CN116806420A - Beam size configuration for demodulation reference signal bundling in uplink random access channel message repetition scenarios - Google Patents

Abstract

Aspects of the present disclosure provide apparatuses, methods, processing systems, and computer-readable media for determining a bundle size of a demodulation reference signal (DMRS) bundle for repeatedly transmitting an uplink Random Access Channel (RACH) message, such as by a User Equipment (UE), and transmitting an uplink RACH message having a DMRS bundle according to the determined bundle size. For example, in some aspects of the disclosure, the uplink RACH message is transmitted with a number of repetitions, and the bundle size is determined as a function of the number of repetitions. In some aspects, the beam size is determined based on the operating frequency band. In some aspects, the beam size is determined based on a duplexing mode in which the UE is operating. In some aspects, the beam size is determined based at least in part on signaling from the base station.

Description

Beam size configuration for demodulation reference signal bundling in uplink random access channel message repetition scenarios

Cross Reference to Related Applications

The present application claims priority to U.S. patent application Ser. No.17/647,439, filed on 7 at 1 month 2022, which claims the benefit and priority of U.S. provisional patent application Ser. No.63/144,211, filed on 1 month 2021, each of which is incorporated herein by reference in its entirety.

Background

Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques related to repeatedly transmitting uplink Random Access Channel (RACH) messages to improve coverage.

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcast, or other similar types of services. These wireless communication systems may employ multiple-access techniques capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, or other resources) with the users. The multiple access technique may rely on any of code division, time division, frequency division, orthogonal frequency division, single carrier frequency division, or time division synchronous code division, to name a few examples. These and other multiple access techniques have been adopted in various telecommunications standards to provide a common protocol that enables different wireless devices to communicate at the urban, national, regional, and even global levels.

Despite the tremendous technological advances made over the years in wireless communication systems, challenges remain. For example, such challenges may include challenges to achieve adequate coverage for performing a Random Access Channel (RACH) procedure associated with certain wireless devices. Accordingly, there is a need for further improvements in wireless communication systems to overcome various challenges.

SUMMARY

Certain aspects may be implemented in a method for wireless communication by a User Equipment (UE). The method generally includes determining a bundle size of a demodulation reference signal (DMRS) bundle for repeatedly transmitted uplink Random Access Channel (RACH) messages; and repeatedly transmitting the uplink RACH message having the DMRS bundling according to the determined bundle size to the base station over a plurality of slots.

Certain aspects may be implemented in a method of wireless communication by a network entity. The method generally includes determining a bundle size of a demodulation reference signal (DMRS) bundle for an uplink Random Access Channel (RACH) message repeatedly transmitted from a User Equipment (UE); receiving the uplink RACH message repeatedly transmitted from the UE over a plurality of slots; and processing the uplink RACH message based on channel estimation performed in consideration of DMRS transmitted in at least some of the plurality of slots according to the determined beam size.

Other aspects provide: an apparatus operable to, configured to, or otherwise adapted to perform the foregoing methods and those described elsewhere herein; a non-transitory computer-readable medium comprising instructions that, when executed by one or more processors of an apparatus, cause the apparatus to perform the aforementioned methods, as well as those methods described elsewhere herein; a computer program product embodied on a computer-readable storage medium comprising code for performing the foregoing methods and those described elsewhere herein; and apparatus comprising means for performing the foregoing methods, as well as those methods described elsewhere herein. By way of example, an apparatus may comprise a processing system, a device with a processing system, or a processing system cooperating over one or more networks.

For purposes of illustration, the following description and the annexed drawings set forth certain features.

Brief Description of Drawings

The drawings depict certain features of the aspects described herein and are not intended to limit the scope of the disclosure.

Fig. 1 is a block diagram conceptually illustrating an example wireless communication network.

Fig. 2 is a block diagram conceptually illustrating aspects of an example of a base station and user equipment.

Fig. 3A-3D depict various example aspects of a data structure for a wireless communication network.

Fig. 4 is a call flow diagram illustrating an example four-step Random Access Channel (RACH) procedure in accordance with certain aspects of the present disclosure.

Fig. 5 is a flowchart illustrating example operations for wireless communication according to certain aspects of the present disclosure.

Fig. 6 is a flowchart illustrating example operations for wireless communication according to certain aspects of the present disclosure.

Fig. 7 is a call flow diagram illustrating an example technique for Physical Uplink Shared Channel (PUSCH) repetition during RACH procedures in accordance with certain aspects of the present disclosure.

Fig. 8 is a call flow diagram illustrating an example technique for retransmission of Physical Uplink Shared Channel (PUSCH) repetition during RACH procedures in accordance with certain aspects of the present disclosure.

Fig. 9 illustrates an example wireless communication device, or portion thereof, operable, configured, or adapted to perform the operations of the methods disclosed herein, in accordance with certain aspects of the present disclosure.

Fig. 10 illustrates an example wireless communication device, or portion thereof, operable, configured, or adapted to perform the operations of the methods disclosed herein, in accordance with certain aspects of the present disclosure.

Detailed Description

Aspects of the present disclosure provide systems and methods for determining a bundle size (bundle size) of a demodulation reference signal (DMRS) bundle (bundling) for repeatedly transmitted uplink Random Access Channel (RACH) messages. For example, in some cases, a User Equipment (UE) may be configured to determine a bundle size for DMRS bundling when repeatedly transmitting an uplink RACH message (e.g., MSG 3), and transmit the uplink RACH message with the DMRS bundling according to the determined bundle size.

The use of repetition may enhance coverage, for example, allowing a base station (e.g., a gNB) to perform combining of signals received over multiple repetitions and increase the chances of successful decoding. Bundling DMRS (where the same or coherent DMRS are transmitted in multiple slots) may also enhance coverage, allowing the base station to consider multiple DMRS when performing channel estimation. Enhanced channel estimation may further increase the chances of successfully decoding the uplink RACH transmission.

Very often, some, but not all, UEs have the ability to transmit Random Access Channel (RACH) messages with repeated and demodulation reference signal (DMRS) bundling. In such cases, a network entity, such as a base station (e.g., a gNB), may configure the UE to have a bundling size for DMRS bundling if uplink RACH messages are repeatedly sent. The techniques disclosed herein provide a flexible and efficient mechanism for signaling such configuration information to a UE.

Wireless communication network introduction

Fig. 1 depicts an example of a wireless communication system 100 in which aspects described herein may be implemented.

In general, the wireless communication network 100 includes various network entities (alternatively, network elements or network nodes) that are typically manageable logical entities associated with, for example, communication devices and/or communication functions associated with the communication devices. For example, various functions of the network and various devices associated with and interacting with the network may be regarded as network entities.

In general, the wireless communication system 100 includes a Base Station (BS) 102, a User Equipment (UE) 104, and one or more core networks, such as an Evolved Packet Core (EPC) 160 and a 5G core network (5 GC) 190, that interoperate to provide wireless communication services.

The base station 102 may provide an access point for a User Equipment (UE) 104 to the EPC 160 and/or core network 190 and may perform one or more of the following functions: user data delivery, radio channel ciphering and ciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio Access Network (RAN) sharing, multimedia Broadcast Multicast Services (MBMS), subscriber and equipment tracking, RAN Information Management (RIM), paging, positioning, delivery of alert messages, and other functions. In various contexts, a base station may include and/or be referred to as a gNB, a node B, an eNB, an access point, a base transceiver station, a radio base station, a radio transceiver, or a transceiver function, or a Transmission and Reception Point (TRP).

The base station 102 communicates wirelessly with the UE 104 via a communication link 120. Each base station 102 may provide communication coverage for various geographic coverage areas 110 that may overlap in some cases. For example, a small cell 102 '(e.g., a low power base station) may have a coverage area 110' that overlaps with the coverage area 110 of one or more macro cells (e.g., a high power base station).

The communication link 120 between the base station 102 and the UE 104 may include Uplink (UL) (also known as reverse link) transmissions from the user equipment 104 to the base station 102 and/or Downlink (DL) (also known as forward link) transmissions from the base station 102 to the user equipment 104. In aspects, communication link 120 may use multiple-input multiple-output (MIMO) antenna techniques including spatial multiplexing, beamforming, and/or transmit diversity.

Examples of UEs 104 include a cellular phone, a smart phone, a Session Initiation Protocol (SIP) phone, a laptop, a Personal Digital Assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player, a camera, a game console, a tablet device, a smart device, a wearable device, a vehicle, an electricity meter, an air pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, a display, or other similar devices. Some UEs 104 may be internet of things (IoT) devices (e.g., parking meters, air pumps, ovens, vehicles, heart monitors, or other IoT devices), always-on (AON) devices, or edge processing devices. The UE 104 may also be more generally referred to as a station, mobile station, subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, or client.

Base station 102 in wireless communication network 100 may include repetition manager 199 (e.g., uplink RACH message repetition manager) that may determine a bundle size for DMRS bundles of repeatedly transmitted uplink RACH messages. Repetition manager 199 may be configured to perform operation 600 shown in fig. 6, as well as other operations described herein for determining bundle size. Additionally, the UE 104 in the wireless network 100 may include a repetition manager 198 (e.g., an uplink RACH message repetition manager) that may be configured to perform the operations 500 shown in fig. 5, as well as other operations described herein for determining the beam size.

Fig. 2 depicts aspects of an example Base Station (BS) 102 and User Equipment (UE) 104.

In general, BS102 includes various processors (e.g., 220, 230, 238, and 240), antennas 234a-t, transceivers 232a-t, and other aspects involved in the transmission of data (e.g., source data 212) and the reception of data (e.g., data sink 239). For example, BS102 may send and receive data between itself and UE 104. BS102 includes a controller/processor 240 that includes a repetition manager 241 (e.g., an uplink RACH message repetition manager). Repetition manager 241 may be configured to implement repetition manager 199 of fig. 1.

BS102 includes a controller/processor 240 that can be configured to implement various functions related to wireless communications. In the depicted example, controller/processor 240 includes a repetition manager 241. Notably, while depicted as an aspect of the controller/processor 240, the repetition manager 241 may additionally or alternatively be implemented in various other aspects of the base station 102 in other implementations.

In general, the UE 104 includes various processors (e.g., 258, 264, 266, and 280), antennas 252a-r, transceivers 254a-r, and other aspects involved in the transmission of data (e.g., source data 262) and the reception of data (e.g., data sink 260). The UE 104 includes a controller/processor 280 that includes a repetition manager 281 (e.g., an uplink RACH message repetition manager). The repetition manager 281 may be configured to implement the repetition manager 198 of fig. 1.

The user equipment 104 includes a controller/processor 280 that may be configured to implement various functions related to wireless communications. In the depicted example, controller/processor 280 includes a repetition manager 281. Notably, while depicted as an aspect of the controller/processor 280, the repetition manager 281 may additionally or alternatively be implemented in various other aspects of the user equipment 104 in other implementations.

Fig. 3A-3D depict aspects of a data structure for a wireless communication network, such as the wireless communication network 100 of fig. 1. Specifically, fig. 3A is a diagram 300 illustrating an example of a first subframe within a 5G (e.g., 5G NR) frame structure, fig. 3B is a diagram 330 illustrating an example of a DL channel within a 5G subframe, fig. 3C is a diagram 350 illustrating an example of a second subframe within a 5G frame structure, and fig. 3D is a diagram 380 illustrating an example of a UL channel within a 5G subframe.

Further discussion regarding fig. 1, 2, and 3A-3D is provided later in this disclosure.

Introduction to mmWave wireless communication

In wireless communications, the electromagnetic spectrum is typically subdivided into various categories, bands, channels, or other features. Subdivision is typically provided based on wavelength and frequency, where frequency may also be referred to as a carrier, subcarrier, channel, tone, or subband.

The electromagnetic spectrum is typically subdivided into various categories, bands, channels, etc., based on frequency/wavelength. In 5G NR, two initial operating bands have been identified as frequency range designated FR1 (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz). It should be appreciated that although a portion of FR1 is greater than 6GHz, FR1 is commonly (interchangeably) referred to as the "sub-6 GHz" band in various documents and articles. Similar naming problems sometimes occur with respect to FR2, which is commonly (interchangeably) referred to as the "millimeter wave" band in various documents and articles, although it is different from the Extremely High Frequency (EHF) band (30 GHz-300 GHz) identified by the International Telecommunications Union (ITU) as the "millimeter wave" band.

The frequency between FR1 and FR2 is commonly referred to as the mid-band frequency. Recent 5G NR studies have identified the operating band of these mid-band frequencies as frequency range designation FR3 (7.125 GHz-24.25 GHz). The frequency bands falling within FR3 may inherit FR1 characteristics and/or FR2 characteristics and thus may effectively extend the characteristics of FR1 and/or FR2 into mid-band frequencies. Additionally, higher frequency bands are currently being explored to extend 5G NR operation above 52.6 GHz. For example, three higher operating bands have been identified as frequency range designation FR4a or FR4-1 (52.6 GHz-71 GHz), FR4 (52.6 GHz-114.25 GHz) and FR5 (114.25 GHz-300 GHz). Each of these higher frequency bands falls within the EHF frequency band.

In view of the above, unless specifically stated otherwise, it should be understood that, if used herein, the term sub-6 GHz and the like may broadly represent frequencies that may be less than 6GHz, may be within FR1, or may include mid-band frequencies. Furthermore, unless specifically stated otherwise, it should be understood that, if used herein, the term "millimeter wave" or the like may broadly mean frequencies that may include mid-band frequencies, may be within FR2, FR4-a or FR4-1 and/or FR5, or may be within the EHF band.

Communications using the mmWave/near mmWave radio frequency band (e.g., 3GHz-300 GHz) may have higher path loss and shorter range than lower frequency communications. Accordingly, in fig. 1, mmWave base station 180 may utilize beamforming 182 with UE 104 to improve path loss and range. To this end, the base station 180 and the UE 104 may each include multiple antennas, such as antenna elements, antenna panels, and/or antenna arrays to facilitate beamforming.

In some cases, the base station 180 may transmit the beamformed signals to the UE 104 in one or more transmit directions 182'. The UE 104 may receive the beamformed signals from the base station 180 in one or more receive directions 182 ". The UE 104 may also transmit the beamformed signals to the base station 180 in one or more transmit directions 182 ". The base station 180 may receive the beamformed signals from the UEs 104 in one or more receive directions 182'. The base station 180 and the UE 104 may then perform beam training to determine the best receive direction and transmit direction for each of the base station 180 and the UE 104. It is noted that the transmission direction and the reception direction of the base station 180 may be the same or different. Similarly, the transmit direction and the receive direction of the UE 104 may be the same or different.

Example RACH procedure

The Random Access Channel (RACH) is so named because it refers to a radio channel (medium) that can be shared by multiple UEs and used by those UEs to (randomly) access the network for communication. For example, RACH may be used for call setup and access to a network for data transmission. In some cases, RACH may be used for initial access to the network when the UE switches from a Radio Resource Control (RRC) connected idle mode to an active mode, or when switching in an RRC connected mode. Furthermore, RACH may be used for Downlink (DL) and/or Uplink (UL) data arrival when the UE is in RRC idle or RRC inactive mode, and when reestablishing a connection with the network.

Fig. 4 is a call flow diagram 400 illustrating an example four-step RACH procedure in accordance with certain aspects of the present disclosure. A first message 404 (MSG 1) may be sent from the UE 104 to the BS102 on a Physical Random Access Channel (PRACH). In this case, the MSG1 may include only the RACH preamble. BS102 may respond with a Random Access Response (RAR) message 406 (MSG 2), which message 406 may include an Identifier (ID) of the RACH preamble, a Timing Advance (TA), an uplink grant, a cell radio network temporary identifier (C-RNTI), and a Backoff Indicator (BI). MSG2 406 may further include PDCCH communications including control information regarding subsequent communications on the PDSCH (e.g., scheduling receipt of subsequent communications on the PDSCH), as illustrated. In response to MSG2 406, MSG3 408 is transmitted from UE 104 to BS102 on PUSCH. MSG3 408 may include one or more of an RRC connection request, a tracking area update request, a system information request, a location lock or location signal request, or a scheduling request. BS102 then responds with MSG4 410, which may include a contention resolution message. In some cases, the UE 104 may also receive system information 402 (e.g., also referred to herein as a system information message) indicating various communication parameters that may be used by the UE 104 to communicate with the BS102.

Aspects related to DMRS bundling

In some aspects, repetition may be implemented for PUSCH transmissions to enhance coverage, such as MSG3 for RACH procedure as depicted in fig. 4. Repetition of a channel generally refers to a technique of transmitting multiple repetitions of the channel, allowing a receiver to combine the repetitions to facilitate decoding of the channel. In other words, each repetition of a channel may include the same data. Thus, the receiver can combine these repetitions to more reliably decode the data associated with the channel. In some aspects, the repetition may include the same data, but include different redundancy versions. In other words, the same data may be encoded differently for reuse of different redundancy versions.

Aspects of the present disclosure provide systems and methods for determining a bundle size of a demodulation reference signal (DMRS) bundle for repeatedly transmitted uplink Random Access Channel (RACH) messages. Bundling DMRSs (e.g., DMRSs in which the same or coherent DMRSs are transmitted in multiple slots) may also enhance coverage, allowing a base station to consider multiple DMRSs when performing channel estimation. The enhanced channel estimation may further improve the chances of successfully decoding the uplink RACH transmission (e.g., MSG3 408 of fig. 4).

In some aspects, a User Equipment (UE) may be configured to determine a bundle size for a DMRS bundle when repeatedly transmitting an uplink RACH message (e.g., MSG 3), and transmit the uplink RACH message with the DMRS bundle according to the determined bundle size.

For DMRS bundling of PUSCH repetitions, assuming K repetitions, there may be one or more DMRS bundle intervals to cover the K repetitions. In some aspects, for unicast PUSCH, the size of the bundle interval may be configured via Radio Resource Control (RRC) signaling, via Downlink Control (DCI), or may be a function of K.

However, for uplink RACH messages (e.g., MSG 3) that are repeatedly sent, such a configuration may not be available to UEs that have not yet established an RRC connection with the network. Aspects of the present disclosure overcome this problem and provide techniques that allow a UE to determine the DMRS bundle size of an uplink RACH message transmitted with repetition and DMRS bundles.

Fig. 5 is a flowchart illustrating example operations 500 for wireless communication by a UE, in accordance with certain aspects of the present disclosure. The operations 500 may be performed, for example, by a UE (such as the UE 104 in the wireless communication system 100, for example). The operations 500 may be implemented as software components executing and running on one or more processors (e.g., the controller/processor 280 of fig. 2, and in some cases, the repetition manager 281). Further, the signal transmission and reception by the UE in operation 500 may be implemented, for example, by one or more antennas (e.g., antenna 252 of fig. 2). In certain aspects, signal transmission and/or reception by the UE may be achieved via a bus interface of one or more processors (e.g., controller/processor 280) to obtain and/or output signals.

Operation 500 begins with: at block 502, a bundle size of demodulation reference signal (DMRS) bundles for repeatedly transmitted uplink Random Access Channel (RACH) messages is determined.

In block 504, the ue repeatedly transmits an uplink RACH message with a DMRS bundle according to the determined bundle size to the base station over a plurality of slots.

The bundle size may be determined in various ways. In some aspects, the DMRS bundle size may be determined as a function of the number of repetitions of an uplink RACH message (e.g., such as MSG3 in fig. 4). In some aspects, the beam size may be determined based at least in part on the operating frequency band and/or based on the multiplexing mode. For example, different bundling sizes may be determined for a Time Division Duplex (TDD) mode and a Frequency Division Duplex (FDD) mode. In some cases, the beam size may be a function of the number of repetitions K.

In some aspects, the beam size is determined based at least in part on signaling from the base station. Such signaling may include at least one of system information (e.g., via a system information block or SIB), a downlink RACH message (e.g., MSG 2/RAR), or a Physical Downlink Control Channel (PDCCH) for the downlink RACH message. In some cases, the bundling size may be configured at least in part via SIB1, a RAR message, or DCI format 1_0 with a Cyclic Redundancy Check (CRC) scrambled by a radio network temporary identifier (e.g., random access RNTI or RA-RNTI).

Fig. 6 is a flow chart illustrating an example operation 600, which example operation 600 may be considered complementary to the operation 500 of fig. 5. For example, operation 600 may be performed by a BS (e.g., such as BS102 in wireless communication network 100) performing a RACH procedure with a UE performing operation 500 of fig. 5. The operations 600 may be implemented as software components executing and running on one or more processors (e.g., the controller/processor 240 of fig. 2, including the repetition manager 241). Further, signal transmission and reception by the BS in operation 600 may be implemented, for example, by one or more antennas (e.g., antenna 234 of fig. 2). In certain aspects, signal transmission and/or reception by the BS may be achieved via bus interfaces of one or more processors (e.g., controller/processor 240) to obtain and/or output signals.

Operation 600 begins with: at block 602, a bundle size of a demodulation reference signal (DMRS) bundle for an uplink Random Access Channel (RACH) message repeatedly transmitted from a User Equipment (UE) is determined.

In block 604, the bs receives uplink RACH messages repeatedly transmitted from UEs over a plurality of time slots.

In block 606, the bs processes the uplink RACH message based on channel estimation performed in consideration of DMRS transmitted in at least some of the plurality of slots according to the determined beam size.

Operations 500 and 600 of fig. 5 and 6 may be depicted in one example with reference to call flow diagram 700 of fig. 7. In some aspects, BS102 may configure UE 104 via system information for transmitting MSG3PUSCH repetition. The UE 104 may also be configured to perform DMRS bundling when sending MSG3PUSCH repetition to the BS 102.

As illustrated, BS102 may indicate a beam size for the DMRS bundling via system information, RAR (MSG 2), and/or PDCCH for the RAR. At 710, the ue 104 determines a beam size from the system information, the RAR (MSG 2), and/or the PDCCH for the RAR. Then, the UE 104 may transmit an MSG3 repetition with DMRS bundling according to the determined beam size to the BS 102.

At 720, bs102 combines and decodes the MSG3 transmission, e.g., based on channel estimation performed using the bundled DMRS. In other words, the beam size may indicate how many of those with DMRS on different slots are considered together for channel estimation. The beam size (how many repetitions are bundled together) is indicated by the number of available slots or the number of repetitions.

In some cases, the bundle size for DMRS bundles may also depend on whether the repeatedly transmitted MSG3 is an initial transmission or a retransmission. In other words, there may be a relationship between DMRS beam sizes for initial transmission and retransmission.

As illustrated by the call flow diagram 800 of fig. 8, the repeated initial transmission of MSG3 may be transmitted by the UE 104 using the first DMRS bundle size (e.g., determined at 810 in one of the manners described above). The initial transmission may not be successfully decoded by BS102 despite DMRS bundling and repetition. Thus, BS102 may schedule retransmissions.

At 820, the ue 104 determines a DMRS beam size for the retransmission and retransmits an MSG3 repetition with a DMRS bundle to the BS102 according to the determined DMRS beam size.

According to a first option, the indication of the beam size for repeated MSG3 as described above may be applied to both the initial and retransmission. According to a second option, the DMRS bundle configuration may be reconfigured for a retransmission (e.g., DCI format 0_0 scrambled with TC-RNTI via scheduling the retransmission).

In some cases, the reconfiguration may be related to the beam size of the original MSG 3. For example, a larger or scaled beam size may be used for retransmission (e.g., twice the beam size may be indicated). As another example, the beam size may increase proportionally to the increase in the number of MSG3 repetitions (e.g., an initial transmission may have 4 repetitions and a beam size of 2, while a retransmission may have 8 repetitions and a beam size of 4).

Example Wireless communication device

Fig. 9 depicts an example communication device 900 including various components operable, configured, or adapted to perform operations for the techniques disclosed herein, such as operation 500 depicted and described with respect to fig. 5. In some examples, the communication device 900 may be a UE 104, such as the UE 104 described with reference to fig. 1 and 2.

The communication device 900 includes a processing system 902 coupled to a transceiver 908 (e.g., a transmitter and/or receiver). The transceiver 908 is configured to transmit (or send) and receive signals (such as the various signals described herein) for the communication device 900 via the antenna 910. The processing system 902 may be configured to perform processing functions for the communication device 900, including processing signals received and/or to be transmitted by the communication device 900.

The processing system 902 includes one or more processors 904 coupled to a computer-readable medium/memory 912 via a bus 906. In certain aspects, the computer-readable medium/memory 912 is configured to store instructions (e.g., computer-executable code) that, when executed by the one or more processors 904, cause the one or more processors 904 to perform the operations illustrated in fig. 5 or other operations for performing various techniques for channel repetition discussed herein.

In the depicted example, computer-readable medium/memory 912 stores code 914 for determining and code 916 for transmitting.

In some cases, code for determining 914 includes code for determining a bundle size of a demodulation reference signal (DMRS) bundle for repeatedly transmitted uplink Random Access Channel (RACH) messages, such as described with respect to fig. 5.

In some cases, code 916 for transmitting includes code for repeatedly transmitting an uplink RACH message with a DMRS bundle according to the determined bundle size to a base station over a plurality of time slots, such as described with respect to fig. 5.

In the depicted example, the one or more processors 904 include circuitry configured to implement code stored in the computer-readable medium/memory 904, including circuitry 924 for determining and circuitry 926 for transmitting.

In some cases, circuitry 924 for determining includes circuitry for determining a bundle size of a DMRS bundle for repeatedly transmitting an uplink RACH message.

In some cases, the circuitry 926 for transmitting includes circuitry for repeatedly transmitting an uplink RACH message with a DMRS bundling according to the determined bundle size to the base station over a plurality of time slots.

The various components of the communication device 900 may provide means for performing the methods described herein, including the operations 500 with reference to fig. 5.

In some examples, the means for transmitting or sending (or means for outputting for transmission) may include the transceiver 254 and/or antenna(s) 252 of the UE 104 illustrated in fig. 2 and/or the transceiver 908 and antenna 910 of the communication device 900 in fig. 9.

In some examples, the means for receiving (or means for obtaining) may include the transceiver 254 and/or antenna(s) 252 of the UE 104 illustrated in fig. 2 and/or the transceiver 908 and antenna 910 of the communication device 900 in fig. 9.

In some examples, the means for determining and the means for transmitting may include various processing system components, such as: one or more processors 920 in fig. 9, or aspects of the UE 104 depicted in fig. 2, a receive processor 258, a transmit processor 264, a Transmit (TX) MIMO processor 266, and/or a controller/processor 280 (including a repetition manager 281).

It is noted that fig. 9 is merely an example of use, and that many other examples and configurations of communication device 900 are possible.

Fig. 10 depicts an example communication device 1000 that includes various components operable, configured, or adapted to perform operations for the techniques disclosed herein, such as the operations depicted and described with respect to fig. 6. In some examples, communication device 1000 may be BS102, such as BS102 described with reference to fig. 1 and 2.

The communication device 1000 includes a processing system 1002 coupled to a transceiver 1008 (e.g., a transmitter and/or a receiver). The transceiver 1008 is configured to transmit (or send) and receive signals (such as the various signals described herein) for the communication device 1000 via the antenna 1010. The processing system 1002 may be configured to perform processing functions for the communication device 1000, including processing signals received and/or to be transmitted by the communication device 1000.

The processing system 1002 includes one or more processors 1004 coupled to a computer-readable medium/memory 1012 via a bus 1006. In certain aspects, the computer-readable medium/memory 1012 is configured to store instructions (e.g., computer-executable code) that, when executed by the one or more processors 1004, cause the one or more processors 1004 to perform the operations illustrated in fig. 6 or other operations for performing various techniques for channel repetition discussed herein.

In the depicted example, computer-readable medium/memory 1012 stores code 1014 for determining, code 1016 for receiving, and code 1018 for processing.

In some cases, the code 1014 for determining includes code for determining a bundle size of a DMRS bundle for an uplink RACH message repeatedly transmitted from the UE, such as described with respect to fig. 6.

In some cases, code 1016 for receiving includes code for receiving an uplink RACH message repeatedly transmitted from a UE over a plurality of time slots, such as described with respect to fig. 6.

In some cases, code for processing 1018 includes code for processing an uplink RACH message based on channel estimation performed in consideration of DMRS transmitted in at least some of the plurality of slots according to the determined beam size, such as described with respect to fig. 6.

In the depicted example, the one or more processors 1004 include circuitry configured to implement code stored in the computer-readable medium/memory 1012, including circuitry 1024 for determining, circuitry 1026 for receiving, and circuitry for processing.

In some cases, the circuitry 1024 for determining includes circuitry for determining a bundle size of a DMRS bundle for an uplink RACH message repeatedly transmitted from the UE.

In some cases, the circuitry 1026 for receiving includes circuitry for receiving an uplink RACH message repeatedly transmitted from the UE over multiple time slots.

In some cases, the circuitry 1028 for processing includes circuitry for processing the uplink RACH message based on channel estimation performed in view of DMRS transmitted in at least some of the plurality of slots according to the determined beam size.

The various components of the communication device 1000 may provide means for performing the methods described herein, including those described with respect to operation 600 of fig. 6.

In some examples, the means for transmitting or sending (or means for outputting for transmission) may include the transceiver 232 and/or antenna(s) 234 of the base station 102 illustrated in fig. 2 and/or the transceiver 1008 and antenna 1010 of the communication device 1000 in fig. 10.

In some examples, the means for receiving (or means for obtaining) may include the transceiver 232 and/or the antenna(s) 234 of the base station illustrated in fig. 2 and/or the transceiver 1008 and antenna 1010 of the communication device 1000 in fig. 10.

In some examples, the means for determining, the means for receiving, and the means for processing may include various processing system components, such as: one or more processors 1004 in fig. 10, or aspects of BS102 depicted in fig. 2, include a receive processor 238, a transmit processor 220, a Transmit (TX) MIMO processor 230, and/or a controller/processor 240 (including a repetition manager 241).

It is noted that fig. 10 is merely an example of use, and that many other examples and configurations of communication device 1000 are possible.

Example clauses

Examples of implementations are described in the following numbered clauses:

clause 1: a method for wireless communication by a User Equipment (UE), comprising: determining a bundle size of a demodulation reference signal (DMRS) bundle for repeatedly transmitted uplink Random Access Channel (RACH) messages; and repeatedly transmitting the uplink RACH message having the DMRS bundling according to the determined bundle size to a base station over a plurality of slots.

Clause 2: the method of clause 1, wherein: the uplink RACH message is transmitted in a repetition number; and the beam size is determined as a function of the number of repetitions.

Clause 3: the method of any of clauses 1 or 2, further comprising determining the number of repetitions based on at least one of system information, a downlink RACH message, or a Physical Downlink Control Channel (PDCCH) for the downlink RACH message.

Clause 4: the method of any of clauses 1-3, wherein the beam size is determined based at least in part on an operating frequency band.

Clause 5: the method of any of clauses 1-3, wherein the beam size is determined based at least in part on a duplexing mode in which the UE is operating.

Clause 6: the method of any of clauses 1-3, wherein the beam size is determined based at least in part on signaling from the base station.

Clause 7: the method of clause 6, wherein the signaling comprises at least one of system information, a downlink RACH message, or a Physical Downlink Control Channel (PDCCH) for the downlink RACH message.

Clause 8: the method of any of clauses 1-7, wherein the uplink RACH message includes a retransmission of an initial transmission of the uplink RACH message.

Clause 9: the method of clause 8, wherein the same bundle size is applied to both the initial transmission of the uplink RACH message and the retransmission of the uplink RACH message.

Clause 10: the method of clause 8, wherein different bundle sizes are applied to the initial and retransmission of the uplink RACH message.

Clause 11: the method of clause 10, wherein the bundle size applied to the retransmission of the uplink RACH message is relative to the bundle size applied to the initial transmission of the uplink RACH message.

Clause 12: a method for wireless communication by a network entity, comprising: determining a bundle size of a demodulation reference signal (DMRS) bundle for an uplink Random Access Channel (RACH) message repeatedly transmitted from a User Equipment (UE); receiving the uplink RACH message repeatedly transmitted from the UE over a plurality of slots; and processing the uplink RACH message based on channel estimation performed in consideration of DMRS transmitted in at least some of the plurality of slots according to the determined beam size.

Clause 13: the method of clause 12, wherein: the uplink RACH message is transmitted in a repetition number; and the beam size is determined as a function of the number of repetitions.

Clause 14: the method of any of clauses 12 or 13, further comprising signaling an indication of the number of repetitions to the UE via at least one of system information, a downlink RACH message, or a Physical Downlink Control Channel (PDCCH) for the downlink RACH message.

Clause 15: the method of any of clauses 12-14, wherein the beam size is determined based at least in part on an operating frequency band.

Clause 16: the method of any of clauses 12-14, wherein the beam size is determined based at least in part on a duplexing mode in which the network entity is operating.

Clause 17: the method of any of clauses 12-14, wherein the beam size is determined based at least in part on signaling from the base station to the UE.

Clause 18: the method of clause 17, wherein the signaling comprises at least one of system information, a downlink RACH message, or a Physical Downlink Control Channel (PDCCH) for the downlink RACH message.

Clause 19: the method of any of clauses 12-18, wherein the uplink RACH message includes a retransmission of an initial transmission of the uplink RACH message.

Clause 20: the method of clause 19, wherein the same bundle size is applied to both the initial transmission of the uplink RACH message and the retransmission of the uplink RACH message.

Clause 21: the method of clause 19, wherein different bundle sizes are applied to the initial and retransmission of the uplink RACH message.

Clause 22: the method of clause 21, wherein the bundle size applied to the retransmission of the uplink RACH message is relative to the bundle size applied to the initial transmission of the uplink RACH message.

Clause 23: an apparatus comprising a memory containing computer-executable instructions and one or more processors configured to execute the computer-executable instructions and cause the one or more processors to perform the method according to any of clauses 1-22.

Clause 24: an apparatus comprising means for performing the method according to any of clauses 1-22.

Clause 25: a non-transitory computer-readable medium comprising computer-executable instructions that, when executed by one or more processors, cause the one or more processors to perform the method according to any of clauses 1-22.

Clause 26: a computer program product embodied on a computer-readable storage medium, comprising code for performing the method according to any of clauses 1-22.

Additional wireless communication network considerations

The techniques and methods described herein may be used for various wireless communication networks (or Wireless Wide Area Networks (WWANs)) and Radio Access Technologies (RATs). Although aspects may be described herein using terms commonly associated with 3G, 4G, and/or 5G (e.g., 5G New Radio (NR)) wireless technologies, aspects of the present disclosure may be equally applicable to other communication systems and standards not explicitly mentioned herein.

The 5G wireless communication network may support various advanced wireless communication services, such as enhanced mobile broadband (emmbb), millimeter wave (mmWave), machine Type Communication (MTC), and/or ultra-reliable, low latency communication for mission critical (URLLC). These services and other services may include latency and reliability requirements.

Returning to fig. 1, various aspects of the present disclosure may be performed within an example wireless communication network 100.

In 3GPP, the term "cell" can refer to a coverage area of a Node B (NB) and/or an NB subsystem serving the coverage area, depending on the context in which the term is used. In an NR system, the terms "cell" and BS, next generation node BS (gNB or gndeb), access Points (APs), distributed Units (DUs), carriers, or Transmission Reception Points (TRPs) may be used interchangeably. The BS may provide communication coverage for macro cells, pico cells, femto cells, and/or other types of cells.

A macro cell may generally cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A picocell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femtocell may cover a relatively small geographic area (e.g., a residence) and may allow restricted access by UEs associated with the femtocell (e.g., UEs in a Closed Subscriber Group (CSG) and UEs of users in the residence). The BS for a macro cell may be referred to as a macro BS. The BS for a pico cell may be referred to as a pico BS. The BS for a femto cell may be referred to as a femto BS or a home BS.

A base station 102 configured for 4G LTE, collectively referred to as an evolved Universal Mobile Telecommunications System (UMTS) terrestrial radio access network (E-UTRAN), may interface with the EPC 160 through a first backhaul link 132 (e.g., an S1 interface). A base station 102 configured for 5G (e.g., 5G NR or next generation RAN (NG-RAN)) may interface with a core network 190 over a second backhaul link 184. The base stations 102 may communicate with each other directly or indirectly (e.g., through the EPC 160 or the core network 190) over a third backhaul link 134 (e.g., an X2 interface). The third backhaul link 134 may be generally wired or wireless.

The small cell 102' may operate in licensed and/or unlicensed spectrum. When operating in unlicensed spectrum, the small cell 102' may employ NR and use the same 5GHz unlicensed spectrum as that used by the Wi-Fi AP 150. Small cells 102' employing NR in the unlicensed spectrum may push up access network coverage and/or increase access network capacity.

Some base stations, such as the gNB 180, may operate in the legacy sub-6 GHz spectrum, millimeter wave (mmWave) frequencies, and/or near mmWave frequencies to be in communication with the UE 104. When the gNB 180 operates in mmWave or near mmWave frequencies, the gNB 180 may be referred to as a mmWave base station.

The communication link 120 between the base station 102 and, for example, the UE 104 may be over one or more carriers. For example, for each carrier allocated in carrier aggregation up to yxmhz (x component carriers) in total for transmission in each direction, base station 102 and UE 104 may use a spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100, 400MHz, and other MHz) bandwidth. These carriers may or may not be contiguous with each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated to DL than UL). The component carriers 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 carrier may be referred to as a secondary cell (SCell).

The wireless communication system 100 further includes a Wi-Fi Access Point (AP) 150 in communication with Wi-Fi Stations (STAs) 152 via a communication link 154 in, for example, a 2.4GHz and/or 5GHz unlicensed spectrum. When communicating in the unlicensed spectrum, the STA 152/AP 150 may perform a Clear Channel Assessment (CCA) prior to communication to determine whether a channel is available.

Some UEs 104 may communicate with each other using a device-to-device (D2D) communication link 158. The D2D communication link 158 may use the DL/UL WWAN spectrum. The D2D communication link 158 may use one or more side link channels such as a physical side link broadcast channel (PSBCH), a physical side link discovery channel (PSDCH), a physical side link shared channel (PSSCH), and a physical side link control channel (PSCCH). D2D communication may be through a variety of wireless D2D communication systems such as, for example, flashLinQ, wiMedia, bluetooth, zigBee, wi-Fi based on the IEEE 802.11 standard, 4G (e.g., LTE), or 5G (e.g., NR), just to name a few options.

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.MME 162 may be in communication with a Home Subscriber Server (HSS) 174. The MME 162 is a control node that handles signaling between the UE 104 and the EPC 160. Generally, MME 162 provides bearer and connection management.

In general, user Internet Protocol (IP) packets are communicated through the serving gateway 166, with the serving gateway 166 itself being connected to the PDN gateway 172. The PDN gateway 172 provides UE IP address allocation as well as other functions. The PDN gateway 172 and BM-SC 170 are connected to IP services 176, which IP services 176 may include, for example, the internet, intranets, IP Multimedia Subsystems (IMS), PS streaming services, and/or other IP services.

The BM-SC 170 may provide functionality for MBMS user service provisioning and delivery. The BM-SC 170 may be used 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 traffic to base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service and may be responsible for session management (start/stop) and for collecting eMBMS related charging information.

The core network 190 may include access and mobility management functions (AMFs) 192, other AMFs 193, session Management Functions (SMFs) 194, and User Plane Functions (UPFs) 195. The AMF 192 may be in communication with a Unified Data Management (UDM) 196.

The AMF 192 is typically a control node that handles signaling between the UE 104 and the core network 190. In general, AMF 192 provides QoS flows and session management.

All user Internet Protocol (IP) packets are transported through the UPF 195, the UPF 195 being connected to the IP service 197 and providing UE IP address assignment and other functions for the core network 190. The IP services 197 may include, for example, the internet, an intranet, an IP Multimedia Subsystem (IMS), PS streaming services, and/or other IP services.

Returning to fig. 2, various example components of BS102 and UE 104 (e.g., wireless communication network 100 of fig. 1) that may be configured to implement aspects of the present disclosure are depicted.

At BS102, transmit processor 220 may receive data from data source 212 and control information from controller/processor 240. The control information may be for a Physical Broadcast Channel (PBCH), a Physical Control Format Indicator Channel (PCFICH), a physical hybrid ARQ indicator channel (PHICH), a Physical Downlink Control Channel (PDCCH), a group common PDCCH (GC PDCCH), and others. In some examples, the data may be for a Physical Downlink Shared Channel (PDSCH).

A Medium Access Control (MAC) -control element (MAC-CE) is a MAC layer communication structure that may be used for control command exchange between wireless nodes. The MAC-CE may be carried in a shared channel, such as a Physical Downlink Shared Channel (PDSCH), a Physical Uplink Shared Channel (PUSCH), or a physical side link shared channel (PSSCH).

Processor 220 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The transmit processor 220 may also generate reference symbols, such as for a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), a PBCH demodulation reference signal (DMRS), and a channel state information reference signal (CSI-RS).

A Transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to Modulators (MODs) 232a-232t in the transceiver. Each modulator 232a-232t in the transceiver may process a respective output symbol stream (e.g., for OFDM) to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Downlink signals from modulators 232a-232t in the transceivers may be transmitted via antennas 234a-234t, respectively.

At the UE 104, antennas 252a-252r may receive the downlink signals from the BS102 and may provide received signals to demodulators (DEMODs) 254a-254r, respectively, in a transceiver. Each demodulator 254a-254r in the transceiver may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator may further process the input samples (e.g., for OFDM) to obtain received symbols.

MIMO detector 256 may obtain received symbols from all of the demodulators 254a-254r in the transceiver, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data to the UE 104 to a data sink 260, and provide decoded control information to a controller/processor 280.

On the uplink, at the UE 104, a transmit processor 264 may receive and process data from a data source 262 (e.g., for a Physical Uplink Shared Channel (PUSCH)) and control information from a controller/processor 280 (e.g., for a Physical Uplink Control Channel (PUCCH)). The transmit processor 264 may also generate reference symbols for a reference signal, e.g., a Sounding Reference Signal (SRS). The symbols from transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by modulators 254a-254r in the transceiver (e.g., for SC-FDM), and transmitted to BS102.

At BS102, uplink signals from UEs 104 may be received by antennas 234a-t, processed by demodulators 232a-232t in a transceiver, detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by UEs 104. The receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to a controller/processor 240.

Memories 242 and 282 may store data and program codes for BS102 and UE 104, respectively.

The scheduler 244 may schedule UEs for data transmission on the downlink and/or uplink.

The 5G may utilize Orthogonal Frequency Division Multiplexing (OFDM) with Cyclic Prefix (CP) on uplink and downlink. 5G may also support half duplex operation using Time Division Duplex (TDD). OFDM and single carrier frequency division multiplexing (SC-FDM) divide the system bandwidth into a plurality of orthogonal subcarriers, which are also commonly referred to as tones and bins. Each subcarrier may be modulated with data. The modulation symbols may be transmitted with OFDM in the frequency domain and SC-FDM in the time domain. The spacing between adjacent subcarriers may be fixed and the total number of subcarriers may depend on the system bandwidth. In some examples, the minimum resource allocation, referred to as a Resource Block (RB), may be 12 consecutive subcarriers. The system bandwidth may also be divided into sub-bands. For example, one subband may cover multiple RBs. NR may support a 15KHz base subcarrier spacing (SCS) and other SCSs may be defined relative to the base SCS (e.g., 30KHz, 60KHz, 120KHz, 240KHz, and others).

As above, fig. 3A-3D depict various example aspects of a data structure for a wireless communication network, such as wireless communication network 100 of fig. 1.

In aspects, the 5G NR frame structure may be Frequency Division Duplex (FDD), where for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated to DL or UL. The 5G frame structure may also be Time Division Duplex (TDD), where for a particular set of subcarriers (carrier system bandwidth), the subframes within the set of subcarriers are dedicated to both DL and UL. In the example provided by fig. 3A and 3C, the 5G frame structure is assumed to be TDD, with subframe 4 configured with slot format 28 (mostly DL) and subframe 3 configured with slot format 34 (mostly UL), where D is DL, U is UL, and X is flexible for use between DL/UL. Although subframes 3, 4 are shown as having slot formats 34, 28, respectively, any particular subframe may be configured with any of a variety of available slot formats 0-61. The slot formats 0, 1 are full DL, full UL, respectively. Other slot formats 2-61 include a mix of DL, UL, and flexible symbols. The UE is configured with a slot format (dynamically configured by DL Control Information (DCI) or semi-statically/statically configured by Radio Resource Control (RRC) signaling) through a received Slot Format Indicator (SFI). Note that the following description also applies to a 5G frame structure that is TDD.

Other wireless communication technologies may have different frame structures and/or different channels. A frame (10 ms) may be divided into 10 equally sized subframes (1 ms). Each subframe may include one or more slots. The subframe may also include a mini slot, which may include 7, 4, or 2 symbols. In some examples, each slot may include 7 or 14 symbols, depending on the slot configuration.

For example, for slot configuration 0, each slot may include 14 symbols, and for slot configuration 1, each slot may include 7 symbols. The symbol on DL may be a Cyclic Prefix (CP) OFDM (CP-OFDM) symbol. The symbols on the UL may be CP-OFDM symbols (for high throughput scenarios) or Discrete Fourier Transform (DFT) -spread OFDM (DFT-s-OFDM) symbols (also known as single carrier frequency division multiple access (SC-FDMA) symbols) (for power limited scenarios; limited to single stream transmission).

The number of slots within a subframe is based on slot configuration and parameter design. For slot configuration 0, different parameter designs (μ) 0 through 5 allow 1, 2, 4, 8, 16, and 32 slots per subframe, respectively. For slot configuration 1, different parameter designs 0 through 2 allow 2, 4, and 8 slots per subframe, respectively. Accordingly, for slot configuration 0 and parameter design μ, there are 14 symbols per slot and 2 per subframe ^μ And each time slot. Subcarrier spacing and symbol length/duration are a function of parameter design. The subcarrier spacing may be equal to 2 ^μ 15kHz, where μ is the parameter design 0 to 5. Thus, parameter design μ=0 has a subcarrier spacing of 15kHz, while parameter design μ=5 has a subcarrier spacing of 480 kHz. Symbol length/duration and subcarriersThe wave intervals are inversely related. Fig. 3A-3D provide examples of a slot configuration 0 having 14 symbols per slot and a parameter design μ=2 having 4 slots per subframe. The slot duration is 0.25ms, the subcarrier spacing is 60kHz, and the symbol duration is approximately 16.67 mus.

The resource grid may be used to represent a frame structure. Each slot includes Resource Blocks (RBs) (also referred to as Physical RBs (PRBs)) that extend for 12 consecutive subcarriers. The resource grid is divided into a plurality of Resource Elements (REs). The number of bits carried by each RE depends on the modulation scheme.

As illustrated in fig. 3A, some REs carry reference (pilot) signals (RSs) for UEs (e.g., UE 104 of fig. 1 and 2). The RS may include a demodulation RS (DMRS) (indicated as R for one particular configuration) for channel estimation at the UE _x Where 100x is a port number, but other DMRS configurations are possible) and a channel state information reference signal (CSI-RS). The RSs may also include beam measurement RSs (BRSs), beam Refinement RSs (BRRSs), and phase tracking RSs (PT-RSs).

Fig. 3B illustrates an example of various DL channels within a subframe of a frame. A Physical Downlink Control Channel (PDCCH) carries DCI within one or more Control Channel Elements (CCEs), each CCE including 9 RE groups (REGs), each REG including 4 consecutive REs in an OFDM symbol.

The Primary Synchronization Signal (PSS) may be within symbol 2 of a particular subframe of a frame. PSS is used by UEs (e.g., 104 of fig. 1 and 2) to determine subframe/symbol timing and physical layer identity.

The Secondary Synchronization Signal (SSS) may be within symbol 4 of a particular subframe of a frame. SSS is used by the UE to determine the physical layer cell identity group number and radio frame timing.

Based on the physical layer identity and the physical layer cell identity group number, the UE may determine a Physical Cell Identifier (PCI). Based on the PCI, the UE may determine the location of the aforementioned DMRS. A Physical Broadcast Channel (PBCH) carrying a Master Information Block (MIB) may be logically grouped with PSS and SSS to form a Synchronization Signal (SS)/PBCH block. The MIB provides the number of RBs in the system bandwidth, and a System Frame Number (SFN). The Physical Downlink Shared Channel (PDSCH) carries user data, broadcast system information such as System Information Blocks (SIBs) not transmitted over the PBCH, and paging messages.

As illustrated in fig. 3C, some REs carry DMRS for channel estimation at the base station (indicated as R for one particular configuration, but other DMRS configurations are possible). The UE may transmit DMRS for a Physical Uplink Control Channel (PUCCH) and DMRS for a Physical Uplink Shared Channel (PUSCH). The PUSCH DMRS may be transmitted in the first one or two symbols of the PUSCH. The PUCCH DMRS may be transmitted in different configurations depending on whether a short PUCCH or a long PUCCH is transmitted and depending on the specific PUCCH format used. The UE may transmit Sounding Reference Signals (SRS). The SRS may be transmitted in the last symbol of the subframe. The SRS may have a comb structure, and the UE may transmit the SRS on one of the comb. The SRS may be used by the base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

Fig. 3D illustrates examples of various UL channels within a subframe of a frame. The PUCCH may be located as indicated in one configuration. The PUCCH carries Uplink Control Information (UCI) such as a scheduling request, a Channel Quality Indicator (CQI), a Precoding Matrix Indicator (PMI), a Rank Indicator (RI), and HARQ ACK/NACK feedback. PUSCH carries data and may additionally be used to carry Buffer Status Reports (BSR), power Headroom Reports (PHR), and/or UCI.

Additional considerations

The following description provides examples of channel repetition in a communication system. The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. The examples discussed herein are not limiting of the scope, applicability, or aspects set forth in the claims. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. For example, changes may be made in the function and arrangement of elements discussed without departing from the scope of the disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Moreover, features described with reference to some examples may be combined in some other examples. For example, an apparatus may be implemented or a method practiced using any number of the aspects set forth herein. In addition, the scope of the present disclosure is intended to cover such an apparatus or method practiced using other structure, functionality, or both, that is complementary to, or different from, the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of the claims.

The techniques described herein may be used for various wireless communication techniques such as 5G (e.g., 5G NR), 3GPP Long Term Evolution (LTE), LTE-advanced (LTE-a), code Division Multiple Access (CDMA), time Division Multiple Access (TDMA), frequency Division Multiple Access (FDMA), orthogonal Frequency Division Multiple Access (OFDMA), single carrier frequency division multiple access (SC-FDMA), time division synchronous code division multiple access (TD-SCDMA), and other networks. The terms "network" and "system" are often used interchangeably. CDMA networks may implement technologies such as Universal Terrestrial Radio Access (UTRA), CDMA2000, and other radios. UTRA includes Wideband CDMA (WCDMA) and other variations of CDMA. cdma2000 covers IS-2000, IS-95, and IS-856 standards. TDMA networks may implement radio technologies such as global system for mobile communications (GSM). OFDMA networks may implement technologies such as NR (e.g., 5G RA), evolved UTRA (E-UTRA), ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, flash-OFDMA, and other radio technologies. UTRA and E-UTRA are parts of Universal Mobile Telecommunications System (UMTS). LTE and LTE-a are versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-a and GSM are described in the literature from an organization named "third generation partnership project" (3 GPP). cdma2000 and UMB are described in literature from an organization named "third generation partnership project 2" (3 GPP 2). NR is an emerging wireless communication technology under development.

The various illustrative logical blocks, modules, and circuits described in connection with the disclosure herein may be implemented or performed with a general purpose processor, a DSP, an ASIC, a Field Programmable Gate Array (FPGA) or other Programmable Logic Device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, a system-on-a-chip (SoC), or any other such configuration.

If implemented in hardware, an example hardware configuration may include a processing system in a wireless node. The processing system may be implemented with a bus architecture. The bus may include any number of interconnecting buses and bridges depending on the specific application of the processing system and the overall design constraints. The bus may link together various circuits including processors, machine-readable media, and bus interfaces. A bus interface may be used to connect network adapters and the like to the processing system via the bus. The network adapter may be used to implement the signal processing functions of the PHY layer. In the case of user equipment (see fig. 1), user interfaces (e.g., keypad, display, mouse, joystick, touch screen, biometric sensor, proximity sensor, light emitting element, and others) may also be connected to the bus. The bus may also link various other circuits such as timing sources, peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further. A processor may be implemented with one or more general-purpose and/or special-purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuitry capable of executing software. Those skilled in the art will recognize how best to implement the functionality described with respect to the processing system, depending on the particular application and the overall design constraints imposed on the overall system.

If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Software should be construed broadly to mean instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. The processor may be responsible for managing the bus and general processing, including the execution of software modules stored on a machine-readable storage medium. A computer readable storage medium may be coupled to a processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. By way of example, machine-readable media may comprise a transmission line, a carrier wave modulated by data, and/or a computer-readable storage medium having instructions stored thereon, separate from the wireless node, all of which may be accessed by a processor through a bus interface. Alternatively or additionally, the machine-readable medium, or any portion thereof, may be integrated into the processor, such as the cache and/or general purpose register file, as may be the case. By way of example, a machine-readable storage medium may comprise RAM (random access memory), flash memory, ROM (read only memory), PROM (programmable read only memory), EPROM (erasable programmable read only memory), EEPROM (electrically erasable programmable read only memory), registers, a magnetic disk, an optical disk, a hard drive, or any other suitable storage medium, or any combination thereof. The machine-readable medium may be implemented in a computer program product.

A software module may comprise a single instruction, or many instructions, and may be distributed over several different code segments, among different programs, and across multiple storage media. The computer readable medium may include a plurality of software modules. These software modules include instructions that, when executed by equipment (such as a processor), cause a processing system to perform various functions. These software modules may include a transmit module and a receive module. Each software module may reside in a single storage device or be distributed across multiple storage devices. As an example, when a trigger event occurs, the software module may be loaded into RAM from a hard drive. During execution of the software module, the processor may load some instructions into the cache to increase access speed. One or more cache lines may then be loaded into a general purpose register file for execution by the processor. Where functionality of a software module is described below, it will be understood that such functionality is implemented by a processor when executing instructions from the software module.

As used herein, a phrase referring to a list of items "at least one of" refers to any combination of these items, including individual members. As an example, "at least one of a, b, or c" is intended to encompass: a. b, c, a-b, a-c, b-c, and a-b-c, as well as any combination having multiple identical elements (e.g., a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b-b, b-b-c, c-c, and c-c-c, or any other ordering of a, b, and c).

As used herein, the term "determining" encompasses a wide variety of actions. For example, "determining" may include calculating, computing, processing, deriving, researching, looking up (e.g., looking up in a table, database, or another data structure), ascertaining, and the like. Also, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in memory), and the like. Also, "determining" may include parsing, selecting, choosing, establishing, and the like.

The methods disclosed herein comprise one or more steps or actions for achieving the method. These method steps and/or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims. Furthermore, the various operations of the above-described methods may be performed by any suitable means capable of performing the corresponding functions. These means may comprise various hardware and/or software components and/or modules including, but not limited to, circuits, application Specific Integrated Circuits (ASICs), or processors. Generally, where there are operations illustrated in the figures, these operations may have corresponding counterpart means-plus-function components with similar numbers.

The following claims are not intended to be limited to the aspects shown herein but are to be accorded the full scope consistent with the language of the claims. Within the claims, reference to an element in the singular is not intended to mean "one and only one" (unless specifically so stated) but rather "one or more". The term "some" means one or more unless specifically stated otherwise. No element of a claim should be construed under the specification of 35u.s.c. ≡112 (f) unless the element is explicitly recited using the phrase "means for … …" or in the case of method claims the element is recited using the phrase "step for … …". The elements of the various aspects described throughout this disclosure are all structural and functional equivalents that are presently or later to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Furthermore, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.

Claims (20)

1. A method for wireless communication by a user equipment, comprising:

Determining a bundle size of a demodulation reference signal (DMRS) bundle for repeatedly transmitted uplink Random Access Channel (RACH) messages; and

the uplink RACH message having a DMRS bundle according to the determined bundle size is repeatedly transmitted to a base station over a plurality of slots.

2. The method of claim 1, wherein:

the uplink RACH message is transmitted in a repetition number; and is also provided with

The beam size is determined as a function of the number of repetitions.

3. The method of claim 2, further comprising determining the number of repetitions based on at least one of system information, a downlink RACH message, or a Physical Downlink Control Channel (PDCCH) for the downlink RACH message.

4. The method of claim 1, wherein the beam size is determined based at least in part on an operating frequency band of the user equipment.

5. The method of claim 1, wherein the beam size is determined based at least in part on a duplexing mode in which the user equipment is operating.

6. The method of claim 1, wherein the beam size is determined based at least in part on signaling from the base station.

7. The method of claim 6, wherein the signaling comprises at least one of system information, a downlink RACH message, or a Physical Downlink Control Channel (PDCCH) for the downlink RACH message.

8. The method of claim 1, wherein the uplink RACH message comprises a retransmission of an initial transmission of the uplink RACH message.

9. The method of claim 8, wherein the same bundle size is applied for both the initial transmission of the uplink RACH message and the retransmission of the uplink RACH message.

10. The method of claim 8, wherein different beam sizes are applied to the initial transmission and the retransmission of the uplink RACH message.

11. A user equipment configured for wireless communication, comprising: a memory including computer-executable instructions; and one or more processors configured to execute the computer-executable instructions and cause the user equipment to:

determining a bundle size of a demodulation reference signal (DMRS) bundle for repeatedly transmitted uplink Random Access Channel (RACH) messages; and

The uplink RACH message having a DMRS bundle according to the determined bundle size is repeatedly transmitted to a base station over a plurality of slots.

12. A non-transitory computer-readable medium comprising computer-executable instructions that, when executed by one or more processors of a user equipment, cause the user equipment to perform a method of wireless communication, the method comprising:

determining a bundle size of a demodulation reference signal (DMRS) bundle for repeatedly transmitted uplink Random Access Channel (RACH) messages; and

the uplink RACH message having a DMRS bundle according to the determined bundle size is repeatedly transmitted to a base station over a plurality of slots.

13. A method for wireless communication by a base station, comprising:

determining a bundle size of a demodulation reference signal (DMRS) bundle for an uplink Random Access Channel (RACH) message repeatedly transmitted from a User Equipment (UE);

receiving the uplink RACH message repeatedly transmitted from the UE over a plurality of slots; and

the uplink RACH message is processed based on channel estimation performed in consideration of DMRS transmitted in at least some of the plurality of slots according to the determined beam size.

14. The method of claim 13, wherein:

the uplink RACH message is transmitted in a repetition number; and is also provided with

The beam size is determined as a function of the number of repetitions.

15. The method of claim 14, further comprising signaling an indication of the number of repetitions to the UE via at least one of system information, a downlink RACH message, or a Physical Downlink Control Channel (PDCCH) for the downlink RACH message.

16. The method of claim 13, wherein the beam size is determined based at least in part on an operating frequency band.

17. The method of claim 13, wherein the beam size is determined based at least in part on a duplexing mode in which the base station is operating.

18. The method of claim 13, wherein the beam size is determined based at least in part on signaling from the base station to the UE.

19. The method of claim 18, wherein the signaling comprises at least one of system information, a downlink RACH message, or a Physical Downlink Control Channel (PDCCH) for the downlink RACH message.

20. The method of claim 13, wherein the uplink RACH message comprises a retransmission of an initial transmission of the uplink RACH message.