Techniques for configuring supplementary downlink support for half-duplex UEs

Abstract

Aspects of the present disclosure provide techniques for configuring a half-duplex UE (HD-UE) to implement supplementary downlink (SDL) in a band combination that may be in the same or different frequency range designations (e.g., FR1 or FR2). In particular, to compensate for loss of downlink coverage and improve load balancing, aspects of the present disclosure configure the UE to perform a random access channel (RACH) (which is a process by which a wireless terminal uses a shared channel to access a mobile network) on an anchor carrier in a time division duplex (TDD) band, and after initial access, the UE may be configured to switch to SDL to receive subsequent downlink signals.

Description

Technical Field

[0001] The present disclosure relates to wireless communication systems, and more particularly, to techniques for configuring supplementary downlink (SDL) for a half-duplex user equipment (HD-UE). Background Art

[0002] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasting. A typical wireless communication system may employ a multiple access technology capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and single carrier frequency division multiple access (SC-FDMA) systems.

[0003] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at the urban, national, regional, and even global levels. For example, fifth generation (5G) wireless communication technology (which may be referred to as new radio (NR)) is envisioned to extend and support a wide variety of use cases and applications with respect to the current mobile network generation. In one aspect, 5G communication technology may include: enhanced mobile broadband that addresses human-centric use cases for accessing multimedia content, services, and data; ultra-reliable low latency communication (URLLC) with certain specifications for latency and reliability; and massive machine type communication that may allow a substantial number of connected devices and the transmission of a relatively low amount of non-latency-sensitive information. However, as the demand for mobile broadband access continues to increase, further improvements in NR communication technology and other technologies may be desirable. Summary of the Invention

[0004] Aspects of the present disclosure provide techniques for configuring a half-duplex UE (HD-UE) to implement supplementary downlink (SDL) in a band combination that may be in the same or different frequency range names (e.g., FR1 or FR2). Specifically, to compensate for loss of downlink coverage and improve load balancing, aspects of the present disclosure configure the UE to perform a random access channel (RACH) on an anchor carrier in a time division duplex (TDD) band (which is a process of using a shared channel for a wireless terminal to access a mobile network), and after initial access, the UE may be configured to switch to SDL to receive subsequent downlink signals.

[0005] In one example, a method for wireless communication is disclosed. The method may include: initiating an initial access (e.g., RACH procedure) with a base station on an anchor carrier in a time division duplex (TDD) band at a user equipment (UE) to synchronize with the base station, wherein the UE is a half-duplex device lacking a duplexer. The method may further include: after completing the initial access procedure, switching from the anchor carrier to a supplementary downlink (SDL) carrier via a switch at the UE to receive subsequent downlink transmissions from the base station. The method may further include: receiving downlink communication from the base station on the SDL.

[0006] In another example, an apparatus for wireless communication. The apparatus may include at least one processor; and a memory coupled to the at least one processor, the memory including instructions executable by the at least one processor to cause the apparatus to perform the following operations: initiating an initial access procedure with a base station on an anchor carrier in a TDD band at a UE to synchronize with the base station, wherein the UE is a half-duplex device lacking a duplexer. The processor may further be configured to execute the instructions to perform the following operations: after completing the initial access procedure, switching from the anchor carrier to an SDL carrier via a switch at the UE to receive subsequent downlink transmissions from the base station. The processor may further be configured to execute the instructions to perform the following operations: receiving downlink communication from the base station on the SDL.

[0007] In some aspects, a non-transitory computer-readable medium includes instructions stored therein that, when executed by a processor, cause the processor to perform the following steps: initiating an initial access procedure with a base station on an anchor carrier in a time division duplex (TDD) band at a user equipment (UE) to synchronize with the base station, wherein the UE is a half-duplex device lacking a duplexer. The processor may further execute the instructions to perform the following operations: after completing the initial access procedure, switching from the anchor carrier to a supplementary downlink (SDL) carrier via a switch at the UE to receive subsequent downlink transmissions from the base station. The processor may further execute the instructions to perform the following operations: receiving downlink communication from the base station on the SDL.

[0008] In some aspects, another apparatus for wireless communication is disclosed. The apparatus may include: a unit for initiating an initial access procedure with a base station on an anchor carrier in a TDD band at a UE to synchronize with the base station, wherein the UE is a half-duplex device lacking a duplexer. The apparatus may further include: a unit for switching from the anchor carrier to a supplementary downlink (SDL) carrier via a switch at the UE after completion of the initial access procedure to receive subsequent downlink transmissions from the base station. The apparatus may further include: a unit for receiving downlink communications from the base station on the SDL.

[0009] To achieve the foregoing and related purposes, one or more aspects include the features described in detail below and particularly pointed out in the claims. The following description and the drawings set forth in detail certain illustrative features of one or more aspects. However, these features are indicative of only some of the various ways in which the principles of the various aspects may be employed, and this description is intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Aspects of the disclosure will be described below in conjunction with the drawings, which are provided for illustration and not limitation of the disclosed aspects, where like reference numerals represent like elements, and in which:

[0011] Figure 1 is a schematic diagram of an example of a wireless communication system in accordance with aspects of the present disclosure;

[0012] Figure 2 is an example table of 5G network deployments that are phased in by incrementally making additional bandwidth available for use in some jurisdictions;

[0013] Figure 3 is a schematic diagram of an example implementation of various components of a base station in accordance with aspects of the present disclosure; and

[0014] Figure 4 is a flowchart of an example of a method of wireless communication implemented by a base station in accordance with aspects of the present disclosure. DETAILED DESCRIPTION

[0015] In recent years, with the introduction of a large number of intelligent handheld devices, the demand for mobile broadband by users has increased sharply. For example, the sharp growth of bandwidth-intensive applications such as video streaming and multimedia file sharing is pushing the limits of current cellular systems. The focus on addressing such demands has mainly been concentrated on traditional smartphones and vertical applications (e.g., vehicle-to-everything (V2X)).

[0016] However, in some scenarios, multiple reduced-capability (RedCap) and / or Internet of Things (IoT) devices may also be connected to the network. RedCap devices and / or IoT devices can be used in several scenarios, including wearable devices, industrial wireless sensors, and video surveillance. Some of these scenarios may involve stationary devices, and there may be a relatively large number of such devices located within a cell.

[0017] Compared to traditional smartphones, RedCap devices require a small form factor. For the purposes of this disclosure and unless otherwise specified, the terms "RedCap device" or "IoT device" may be used interchangeably with "UE". The small form factor of RedCap limits the antenna dimensional size and radiation efficiency in the device. To further reduce the device cost, the duplexer typically integrated in a smartphone may be replaced by a relatively low-cost switch in RedCap / IoT devices.

[0018] For reference, a "duplexer" is a hardware device integrated in a smartphone to allow two-way communication (e.g., uplink and downlink) concurrently on the same transmission line (e.g., antenna). This is typically achieved through filters for separating the frequencies of interest, allowing two different frequency signals to be sent and received from the same antenna. However, as described above, due to size and cost constraints, the duplexer may be replaced by a lower-cost "switch" in RedCap devices. Incorporating a switch (as opposed to a duplexer) may limit the duplex mode of RedCap devices and increase the noise experienced at the RedCap device. The loss of antenna efficiency and the increase in noise figure may lead to the degradation of the uplink coverage of RedCap devices.

[0019] To compensate for the loss of uplink coverage, HD-FDD UEs can be configured to support SUL and / or normal uplink (NUL). In particular, the current 5G NR system can operate in one or more frequency bands within the electromagnetic spectrum. The electromagnetic spectrum is typically subdivided into various categories, frequency bands, channels, etc. based on frequency / wavelength. In 5G NR, two initial operating frequency bands have been identified as the frequency range (FR) names FR1 (410 MHz - 7.125 GHz) and FR2 (24.25 GHz - 52.6 GHz).

[0020] In some jurisdictions, the current 5G network deployments are being gradually adopted by incrementally making additional bandwidth available for use. For example, in some countries, the first phase of the deployment may include the utilization of an anchor carrier (e.g., 100 MHz in the 2.6 GHz band or 3.5 GHz), and the second phase may include making supplementary bands available. However, compared to lower bands, higher bands may suffer greater path loss and penetration loss of signals. Therefore, in some cases, the supplementary bands at lower frequencies may provide better coverage than the anchor carrier.

[0021] Due to the higher frequencies and smaller portions of the uplink resource allocation, this problem is more severe for uplink communication. Thus, generally, the cell coverage in the uplink direction (e.g., from the UE to the base station) may be lower than that in the downlink direction (e.g., from the base station to the UE), partly because the UE Tx power (i.e., the uplink power) is not as strong as the base station transmitter power (i.e., the downlink power).

[0022] To compensate for this problem, after the UE initially obtains access to the network via an anchor carrier (e.g., 2.6 GHz or 3.5 GHz), the UE can be redirected to a supplementary band (e.g., 2.1 GHz or 700 MHz). For example, the UE can be configured to utilize an SUL carrier in the 1.8 GHz band, while the NUL TDD carrier can be in the 3.5 GHz band. This is because the cell coverage may be inversely proportional to the band used for communication (e.g., as the frequency gets lower, the cell coverage gets larger).

[0023] According to aspects of the present disclosure, to compensate for the loss of downlink coverage and improve load balancing, a half-duplex UE (HD-UE) can also be configured to support supplementary downlink (SDL) in cases where the UE is not equipped with a duplexer. To this end, features of the present disclosure include implementing techniques for configuring the HD-UE to implement SDL in a band combination that may be in the same or different FR (e.g., FR1 or FR2).

[0024] Thus, in some examples, the UE can obtain a synchronization signal block (SSB) from an anchor carrier from the base station in a time-division duplex (TDD) band. In some cases, the SSB can be configured separately for the HD-UE. In other aspects, the SSB can be shared between the HD-UE and a legacy UE. System information (SI) messages dedicated to RedCap devices can be sent from the base station to the UE on the SDL in FR1 or on the anchor carrier in the TDD band. Thus, the UE can perform a random access channel (RACH) (which is a process by which a wireless terminal uses a shared channel to access a mobile network) on the anchor carrier in the TDD band, and after the initial access (RACH process), the UE can switch to the SDL to receive subsequent downlink signals.

[0025] According to one aspect of the present disclosure, the handover from the anchor carrier to the SDL (after initial access) can be triggered by the base station or the UE itself. In particular, in some examples, the Channel State Information Reference Signal (CSI-RS), or Tracking Reference Signal (TRS), or SSB can be configured on the SDL for Reference Signal Received Power (RSRP) / Reference Signal Received Quality (RSRQ) measurements. Regarding UE-triggered handover, if the RSRP / RSRQ of the SDL or NDL is below a network-configured threshold, the UE can send a Scheduling Request (SR) to the base station to request the UE to handover the downlink carrier (i.e., NDL to SDL or SDL to NDL). Regarding base-station-triggered handover, the UE can be redirected to the NDL or SDL when the reported RSRP / RSRQ of the SDL or NDL is below the network-configured threshold. However, in one scenario, the UE can continue to send the uplink signal on the anchor carrier when the downlink is handed over to the SDL.

[0026] In another aspect, in addition to the TDD anchor carrier, the SDL and SUL can also be supported to achieve coverage and load balancing. In such a case, the UE can perform RACH on the anchor carrier in the TDD band or on the SUL in FR1. And after initial access, the UE can switch to the SDL to receive the downlink signal that may be triggered by the base station or the UE, as discussed above. Specifically, the CSI-RS / TRS or SSB can be configured on the SDL for RSRP / RSRQ measurements to determine whether the UE should handover between the NDL and the SDL. The UE can also send the uplink signal based on the carrier indicated by the Downlink Control Information (DCI) or Radio Resource Control (RRC) signaling on the downlink carrier (e.g., the anchor carrier or SUL in TDD).

[0027] In some aspects, the Bandwidth Part (BWP) can be configured for the SDL of the HD-UE. In particular, when the downlink and uplink carriers of the HD-UE belong to the same FR, the numerology of the downlink BWP and the numerology of the uplink BWP may be the same or different. However, when the downlink and uplink carriers of the HD-UE belong to different FRs, the numerology of the downlink BWP and the numerology of the uplink BWP may be different.

[0028] In some examples, the SDL band may require at least one bit to be indicated as an SDL band in the SI (e.g., MIB or SIB1), or alternatively, the band number may be different from that of the normal paired spectrum, in which the UE can identify the SDL band via the band number. In some aspects, the BWP configuration on the SDL can be configured by a Physical Broadcast Channel (PBCH) sent on an anchor carrier in a TDD band dedicated to the HE-UE. In other cases, the BWP configuration on the SDL can be configured by the SI sent on an anchor carrier in TDD and shared with legacy UEs or dedicated to HD-UEs. Alternatively, the BWP configuration can also be hard-coded in the specification.

[0029] Reference is now made to Figures 1-4 Describe the various aspects in more detail. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. However, it is evident that such aspects may be practiced without these specific details. Additionally, as used herein, the term "component" can be part of a portion that makes up a system, can be hardware, firmware, and / or software stored on a computer-readable medium, and can be divided into other components.

[0030] The following description provides examples without limiting the scope, applicability, or examples set forth in the claims. Changes may be made in the functionality and arrangement of the elements discussed without departing from the scope of the present disclosure. Various processes or components may be omitted, replaced, or added as appropriate to each example. For instance, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, features described with respect to some examples may be combined into other examples.

[0031] Figure 1FIG. is a diagram illustrating an example of a wireless communication system and an access network 100. A wireless communication system (also referred to as a wireless wide area network (WWAN)) may include base stations 102, UEs 104, an evolved packet core (EPC) 160, and / or a 5G core (5GC) 190. The base stations 102 may include macro cells (high-power cellular base stations) and / or small cells (low-power cellular base stations). Macro cells may include base stations. Small cells may include femto cells, pico cells, and micro cells. In an example, the base stations 102 may further include gNBs 180, as further described herein. In one example, in accordance with aspects described herein, some UEs 104 of the wireless communication system may have a modem and an HD-UE SDL configuration component 305 for configuring the HD-UE to implement SDL in a band combination that may be in the same or different frequency ranges (FRs). Aspects of the present disclosure provide techniques for configuring a half-duplex to implement SDL in a band combination that may be in the same or different frequency range (FR) names (e.g., FR1 or FR2). In particular, to compensate for the loss of downlink coverage and improve load balancing, aspects of the present disclosure configure a UE to perform a random access channel (RACH) (which is a process of a shared channel used by a wireless terminal to access a mobile network) on an anchor carrier in a time-division duplex (TDD) band, and after initial access, the UE may be configured to switch to SDL to receive subsequent downlink signals.

[0032] Base stations 102 configured for 4G LTE (which may be collectively referred to as an evolved universal mobile telecommunications system (UMTS) terrestrial radio access network (E-UTRAN)) may be interfaced with the EPC 160 via a backhaul link 132 (e.g., using an S1 interface). Base stations 102 configured for 5G NR (which may be collectively referred to as a next-generation RAN (NG-RAN)) may be interfaced with the 5GC 190 via a backhaul link 184. In addition to other functions, the base stations 102 may also perform one or more of the following functions: transmission of user data, wireless channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), user and device tracking, radio access network information management (RIM), paging, positioning, and transmission of warning messages. The base stations 102 may communicate with each other directly or indirectly (e.g., via the EPC 160 or 5GC 190) via a backhaul link 134 (e.g., using an X2 interface). The backhaul link 134 may be wired or wireless.

[0033] Base station 102 may communicate wirelessly with one or more UEs 104. Each base station 102 in base station 102 may provide communication coverage for a corresponding geographical coverage area 110. There may be overlapping geographical coverage areas 110. For example, small cell 102' may have a coverage area 110' that overlaps with the coverage area 110 of one or more macro base stations 102. A network including both small cells and macro cells may be referred to as a heterogeneous network. The heterogeneous network may also include a home evolved Node B (eNB) (HeNB) which may provide services to a restricted group (which may be referred to as a closed subscriber group (CSG)). The communication link 120 between base station 102 and UE 104 may include an uplink (UL) (also referred to as a reverse link) transmission from UE 104 to base station 102 and / or a downlink (DL) (also referred to as a forward link) transmission from base station 102 to UE 104. The communication link 120 may use multiple-input multiple-output (MIMO) antenna technology, which includes spatial multiplexing, beamforming, and / or transmit diversity. The communication link may be over one or more carriers. Base station 102 / UE 104 may use a spectrum with a bandwidth of up to a total of Yx MHz (e.g., for x component carriers) allocated in carrier aggregation with up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) per carrier for transmission in the DL and / or UL directions. The carriers may be adjacent to each other or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to the DL and UL (e.g., more or fewer carriers may be allocated for the DL compared to the UL). A component carrier may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as a primary cell (PCell), and the secondary component carriers may be referred to as secondary cells (SCells).

[0034] In another example, certain UEs 104 may communicate with each other using device-to-device (D2D) communication links 158. The D2D communication links 158 may use DL / UL WWAN spectrum. The D2D communication links 158 may use one or more sidelink channels, e.g., physical sidelink broadcast channel (PSBCH), physical sidelink discovery channel (PSDCH), physical sidelink shared channel (PSSCH), and physical sidelink control channel (PSCCH). D2D communication may be through various wireless D2D communication systems, e.g., FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR.

[0035] The wireless communication system may further include a Wi-Fi access point (AP) 150 that communicates with a Wi-Fi station (STA) 152 via a communication link 154 in the 5 GHz unlicensed spectrum. When communicating in the unlicensed spectrum, the STA 152 / AP 150 may perform a clear channel assessment (CCA) before communicating to determine whether the channel is available.

[0036] The small cell 102’ may operate in licensed and / or unlicensed spectrum. When operating in the unlicensed spectrum, the small cell 102’ may adopt NR and use the same 5 GHz unlicensed spectrum as that used by the Wi-Fi AP 150. The small cell 102’ adopting NR in the unlicensed spectrum may enhance coverage and / or increase the capacity of the access network.

[0037] The base station 102 (whether a small cell 102’ or a large cell (e.g., a macro base station)) may include an eNB, a gNodeB (gNB), or other types of base stations. Some base stations, such as the gNB 180, may operate one or more frequency bands within the electromagnetic spectrum. The electromagnetic spectrum is generally subdivided into various categories, frequency bands, channels, etc. based on frequency / wavelength. In 5G NR, two initial operating frequency bands have been identified as the frequency range names FR1 (410 MHz - 7.125 GHz) and FR2 (24.25 GHz - 52.6 GHz). The frequency between FR1 and FR2 is sometimes referred to as the mid-band frequency. Although a part of FR1 is greater than 6 GHz, FR1 is generally (interchangeably) referred to as the “below 6 GHz” band in various documents and articles. Similar naming issues sometimes occur with respect to FR2. Although different from the extremely high frequency (EHF) band (30 GHz - 300 GHz), which is identified by the International Telecommunication Union (ITU) as the “millimeter wave” band, FR2 is generally (interchangeably) referred to as the “millimeter wave” (mmW) band in documents and articles.

[0038] Considering the above aspects, unless otherwise specifically stated, it should be understood that if the term “below 6 GHz” etc. is used herein, it may broadly represent a frequency that may be less than 6 GHz, may be within FR1, or may include the mid-band frequency. Additionally, unless otherwise specifically stated, it should be understood that if the term “millimeter wave” etc. is used herein, it may broadly represent a frequency that may include the mid-band frequency, may be within FR2, or may be within the EHF band. Communication using the mmW radio frequency band has extremely high path loss and short distance. The mmW base station 180 may utilize beamforming 182 with the UE 110 to compensate for the path loss and short distance.

[0039] The base station 102 cited in this document may include a gNB 180. The EPC 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may communicate with a Home Subscriber Server (HSS) 174. The MME 162 is a control node that processes signaling between the UE 104 and the EPC 160. Generally, the MME 162 provides bearer and connection management. All User Internet Protocol (IP) packets are transmitted through the Serving Gateway 166, which itself is connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation and other functions. The PDN Gateway 172 and the BM-SC 170 are connected to an IP service 176. The IP service 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS streaming service, and / or other IP services. The BM-SC 170 may provide functions for MBMS user service provisioning and delivery. The BM-SC 170 may act as an entry point for content provider MBMS transmissions, may be used to authorize and initiate MBMS bearer services within a Public Land Mobile Network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS services to the base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area for a specific service broadcast, and may be responsible for session management (start / stop) and collecting charging information related to eMBMS.

[0040] The 5GC 190 may include an Access and Mobility Management Function (AMF) 192, other AMFs 193, a Session Management Function (SMF) 194, and a User Plane Function (UPF) 195. The AMF 192 may communicate with a Unified Data Management Unit (UDM) 196. The AMF 192 may be a control node that processes signaling between the UE 104 and the 5GC 190. Generally, the AMF 192 may provide QoS flow and session management. User Internet Protocol (IP) packets (e.g., from one or more UEs 104) may be transmitted through the UPF 195. The UPF 195 may provide UE IP address allocation for one or more UEs and other functions. The UPF 195 is connected to an IP service 197. The IP service 197 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS streaming service, and / or other IP services.

[0041] A base station may also be referred to as a gNB, Node B, evolved Node B (eNB), access point, base station transceiver, radio base station, radio transceiver, transceiver function, basic service set (BSS), extended service set (ESS), transmit receive point (TRP), or some other suitable term. The base station 102 provides an access point to the EPC 160 or 5GC 190 for the UE 104. Examples of the UE 104 include a cellular phone, smartphone, session initiation protocol (SIP) phone, laptop computer, personal digital assistant (PDA), satellite radio unit, global positioning system, multimedia device, video device, digital audio player (e.g., MP3 player), camera, game console, tablet computer, smart device, wearable device, vehicle, electricity meter, gas pump, large or small kitchen appliance, healthcare device, implant, sensor / actuator, display, or any other similar functional device. Some of the UEs 104 may be referred to as IoT devices (e.g., parking meter, gas pump, oven, vehicle, heart monitor, etc.). IoT UEs may include machine type communication (MTC) / enhanced MTC (eMTC, also referred to as category (CAT)-M, Cat M1) UEs, NB-IoT (also referred to as CAT NB1) UEs, and other types of UEs. In the present disclosure, eMTC and NB-IoT may refer to future technologies that may evolve from or be based on these technologies. For example, eMTC may include FeMTC (further eMTC), eFeMTC (further enhanced eMTC), mMTC (massive MTC), etc., and NB-IoT may include eNB-IoT (enhanced NB-IoT), FeNB-IoT (further enhanced NB-IoT), etc. The UE 104 may also be referred to as a station, mobile station, user station, mobile unit, user unit, radio unit, remote unit, mobile device, radio device, radio communication device, remote device, mobile user station, access terminal, mobile terminal, radio terminal, remote terminal, cell phone, user agent, mobile client, client, or some other suitable term.

[0042] Similarly, one or more base stations (e.g., gNB 102) or UEs 104 (e.g., for sidelink communication) may generate DCI in accordance with aspects of the present disclosure, and signal full-duplex capabilities and beam assignments for uplink and downlink concurrent communication on the same frequency band.

[0043] Figure 2It is an example table of 5G network deployment gradually adopted in some jurisdictions by incrementally making additional bandwidth available for use. For example, in some countries, the first phase of deployment may include the utilization of an anchor carrier (e.g., 100 MHz in the 2.6 GHz band or 3.5 GHz), and the second phase may include making supplementary frequency bands available. However, compared with lower frequency bands, higher frequency bands may suffer greater path loss and penetration loss of signals. Therefore, in some cases, supplementary frequency bands at lower frequencies can provide better coverage than the anchor carrier.

[0044] Figure 3 It shows the hardware components and sub-components of the user equipment 104 for implementing one or more methods (e.g., method 400) described herein according to various aspects of the present disclosure. For example, an example implementation of the user equipment 104 may include various components, some of which have been described above, but including components such as one or more processors 312, a memory 316, and a transceiver 302 that communicate via one or more buses 344, which may operate in conjunction with the HD-UE SDL configuration component 305 to perform functions related to one or more methods (e.g., 400) described herein that include the present disclosure.

[0045] In some aspects, the HD-UE SDL configuration component 305 may configure the HD-UE to implement techniques for supplementary downlink (SDL) in a band combination that may be in the same or different frequency range (FR) names (e.g., FR1 or FR2). Specifically, to compensate for the loss of downlink coverage and improve load balancing, aspects of the present disclosure configure the UE to perform RACH (which is a process for a wireless terminal to access a shared channel of a mobile network) on an anchor carrier in a time division duplex (TDD) band, and after initial access, the UE may be configured to switch to SDL to receive subsequent downlink signals.

[0046] The HD-UE SDL configuration component 305 may also obtain the SSB from the anchor carrier in the TDD band from the base station. In some cases, the SSB may be configured separately for the HD-UE. In other aspects, the SSB may be shared between the HD-UE and a legacy UE. The system information (SI) message dedicated to the RedCap UE may be sent from the base station to the UE on the SDL in FR1 or on the anchor carrier in the TDD band. Therefore, the UE may perform a random access channel (RACH) (which is a process for a wireless terminal to access a shared channel of a mobile network) on the anchor carrier in the TDD band, and after initial access, the UE may switch to SDL to receive subsequent downlink signals.

[0047] The HD-UE SDL configuration component 305 may also include a signal measurement component 310, which is used to switch from the anchor carrier to SDL (after initial access), which may be triggered by the base station or the UE itself. Specifically, the signal measurement component 310 of the UE may trigger the handover. If the RSRP / RSRQ of SDL or NDL is lower than the network-configured threshold, the UE may send a scheduling request (SR) to the base station to request the UE to switch the downlink carrier (i.e., NDL to SDL or SDL to NDL). In another aspect, in addition to the TDD anchor carrier, SDL and SUL may also be supported to achieve coverage and load balancing. In such a case, the UE may perform RACH on the anchor carrier in the TDD band or on the SUL in FR1. And after initial access, the UE may switch to SDL to receive downlink signals that may be triggered by the base station or the UE, as discussed above. Specifically, CSI-RS / TRS or SSB may be configured on SDL for RSRP / RSRQ measurement to determine whether the UE should switch between NDL and SDL. The UE may also send uplink signals based on the carrier indicated by downlink control information (DCI) or radio resource control (RRC) signaling on the downlink carrier (e.g., the anchor carrier in TDD or SUL).

[0048] One or more processors 312, a modem 314, a memory 316, a transceiver 302, an RF front end 388, and one or more antennas 365 may be configured to support voice and / or data calls (simultaneously or non-simultaneously) in one or more radio access technologies. In one aspect, one or more processors 312 may include a modem 314 that uses one or more modem processors. Various functions related to the full-duplex communication manager component 350 may be included in the modem 314 and / or the processor 312, and in one aspect, may be executed by a single processor, while in other aspects, different functions among these functions may be executed by a combination of two or more different processors. For example, in one aspect, one or more processors 312 may include any one or any combination of the following: a modem processor, or a baseband processor, or a digital signal processor, or a transmit processor, or a receive processor, or a transceiver processor associated with the transceiver 302. In other aspects, some of the features of one or more processors 312 and / or the modem 314 associated with the HD-UE SDL configuration component 305 may be executed by the transceiver 302.

[0049] The memory 316 may be configured to store data used herein and / or a local version of the application 375 executed by the at least one processor 312 or one or more sub-components of the HD-UE SDL configuration component 305 and / or its sub-components. The memory 316 may include any type of computer-readable medium that can be used by a computer or the at least one processor 312, such as, for example, random access memory (RAM), read-only memory (ROM), magnetic tape, magnetic disk, optical disk, volatile memory, non-volatile memory, and any combination thereof. In one aspect, for example, the memory 316 may be a non-transitory computer-readable storage medium storing one or more computer-executable codes, wherein when the UE 104 is operating the at least one processor 312 to execute one or more sub-components of the HD-UE SDL configuration component 305 and / or its sub-components, the one or more computer-executable codes are used to define the HD-UE SDL configuration component 305 and / or one or more sub-components of its sub-components, and / or data associated therewith.

[0050] The transceiver 302 may include at least one receiver 306 and at least one transmitter 308. The receiver 306 may include hardware, firmware, and / or software code executable by a processor, the code including instructions and being stored in a memory (e.g., a computer-readable medium). The receiver 306 may be, for example, a radio frequency (RF) receiver. In one aspect, the receiver 306 may receive signals transmitted by the at least one base station 102. Additionally, the receiver 306 may process such received signals and may also obtain measurement results of the signals, such as but not limited to Ec / Io, SNR, RSRP, RSSI, etc. The transmitter 308 may include hardware, firmware, and / or software code executable by a processor, the code including instructions and being stored in a memory (e.g., a computer-readable medium). Suitable examples of the transmitter 308 may include but are not limited to RF transmitters.

[0051] Furthermore, in one aspect, the sending device may include an RF front end 388, which may operate communicatively with one or more antennas 365 and the transceiver 302 to receive and send radio transmissions, such as, for example, wireless communications transmitted by the at least one base station 102 or wireless transmissions transmitted by the UE 104. The RF front end 388 may be connected to one or more antennas 365 and may include one or more low noise amplifiers (LNAs) 390, one or more switches 392, one or more power amplifiers (PAs) 398, and one or more filters 396 for sending and receiving RF signals.

[0052] In one aspect, the LNA 390 can amplify the received signal to a desired output level. In one aspect, each LNA 390 can have a specified minimum gain value and a maximum gain value. In one aspect, the RF front end 388 can use one or more switches 392 to select a particular LNA 390 and its specified gain value based on the desired gain value for a particular application.

[0053] In addition, for example, the RF front end 388 can use one or more PAs 398 to amplify the signal for RF output to a desired output power level. In one aspect, each PA 398 can have a specified minimum gain value and a maximum gain value. In one aspect, the RF front end 388 can use one or more switches 392 to select a particular PA 398 and its specified gain value based on the desired gain value for a particular application.

[0054] In addition, for example, the RF front end 388 can use one or more filters 396 to filter the received signal to obtain an input RF signal. Similarly, in one aspect, for example, corresponding filters 396 can be used to filter the output from the corresponding PAs 398 to produce an output signal for transmission. In one aspect, each filter 396 can be connected to a particular LNA 390 and / or PA 398. In one aspect, the RF front end 388 can use one or more switches 392 to select a transmit path or a receive path that uses the specified filter 396, LNA 390, and / or PA 398 based on a configuration specified by, for example, the transceiver 302 and / or the processor 312.

[0055] Thus, the transceiver 302 can be configured to transmit and receive wireless signals via the RF front end 388 and one or more antennas 365. In one aspect, the transceiver 302 can be tuned to operate at a specified frequency such that the transmitting device can communicate with, for example, one or more UEs 104 or one or more cells associated with one or more base stations 102. In one aspect, for example, the modem 314 can configure the transceiver 302 to operate at a specified frequency and power level based on the configuration of the transmitting device and the communication protocol used by the modem 314.

[0056] In one aspect, the modem 314 can be a multi-band multi-mode modem that can process digital signals and communicate with the transceiver 302 such that the transceiver 302 is used to transmit and receive digital data. In one aspect, the modem 314 can be multi-band and can be configured to support multiple frequency bands for a particular communication protocol. In one aspect, the modem 314 can be multi-mode and configured to support multiple operating networks and communication protocols. In one aspect, the modem 314 can control one or more components of the transmitting device (e.g., RF front end 388, transceiver 302) based on a specified modem configuration to enable transmission and / or reception of signals from the network. In one aspect, the modem configuration can be based on the mode of the modem 314 and the frequency band in use. In another aspect, the modem configuration can be based on base station configuration information associated with the transmitting device (such as provided by the network during cell selection and / or cell reselection).

[0057] Referring Figure 4 , an example method 400 for wireless communication according to aspects of the present disclosure can be performed by one or more UEs 104 as referred to Figure 1 discussed. Although method 400 is described below in terms of elements of UE 104, one or more of the steps described herein can be implemented using other components.

[0058] At block 405, method 400 can include: initiating an initial access procedure with a base station on an anchor carrier in a time division duplex (TDD) frequency band at a user equipment (UE) to synchronize with the base station, where the UE is a half-duplex device lacking a duplexer. Aspects of block 405 can be performed by the transceiver 302 that receives communication from the base station 102 via one or more antennas 365, as referred to Figure 3 described. Accordingly, one of the transceiver 302, the HD-UE SDL configuration component 305, the modem 314, the processor 312, and / or the UE 104 or its subcomponents can define a unit for initiating an initial access procedure with a base station on an anchor carrier in a time division duplex (TDD) frequency band at a user equipment (UE) to synchronize with the base station, where the UE is a half-duplex device lacking a duplexer.

[0059] In some examples, initiating the initial access procedure can include: receiving at least one or more of a synchronization signal block (SSB) or a system information (SI) message from the base station on the anchor carrier in the TDD frequency band at the UE; and initiating the initial access procedure based on one or more SSBs or SI messages received from the base station on the anchor carrier in the TDD frequency band.

[0060] In some aspects, method 400 may further include: receiving, from a base station, a bandwidth part (BWP) configuration of an SDL carrier, where the BWP configuration is received via a physical broadcast channel (PBCH) transmitted on an anchor carrier in a TDD band dedicated to the UE or via a system information message transmitted on the anchor carrier in the TDD band and shared with legacy UEs.

[0061] At block 410, method 400 may include: after completing an initial access procedure, switching from an anchor carrier to a supplementary downlink (SDL) carrier via a switch at the UE to receive subsequent downlink transmissions from the base station. Aspects of block 410 may be performed by the HD-UE SDL configuration component 305 and the signal measurement component 310 as described with reference to Figure 3 Thus, one of the transceiver 302, the HD-UE SDL configuration component 305, the signal measurement component 310, the modem 314, the processor 312, and / or the UE 104 or its sub-components may define a unit for switching from an anchor carrier to a supplementary downlink (SDL) carrier via a switch at the UE after completing an initial access procedure to receive subsequent downlink transmissions from the base station.

[0062] In some examples, the switch from the anchor carrier to the supplementary downlink (SDL) carrier may be triggered by the UE or the base station. The method may include: measuring one or both of the reference signal received power (RSRP) or the reference signal received quality (RSRQ) on the SDL carrier; and determining whether the measurement of one or both of the RSRP or the RSRQ is less than a network-configured threshold. The method may further include: sending a scheduling request to the base station for requesting to switch the downlink communication back from the SDL carrier to the anchor carrier based on determining that the measurement of one or both of the RSRP or the RSRQ is less than the network-configured threshold; and receiving, in response to the scheduling request, a message to switch the downlink communication back from the SDL carrier to the anchor carrier from the base station. The method may further include: switching from the SDL carrier to the anchor carrier for subsequent downlink communication from the base station.

[0063] At block 415, method 400 may include: receiving downlink communication from the base station on the SDL. Aspects of block 415 may be performed by the transceiver 302, which receives communication from the base station 102 via one or more antennas 365, as described with reference to Figure 3 Thus, one of the transceiver 302, the HD-UE SDL configuration component 305, the modem 314, the processor 312, and / or the UE 104 or its sub-components may define a unit for receiving downlink communication from the base station on the SDL.

[0064] In some examples, method 400 may further include: sending uplink communication on an anchor carrier in a TDD band.

[0065] The above detailed description set forth in connection with the accompanying drawings describes examples, and does not represent the only examples that may be implemented or that are within the scope of the claims. The term "example" as used in this description means "serving as an example, instance, or illustration" and is not "preferred" or "advantageous over other examples". For the purpose of providing an understanding of the described technology, the detailed description includes specific details. However, the technology may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

[0066] Information and signals may be represented using any of a variety of different technologies and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or particles, optical fields or particles, computer-executable code or instructions stored on a computer-readable medium, or any combination thereof.

[0067] The various illustrative blocks and components described in connection with the present disclosure may be implemented or performed with a specially-programmed device designed to perform the functions described herein, such as, but not limited to, a processor, a digital signal processor (DSP), an ASIC, an FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. A specially-programmed processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A specially-programmed processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0068] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions can be stored on or transmitted via a non-transitory computer-readable medium as one or more instructions or code. Other examples and implementations are within the scope and spirit of the present disclosure and the appended claims. For example, due to the nature of software, the functions described above can be implemented using software executed by a specially programmed processor, hardware, firmware, hardwiring, or any combination of these items. The features for implementing the functions can also be physically located at various positions, including being distributed such that part of the functions are implemented at different physical locations. Further, as used herein (including in the claims), the "or" in a list of items used with "at least one of" indicates a disjunctive list, such that, for example, a list of "at least one of A, B, or C" means A or B or C or AB or AC or BC or ABC (i.e., A and B and C).

[0069] Computer-readable media includes both computer storage media and communication media, where the communication media includes any medium that facilitates transfer of a computer program from one place to another. The storage media can be any available medium that can be accessed by a general or special purpose computer. By way of example and not limitation, computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code units in the form of instructions or data structures and that can be accessed by a general or special purpose computer or a general or special purpose processor. Additionally, any connection is properly termed a computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technology (such as infrared, radio, and microwave), then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technology (such as infrared, radio, and microwave) is included in the definition of the medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc, where disks typically reproduce data magnetically, while discs reproduce data optically using lasers. Combinations of the above are also included within the scope of computer-readable media.

[0070] The detailed description set forth above in connection with the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. For the purpose of providing a thorough understanding of the various concepts, the detailed description includes specific details. However, it will be apparent to those skilled in the art that the concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

[0071] Certain aspects of the telecommunications system are also presented with reference to various apparatus and methods. These apparatus and methods are described in the detailed implementation and are also illustrated in the drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements"). These elements can be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends on the particular application and the design constraints imposed on the overall system.

[0072] By way of example, an element, or any part of an element, or any combination of elements can be implemented as a "processing system" including one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, system on a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described throughout this disclosure. One or more processors in the processing system can execute software. Whether referred to as software, firmware, middleware, microcode, hardware description language, or other names, software should be broadly construed to mean instructions, instruction sets, code, code segments, program code, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, processes, functions, etc.

[0073] Note that the techniques described herein can be used in various wireless communication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and other systems. The terms "system" and "network" are often used interchangeably. CDMA systems may implement radio technologies such as CDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers the IS-2000, IS-95, and IS-856 standards. Releases 0 and A of IS-2000 are commonly referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD), etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. TDMA systems may implement radio technologies such as Global System for Mobile Communications (GSM). OFDMA systems may implement radio technologies such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM TM etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). 3GPP Long Term Evolution (LTE) and enhanced LTE (LTE-A) are new versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). CDMA2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). The techniques described herein can be used in the systems and radio technologies mentioned above and other systems and radio technologies, including cellular (e.g., LTE) communication on shared radio frequency spectrum bands. However, for illustrative purposes, the following description is of the LTE / LTE-A and / or 5G New Radio (NR) systems, and the LTE or 5G NR terms are used in most of the following description, but the techniques are applicable to applications other than LTE / LTE-A and 5G NR applications (e.g., applicable to other next-generation communication systems).

[0074] A previous description of the present disclosure is provided to enable those skilled in the art to implement or use the present disclosure. Various modifications to the present disclosure will be apparent to those skilled in the art, and the general principles defined herein can be applied to other variations without departing from the spirit or scope of the present disclosure. Additionally, although the elements of the described aspects and / or embodiments may be described or claimed in the singular, the plural is contemplated unless explicitly limited to the singular. Moreover, unless otherwise stated, all or part of any aspect and / or embodiment may be used in conjunction with all or part of any other aspect and / or embodiment. Accordingly, the present disclosure is not limited to the examples and designs described herein, but is accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication, comprising: initiating an initial access procedure with a base station on an anchor carrier in a time division duplex (TDD) band at a user equipment (UE) to synchronize with the base station, wherein the UE is a half-duplex device lacking a duplexer; after completing the initial access procedure, switching from the anchor carrier to a supplementary downlink (SDL) carrier via a switch at the UE to receive subsequent downlink transmissions from the base station, wherein the SDL carrier is at a lower frequency than the anchor carrier; and receiving downlink communication from the base station on the SDL.

2. The method according to claim 1, wherein Initiating the initial access procedure with the base station on the anchor carrier in the TDD band comprises: receiving, at the UE, at least one or more synchronization signal blocks (SSBs) or system information (SI) messages from the base station on the anchor carrier in the TDD band; and initiating the initial access procedure based on the one or more SSBs or SI messages received from the base station on the anchor carrier in the TDD band.

3. The method according to claim 1, further comprising: transmitting uplink communication on the anchor carrier in the TDD band.

4. The method according to claim 1, wherein The switching from the anchor carrier to the supplementary downlink SDL carrier is triggered by the UE or the base station.

5. The method according to claim 1, further comprising: measuring one or both of the reference signal received power (RSRP) or the reference signal received quality (RSRQ) on the SDL carrier; determining whether the measurement of the one or both of the RSRP or RSRQ is less than a network-configured threshold; sending a scheduling request to the base station for requesting to switch the downlink communication back from the SDL carrier to the anchor carrier based on determining that the measurement of the one or both of the RSRP or RSRQ is less than the network-configured threshold; receiving, in response to the scheduling request, a message from the base station for switching the downlink communication back from the SDL carrier to the anchor carrier; and switching from the SDL carrier to the anchor carrier for subsequent downlink communication from the base station.

6. The method according to claim 1, further comprising: receiving a bandwidth part (BWP) configuration of the SDL carrier from the base station, wherein the BWP configuration is received via a physical broadcast channel (PBCH) sent on the anchor carrier in the TDD band dedicated to the UE or through a system information message sent on the anchor carrier in the TDD band and shared with legacy UEs.

7. An apparatus for wireless communication, comprising: at least one processor; and a memory coupled to the at least one processor, the memory comprising instructions executable by the at least one processor to cause the apparatus to perform the following operations: initiating an initial access procedure with a base station on an anchor carrier in a time division duplex (TDD) band at a user equipment (UE) to synchronize with the base station, wherein the UE is a half-duplex device lacking a duplexer; After completing the initial access procedure, switch from the anchor carrier to a supplementary downlink (SDL) carrier via a switch at the UE to receive subsequent downlink transmissions from the base station, where the SDL carrier is at a lower frequency than the anchor carrier; and Receive downlink communication from the base station on the SDL.

8. The apparatus according to claim 7, wherein The processor is further configured to execute the instructions to perform any of the methods according to claims 2-6.

9. A non-transitory computer-readable medium storing instructions executable by a processor for wireless communication, the instructions including those for performing the following operations: Initiate an initial access procedure with a base station on an anchor carrier in a time division duplex (TDD) band of a user equipment (UE) to synchronize with the base station, where The UE is a half-duplex device lacking a duplexer; After completing the initial access procedure, switch from the anchor carrier to a supplementary downlink (SDL) carrier via a switch at the UE to receive subsequent downlink transmissions from the base station, where the SDL carrier is at a lower frequency than the anchor carrier; And Receive downlink communication from the base station on the SDL.

10. The non-transitory computer-readable medium according to claim 9, wherein, The processor further includes instructions for performing any of the methods according to claims 2-6.

11. An apparatus for wireless communication, comprising: A unit for initiating an initial access procedure with a base station on an anchor carrier in a time-division duplex (TDD) band at a user equipment (UE) to synchronize with the base station, where the UE is a half-duplex device lacking a duplexer; A unit for switching from the anchor carrier to a supplementary downlink (SDL) carrier via a switch at the UE after completing the initial access procedure to receive subsequent downlink transmissions from the base station, where the SDL carrier is at a lower frequency than the anchor carrier; and A unit for receiving downlink communication from the base station on the SDL.

12. The apparatus according to claim 11, further comprising a unit for performing any of the methods according to claims 2-6.

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