O-ran IQ scaling adjustment methods

Abstract

A system for O-RAN IQ scaling adjustments includes one or more distributed units configured to communicatively couple the system to one or more core networks, wherein a distributed unit is configured to implement first compression / decompression schemes for compressing / decompressing IQ data. The system also includes one or more radio units communicatively coupled to the one or more distributed units and configured to implement second compression / decompression schemes for compressing / decompressing the IQ data, wherein a radio unit in the one or more radio units is configured to wirelessly transmit and receive radio frequency signals to and from user equipment in a coverage area associated with the radio unit. Further, gain settings for at least one of the one or more distributed units and the one or more radio units are adjusted based on a gain misalignment between the one or more distributed units and the one or more radio units.

Description

Docket No. 7623 WO W1 / 376.2207WO01O-RAN IQ SCALING ADJUSTMENT METHODS CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims benefit of U.S. Provisional Patent Application No. 63 / 752,074, filed on January 31, 2025, the contents of which are incorporated herein in its entirety.BACKGROUND

[0002] Wireless communications service providers are deploying 5G radio access networks (RANs). Such 5G radio access networks are configured to satisfy the open radio access network (O-RAN) Alliance specifications (“O-RAN specifications’'). The O-RAN specifications include without limitation, the O-RAN fronthaul working group control, user and synchronization plane specification (0RAN-WG4 CUS.0-V04.00), and O-RAN Alliance working group 4 management plane specification (ORAN-WG4.MP.0-v04.00.00); the O-RAN specifications are hereby incorporated by reference herein in their entirety.

[0003] The O-RAN specifications permit interoperability of RAN components, e.g., O-RAN specification-compliant radios (or O-RAN radio units or O-RAN radios) and O-RAN specification-compliant distributed units (or O-RAN distributed units) made by different vendors. The O-RAN distributed unit may be executed on a server system, e.g., local server network(s) and / or cloud computing system(s). The O-RAN distributed unit (O-DU) may comprise virtual baseband unit(s). The O-RAN specifications utilize message protocols to communicate between remote radio units and virtual baseband units that differ from those used in legacy sy stems, e.g., 4G specification-compliant radio access networks (or 4G radio access networks). A virtual baseband unit processes, e.g., encodes, baseband data received from and sent to the radio(s). A radio transmits and / or receives data at one or more frequencies translated above baseband. The virtual baseband unit and radio(s) are components of a communications system such as a cellular communications system.SUMMARY

[0004] Systems and methods for O-RAN IQ scaling adjustments are described herein. In certain embodiments, a system includes one or more distributed units configured to communicatively couple the system to one or more core networks, wherein a distributed unit is configured to implement first compression / decompression schemesDocket No. 7623 WO W1 / 376.2207WO01for compressing / decompressing IQ data. The system also includes one or more radio units communicatively coupled to the one or more distributed units and configured to implement second compression / decompression schemes for compressing / decompressing the IQ data, wherein a radio unit in the one or more radio units is configured to wirelessly transmit and receive radio frequency signals to and from user equipment in a coverage area associated with the radio unit. Further, gain settings for at least one of the one or more distributed units and the one or more radio units are adjusted based on a gain misalignment between the one or more distributed units and the one or more radio units.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Drawings accompany this description and depict only some embodiments associated with the scope of the appended claims. Thus, the described and depicted embodiments should not be considered limiting in scope. The accompanying drawings and specification describe the exemplar)’ embodiments, and features thereof, with additional specificity and detail, in which:

[0006] FIG. 1 is a block diagram illustrating a shared network system according to an aspect of the present disclosure;

[0007] FIG. 2 is a diagram illustrating an example of selecting gain within compressed and decompressed data according to an aspect of the present disclosure;

[0008] FIGs. 3A-3C are flowchart diagrams of different methods for manually detecting misalignments in scaling according to an aspect of the present disclosure;

[0009] FIGs. 4A-4C are flowchart diagrams of different methods for detecting scaling misalignments in the downlink by RUs during runtime according to an aspect of the present disclosure;

[0010] FIGs. 5A-5D are flowchart diagrams of different methods for detecting scaling misalignments in the uplink by RUs during runtime according to an aspect of the present disclosure;

[0011] FIGs. 6A-6B are flowchart diagrams of different methods for detecting scaling misalignments in the uplink by a DU during runtime according to an aspect of the present disclosure; and

[0012] FIG. 7 is a flo chart diagram of a method for mitigating scaling misalignments according to an aspect of the present disclosure.Docket No. 7623 WO W1 / 376.2207WO01

[0013] Per common practice, the drawings do not show the various described features according to scale, but the drawings show the features to emphasize the relevance of the features to the example embodiments.DETAILED DESCRIPTION

[0014] The following detailed description refers to the accompanying drawings that form a part of the present specification. The drawings, through illustration, show specific illustrative embodiments. However, it is to be understood that other embodiments may be used and that logical, mechanical, and electrical changes may be made.

[0015] In O-RAN systems, an O-RAN distributed unit (O-DU) communicates with an O-RAN radio unit (O-RU) through a digital interface. In some systems, the O-DU and the O-RU communicate downlink (DL) and uplink (UL) IQ data through the digital interface. In particular, the DL and UL IQ data communicated through the digital interface can be compressed with various compressing schemes. When different compression schemes are used, channel bandwidth and subcarrier spacing can also vary. Due to different compression schemes, channel bandwidths, and subcarrier spacing, the bit-width and the scaling of the IQ words can also vary. A detailed description of the O-RAN U-Plane protocol along with the digital power scaling for DL and UL signals can be found in chapter 8 of O-RAN Working Group 4 (Open Fronthaul Interfaces WG) Control, User and Synchronization Plane Specification version 16.01 from August 2024 (O-RAN. WG4.CUS.0-vl6.01, pages 272-296), which is incorporated herein by reference.

[0016] However, when implemented, the protocol may be interpreted in different ways in different O-DUs and O-RUs, such that the O-DUs and O-RUs within a system may implement different compression schemes. In particular, when different vendors provide the O-DUs and O-RUs, the vendors may interpret the standards differently, leading to compression discrepancies. The misalignment of scaling applied during compression schemes may lead the DL signal to be transmitted through an antenna or antenna port for the O-RU at too low or too high of the output power. For example, when the frequency domain signal power of the IQ data for a certain channel configuration transmitted by the O-DU is lower than the expected signal power received by the O-RU, then the signal power of the analog time domain signal transmitted by the O-DU will also be too low.Docket No. 7623 WO W1 / 376.2207WO01

[0017] Further, the different implementations of compression schemes may also lead to scaling misalignments that affect the UL signal. In particular, the decompression algorithm used by the O-DU may not match the compression algorithm used by the O-RU. The mismatch in compression algorithms may lead the O-DU to be unaware of the scalings applied to UL signals by the O-RU, leading the O-DU to be unaware of the signal power of the RF signal received by the O-RU. As some behavior of the O-DU relies on awareness of the signal power of the RF signal (like transmit power control (TPC)), if the O-DU is unaware of the RF power due to a scaling misalignment, the system may perform poorly due to degradations in the UL throughput.

[0018] Systems and methods are described herein for detecting and mitigating misalignment in compression schemes. In particular, as described herein, compression misalignments may be detected both manually or dynamically. When misalignments are detected manually, the communication system enters a test operational mode before detecting the misalignment in compression schemes. When misalignments are detected dynamically, one or more components may detect the misalignment during normal system operation. Additionally, the systems may detect and mitigate misalignments in both the UL and DL directions.

[0019] FIG. 1 is a block diagram illustrating an example of a communication system 100. In the example shown in FIG. 1, the communication system 100 is implemented using an O-RAN or other point-to-multipoint distributed base station architecture. The communication system 100 may also be referred to here as an “O-RAN” or an “O-RAN system.” For example, communication system 100 includes one or more central units 101 at least one distributed unit (DU or O-DU) 103, one or more intermediate nodes / switches 105-1 - 105-3 (referenced herein generally as intermediate nodes / switches 105), at least one system manager 109, and one or more radio units (RU or O-RU) (such as radio unit (RU) 107-1 and any quantity of optional radio unit (RU) 107-2 through optional radio unit (RU) 107-X, referenced herein generally as RU(s) 107) configured to serve at least one user equipment (UE) 111-1 - 111-M (referenced herein generally as UE(s) 111) within the site at which wireless services is being provided.

[0020] In some examples, at least one CU 101 and at least one DU 103 may implement a “base station,” “base station entity.” or “base station system” (which in the context of a fourth generation (4G) Long Term Evolution (LTE) system, may alsoDocket No. 7623 WO W1 / 376.2207WO01be referred to as an “evolved NodeB,’’ “eNodeB,’’ or “eNB”; in the context of a fifth generation (5G) New Radio (NR) system, may also be referred to as a “gNodeB” or “gNB”; and may take different names in other current or future generations of radio access networks (RAN) and communication networks). In some examples, the at least one CU 101 and / or at least one DU 103 are located remotely from the site at which wireless service is being provided, e g., in centralized banks of nodes. In optional embodiments, some of the functionality of the CU 101 and DU 103 may be implemented as part of a baseband controller 106 located at a site where the baseband controller 106 communicates with a device management system such as the system manager 109. Additionally, the RUs 107 may be physically separated from each other at the site at which wireless service is being provided, although they are each communicatively coupled to the one or more DUs 103 via the at least one fronthaul network 113. A base station may be used to provide UEs 111 with mobile access to a mobile network operator’s (MNO) core network 115 to enable UEs 111 to wirelessly communicate data and voice (using, for example, Voice over LTE (VoLTE) technology or a 3GPP 5G RAN providing wireless service using a 5G air interface).

[0021] In certain embodiments, the communication system 100 implements a base station as a respective 5GNR gNB. In such a configuration, each CU 101 implements Layer 3 and non-time critical Layer 2 functions for the 5GNR gNB. In examples, each CU 101 may be further partitioned into at least one control-plane entity (“UUCP”) and at least one user-plane entity (“CU-UP”) that handles the control-plane and user-plane processing of the CU 101, respectively. In examples, each DU 103 is configured to implement the time-critical Layer 2 functions and, except as described below, at least some of the Layer 1 functions for the gNB. In this example, each RU 107 is configured to implement the physical layer functions for the gNB that are not implemented in the DU 103 as well as the RF interface. Further, in some implementations, the intermediate nodes / switches 105 may also perform some of the Layer 2 or physical layer functions. Also, each RU 107 includes or is coupled to a respective set of one or more antennas used to radiate downlink RF signals to UEs 111 and receive uplink RF signals transmitted by UEs 111.

[0022] In general, the communication system 100 is configured to provide wireless service to various items of user equipment (UEs) 111 (such as user equipment (UE) 111-1 and any quantity of optional user equipment (UE) 111-2 through optional user equipment (UE) 111 -B). Unless explicitly stated to the contrary, references to LayerDocket No. 7623 WO W1 / 376.2207WO011, Layer 2, Layer 3, and other or equivalent layers (such as the Physical Layer or the Media Access Control (MAC) Layer) refer to layers of the particular wireless interface (for example. Fourth Generation (4G) Long Term Evolution (LTE) or Fifth Generation (5G) New Radio (NR)) used for wirelessly communicating with UEs 111. Furthermore, it is also to be understood that 5G NR embodiments can be used in both standalone and non-standalone modes (or other modes developed in the future), and the following description is not intended to be limited to any particular mode.Moreover, although some embodiments are described here as being implemented for use with 5G NR, other embodiments can be implemented for use with other wireless interfaces, and the following description is not intended to be limited to any particular wireless interface.

[0023] In examples, the at least one CU 101 is communicatively coupled to at least one corresponding core network 115 of the associated wireless operator via at least one backhaul network 117. The at least one backhaul network 117 is ty pically a public wide area network such as the Internet, though it is understood that the at least one backhaul network 117 can be implemented in other ways. In examples, at least one DU 103 is communicatively coupled to at least one CU 101 via at least one midhaul network. In examples, the midhaul interface promulgated by the O-RAN Alliance is used for the midhaul network between the DU 103 and the at least one CU 101. In examples, at least one RU 107 is communicatively coupled to at least one DU 103 via at least one fronthaul network 113. In examples, the fronthaul interface promulgated by the O-RAN Alliance is used for the fronthaul network 113 between each RUs 107 and the respective DU 103. In examples, each of the backhaul network 117, the midhaul network, and / or the fronthaul network 113 may be implemented with one or more switches, routers, and / or other networking devices. For example, the fronthaul network 113 may include the intermediate node / s witches 105. In some examples, the backhaul network 117, the midhaul network, and / or the fronthaul network 113 may be implemented with switched Ethernet using a switched Ethernet network and an Ethernet switch.

[0024] Although FIG. 1 (and the description set forth herein more generally) is described in the context of 5G embodiments where each logical base station entity7is partitioned into a CU 101, DUs 103, and RUs 107 and, for at least some of the physical channels, some physical-layer processing is performed in the DUs 103 with the remaining physical-layer processing being performed in the RUs 107 orDocket No. 7623 WO W1 / 376.2207WO01intermediate node / switches 105, it is to be understood that the techniques described here can be used with other wireless interfaces (for example, 4G LTE) and with other ways of implementing a base station entity (for example, using a conventional baseband band unit (BBU) / remote radio head (RRH) architecture). Accordingly, references to a CU, DU, or RU in this description and associated figures can also be considered to refer more generally to any entity (including, for example, any “base station’7or “RAN” entity) implementing any of the functions or features described here as being implemented by a CU, DU, or RU.

[0025] Each CU 101, DU 103, intermediate nodes / switches 105, and RUs 107 and any of the specific features described here as being implemented thereby, can be implemented in hardware, software, or combinations of hardware and software, and the various implementations (whether hardware, software, or combinations of hardware and software) can also be referred to generally as ■■circuitry." a “circuit,” or “circuits” that is or are configured to implement at least some of the associated functionality. When implemented in software, such software can be implemented in software or firmware executing on one or more suitable programmable processors (or other programmable device) or configuring a programmable device (for example, processors or devices included in or used to implement special-purpose hardware, general-purpose hardware, and / or a virtual platform). In such a software example, the software can comprise program instructions that are stored (or otherwise embodied) on or in an appropriate non-transitory storage medium or media (such as flash or other non-volatile memory, magnetic disc drives, and / or optical disc drives) from which at least a portion of the program instructions are read by the programmable processor or device for execution thereby (and / or for otherwise configuring such processor or device) in order for the processor or device to perform one or more functions described here as being implemented the software. Such hardware or software (or portions thereof) can be implemented in other ways (for example, in a field programmable gate array (FPGA), application specific integrated circuit (ASIC), etc.).

[0026] Moreover, each CU 101, DU 103, intermediate nodes / switches 105. and RUs 107, can be implemented as a physical network function (PNF) (for example, using dedicated physical programmable devices and other circuitry) and / or a virtual network function (VNF) (for example, using one or more general purpose servers (possibly with hardware acceleration) in a scalable cloud environment and in different locations within an operator’s network (for example, in the operator’s “edge cloud” or “centralDocket No. 7623 WO W1 / 376.2207WO01cloud”). Each VNF can be implemented using hardware virtualization, operating system virtualization (also referred to as containerization), and application virtualization, as well as various combinations of two or more of the preceding. Where containerization is used to implement a VNF, it may also be referred to as a “containerized network function” (CNF). For example, in the exemplary7embodiment shown in FIG. 1, each RU 107 and fronthaul multiplexer (FHM) is implemented as a PNF and is deployed in or near a physical location where radio coverage is to be provided, and each CU 101 and DU 103 is implemented using a respective set of one or more VNFs deployed in a distributed manner within one or more clouds (for example, within an “edge” cloud or “central” cloud). Each CU 101, DU 103, intermediate nodes / switches 105, and RUs 107, and any of the specific features described here as being implemented thereby, can be implemented in other ways.

[0027] The links shown in the communication system 100 in FIG. 1 show all the RUs 107 being connected to the fronthaul network 113 (which could be implemented with one or more intermediate nodes / switches 105, which may include switches, routers, and / or other networking devices). The actual physical links between devices in the backhaul network 117, the midhaul network, and / or the fronthaul network 113 may be implemented using different media, such as conductive media (copper, multi-rate, multi-mode cables, etc.) and optical media (fiber optic cables). In examples, each RU 107 and each physical node on which each DU 103 is implemented includes one or more Ethernet network interfaces to couple each RU 107 and each physical node implementing the DU 103 to the fronthaul network 113 in order to facilitate communications between the DU 103 and the RUs 107.

[0028] The RUs 107 may be deployed at a site to provide wireless coverage and capacity for one or more wireless network operators. The site at which wireless service is being provided may cover, for example, a building or campus or other grouping of buildings (used, for example, by one or more businesses, governments, or other enterprise entities) or some other public venue (such as a hotel, resort, amusement park, hospital, shopping center, university campus, arena, or an outdoor area such as a ski area, stadium or a densely populated downtown area). In some configurations, the site at which wireless service is being provided is at least partially (and optionally entirely) indoors, but other alternatives are possible.

[0029] Each UE 111 may be a computing device with at least one processor that executes instructions stored in memory, e.g., a mobile phone, tablet computer, mobileDocket No. 7623 WO W1 / 376.2207WO01media device, mobile gaming device, laptop computer, vehicle-based computer, desktop computer, etc.

[0030] Each CU 101, DU 103, intermediate node / switch 105, and RU 107 can be implemented so as to use an air interface that supports one or more of frequencydivision duplexing (FDD) and / or time-division duplexing (TDD). Also, the CU 101, DUs 103, intermediate node / switch 105. and RUs 107 can be implemented to use an air interface that supports one or more of the multiple-input-multiple-output (MIMO), single-input-single-output (SISO), single-input-multiple-output (SIMO), and / or beamforming schemes. For example, the CU 101, DUs 103, and RUs 107 can implement one or more of the 5G NR transmission modes. Moreover, the communication system 100 can be configured to support multiple air interfaces and / or to support multiple wireless operators.

[0031] In examples in the downlink, the DU 103 communicates downlink controlplane messages, downlink user-plane messages, and uplink control-plane messages to the RU 107-1, which uses the downlink control-plane and downlink user-plane messages to wirelessly transmit downlink radio frequency signals using a respective set of antennas for reception by UEs 111.

[0032] In examples in the uplink, the RUs 107 wirelessly receive uplink radio frequency signals transmitted from UEs 111 using a respective set of antennas and generate uplink user-plane data from the received RF signals. In examples, an intermediate node / switch 105 may also combine user data received from the RUs 107. In examples, the combining is an uplink summation. In examples, the combining is uplink coherent combining that requires phase information for the data.

[0033] In examples in the uplink, for each uplink slot, the serving DU 103 schedules one or more UEs 111 to transmit during that slot. In examples, the DU 103 sends uplink control-plane messages to each RU 107 identifying the resource blocks (RBs) for which the RU 107 should provide baseband IQ data. The RBs for which the RU 107 should provide baseband IQ data are also referred to here as "‘front-haul ed RBs.”

[0034] In embodiments where the baseband IQ data communicated over the fronthaul comprises frequency-domain baseband IQ data, the front-hauled RBs comprise only those RBs that have been assigned to the scheduled UEs 111 for uplink transmissions during that slot. In embodiments w here the baseband IQ data communicated over the fronthaul comprises time-domain baseband IQ data, the front-hauled RBs comprise all of the RBs for the slot (due to the time-domain nature of the baseband IQ data).Docket No. 7623 WO W1 / 376.2207WO01During each uplink slot, for each antenna port, each RU 107 generates respective baseband IQ data for each front-hauled RB from an uplink RF analog signal received via a respective one of the antennas associated with that RU 107. For each RU 107, for each uplink slot, the RU 107 generates an uplink user-plane message that includes the baseband IQ data generated at that RU 107 for the various front-hauled RBs and antenna ports and communicates the uplink user-plane messages northbound.

[0035] Each CU 101, DU 103. intermediate node / switch 105, and RU 107, and any of the specific features described here as being implemented thereby, can be implemented in other ways. Additionally, it should be noted that the systems and methods described herein may also be used in other distributed RANs, e.g., a distributed antenna system (DAS).

[0036] In additional embodiments, the DU 103 and intermediate node / switches 105 may implement fronthaul multiplexers (FHM). For example, FHM functionality may be integrated into the DU 103, one or more of the intermediate node / switches 105, or one or more of the RUs 107. Alternatively, one or more of the intermediate node / switches may operate as independent FHMs.

[0037] In embodiments employing FHM, the DU 103 may replicate downlink packet streams (from the CU) for each RU 107. Also, intermediate nodes / s witches 105 may use combining / digital summation on the uplink packet stream from the RUs 107 (before sending to the DU). The combining / digital summation includes: (1) adding the corresponding in-phase (I) samples in corresponding physical resource blocks (PRBs) (from all the connected RUs 107); (2) adding the corresponding quadrature-phase (Q) samples in corresponding PRBs (from all the connected RUs 107); and (3) sending a combined stream of I / Q data from the node employing FHM to the DU 103. The combining / digital summation may optionally include some overflow management. Using the shared cell implementation, the DU 103 can send and receive a single packet stream (with a bandwidth of approximately N PRBs) instead of M packet streams (one for each RU 107 with a total bandwidth of approximately N PRBs x M RUs). By reducing the transmitted to and received data from the RU 107 to a single stream of N PRBs, the employment of FHM within a shared cell implementation more efficiently uses the available bandwidth.

[0038] In additional embodiments, the system 100 may include a system manager 109 that communicates with the various components of the system 100 that are deployed within a system. The system manager 109 may function as a network managementDocket No. 7623 WO W1 / 376.2207WO01system that performs configuration management of the system components, fault management, performance management, resource provisioning, and software management. The system manager 109 may communicate the various components of the system 100 through ethemet connections, wireless communication links, and the like. The system manager 109 may allow a neutral host to manage the use of the components of the system 100 by one or more MNOs.

[0039] In certain embodiments, the DU 103 and one of the RUs 107 may employ different IQ compression schemes in at least one of the uplink and downlink directions. As used herein, compression schemes may refer to schemes that compress IQ data that is transmitted between different components within a system. When a DU 103 or RU 107 employs a compression scheme, the compression scheme may include scaling the IQ data. The scaling employed by the DU 103 or RU 107 may result in scaling misalignments. When a scaling misalignment occurs, a component may receive IQ data at unexpected power levels, which can negatively impact subsequent signal transmissions or processing. Accordingly, the DU 103 and RUs 107 may be configured to detect and mitigate scaling misalignments in both the UL and DL between DUs 103 and RUs 107.

[0040] In certain embodiments, the DU 103 and the RU 107 may be designed to accommodate a wide range of fronthaul pow er levels in order to be compatible with multiple components. As DUs 103 and RUs 107 can accommodate wide ranges of power levels, the dynamic range may be too wide to accommodate within a native word length (NWU) for the DU 103 and the RUs 107. As used herein, the NWL refers to the bit-width of decompressed IQ data. When compressed, the encoded-word length may depend on the compression mode and bit-width used. Accordingly, as the encoded-word length varies, the DU 103 or RU 107 may be designed to have a selectable gain in compression / decompression.

[0041] FIG. 2 is a diagram illustrating an example of selecting gain within compressed and decompressed data by a component receiving IQ data. For example, when employing a 9-bit block floating-point compression method, with 9-bit blockfloating-point, the size of the uncompressed word 207 is 24 bits (9-bit mantissa 201 plus up to 15 bits available for shifting (4-bit unsigned exponent 203)). If the native word length is 16 bits, rather than taking the slice 209 at a fixed 16-bit location within the 24 bits of the uncompressed word 207. a device may be configured to shift theDocket No. 7623 WO W1 / 376.2207WO01slice 209 at a configurable offset within the 24 bits of the uncompressed word 207. This allows a device to accommodate a wide range of DL / UL gains at a reduced cost.

[0042] In an exemplary implementation, a component may shift the 16 bits of the NWL at a selectable slice 209 within the uncompressed word 207 to either amplify or attenuate the received data based on the detected power level of the compressed IQ data. As the slice 209 is 16 bits in length, the uncompressed word 207 has a length that is 8 bits longer, where 8 bits can represent a gain or attenuation of 48 dB to the 16 bits of the NWL. For example, shifting the NWL to the right by 8 bits corresponds to an attenuation of 48 dB, and shifting the NWL to the left by 8 bits corresponds to an amplification of 48 dB. As shown, if the compressed data is 9 bits, the data could be shifted up to 15 bits within the uncompressed word 207. Accordingly, a device (like the DU 103 or RUs 107), when compressing or decompressing data, may shift the data to adjust the gain of data to a desired level. Thus, a DU 103 and RUs 107 may detect the power level of data to be compressed or compressed data and then shift the data to amplify or attenuate the data to compensate for differences in power levels that arise from different scalings implemented by a DU 103 and RUs 107.

[0043] In certain embodiments, the DU 103 and RUs 107 may implement one or more methods to detect when to amplify or attenuate IQ data to reduce negative effects that result from differences in compression schemes. Further, the methods for detecting differences in compression schemes may be employed either manually or during runtime. When a detection method is performed manually, the communication system 100 may enter a test mode for the purpose of measuring power levels for signals transmitted between a DU 103 and a connected RU 107. Further, detection may be performed with both UL and DL communications. Also, the detection may be performed by the DU 103 or an RU 107. As stated above, when the power levels are measured, a component may adjust the power level of the signal to be at appropriate power levels for desired operation of the communication system 100.

[0044] In certain embodiments, the communication system 100 may include devices that can control the communication system 100, which dictate when the system communication system 100 enters a test mode and can control the communication system 100 when in the test mode. For example, the system manager 109 may include an integrator component that can control the operations of components within the communication system 100 in relation to test mode operation. The system manager 109 is able to command components to perform certain functions that may includeDocket No. 7623 WO W1 / 376.2207WO01imitating other devices, sending particular messages, and adjusting gain performance. While shown as being part of the system manager 109, an integrator may be a separate device in communication with one or more components of the communication system 100. Additionally, the integrator may also include an integrator UE 112, where the integrator UE 112 is a device configured to imitate the operation of a potential UE in communication with one or more RUs 107. The integrator UE 112 may communicate with one or more RUs 107 when the RUs 107 are operating in a test mode to aid in identifying appropriate gain adjustments in the operation of RUs 107 and the DU 103 to compensate for differences in compression schemes.

[0045] FIGs. 3A-3C are flowchart diagrams of different methods for manually detecting misalignments in scaling between RUs 107 and a DU 103. As described herein, to manually detect scaling alignments, the communication system 100 may enter a test mode. The test mode may be controlled by the system manager / integrator 109. Alternatively, a test mode may be controlled by a DU 103 or one or more of the RUs 107.

[0046] FIG. 3 A is a flowchart diagram of a method 300 for performing a manual alignment of scaling in the DL within the RU or the DU. Method 300 proceeds at 301, where a configuration is received through the M-Plane. For example, before the communication system 100 can begin operating, the different components of the communication system 100 are configured. To configure the different components, the DU 103 may communicate configuration information through the M-Plane, and the RUs 107 are part of the components that are configured for communication by receiving configuration information through the M-Plane. After receiving the configuration information through the M-Plane, the method 300 may proceed at 303, where it is determined whether the RUs 107 or an RU in a set of RUs 107 is appropriately configured. If the RU 107 is not appropriately configured, the method 300 returns to 301, where further configuration information is communicated through the M-Plane.

[0047] If the RU 107 is appropriately configured, the method 300 proceeds to 305, where the communication system 100 enters a test mode where gains can be manually aligned within the communication system 100. For example, the system manager / integrator 109 may communicate with the different components of the 100 to enter a test mode. When the communication system 100 enters a test mode, one orDocket No. 7623 WO W1 / 376.2207WO01more RUs 107 may enter a state where gains can be aligned. The test mode may be used in conjunction with an integrator during deployment of the communication system 100 or during an interoperability test phase before the communication system 100 is used for regular operation. In some implementations, the entire communication system 100 may enter a test mode. Alternatively, a component within the communication system 100 may enter a test mode specific to that component. In some implementations, a component in the communication system 100 may be able to enter a test mode or direct the system or other components to enter a test mode without being controlled by a system manager / integrator 109.

[0048] When the communication system 100 enters a test mode, or a component (like an RU 107 or DU 103) enters a test mode, the method 300 proceeds at 307. where power levels are decoded from communicated signals. For example, an RU 107 may receive communication signals from the DU. Upon receiving the signals from the DU 103, the RU 107 may decode or analyze the signals to identify the expected power levels for the received signal. Alternatively, an external device may also analyze the signals to identify the expected power levels. For example, an external device may acquire the signals through a packet capture implemented in a network interface or receive the signals directly from the RU 107. Examples of signals that can be decoded by the RU 107 or other device (like the system manager / integrator 109) may include SSB power, the PDSCH RE power, and the ss-PBCH-BlockPower found in the system information block 1 (SIB1). These signals are examples of signals having power information, and other signals from which power information may be decoded may also be used by the RU 107 or other components to acquire power-level information.

[0049] When the RU 107 has acquired the power information from the received signals, the method 300 may proceed at 309, where power levels are measured. For example, the system manager / integrator 109 may measure the power level transmitted from an antenna associated with the RU 107. Alternatively, the integrator UE 112 may measure the power level transmitted from the antenna associated with the RU 107. Further, another device may measure the power level through either a manual or equipment-guided process.

[0050] When the power levels are measured, the method 300 proceeds at 311, where it is determined whether the measured power levels equal the expected power levels. If the measured power does not equal the decoded power, the method 300 proceeds atDocket No. 7623 WO W1 / 376.2207WO01313, where gain configurations are adjusted based on the comparison. For example, the system manager / integrator 109 may calculate the difference between the expected transmit power from the antenna based on the decoded power level and the actual transmitted power level from the antenna coupled to the RU 107. After calculating the difference, the system manager / integrator 109 may reconfigure a gain component within the communication system 100 to compensate for the difference. For example, the system manager / integrator 109 may direct the DU 103 or the RU 107 to adjust a gain to rectify the difference. Alternatively, the calculation may be performed by one of the DU 103 or the RU 107, and the DU 103 or RU 107 may control the reconfiguration of the gain.

[0051] When the gain has been reconfigured, the method 300 may return to 307, where signals are sent by the DU 103 and decoded by the RU 107. Additionally, the method 300 also returns to 309, where the power levels are measured. Further, the method 300 returns to 311 to determine whether the measured power equals the expected power. If the measured power level equals the expected power level, the method proceeds to 315 and exits the test mode.

[0052] FIG. 3B is a flowchart diagram of a method 320 for performing a manual alignment of scaling in the UL within the RU or the DU. Method 320 proceeds at 321, where a configuration is received through the M-Plane. For example, before the communication system 100 can begin operating, the different components of the communication system 100 are configured. To configure the different components, the DU 103 may communicate configuration information through the M-Plane, and the RUs 107 are part of the components that are configured for communication by receiving configuration information through the M-Plane. After receiving the configuration information through the M-Plane, the method 320 may proceed at 323, where it is determined whether the RUs 107 or an RU in a set of RUs 107 is appropriately configured. If the RU 107 is not appropriately configured, the method 320 returns to 321, where further configuration information is communicated through the M-Plane.

[0053] If the RU 107 is appropriately configured, the method 320 proceeds to 325, where the communication system 100 enters a test mode where gains can be manually aligned within the communication system 100. For example, the system manager / integrator 109 may communicate with the different components of the 100 to enter a test mode. When the communication system 100 enters a test mode, one orDocket No. 7623 WO W1 / 376.2207WO01more RUs 107 may enter a state where gains can be aligned. The test mode may be used in conjunction with an integrator during deployment of the communication system 100 or during an interoperability test phase before the communication system 100 is used for regular operation. In some implementations, the entire communication system 100 may enter a test mode. Alternatively, a component within the communication system 100 may enter a test mode specific to that component. In some implementations, a component in the communication system 100 may be able to enter a test mode or direct the system or other components to enter a test mode without being controlled by a system manager / integrator 109.

[0054] When the communication system 100 enters a test mode, or a component (like an RU 107 or DU 103) enters a test mode, the method 320 proceeds at 327. where signals are sent at known power levels to the DU 103. For example, an RU 107 may send RACH attempts to the DU at known power levels. When the RU 107 begins sending the RACH attempts to the DU at known power levels, the method 320 proceeds at 329, where the DU 103 records the measured power levels of the signals sent from the RU 107.

[0055] When the RU 107 has sent multiple RACH attempts to the DU 103, and the DU 103 has recorded the measured power levels of the received signals, the method 320 proceeds at 331, where the average received power levels at the DU 103 are calculated. For example, the system manager / integrator 109 may access logs stored on the DU 1 3, where the logs store the received power levels. After accessing the logs, the system manager / integrator 109 may calculate the average received power levels. Alternatively, an RU 107 or external device (like the system manager / integrator 109) may access the stored power levels by sending requests that the DU 103 provides PRACH power levels, where the RU 107 may then calculate the average pow er levels.

[0056] When the average power level received by the DU is calculated, the method 320 proceeds at 333, where it is determined whether the average power levels equal the expected pow er levels transmitted from the RU 107. If the average power does not equal the expected power level, the method 320 proceeds at 335, where gain configurations are adjusted based on the comparison. For example, the system manager / integrator 109 may calculate the difference between the average received power levels and the actual transmitted power level from the RU 107. After calculating the difference, the system manager / integrator 109 may reconfigure a gainDocket No. 7623 WO W1 / 376.2207WO01component within the communication system 100 to compensate for the difference. For example, the system manager / integrator 109 may direct the DU 103 or the RU 107 to adjust a gain to rectify the difference. Alternatively, the calculation may be performed by one of the DU 103 or the RU 107, and the DU 103 or RU 107 may control the reconfiguration of the gain.

[0057] When the gain has been reconfigured, the method 320 may return to 327, where signals are sent by the RU 107 and measured by the DU 103. Additionally, the method 320 also returns to 329, where the power levels are recorded. Also, the method 320 returns to 331, where the average power level of signals received at the DU is calculated. Further, the method 320 returns to 331 to determine whether the measured power equals the expected power. If the measured power level equals the expected power level, the method proceeds to 337 and exits the test mode.

[0058] FIG. 3C is a flowchart diagram of a method 340 for performing a manual alignment of scaling in the UL within the RU or the DU. Method 340 proceeds at 341, where a configuration is received through the M-Plane. For example, before the communication system 100 can begin operating, the different components of the communication system 100 are configured. To configure the different components, the DU 103 may communicate configuration information through the M-Plane, and the RUs 107 are part of the components that are configured for communication by receiving configuration information through the M-Plane. After receiving the configuration information through the M-Plane, the method 340 may proceed at 343, where it is determined whether the RUs 107 or an RU in a set of RUs 107 is appropriately configured. If the RU 107 is not appropriately configured, the method 300 returns to 341, where further configuration information is communicated through the M-Plane.

[0059] If the RU 107 is appropriately configured, the method 340 proceeds to 345, where the communication system 100 enters a test mode, as discussed above, in connection with FIGs. 3 A and 3B. When the communication system 100 enters a test mode, or a component (like an RU 107 or DU 103) enters a test mode, the method 340 proceeds at 347, where reference signals are requested from a UE. For example, a DU 103 may send requests to UEs to send sounding reference signals (SRS). In particular, the DU 103 may send requests to an integrator UE 112. The UE 112 will then respond to the request by sending an SRS that is received by the DU 103.Docket No. 7623 WO W1 / 376.2207WO01

[0060] In certain embodiments, when the DU 103 receives the SRS from the UE (like the UE 112), the method 340 may proceed at 349. where the power of the received reference signal is measured at the DU 103. When the DU 103 has measured the received reference signal, the method 340 may proceed at 351, where it is determined whether the measured power levels equal the expected power levels. For example, the DU 103 may determine whether the SRS received power aligns with an expected link budget. If the measured power does not equal the expected power, the method 340 proceeds at 353, where gain configurations are adjusted based on the comparison. For example, the system manager / integrator 109 may calculate the difference between the expected power from an expected link budget and the measured power level of the received reference signal at the DU 103. After calculating the difference, the system manager / integrator 109 may reconfigure a gain component within the communication system 100 to compensate for the difference. For example, the system manager / integrator 109 may direct the DU 103 or the RU 107 to adjust a gain to rectify the difference. Alternatively, the calculation may be performed by the DU 103, and the DU 103 may control the reconfiguration of the gain.

[0061] When the gain has been reconfigured, the method 340 may return to 347, where the DU requests reference signals from aUE. Additionally, the method 340 also returns to 349. where the power levels of the received reference signal are measured. Further, the method 340 returns to 351 to determine whether the measured power equals the expected power. If the measured power level equals the expected power level, the method proceeds to 315 and exits the test mode.

[0062] FIGs. 4A-4C are flowchart diagrams of different methods for detecting scaling misalignments between RUs 107 and a DU 103 in the downlink by RUs 107 during runtime. In particular, an RU 107 may be able to detect scaling misalignments during the normal operation of the communication system 100.

[0063] FIG. 4A is a flowchart diagram of a method 400 for detecting and adjusting for scaling misalignments based on measuring the signal synchronization block (SSB). The SSB is a combination of signals used in wireless communications during the cell search procedure to synchronize the operation of different components. In particular, a base station periodically transmits the SSB through the communication system 100 to a UE 111, where the UE 111 uses the SSB to perform initial time and frequency synchronization when first accessing a cell. The multiple signals of the SSB include a primary synchronization signal (PSS), a physical broadcast channelDocket No. 7623 WO W1 / 376.2207WO01(PBCH) signal, and a secondary synchronization signal (SSS). The PSS / SSS in the SSB may be BPSK modulated and comprise a specific number of resource elements (REs). The base station may also transmit a power level for the SSB to the UE on SIB1. Further, the base station may periodically transmit the PSS and SSS even when no traffic is required. Accordingly, the RU 107 may use the periodic signal to calculate the scaling difference between power levels to achieve the desired output power at an associated antenna.

[0064] In certain embodiments, the method 400 proceeds at 401, where synchronization signals are received. For example, the RU 107 may receive periodic synchronization signals, like the SSB, that include the PSS / SSS signals. Further, as the PSS / SSS in the SSB is BPSK modulated, the signals maintain a consistent power level. However, the PSS may be subject to a power offset (and also the PBCH), thus, measuring the power of the signal from the PSS may be difficult as information about the offset is not communicated to the UE 111. In contrast to the PSS, the SSS is not subject to an unknown offset. Accordingly, the SSS may be measured to acquire knowledge of the signal powder. Accordingly, when the RU 107 has received synchronization signals from the DU 103, the method 400 proceeds at 403, where pow er levels of the synchronization signals are measured. For example, the RU 107 may measure the power of the SSS within the SSB in signals received from the DU 103. As the SSS is BPSK modulated, the power level may be consistent, and the power level may be accurately determined based on a small sample of measurements as compared to calculating an average powder based on many measurements.

[0065] In further embodiments, when the power levels of the synchronization signals are measured, the method 400 proceeds at 405, where the measured power levels are compared to the rated output power. For example, the RU 107 may compare the measured power level against the rated output power for the RU 107 to identify a difference betw een the pow er levels. After comparing the different pow er levels, the method 400 proceeds at 407. where the gain configuration is adjusted based on the comparison. For example, the RU 107 may adjust its gain configuration to account for any identified differences in the measured power level and the rated output power level of the RU 107. Alternatively, the RU 107 may communicate with a system manager 109 or directly with the DU 103 to adjust the gain configuration of the DU 103 to account for the identified differences in the measured and rated power levels.Docket No. 7623 WO W1 / 376.2207WO01Further, the gain configuration may be adjusted so the RU 107 transmits signals at a configured power level as compared to the rated power level.

[0066] FIG. 4B is a flowchart diagram of a method 420 for detecting and adjusting for scaling misalignments based on measurements of the Physical Downlink Shared Channel (PDSCH). As compared to the sy nchronization signals, the PDSCH is primarily used for user data. For example, once a call is established with a UE 111. the PDSCH carries the bulk of the transmitted data. Accordingly, the power of the PDSCH signal should meet a desired power level. In contrast to the PSS and SSS signals (which are BPSK modulated), the PDSCH signals are QAM modulated. Accordingly, the pow er level of the resource elements associated with the PDSCH may vary depending on the modulation order. As the RU 107 is unaware of the modulation order of the PDSCH signals, the RU 107 can acquire the pow er level by averaging a sufficient number of acquired measurements to ensure an accurate measurement of the power level.

[0067] In certain embodiments, based on the characteristics of the PDSCH, the method 420 proceeds at 421, where PDSCH power levels are monitored for detecting the presence of used resource elements. For example, the DU 103 may establish data transmissions with a UE 111, where the PDSCH is used for exchanging user data. The RU 107 may then monitor PDSCH power levels to detect the presence of used resource elements. If the RU 107 detects the presence of used resource elements, the method 420 proceeds at 423, where the average RE power level is measured for the PDSCH symbols. For example, as the pow er level of the PDSCH symbols varies over time, the RU 107 may measure the power level for multiple PDSCH symbols to measure the average RE power level.

[0068] In further embodiments, when the average RE power level for the PDSCH symbols is measured, the method 400 proceeds at 425, where the average power level is compared to the expected output power. For example, the RU 107 may compare the measured maximum power level against the rated output power for the RU 107 to identify a difference between the power levels. After comparing the different power levels, the method 400 proceeds at 427, where the gain configuration is adjusted based on the comparison. For example, the RU 107 may adjust its gain configuration to account for any identified differences in the measured power level and the rated output power level of the RU 107. Alternatively, the RU 107 may communicate with a system manager 109 or directly with the DU 103 to adjust the gain configuration ofDocket No. 7623 WO W1 / 376.2207WO01the DU 103 to account for the identified differences in the measured and rated power levels.

[0069] FIG. 4C is a flowchart diagram of a method 440 for detecting and adjusting for scaling misalignments based on decoding a target power level. Some signals received by an RU 107 may encode a target power level for transmissions from an associated antenna. For example, the system information block 1 (SIB1) may provide a field for encoding a target power level within the “ss-PBCH-BlockPowef ’ field. Accordingly, a device may decode the “ss-PBCH-BlockPower” field in the SIB1 to acquire a target power level.

[0070] In certain embodiments, the method 440 may proceed at 441, where a message having system information block 1 is received. For example, the RU 107 may receive a message having the SIB I, originally transmitted from a base station. Upon receiving the message having the SIB1, the method 440 may proceed at 443, where the message is decoded to acquire a target power level. For example, the RU 107 may decode the 'ss-PBCH-BlockPower" field within the SIB1, which encodes a target power level for the antenna port for the RU 107. Accordingly, the RU 107 may acquire the target power level. Further, the method 440 may proceed at 445, where the average RE power is measured in the synchronization signal. For example, the RU may acquire the average RE power as discussed above in connection with method 420 or in connection with method 400.

[0071] In further embodiments, when the target power level is decoded, the method 440 proceeds at 447, where the measured average powder is compared to the target output power level. For example, the RU 107 may compare the measured average power level against the decoded target output power level to identify a difference between the power levels. After comparing the different power levels, the method 400 proceeds at 449, where the gain configuration is adjusted based on the comparison. For example, the RU 107 may adjust its gain configuration to account for any identified differences in the measured power level and the decoded target output power level of the RU 107. Alternatively, the RU 107 may communicate with a system manager 109 or directly with the DU 103 to adjust the gain configuration of the DU 103 to account for the identified differences in the measured and target powder levels. Further, the gain configuration may be adjusted so the RU 107 transmits signals at a configured power level as compared to the target power level.Docket No. 7623 WO W1 / 376.2207WO01

[0072] FIGs. 5A-5D are flowchart diagrams of different methods for detecting scaling misalignments between RUs 107 and a DU 103 in the uplink by RUs 107 during runtime. FIG. 5 A is a flowchart diagram of a method 500 where the RU 107 simulates a UE to determine an uplink gain expected by the DU 103. For example, the method 500 proceeds at 501, where a UE is simulated on an RU 107. For example, the RU 107 may simulate a UE by sending RACH signals to the DU 103. Further, the RU 107 may send the RACH signals to the DU 103 over a wide range of power levels. After sending the signals from the RUs 107 to the DU 103, the method 500 may proceed to 503, where responses from the DU are monitored. For example, when an RU 107 sends a signal to the DU 103, the RU 107 awaits responses from the DU 103.

[0073] In certain embodiments, when the DU 103 receives a RACH signal from the RU 107, the DU 103 will respond to the RACH signal if the RACH signal is provided within a range of power levels for w hich the DU 103 can recognize the signal. For example, if the pow er level of the RACH signal is too low noise may interfere with the abil i ty of the DU 103 to recognize the signal. Conversely, if the power level of the RACH signal is too high, saturation of the signal may prevent the DU 103 from recognizing the signal. As the DU 103 receives RACH signals at a range of power levels, the DU 103 may respond to signals that are at a range where the signals are recognizable. For example, the DU 103 may respond to recognizable signals with a msg2. Thus, the method 500 may proceed at 505, where a range of UL gains are identified. For example, when the RU 107 receives a message from the DU 103 in response to the RACH signals, the RU 107 may identify the power level of the sent RACH signal. As the RU 107 receives multiple messages from the DU 103 associated with multiple power levels, the RU 107 may then identify a range of power levels associated with the multiple messages. Further, after identifying the range of power levels, the method 500 may proceed at 507, where a gain is selected based on the identified range of UL gains. For example, the RU 107 may select a gain associated with the average range of the range of UL gains. Alternatively, the RU 107 may select a gain at a certain level above the floor gain (for example, 20 dB above the identified power floor).

[0074] FIG. 5B is a flow chart diagram of a method 520 where an RU 107 simulates a UE and monitors DU responses to characterize the operation of the DU 103. For example, the method 520 proceeds at 521. where a UE is simulated on an RU 107. For example, the RU 107 may simulate a UE until the RU 107 is able to send physicalDocket No. 7623 WO W1 / 376.2207WO01uplink shared channel (PUSCH) messages to the DU 103. When the RU 107 is able to simulate the UE and send the PUSCH messages, the method 520 proceeds to 523, where messages are transmitted at low power and low noise levels. For example, the RU 107 may send a PUSCH message at a low power level and a low noise level. The RU 107 may send the message at a power level low enough that the DU 103 is unlikely to receive the message accurately. In response to receiving the message from the RU 107, the DU 103 may measure the signal-to-noise ratio and the received power level. Based on these measurements, the DU 103 may respond with a negative acknowledgment (a NACK in accordance with HARQ) to spur a retransmission or respond with a transmit power control (TPC) command directing the RU 107 to increase the transmission power. When the DU 103 responds with a NACK or TPC, the response may indicate that the DU 103 has added quantization noise in response to an expected higher power level. As the DU 103 responds to the low power and low noise messages, the method 520 proceeds at 525, where a gain floor is identified based on responses from the DU 103. For example, in response to receiving a NACK or a TPC, the RU 107 may incrementally increase the power of the messages until the DU 103 does not send a NACK or TPC in response to the sent messages. When the RU 107 sends a message to the DU 103 and does not receive a NACK or TPC in response to the sent message, the RU 107 may determine that the associated power level of the most recently sent message is a gain floor.

[0075] In further embodiments, when the RU 107 has identified the gain floor or, alternatively, before the RU 107 has identified the gain floor and after the RU 107 has established communications with the DU 103 and is able to simulate a UE and send PUSCH messages, the method 520 may proceed at 527. where messages are transmitted at high power and high noise. For example, if the power of signals received from the DU 103 surpasses a certain threshold, increasing the transmit power may further saturate the receiver of the DU 103. If these increases are performed within a noisy environment, the increases may lead to runaway scenarios where the DU 103 continues to instruct the RU 107 to increase the transmit power even when the receivers of the DU 103 are saturated.

[0076] In some embodiments, when the RU 107 is transmitting higher power messages, the method 520 may proceed to 529, where the power cap is identified based on responses from the DU 103. For example, the RU 107 may send a high power / high noise signal to the DU 103. The RU 107 may then incrementally increaseDocket No. 7623 WO W1 / 376.2207WO01the power of the transmission until TPC messages from the DU 103 begin to consistently instruct the RU 107 to lower the transmission power. When the DU 103 consistently instructs the RU 107 to lower the transmission power, the RU 107 may identify the associated power level as the power cap, representing the maximum desired receive power. Thus, by empirically sending messages and adjusting characteristics of transmissions, the RU 107 may observe and characterize the performance of the DU. In particular, the RU 107 may gain information about the gain floor and power cap, among other characteristics. Further, the RU 107 may also send messages with low power / high noise, high power / low noise, and other signal characteristics. When the RU 107 has characterized the performance of the DU 103, the method 520 may proceed at 531. where the gain setting is determined based on the gain floor, power cap, and operational parameters of the RU 107. For example, the RU 107 may select a gain that ensures the DU 103 operates within an operable range for the RU 107. As the RU 107 is aware of the noise floor and the maximum receive power, the RU 107 can identify appropriate gain settings.

[0077] FIG. 5C is a flowchart diagram of a method 540 for an RU 107 that performs UL gain alignment by monitoring communications between a DU 103 and UEs 111 on the RACH channel. For example, the method 540 may proceed at 541, where an initial power level is set by the RU 107. For example, before a DU 103 establishes a connection with a UE 111. the RU 107 may set an initial power level. The initial power level may be a low power level that the RU 107 may expect to be too low of the power level such that the DU 103 does not initially respond to a msgl on the RACH channel from the UE relayed to the DU 103 by the RU 107. After setting the initial power level, the method 540 may proceed at 543. where a RACH signal is received. For example, the RU 107 may receive a msgl from a UE 111 attempting to establish a connection with the DU 103 through a RACH channel.

[0078] In further embodiments, upon receiving the RACH signal from a UE 111, the method proceeds at 545, where the RACH signal is relayed at the set power level. For example, after the RU 107 receives a RACH signal from a UE 111 in the coverage area associated with the RU 107, the RU 107 may provide the msgl from the UE 111 to the DU 103 at the set power level, which is the initial pow er level when the process starts but can change as the process iteratively continues. If the msgl is relayed to the DU 103 at a sufficient power level, the DU 103 responds to the UE 111 with a msg2. Accordingly, the method 540 proceeds at 547, where the RU 107 determines whetherDocket No. 7623 WO W1 / 376.2207WO01the DU 103 responds to the relayed message. For example, when the RU 107 relays the message at the set power level to the DU 103, the RU 107 waits for a period of time to receive the msg2 from the DU 103. If the period of time expires, the RU 107 determines that the DU 103 did not receive the relayed message due to the transmit power being too low.

[0079] When the RU 107 determines that the DU 103 did not receive the relayed message, the method 540 proceeds at 549, where the power level changes. For example, the RU 107 may incrementally increase the set power level. After changing the set power level, the method 540 returns to 545, where the RU 107 relays the message to the DU 103 at the increased power level. This process can be iteratively performed until the DU 103 responds to the relayed message with the msg2. When the DU 103 responds to the relayed message with the msg2, the method 540 proceeds at 551, where the gain is set based on the set power level. For example, the RU 107 with knowledge of the set power level at which the DU 103 responds, the RU 107 may identify gain misalignments and make adjustments to the gain on the RU 107 or instruct the DU 103 (or a system manager / integrator 109 to make any necessary gain adjustments). While method 540 is described as beginning with a low-power level and incrementally increasing the power level, the method 540 could begin with a high-power level and incrementally decreasing the power level.

[0080] In some alternative implementations, the method 540 may be performed manually. For example, before proceeding at 541, the method 540 may enter a test mode before proceeding at 541. In particular, the RU 107 and the DU 103 may operate as disclosed above with respect to method 540. However, the RU 107 and the DU 103 may interact with an integrator UE 112 as compared to a collective group of operational UEs 111.

[0081] FIG. 5D is a flowchart diagram of a method 560 for an RU 107 that monitors signal information associated with the physical uplink shared channel (PUSCH) during operation. The method 560 proceeds at 561, where the power of UE signals is monitored. For example, as part of receiving PUSCH signals, the RU 107 may monitor the power of PUSCH signals and the accompanying demodulation-reference signal (DMRS). When the RU 107 receives the signals, the method 560 proceeds at 563, where it is determined whether the pow er of the received signals is too high. For example, the RU 107 may compare the power of the received signals against an expected power level, and if the receive power is higher than the expected powerDocket No. 7623 WO W1 / 376.2207WO01level, the RU 107 may determine that the power of the received signals is too high. When the signal power is determined to be too high, the method 560 proceeds at 565, where the gain is increased on the RU 107 to force TPC down signals from the DU 103.

[0082] In certain embodiments, in addition to checking whether the receive power is too high, the RU 107 can also check if the DMRS SNR is consistently low. A consistently low DMRS SNR may imply that the DU 103 has set the TPC cap too early and is not instructing the UEs 111 to power up as much as desired. Accordingly, the method 560 may proceed at 567, where the RU 107 checks if the DMRS SNR is consistently too low. If the DMRS SNR is consistently too low, the method 560 proceeds at 569, where the gain of the RU 107 is decreased. For example, when the RU 107 decreases the gain, the DU 103 may begin sending TPC up commands to the UE 111 to increase the UE power.

[0083] In further embodiments, the RU 107 can also check if the DMRS SNR is consistently high. When the DMRS SNR is consistently high, the RU 107 may determine that the DU 103 has not reached the TPC cap. When the TPC cap has not been reached, the RU 107 may increase the gain to cause the DU 103 to more quickly reach the TPC cap. Additionally, a consistently high DMRS SNR may indicate that the DU 103 is introducing quantization noise because the scaling of the data is too low. Accordingly, the method 560 may proceed to 571, where the RU 107 checks to see if the DMRS SNR is consistently too high. If the DMRS SNR is consistently too high, the method 560 may proceed to 573, where the gain is increased. For example, the RU 107 may increase its gain. After checking the UE signals, the method 560 may proceed to 561, where the RU continues to monitor the power of the UE signals. For example, the RU 107 may monitor the UE signals throughout operation.Alternatively, the RU 107 may monitor the UE signals periodically or in response to communication events like the establishment of communications with a UE or other performance changes.

[0084] FIGs. 6A-6B are flowchart diagrams of different methods for detecting scaling misalignments between RUs 107 and a DU 103 in the uplink by a DU 103 during runtime. For example, the DU 103 may use the UL gain of the RU 107 to convert the signal power from the fronthaul (which is in dBFS) to the transmit power at the antenna associated with the RU 107 (which is in dBm). The DU 103 uses the UL gainDocket No. 7623 WO W1 / 376.2207WO01for power control and receive power reporting. Accordingly, the DU 103 may also perform various methods to estimate the UL gain for the RU 107.

[0085] FIG. 6A is a flowchart diagram of a method 600 for estimating the UL gain of the RU 107 by monitoring the transmit noise. In some implementations, the method 600 proceeds at 601, where thermal noise is identified. For example, the DU 103 may measure the thermal noise in received signals. Additionally, the method 600 proceeds at 603, where a reasonable noise figure is identified. For example, the DU 103 may identify a reasonable noise figure based on measured characteristics of unallocated physical resource blocks or PRACH signals with no detection in the received signals. Once the thermal noise is measured and the reasonable noise figure is identified, the method 600 proceeds at 605. where a noise floor is estimated based on the thermal noise and reasonable noise figure. With the estimated noise floor, the method 600 proceeds at 607, where the gain is adjusted based on the estimated noise floor. For example, when the DU 103 estimates the noise floor, the DU 103 can identify a difference between the thermal noise and the reasonable noise figure and use the difference to estimate an RU UL gain. The DU 103 may then use the estimated RU UL gain for power control and transmit power reporting.

[0086] FIG. 6B is a flowchart diagram of a method 620 for estimating the UL gain of the RU 107 by measuring the received power. The method 620 proceeds at 621, where a PRACH signal is received. For example, the DU 103 may receive a PRACH signal from the RU 107. When the DU 103 receives the PRACH signal, the method 620 proceeds at 623, where the signal power is measured. For example, the DU 103 may analyze the received PRACH signal to identify the receive power of the PRACH signal. Further, the method 620 proceeds at 625, where the received target power is decoded. For example, the DU 103 may decode information in received signals that provide an expected received target power, such as the “preambleReceivedTargetPower.” The “preambleReceivedTarget Power’" is a parameter that specifies a target power level for the PRACH. In particular, a UE 111 adjusts transmit power so the PRACH signal is received by the DU 103 above a target power level. When the DU 103 decodes the information in the received signal and measures the received signal, the method 620 proceeds at 627, where the gain is adjusted based on the difference between the measured signal power and the decoded received target power. For example, the DU 103 may use the difference between theDocket No. 7623 WO W1 / 376.2207WO01measured signal power and the decoded received target power to identify the UL gain for the RU 107.

[0087] FIGs. 3A-6B illustrate multiple methods for monitoring the gains and identify ing gain misalignments in test and operational modes. Also, the multiple methods may be used to identify gain misalignments in both UL and DL directions by both an RU 107 and a DU 103. The communication system 100 may use any combination of methods to provide redundant methods for detecting gain misalignments. Further, the multiple methods may be employed to verify that gain misalignments are accurately identified.

[0088] FIG. 7 is a flowchart diagram of a method 700 for mitigating scaling misalignments. The method 700 proceeds at 701, where one or more DUs are communicatively coupled to one or more core networks, wherein a DU is configured to implement a first compression scheme for compressing IQ data. The method 700 also proceeds at 703, where one or more RUs are communicatively coupled to the one or more DUs, wherein at least one RU is configured to implement a second compression scheme for compressing the IQ data. Further, the method 700 proceeds at 705, where a gain misalignment arising from differences in the first compression scheme and the second compression scheme is identified. Additionally, the method 700 proceeds at 707, where a gain setting on at least one of the one or more DUs and the one or more RUs is adjusted to compensate for the gain misalignments.Example Embodiments

[0089] Example 1 includes a system comprising: one or more distributed units configured to communicatively couple the system to one or more core networks, wherein a distributed unit is configured to implement first compression / decompression schemes for compressing / decompressing IQ data; and one or more radio units communicatively coupled to the one or more distributed units and configured to implement second compression / decompression schemes for compressing / decompressing the IQ data, wherein a radio unit in the one or more radio units is configured to wirelessly transmit and receive radio frequency signals to and from user equipment in a coverage area associated with the radio unit; wherein gain settings for at least one of the one or more distributed units and the one or more radio units are adjusted based on a gain misalignment between the one or more distributed units and the one or more radio units.Docket No. 7623 WO W1 / 376.2207WO01

[0090] Example 2 includes the system of Example 1, wherein at least one of the one or more distributed units and the one or more radio units are configured to enter a test mode, wherein the gain misalignment is identified in the test mode.

[0091] Example 3 includes the system of Example 2, wherein the gain settings for the at least one of the one or more distributed units and the one or more radio units are adjusted based on a comparison of an expected power level acquired from a decoded communicated signal against a measured signal power level.

[0092] Example 4 includes the system of any of Examples 2-3, wherein the one or more radio units is configured to send signals at known power levels to the one or more distributed units configured to measure and record power levels of the signals, wherein the gain settings are adjusted based on a comparison of expected power levels against an average of the recorded power levels measured by the one or more distributed units.

[0093] Example 5 includes the system of any of Examples 2-4, wherein at least one of an integrator and integrator user equipment is configured to interact with the system during the test mode.

[0094] Example 6 includes the system of Example 5, wherein the one or more distributed units are configured to request reference signals from the integrator user equipment, measure received reference signals from the integrator user equipment, and adjust the gain settings based on a comparison of the measurements from the measured received reference signals and an expected power level.

[0095] Example 7 includes the system of any of Examples 1-6, wherein the gain misalignment is identified and mitigated during normal operation of the system.

[0096] Example 8 includes the system of Example 7, wherein the one or more radio units are configured to identify and mitigate the gain misalignment for downlink signals.

[0097] Example 9 includes the system of Example 8, wherein the one or more radio units is configured to measure power levels of synchronization signals and adjust the gam settings based on a comparison of the measured power levels against a rated output pow er for the one or more radio units.

[0098] Example 10 includes the system of any of Examples 8-9, wherein the one or more radio units is configured to measure an average resource element pow er level for PDSCH symbols and adjust the gain settings based on a comparison of the average resource element power level against an expected output power.Docket No. 7623 WO W1 / 376.2207WO01

[0099] Example 11 includes the system of any of Examples 8-10. wherein the one or more radio units is configured to acquire a target power level by decoding a message from a base station and adjust the gain settings based on a comparison of the target power level against a measured power average resource element power.

[0100] Example 12 includes the system of any of Examples 7-11, wherein the one or more radio units are configured to identify the gain misalignment for uplink signals.

[0101] Example 13 includes the system of Example 12, wherein the one or more radio units is configured to simulate the user equipment by sending RACH signals at multiple power levels to the one or more distributed units, identifying a range of power levels in the multiple power levels where the one or more radio units receives a response from the one or more distributed units.

[0102] Example 14 includes the system of any of Examples 12-13, wherein the one or more radio units is configured to simulate the user equipment, transmit messages to the one or more distributed units at a range of power levels and a range of noise levels, identify a gain floor and a power cap based on responses from the one or more distributed units, and adjust the gain settings based on the gain floor, the power cap, and operational parameters for the one or more radio units.

[0103] Example 15 includes the system of any of Examples 12-14, wherein the one or more radio units is configured to relay RACH signals from the user equipment to the one or more distributed units at different power levels and adjust the gain settings based on determining when the one or more distributed units respond to the one or more radio units.

[0104] Example 16 includes the system of any of Examples 12-15, wherein the one or more radio units are configured to identify the gain settings based on monitoring received power from the user equipment and signal to noise ratios of demodulation reference signals.

[0105] Example 17 includes the system of any of Examples 7-16, wherein the one or more distributed units are configured to identify the gain misalignment for uplink signals.

[0106] Example 18 includes the system of Example 17, wherein the one or more distributed units are configured to identify the gain settings based on an estimated noise floor based on thermal noise and an identified noise figure.Docket No. 7623 WO W1 / 376.2207WO01

[0107] Example 19 includes the system of any of Examples 17-18, wherein the one or more distributed units are configured to identify the gain settings based on a comparison of a measured signal power and a decoded received target power.

[0108] Example 20 includes a method comprising: communicatively coupling one or more distributed units to one or more core networks, wherein a distributed unit is configured to implement first compression / decompression schemes for compressing / decompressing IQ data; communicatively coupling one or more radio units to the one or more distributed units, each of the one or more radio units being configured to wirelessly transmit and receive radio frequency signals to and from user equipment in a coverage area associated with each radio unit in the one or more radio units, wherein at least one radio unit in the one or more radio units is configured to implement second compression / decompression schemes for compressing / decompressing the IQ data; identifying a gain misalignment between the one or more distributed units and the one or more radio units; and adjusting a gain setting on at least one of the one or more distributed units and the one or more radio units to compensate for the gain misalignments.

[0109] Example 21 includes the method of Example 20, wherein identify ing the gain misalignment further comprises entering a test mode.

[0110] Example 22 includes the method of Example 21, wherein adjusting the gain setting further comprises comparing an expected power level acquired from a decoded communicated signal against a measured signal power level.

[0111] Example 23 includes the method of any of Examples 21-22, wherein identifying the gain misalignment further comprises: sending signals from the one or more radio units at known power levels to the one or more distributed units; recording measured power levels of the signals on the one or more distributed units; calculating an average power level for the measured power level; and comparing the average power level against an expected power level.

[0112] Example 24 includes the method of any of Examples 21-23. wherein identifying the gain misalignment further comprises: requesting reference signals from integrator user equipment; measuring received reference signals from the integrator user equipment, and comparing measurements of the measured received reference signals and an expected power level.

[0113] Example 25 includes the method of any of Examples 20-24. wherein identify ing the gain misalignment further comprises identifying the gain misalignmentDocket No. 7623 WO W1 / 376.2207WO01during normal operation of the one or more distributed units and the one or more radio units.

[0114] Example 26 includes the method of Example 25, wherein identifying the gain misalignment further comprises identifying the gain misalignment in the one or more radio units for downlink signals.

[0115] Example 27 includes the method of Example 26, wherein identifying the gain misalignment further comprises: measuring power levels of synchronization signals; and comparing the measured power levels against a rated output power for the one or more radio units.

[0116] Example 28 includes the method of any of Examples 26-27, wherein identifying the gain misalignment further comprises: measuring an average resource element power level for PDSCH symbols; and comparing the average resource element power level against an expected output power.

[0117] Example 29 includes the method of any of Examples 26-28, wherein identifying the gain misalignment further comprises: decoding a message from a base station; acquiring a target power level from the decoded message; and comparing the target power level against a measured power average resource element power.

[0118] Example 30 includes the method of any of Examples 25-29, wherein identifying the gain misalignment further comprises identifying the gain misalignment in the one or more radio units for uplink signals.

[0119] Example 31 includes the method of Example 30, wherein identifying the gain misalignment further comprises: Simulating the user equipment by sending RACH signals at multiple power levels to the one or more distributed units; and identifying a range of power levels in the multiple power levels where the one or more radio units receives a response from the one or more distributed units.

[0120] Example 32 includes the method of any of Examples 30-31, wherein identifying the gain misalignment further comprises: Simulating the user equipment; transmitting messages to the one or more distributed units at a range of power levels and a range of noise levels; identifying a gain floor and a power cap based on responses from the one or more distributed units; and identify the gain settings based on the gain floor, the power cap, and operational parameters for the one or more radio units.

[0121] Example 33 includes the method of any of Examples 30-32. wherein identify ing the gain misalignment further comprises: relaying RACH signals from theDocket No. 7623 WO W1 / 376.2207WO01user equipment to the one or more distributed units at different power levels; and determining when the one or more distributed units respond to the one or more radio units.

[0122] Example 34 includes the method of any of Examples 30-33, wherein identify ing the gain misalignment further comprises: monitoring received power from the user equipment and signal to noise ratios of demodulation reference signals.

[0123] Example 35 includes the method of any of Examples 25-34, wherein identifying the gain misalignment further comprises identifying the gain misalignment in the one or more distributed units for uplink signals.

[0124] Example 36 includes the method of Example 35, wherein identifying the gain misalignment further comprises estimating a noise floor based on thermal noise and an identified noise figure.

[0125] Example 37 includes the method of any of Examples 35-36, wherein identifying the gain misalignment further comprises comparing a measured signal power and a decoded received target power.

[0126] Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement, which is calculated to achieve the same purpose, may be substituted for the specific embodiments shown. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.

Claims

Docket No. 7623 WO W1 / 376.2207WO01CLAIMSWhat is claimed is:

1. A system comprising:one or more distributed units configured to communicatively couple the system to one or more core networks, wherein a distributed unit is configured to implement first compression / decompression schemes for compressing / decompressing IQ data; andone or more radio units communicatively coupled to the one or more distributed units and configured to implement second compression / decompression schemes for compressing / decompressing the IQ data, wherein a radio unit in the one or more radio units is configured to wirelessly transmit and receive radio frequency signals to and from user equipment in a coverage area associated with the radio unit;wherein gain settings for at least one of the one or more distributed units and the one or more radio units are adjusted based on a gain misalignment between the one or more distributed units and the one or more radio units.

2. The system of claim 1, wherein at least one of the one or more distributed units and the one or more radio units are configured to enter a test mode, wherein the gain misalignment is identified in the test mode.

3. The system of claim 2, wherein the gain settings for the at least one of the one or more distributed units and the one or more radio units are adjusted based on a comparison of an expected power level acquired from a decoded communicated signal against a measured signal power level.

4. The system of claim 2, wherein the one or more radio units is configured to send signals at known power levels to the one or more distributed units configured to measure and record power levels of the signals, wherein the gain settings are adjusted based on a comparison of expected power levels against an average of the recorded power levels measured by the one or more distributed units.

5. The system of claim 2, wherein at least one of an integrator and integrator user equipment is configured to interact with the system during the test mode.Docket No. 7623 WO W1 / 376.2207WO016. The system of claim 5, wherein the one or more distributed units are configured to request reference signals from the integrator user equipment, measure received reference signals from the integrator user equipment, and adjust the gain settings based on a comparison of the measurements from the measured received reference signals and an expected power level.

7. The system of claim 1, wherein the gain misalignment is identified and mitigated during normal operation of the system.

8. The system of claim 7, wherein the one or more radio units are configured to identify and mitigate the gain misalignment for downlink signals.

9. The system of claim 8, wherein the one or more radio units is configured to measure power levels of synchronization signals and adjust the gain settings based on a comparison of the measured power levels against a rated output power for the one or more radio units.

10. The system of claim 8, wherein the one or more radio units is configured to measure an average resource element power level for PDSCH symbols and adjust the gain settings based on a comparison of the average resource element power level against an expected output power.

11. The system of claim 8. wherein the one or more radio units is configured to acquire a target power level by decoding a message from a base station and adjust the gain settings based on a comparison of the target power level against a measured power average resource element power.

12. The system of claim 7, wherein the one or more radio units are configured to identify7the gain misalignment for uplink signals.

13. The system of claim 12, wherein the one or more radio units is configured to simulate the user equipment by sending RACH signals at multiple power levels to the one or more distributed units, identifying a range of power levels in the multiple power levels where the one or more radio units receives a response from the one or more distributed units.Docket No. 7623 WO W1 / 376.2207WO0114. The system of claim 12, wherein the one or more radio units is configured to simulate the user equipment, transmit messages to the one or more distributed units at a range of power levels and a range of noise levels, identify a gain floor and a power cap based on responses from the one or more distributed units, and adjust the gain settings based on the gain floor, the power cap, and operational parameters for the one or more radio units.

15. The system of claim 12, wherein the one or more radio units is configured to relay RACH signals from the user equipment to the one or more distributed units at different power levels and adjust the gain settings based on determining when the one or more distributed units respond to the one or more radio units.

16. The system of claim 12, wherein the one or more radio units are configured to identify the gain settings based on monitoring received power from the user equipment and signal to noise ratios of demodulation reference signals.

17. The system of claim 7, wherein the one or more distributed units are configured to identify the gain misalignment for uplink signals.

18. The system of claim 17, wherein the one or more distributed units are configured to identify the gain settings based on an estimated noise floor based on thermal noise and an identified noise figure.

19. The system of claim 17, wherein the one or more distributed units are configured to identify the gain settings based on a comparison of a measured signal power and a decoded received target power.

20. A method comprising:communicatively coupling one or more distributed units to one or more core networks, wherein a distributed unit is configured to implement first compression / decompression schemes for compressing / decompressing IQ data;communicatively coupling one or more radio units to the one or more distributed units, each of the one or more radio units being configured to wdrelessly transmit and receive radio frequency signals to and from user equipment in a coverage area associated with each radio unit in the one or more radio units, wherein at leastDocket No. 7623 WO W1 / 376.2207WO01one radio unit in the one or more radio units is configured to implement second compression / decompression schemes for compressing / decompressing the IQ data;identifying a gain misalignment between the one or more distributed units and the one or more radio units; andadjusting a gain setting on at least one of the one or more distributed units and the one or more radio units to compensate for the gain misalignments.

21. The method of claim 20, wherein identifying the gain misalignment further comprises entering a test mode.

22. The method of claim 21, wherein adjusting the gain setting further comprises comparing an expected power level acquired from a decoded communicated signal against a measured signal power level.

23. The method of claim 21, wherein identifying the gain misalignment further comprises:sending signals from the one or more radio units at known power levels to the one or more distributed units;recording measured power levels of the signals on the one or more distributed units;calculating an average power level for the measured power level; and comparing the average pow er level against an expected power level.

24. The method of claim 21, wherein identifying the gain misalignment further comprises:requesting reference signals from integrator user equipment; measuring received reference signals from the integrator user equipment, and comparing measurements of the measured received reference signals and an expected power level.

25. The method of claim 20, wherein identifying the gain misalignment further comprises identifying the gain misalignment during normal operation of the one or more distributed units and the one or more radio units.Docket No. 7623 WO W1 / 376.2207WO0126. The method of claim 25, wherein identifying the gain misalignment further comprises identifying the gain misalignment in the one or more radio units for downlink signals.

27. The method of claim 26, wherein identify ing the gain misalignment further comprises:measuring power levels of synchronization signals; andcomparing the measured power levels against a rated output power for the one or more radio units.

28. The method of claim 26, wherein identifying the gain misalignment further comprises:measuring an average resource element power level for PDSCH symbols; and comparing the average resource element power level against an expected output power.

29. The method of claim 26, wherein identifying the gain misalignment further comprises:decoding a message from a base station;acquiring a target power level from the decoded message; and comparing the target power level against a measured power average resource element power.

30. The method of claim 25, wherein identifying the gain misalignment further comprises identifying the gain misalignment in the one or more radio units for uplink signals.

31. The method of claim 30, wherein identifying the gain misalignment further comprises:Simulating the user equipment by sending RACH signals at multiple power levels to the one or more distributed units; andidentifying a range of power levels in the multiple power levels where the one or more radio units receives a response from the one or more distributed units.

32. The method of claim 30, wherein identifying the gain misalignment further comprises:Docket No. 7623 WO W1 / 376.2207WO01Simulating the user equipment;transmitting messages to the one or more distributed units at a range of power levels and a range of noise levels;identifying a gain floor and a power cap based on responses from the one or more distributed units; andidentify the gain settings based on the gain floor, the power cap, and operational parameters for the one or more radio units.

33. The method of claim 30, wherein identifying the gain misalignment further comprises:relaying RACH signals from the user equipment to the one or more distributed units at different power levels; anddetermining when the one or more distributed units respond to the one or more radio units.

34. The method of claim 30, wherein identifying the gain misalignment further comprises:monitoring received power from the user equipment and signal to noise ratios of demodulation reference signals.

35. The method of claim 25, wherein identifying the gain misalignment further comprises identifying the gain misalignment in the one or more distributed units for uplink signals.

36. The method of claim 35, wherein identifying the gain misalignment further comprises estimating a noise floor based on thermal noise and an identified noise figure.

37. The method of claim 35, wherein identifying the gain misalignment further comprises comparing a measured signal power and a decoded received target power.

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