaul split radio units in accordance with aspects of the present disclosure. In some examples, RU hardware <NUM> may implement aspects of wireless communication system <NUM>. In this example, a RU <NUM>-m is configurable for performing various different baseband and RF functions for a 2x2 small cell or in a CoMP deployment.

In this example, the RU <NUM>-m may include a network port <NUM> (e.g., a <NUM> GB Ethernet port), a network interface controller (NIC) <NUM>, a NPU <NUM>, a RU processor <NUM>, and an RF card <NUM>. The RF card <NUM> may include, in this example, an RF processor <NUM> (e.g., a Qualcomm Snapdragon-based RF processor) an RF front end <NUM> (e.g., including transmit/receive chains with ADC, amplification components, analog phase-shift components, etc.), and antenna ports <NUM>. In this example, four antenna ports <NUM> are present. As discussed herein, RU <NUM>-m may be configured to perform different functions based on a desired deployment and other components (e.g., CU/DU components) that may be coupled with the RU <NUM>-m. In some cases, memory <NUM> may include configuration information that may be used to configure functionality of the RU <NUM>-m. In other cases, the RU processor <NUM>, NPU <NUM>, or combinations thereof, may include memory that may be used to store configuration information. In some cases, the configuration information may be programmable such that the RU <NUM>-m may be reconfigurable to perform different functions at different times. In some cases, the configuration information may include runtime configuration information that is used to configure the RU <NUM>-m, or may include a boot image that is used at power-on or reset of the RU <NUM>-m. In some cases, RU <NUM>-m may be used on small cell deployments (e.g., supporting two transmit and four receive channels), or in deployments that implement CoMP (e.g., supporting two transmit and two receive channels).

<FIG> illustrates an example of a RU hardware <NUM> that supports methods and apparatus for flexible configuration of fronthaul split radio units in accordance with aspects of the present disclosure. In some examples, RU hardware <NUM> may implement aspects of wireless communication system <NUM>. In this example, a RU <NUM>-n is configurable for performing various different baseband and RF functions for a 4x4 small cell or in a CoMP deployment.

In this example, the RU <NUM>-n may include a network port <NUM> (e.g., a <NUM> GB Ethernet port), a network interface controller (NIC) <NUM>, a NPU <NUM>, and multiple RU processors <NUM> that are each associated with an RF card <NUM>. The RF cards <NUM> may include, in this example, an RF processor <NUM>, an RF front end <NUM> (e.g., including transmit/receive chains with ADC, amplification components, analog phase-shift components, etc.), and antenna ports <NUM>. In this example, four antenna ports <NUM> are present at each RF card <NUM>. As discussed herein, RU <NUM>-n may be configured to perform different functions based on a desired deployment and other components (e.g., CU/DU components) that may be coupled with the RU <NUM>-n. In some cases, memory <NUM> may include configuration information that may be used to configure functionality of the RU <NUM>-n. In other cases, the RU processors <NUM>, NPU <NUM>, or combinations thereof, may include memory that may be used to store configuration information. In some cases, the configuration information may be programmable such that the RU <NUM>-n may be reconfigurable to perform different functions at different times. In some cases, the configuration information may include runtime configuration information that is used to configure the RU <NUM>-n, or may include a boot image that is used at power-on or reset of the RU <NUM>-n. In some cases, RU <NUM>-n may be used on small cell deployments (e.g., supporting four transmit and four receive channels), or in deployments that implement CoMP (e.g., supporting four transmit and four receive channels).

<FIG> illustrates an example of a RU hardware <NUM> that supports methods and apparatus for flexible configuration of fronthaul split radio units in accordance with aspects of the present disclosure. In some examples, RU hardware <NUM> may implement aspects of wireless communication system <NUM>. In this example, a RU <NUM>-o is configurable for performing various different baseband and RF functions for a 16x16 M-MIMO deployment.

In this example, the RU <NUM>-o may include a network port <NUM> (e.g., a <NUM> GB Ethernet port), a switch <NUM> (e.g., a PCIe switch), multiple precoding/combining processors <NUM>, and multiple RU processors <NUM> that are each associated with an RF card <NUM>. The RF cards <NUM> may include, in this example, an RF processor, an RF front end, and antenna ports <NUM>. In this example, two antenna ports <NUM> are present at each RF card <NUM>. As discussed herein, RU <NUM>-o may be configured to perform different functions based on a desired deployment and other components (e.g., CU/DU components) that may be coupled with the RU <NUM>-o. In some cases, memory <NUM> may include configuration information that may be used to configure functionality of the RU <NUM>-o. In other cases, the RU processors <NUM>, precoding/combining processors <NUM>, or combinations thereof, may include memory that may be used to store configuration information. In some cases, the configuration information may be programmable such that the RU <NUM>-o may be reconfigurable to perform different functions at different times. In some cases, the configuration information may include runtime configuration information that is used to configure the RU <NUM>-o, or may include a boot image that is used at power-on or reset of the RU <NUM>-o. In some cases, RU <NUM>-o may be used in M-MIMO deployments, <NUM> Tx/Tx channels, and <NUM> layers. The RU <NUM>-o may also be used in other deployments and configured to perform functions based on the particular deployment.

<FIG> illustrates an example of a DU hardware <NUM> that supports methods and apparatus for flexible configuration of fronthaul split radio units in accordance with aspects of the present disclosure. In some examples, DU hardware <NUM> may implement aspects of wireless communication system <NUM>.

In this example, DU <NUM>-h may include a number of BB/MAC/RLC processors <NUM> that are coupled with a switch <NUM> (e.g., a PCI-e switch) and a network port <NUM> (e.g., a PCIe port). In some cases, the DU <NUM>-h may be implemented in a PCI card, and multiple DUs <NUM>-h may be deployed in a system. In some cases, each BB/MAC/RLC processor <NUM> may provide processing capabilities for baseband functions, MAC/RLC functions, or any combinations thereof. In some cases, memory <NUM> may include configuration information that may be used to configure functionality of the DU <NUM>-h. In other cases, the BB/MAC/RLC processors <NUM> may include memory that may be used to store configuration information. In some cases, the configuration information may be programmable such that the DU <NUM>-h may be reconfigurable to perform different functions at different times. In some cases, the configuration information may include runtime configuration information that is used to configure the DU <NUM>-h, or may include a boot image that is used at power-on or reset of the DU <NUM>-h.

<FIG> shows a block diagram <NUM> of a device <NUM> that supports methods and apparatus for flexible configuration of fronthaul split radio units in accordance with aspects of the present disclosure. The device <NUM> may be an example of aspects of a base station <NUM> or RU <NUM> as described herein. The device <NUM> may include a receiver <NUM>, BB/RF processing components <NUM>, and a transmitter <NUM>. The device <NUM> may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

The receiver <NUM> 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 methods and apparatus for flexible configuration of fronthaul split radio units, etc.). Information may be passed on to other components of the device <NUM>. The receiver <NUM> may be an example of aspects of the transceiver <NUM> described with reference to <FIG>. The receiver <NUM> may utilize a single antenna or a set of antennas.

In some cases, the BB/RF processing components <NUM> may be examples of NPUs, RU processors, and RF components of a RU, as discussed herein. BB/RF processing components <NUM> may identify configuration information that includes a first set of functions to be performed at the radio unit, where the radio unit has a capability to perform radio frequency functions, baseband functions, medium access control functions, or any combinations thereof, and the first set of functions includes at least one radio frequency function, configure the first set of functions at the radio unit based on the identifying, where the first set of functions includes a first set of downlink functions and a first set of uplink functions, receive, from a central unit or a distributed unit that performs a second set of functions, downlink signals that are to be processed according to the first set of downlink functions, process the downlink signals according to the first set of downlink functions to generate a downlink communication, and transmit the downlink communication to at least one UE.

In some cases, the BB/RF processing components <NUM> may be examples of NPUs, DU processors, or other components of a DU, as discussed herein. The BB/RF processing components <NUM> in such cases may identify configuration information that includes a second set of functions to be performed at the distributed unit, where a radio unit coupled with the distributed unit performs a first set of functions including radio frequency functions for radio frequency communications with at least one UE, and where the distributed unit has a capability to perform baseband functions, medium access control functions, or any combinations thereof, and the second set of functions includes at least one medium access control function, configure the second set of functions at the distributed unit based on the identifying, where the second set of functions includes a second set of downlink functions and a second set of uplink functions, receive, from a central unit, downlink data that is to be processed according to the second set of downlink functions, process the downlink data according to the second set of downlink functions to generate downlink signals for processing and transmission by the radio unit, and communicate the downlink signals to the radio unit for processing according to the first set of functions and transmission to the UE. The BB/RF processing components <NUM> may be an example of aspects of the BB/RF processing components <NUM> described herein.

The BB/RF processing components <NUM>, or sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the BB/RF processing components <NUM>, or its sub-components may be executed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC), a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

The BB/RF processing components <NUM>, or sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the BB/RF processing components <NUM>, or sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the BB/RF processing components <NUM>, or sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

<FIG> shows a block diagram <NUM> of a device <NUM> that supports methods and apparatus for flexible configuration of fronthaul split radio units in accordance with aspects of the present disclosure. The device <NUM> may be an example of aspects of a device <NUM>, or a base station <NUM> as described herein. The device <NUM> may include a receiver <NUM>, BB/RF processing components <NUM>, and a transmitter <NUM>. The device <NUM> may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

The BB/RF processing components <NUM> may be an example of aspects of the BB/RF processing components <NUM> as described herein. The BB/RF processing components <NUM> may include a configuration manager <NUM>, a RU processor <NUM>, an RF front end <NUM>. The BB/RF processing components <NUM> may be an example of aspects of the BB/RF processing components <NUM> described herein.

The configuration manager <NUM> may identify configuration information that includes a first set of functions to be performed at the radio unit, where the radio unit has a capability to perform radio frequency functions, baseband functions, medium access control functions, or any combinations thereof, and the first set of functions includes at least one radio frequency function and configure the first set of functions at the radio unit based on the identifying, where the first set of functions includes a first set of downlink functions and a first set of uplink functions.

The RU processor <NUM> may receive, from a central unit or a distributed unit that performs a second set of functions, downlink signals that are to be processed according to the first set of downlink functions and process the downlink signals according to the first set of downlink functions to generate a downlink communication.

The RF front end <NUM> may transmit the downlink communication to at least one UE.

<FIG> shows a block diagram <NUM> of BB/RF processing components <NUM> that supports methods and apparatus for flexible configuration of fronthaul split radio units in accordance with aspects of the present disclosure. The BB/RF processing components <NUM> may be an example of aspects of BB/RF processing components <NUM>, BB/RF processing components <NUM>, or BB/RF processing components <NUM> described herein. The BB/RF processing components <NUM> may include a configuration manager <NUM>, a RU processor <NUM>, an RF front end <NUM>, a FFT/CP manager <NUM>, and a baseband processing manager <NUM>. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

The configuration manager <NUM> may identify configuration information that includes a first set of functions to be performed at the radio unit, where the radio unit has a capability to perform radio frequency functions, baseband functions, medium access control functions, or any combinations thereof, and the first set of functions includes at least one radio frequency function. In some examples, the configuration manager <NUM> may configure the first set of functions at the radio unit based on the identifying, where the first set of functions includes a first set of downlink functions and a first set of uplink functions.

In some examples, the configuration manager <NUM> may receive updated configuration information that provides a reconfigured first set of functions that include more or fewer baseband functions that are to be performed at the radio unit. In some examples, the configuration manager <NUM> may reconfigure the first set of functions at the radio unit based on the updated configuration information.

In some examples, a set of radio units support coordinated multipoint (CoMP) communications where same transport blocks are transmitted by the set of radio units to the UE with non-coherent precoding, and the set of radio units receive and independently decode uplink communications from the UE. In some examples, a set of radio units support coordinated multipoint (CoMP) communications with coherent or non-coherent precoding. In some examples, a set of radio units support massive multiple-input-multiple-output (M-MIMO) communications a set of UEs.

In some cases, the radio unit hosts baseband and radio frequency functions, and is collocated with the distributed unit that hosts medium access control and radio link control functions. In some cases, the radio unit hosts baseband and radio frequency functions, and medium access control and radio link control functions are split between the radio unit and the central unit. In some cases, the radio unit hosts radio frequency functions, the distributed unit hosts baseband functions, medium access control, and radio link control functions. In some cases, the radio unit hosts radio frequency functions and baseband functions including precoding and combining, and the distributed unit hosts medium access control and radio link control functions.

The RU processor <NUM> may receive, from a central unit or a distributed unit that performs a second set of functions, downlink signals that are to be processed according to the first set of downlink functions. In some examples, the RU processor <NUM> may process the downlink signals according to the first set of downlink functions to generate a downlink communication. In some examples, the RU processor <NUM> may process the received radio frequency signals according to the first set of uplink functions to generate processed uplink signals. In some examples, the RU processor <NUM> may provide the processed uplink signals to the central unit or the distributed unit to be processed according to the second set of functions. In some examples, the RU processor <NUM> may communicate with the UE and the central unit or distributed unit using the reconfigured first set of functions.

In some cases, the first set of functions includes only the radio frequency functions and where the downlink signals and the processed uplink signals include digital I/Q samples. In some cases, the second set of functions are performed at the distributed unit and include the baseband functions and the medium access control functions. In some cases, the first set of functions includes the radio frequency functions and a first subset of baseband functions, and where the downlink signals and the processed uplink signals include digitally precoded tones.

In some cases, the first set of functions includes the radio frequency functions and a first subset of baseband functions, and where the downlink signals and the processed uplink signals include non-precoded tones. In some cases, the first set of functions includes the radio frequency functions and a first subset of baseband functions, and where the downlink signals and the processed uplink signals include digital information bits.

The RF front end <NUM> may transmit the downlink communication to at least one UE. In some examples, the RF front end <NUM> may receive radio frequency signals from the UE in a set of wireless resources associated with an uplink allocation granted to the UE for an uplink communication.

In some cases, the first set of downlink functions include a digital-to-analog conversion function and a transmit analog beamforming function, and the first set of uplink functions include a receive analog beamforming function and an analog-to-digital conversion function.

The FFT/CP manager <NUM> may perform FFT and CP operations. In some cases, the first subset of baseband functions include Fourier transform processing and cyclic prefix addition for the downlink signals, and include cyclic prefix removal and Fourier transform processing for uplink signals. In some cases, the first subset of baseband functions include Fourier transform processing, cyclic prefix addition, resource mapping, and digital precoding for the downlink signals, and include cyclic prefix removal, Fourier transform processing, and resource demapping processing for uplink signals. In some cases, the first set of functions includes the radio frequency functions and a first subset of baseband functions, and where the downlink signals include encoded bits and the processed uplink signals include log likelihood ratio (LLR) metrics.

In some cases, the first subset of baseband functions include Fourier transform processing, cyclic prefix addition, resource mapping, digital precoding, layer mapping, and modulation for the downlink signals, and include cyclic prefix removal, Fourier transform processing, resource demapping processing, channel estimation and equalization, inverse discrete Fourier transform (IDFT) processing, and demodulation for uplink signals.

In some cases, the first subset of baseband functions include Fourier transform processing, cyclic prefix addition, resource mapping, digital precoding, layer mapping, modulation, scrambling, rate-matching, and coding for the downlink signals, and include cyclic prefix removal, Fourier transform processing, resource demapping processing, channel estimation and equalization, inverse discrete Fourier transform (IDFT) processing, demodulation, descrambling, de-rate-matching, and decoding for uplink signals.

In some cases, the uplink signals from the radio unit and the downlink signals to the radio unit include digital I/Q samples, and the second set of functions includes all baseband functions and medium access control functions.

In some cases, the downlink signals and the uplink signals include digitally precoded tones, and where the second set of functions include a subset of baseband functions and the medium access control functions, and where the radio unit performs one or more baseband functions that are not included in the subset of baseband functions.

<FIG> shows a diagram of a system <NUM> including a device <NUM> that supports methods and apparatus for flexible configuration of fronthaul split radio units in accordance with aspects of the present disclosure. The device <NUM> may be an example of or include the components of device <NUM>, device <NUM>, or a base station <NUM> as described herein, and include a DU, RU, or both. The device <NUM> may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a BB/RF processing components <NUM>, a network communications manager <NUM>, a transceiver <NUM>, an antenna <NUM>, memory <NUM>, a processor <NUM>, and an inter-station communications manager <NUM>. These components may be in electronic communication via one or more buses (e.g., bus <NUM>).

The BB/RF processing components <NUM> when implemented in a RU may identify configuration information that includes a first set of functions to be performed at the radio unit, where the radio unit has a capability to perform radio frequency functions, baseband functions, medium access control functions, or any combinations thereof, and the first set of functions includes at least one radio frequency function, configure the first set of functions at the radio unit based on the identifying, where the first set of functions includes a first set of downlink functions and a first set of uplink functions, receive, from a central unit or a distributed unit that performs a second set of functions, downlink signals that are to be processed according to the first set of downlink functions, process the downlink signals according to the first set of downlink functions to generate a downlink communication, and transmit the downlink communication to at least one UE.

The BB/RF processing components <NUM> when implemented in a DU may identify configuration information that includes a second set of functions to be performed at the distributed unit, where a radio unit coupled with the distributed unit performs a first set of functions including radio frequency functions for radio frequency communications with at least one UE, and where the distributed unit has a capability to perform baseband functions, medium access control functions, or any combinations thereof, and the second set of functions includes at least one medium access control function, configure the second set of functions at the distributed unit based on the identifying, where the second set of functions includes a second set of downlink functions and a second set of uplink functions, receive, from a central unit, downlink data that is to be processed according to the second set of downlink functions, process the downlink data according to the second set of downlink functions to generate downlink signals for processing and transmission by the radio unit, and communicate the downlink signals to the radio unit for processing according to the first set of functions and transmission to the UE.

The processor <NUM> 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 <NUM> may be configured to operate a memory array using a memory controller. In some cases, a memory controller may be integrated into processor <NUM>. The processor <NUM> may be configured to execute computer-readable instructions stored in a memory (e.g., the memory <NUM>) to cause the device <NUM> to perform various functions (e.g., functions or tasks supporting methods and apparatus for flexible configuration of fronthaul split radio units).

<FIG> shows a flowchart illustrating a method <NUM> for flexible configuration of fronthaul split radio units in accordance with aspects of the present disclosure. The operations of method <NUM> may be implemented by a radio unit or its components as described herein. For example, the operations of method <NUM> may be performed by a BB/RF processing components as described with reference to <FIG>. In some examples, a base station or RU may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

At <NUM>, the radio unit identifies configuration information that includes a first set of functions to be performed at the radio unit, where the radio unit has a capability to perform radio frequency functions, baseband functions, medium access control functions, or any combinations thereof, and the first set of functions includes at least one radio frequency function. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a configuration manager as described with reference to <FIG>.

At <NUM>, the radio unit configures the first set of functions at the radio unit based on the identifying, where the first set of functions includes a first set of downlink functions and a first set of uplink functions. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a configuration manager as described with reference to <FIG>.

At <NUM>, the radio unit receives, from a central unit or a distributed unit that performs a second set of functions, downlink signals that are to be processed according to the first set of downlink functions. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a RU processor as described with reference to <FIG>.

At <NUM>, the radio unit processes the downlink signals according to the first set of downlink functions to generate a downlink communication. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a RU processor as described with reference to <FIG>.

At <NUM>, the radio unit transmits the downlink communication to at least one UE. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by an RF front end as described with reference to <FIG>.

At <NUM>, the radio unit receives radio frequency signals from the UE in a set of wireless resources associated with an uplink allocation granted to the UE for an uplink communication. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by an RF front end as described with reference to <FIG>.

At <NUM>, the radio unit processes the received radio frequency signals according to the first set of uplink functions to generate processed uplink signals. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a RU processor as described with reference to <FIG>.

At <NUM>, the radio unit provides the processed uplink signals to the central unit or the distributed unit to be processed according to the second set of functions. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a RU processor as described with reference to <FIG>.

<FIG> shows a flowchart illustrating a method <NUM> for flexible configuration of fronthaul split radio units in accordance with aspects of the present disclosure. The operations of method <NUM> may be implemented by an RU or its components as described herein. For example, the operations of method <NUM> may be performed by a BB/RF processing components as described with reference to <FIG>. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

At <NUM>, the radio unit may receive updated configuration information that provides a reconfigured first set of functions that include more or fewer baseband functions that are to be performed at the radio unit. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a configuration manager as described with reference to <FIG>.

At <NUM>, the radio unit may reconfigure the first set of functions at the radio unit based on the updated configuration information. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a configuration manager as described with reference to <FIG>.

At <NUM>, the radio unit may communicate with the UE and the central unit or distributed unit using the reconfigured first set of functions. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a RU processor as described with reference to <FIG>.

<FIG> shows a flowchart illustrating a method <NUM> for flexible configuration of fronthaul split radio units in accordance with aspects of the present disclosure. The operations of method <NUM> may be implemented by a DU or its components as described herein. For example, the operations of method <NUM> may be performed by a BB/RF processing components as described with reference to <FIG>. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

At <NUM>, the DU identifies configuration information that includes a second set of functions to be performed at the distributed unit, where a radio unit coupled with the distributed unit performs a first set of functions including radio frequency functions for radio frequency communications with at least one UE, and where the distributed unit has a capability to perform baseband functions, medium access control functions, or any combinations thereof, and the second set of functions includes at least one medium access control function. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a configuration manager as described with reference to <FIG>.

At <NUM>, the DU configures the second set of functions at the distributed unit based on the identifying, where the second set of functions includes a second set of downlink functions and a second set of uplink functions. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a configuration manager as described with reference to <FIG>.

At <NUM>, the DU receives, from a central unit, downlink data that is to be processed according to the second set of downlink functions. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a DU processor as described with reference to <FIG>.

At <NUM>, the DU processes the downlink data according to the second set of downlink functions to generate downlink signals for processing and transmission by the radio unit. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a DU processor as described with reference to <FIG>.

At <NUM>, the DU communicates the downlink signals to the radio unit for processing according to the first set of functions and transmission to the UE. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a DU processor as described with reference to <FIG>.

At <NUM>, the DU receives uplink signals from the radio unit. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a DU processor as described with reference to <FIG>.

At <NUM>, the DU processes the received uplink signals according to the second set of uplink functions to generate uplink data. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a DU processor as described with reference to <FIG>.

At <NUM>, the DU communicates the uplink data to the central unit. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a DU processor as described with reference to <FIG>.

At <NUM>, the DU may receive updated configuration information that provides a reconfigured second set of functions that include more or fewer baseband functions that are to be performed at the distributed unit. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a configuration manager as described with reference to <FIG>.

At <NUM>, the DU may reconfigure the second set of functions at the distributed unit based on the updated configuration information. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a configuration manager as described with reference to <FIG>.

At <NUM>, the DU may communicate with the radio unit and the central unit using the reconfigured second set of functions. The operations of <NUM> may be performed according to the methods described herein. In some examples, aspects of the operations of <NUM> may be performed by a configuration manager as described with reference to <FIG>.

For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these.

A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include random-access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium.

For example, an example step that is described as "based on condition A" may be based on both a condition A and a condition B without departing from the scope of the present disclosure.

Claim 1:
A method for wireless communication at a radio unit (<NUM>; <NUM>; <NUM>; <NUM>) of a wireless communications system, comprising:
identifying (<NUM>; <NUM>), at power-on or reset of the radio unit, configuration information that includes a first set of functions to be performed at the radio unit, wherein the radio unit has a capability to perform radio frequency functions and at least some baseband functions, and the first set of functions includes at least the radio frequency functions;
configuring (<NUM>; <NUM>) the first set of functions at the radio unit based at least in part on the identifying, wherein the first set of functions includes a first set of downlink functions and a first set of uplink functions;
receiving (<NUM>; <NUM>), from a distributed unit (<NUM>) that performs a second set of functions, downlink signals (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>) that are to be processed according to the first set of downlink functions;
processing (<NUM>; <NUM>) the downlink signals according to the first set of downlink functions to generate a downlink communication;
transmitting (<NUM>; <NUM>) the downlink communication (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>) to at least one user equipment, UE (<NUM>);
receiving (<NUM>) radio frequency signals (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>) from the UE in a set of wireless resources associated with an uplink allocation granted to the UE for an uplink communication;
processing (<NUM>) the received radio frequency signals according to the first set of uplink functions to generate processed uplink signals; and
providing (<NUM>) the processed uplink signals (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>) to the distributed unit (<NUM>) to be processed according to the second set of functions.