Repetition of downlink control channels based on uplink messages

The aspects described herein may enable a base station to repeat a downlink control channel based on one or more indications received from a user equipment (UE). This may allow the base station to efficiently use network resources to enhance coverage of downlink control channels for different steps of a network access procedure as needed by a UE. For example, a UE may determine to activate or deactivate repetition of a downlink control channel associated with a network access procedure. The UE may transmit an indication configured to activate or deactivate repetition of the downlink control channel.

BACKGROUND

Technical Field

The present disclosure relates generally to communication systems, and more particularly, to repetition of downlink control channels based on uplink (UL) messages.

INTRODUCTION

SUMMARY

A base station may repeat a downlink (DL) control channel for a message (e.g., a message to a user equipment (UE) on a physical downlink shared channel (PDSCH)) to enhance coverage in a cell. For example, the DL control channel may be associated with a message for a network access procedure. Depending on network conditions and/or other factors, however, downlink control channels for some messages may need less repetition than downlink control channels for other messages. The aspects described herein may enable a base station to selectively repeat a downlink control channel based on one or more indications received from a UE. This may allow the base station to efficiently use network resources to enhance coverage of downlink control channels for different stages of a network access procedure as needed by a UE.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus determines to activate or deactivate repetition of a downlink control channel associated with a network access procedure. The apparatus transmits an indication configured to activate or deactivate repetition of the downlink control channel.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus receives, from a user equipment (UE), an indication configured to activate or deactivate repetition of the downlink control channel associated with a network access procedure. The apparatus repeats the downlink control channel or not repeating the downlink control channel based on the indication.

DETAILED DESCRIPTION

The electromagnetic spectrum is often subdivided, based on frequency/wavelength, into various classes, bands, channels, etc. In 5G NR two initial operating bands have been identified as frequency range designations FR1 (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz). It should be understood that although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “sub 6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a “millimeter wave” band in documents and articles, despite being different from the extremely high frequency (EHF) band which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band. EHF is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters.

Referring again toFIG.1, in certain aspects, the UE104may be configured to transmit an indication configured to activate or deactivate repetition of a downlink control channel associated with a network access procedure (198). Although the following description may be focused on 5G NR, the concepts described herein may be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

FIG.4is a signal flow diagram illustrating an example network access procedure400performed between a UE (e.g., UE402) and a base station (e.g., base station404). The network access procedure400may be a 4-step random access (RA) procedure and may be initiated by the UE402for initial access to the network (e.g., to achieve UL synchronization with the base station404). As shown inFIG.4, the UE402may receive cell detection information406from the base station404. In some aspects of the disclosure, the cell detection information406may include a synchronization signal (SS)/PBCH block (SSB) and random access channel (RACH) configuration information.

The UE402may initiate the network access procedure400by transmitting a PRACH preamble in message 1 (Msg1)408. Upon detection of the PRACH preamble, the base station404may transmit a message 2 (Msg2)410including a random access response (RAR). The base station404may use a PDCCH for scheduling and a PDSCH for transmitting the message 2410. The RAR in the message 2 (Msg2)410may include a UL grant for the UE402. The UE402may use the UL grant to transmit a message 3 (Msg3)412including a radio resource control (RRC) connection request on the PUSCH. The base station404may transmit a contention resolution via the message 4 (Msg4)414using the PDCCH for scheduling and the PDSCH for transmitting the message 4414. The UE402may transmit an uplink (UL) message416(e.g., on PUSCH) after receiving the message 4 (Msg4)414.

A base station may transmit a downlink (DL) control channel, such as a broadcast PDCCH, during one or more steps of a network access procedure, such as the previously described 4-step random access procedure inFIG.4. For example, a base station may transmit a broadcast PDCCH for remaining minimum system information (RMSI), a broadcast PDCCH for message 2 (Msg2)410, and/or a broadcast PDCCH for message 4 (Msg4)414. In some scenarios, a downlink (DL) control channel may need coverage enhancement in 5G NR (e.g., in FR2). A base station may achieve such coverage enhancement by repeating the DL control channel.

Broadcast PDCCHs for some messages, however, may need less repetition (e.g., due to an additional enhancement or required resources) than broadcast PDCCHs for other messages. The aspects described herein may enable a base station to selectively repeat a downlink (DL) control channel associated with a network access procedure based on one or more indications received from a UE. This may allow the base station to efficiently use network resources to enhance coverage of broadcast PDCCHs for different steps of a network access procedure as needed by a UE.

The term “broadcast PDCCH” as used herein may refer to a PDCCH transmitted from a base station to a UE before an RRC connection is established with the UE. A broadcast PDCCH from a base station may be intended for the UE that transmitted a physical random access channel (PRACH) preamble. For example, a PDCCH transmitted to a UE (e.g., the UE402) from a base station (e.g., the base station4040) during a network access procedure (e.g., the previously described 4-step random access procedure inFIG.4) may be considered a broadcast PDCCH.

FIG.5is a signal flow diagram illustrating repetition of a downlink control channel associated with a network access procedure based on an uplink message in accordance with various aspects of the disclosure. At502, the base station404may obtain configuration information including a set of indications for activating or deactivating repetition of a set of downlink control channels (also referred to as a set of repeatable downlink control channels). In some examples, the set of indications may include at least one indication for each different downlink control channel in the set of downlink control channels. In some aspects of the disclosure, the set of downlink control channels may be associated with a network access procedure (e.g., the previously described 4-step random access procedure inFIG.4) that may be performed with the UE402.

The base station404may be configured to repeat a downlink control channel m times, where m is a positive integer. In some aspects of the disclosure, the base station may determine the value of m from either a standard specification being implemented by the base station404, system information provided to the base station404, an indication for activating repetition of the downlink control channel received from the UE402, or from a previously received message. In some aspects of the disclosure, when repetition of a downlink control channel is activated, the base station404may repeat the same downlink control channel (e.g., the same PDCCH) over multiple monitoring occasions of the downlink control channel (e.g., over multiple monitoring occasions of the PDCCH).

In some examples, the set of downlink control channels that may be repeated from the base station404(e.g., the set of repeatable downlink control channels) may include at least one of a physical downlink control channel (PDCCH) for remaining minimum system information (RMSI), a PDCCH for a random access response message (e.g., message 2 (Msg 2)410inFIG.4), a PDCCH for a retransmission grant of a radio resource connection (RRC) connection setup message, a PDCCH for a contention resolution message (e.g., message 4 (Msg 4)414inFIG.4), or a unicast PDCCH before a channel state information (CSI) report is transmitted from the UE402.

In some examples, the set of indications may include at least one of a physical random access channel (PRACH) preamble from a preconfigured subset of PRACH preambles, a PRACH preamble repeated over multiple random access channel (RACH) occasions, a PRACH preamble on a predefined subset of RACH occasions, a PRACH preamble using a designated resource allocation (e.g., a resource allocation from a designated set of frequency allocations or resource blocks), a request or a predefined message in a radio resource connection (RRC) connection request message (e.g., message 3 (Msg 3)412inFIG.4), and/or a first uplink transmission after reception of a contention resolution message (e.g., the first UL message416after message 4 (Msg4)414inFIG.4).

In one example, the base station404may be configured to repeat a PDCCH for a random access response message (e.g., a broadcast PDCCH for message 2 (Msg2) 410) and/or a PDCCH for a retransmission grant of a radio resource connection (RRC) connection setup message (e.g., a broadcast PDCCH for a transmission grant of message 3 (Msg3)412) when the UE402transmits a PRACH preamble (e.g., in the message 1 (Msg1)408) from a preconfigured subset of PRACH preambles, a PRACH preamble repeated over multiple RACH occasions, a PRACH preamble on a predefined subset of RACH occasions, or a PRACH preamble with a designated resource allocation (e.g., a predefined frequency allocation or a predefined resource block allocation).

In another example, the base station404may be configured to repeat a PDCCH for a contention resolution message (e.g., a broadcast PDCCH for message 4 (Msg4) 414) and/or a unicast PDCCH before a channel state information (CSI) report transmission from the UE402when the UE402includes an explicit request or a predefined message in a radio resource connection (RRC) connection request message (e.g., message 3 (Msg 3)412inFIG.4). In some examples, the base station404may be configured to deactivate repetition of the PDCCH for a contention resolution message (e.g., a broadcast PDCCH for message 4 (Msg4)414) and/or a unicast PDCCH before a channel state information (CSI) report transmission from the UE402when the UE402includes an implied indication to deactivate repetition of the PDCCH for a contention resolution message. For example, the implied indication may be a beam reporting in the radio resource connection (RRC) connection request message (e.g., a message 3 (Msg 3)412inFIG.4), in which case the base station404may deactivate repetition of the PDCCH for a contention resolution message (e.g., a broadcast PDCCH for message 4 (Msg4)414).

The base station404may transmit a message504including the configuration information. In some aspects of the disclosure, the base station404may optionally transmit a message505including an identifier (e.g., a unique k-bit identifier discussed herein with reference toFIG.6) associated with the configuration information.

The UE402may receive the message504and may obtain the configuration information from the message504. At506, the UE402may determine to activate repetition of a downlink control channel associated with a network access procedure. In some aspects of the disclosure, the UE402may determine to activate repetition of a downlink control channel based on channel conditions (e.g., based on one or more signal measurements). In one example, the UE402may determine to activate repetition of a downlink control channel based on a reference signal received power (RSRP) measurement for an SSB. In this example, the UE402may determine to activate repetition of a downlink control channel if the RSRP measurement is less than a threshold. In some examples, the type of signal measurement and/or value of the threshold to be applied by the UE402for the determination may be configured by the base station404or may be selected by the UE402.

In another example, the UE402may determine to activate repetition of a downlink control channel based on at least one criterion received from the base station404. For example, during a random access procedure (e.g., the 4-step RA procedure previously described with reference toFIG.4), the base station404may transmit a message 2 (e.g., message 2 (Msg 2)410inFIG.4) that includes at least one criterion (e.g., a type of signal to be measured by the UE402and a threshold for that signal) to be applied by the UE402when determining to activate repetition for a PDCCH using message 3 (e.g., a message 3 (Msg 3)412inFIG.4).

In some examples, the type of signal measurement and/or value of the threshold to applied by the UE402for the determination to activate repetition of a downlink control channel may be configured by the base station404(e.g., via system information) or may be selected by the UE402. In other examples, the UE402may use a combination of any of the previously described measurements and thresholds when determining to activate repetition of a downlink control channel. In some examples, the UE402may use the type of signal measurement and/or value of the threshold when determining whether to deactivate repetition of a downlink control channel (e.g., in scenarios where the UE402may have previously activated repetition of a downlink control channel, but may no longer need any further repetitions of downlink control channels based on current channel measurements).

At508, the UE402may select an indication configured to activate repetition of the downlink control channel from the set of indications in the configuration information. The UE402may transmit a message510including the selected indication. For example, the message510may be the message 1 (Msg1)408of the previously described 4-step random access procedure inFIG.4and may include a PRACH preamble from a preconfigured subset of PRACH preambles. The base station404may be configured to repeat the PDCCH for a next message of a network access procedure (e.g., for the message 2 (Msg2)410of the 4-step random access procedure) in response to receiving a PRACH preamble from the preconfigured subset of PRACH preambles.

At512, the base station404may determine to repeat the downlink control channel for a next message of the network access procedure based on the indication. In some aspects of the disclosure, the base station404may automatically repeat the downlink control channel for the next message of the network access procedure after receiving the indication in the message510. In other aspects of the disclosure, the base station404may determine whether or not to repeat the downlink control channel for the next message of the network access procedure based on one or more conditions defined by the network.

For example, if the indication in the message510includes a PRACH preamble from a preconfigured subset of PRACH preambles, the base station404may determine to repeat the PDCCH for the next message of the network access procedure (e.g., for the message 2 (Msg2)410of the 4-step random access procedure). Accordingly, the base station404may transmit the downlink control channel514for the next message of the network access procedure (e.g., for the message 2 (Msg2)410of the 4-step random access procedure), followed by a first repetition516of the downlink control channel. As shown inFIG.5, the base station404may send up to an Nth repetition518of the downlink control channel. In some aspects of the disclosure, the value of N may be predefined in a standard specification being implemented by the base station404.

In some aspects of the disclosure, if the base station404has the option of determining whether or not to repeat the downlink control channel for the next message of the network access procedure after receiving the indication in the message510, the UE402may perform blind decoding to decode the downlink control channel (e.g., to obtain control information in the downlink control channel). In this case, the UE402may be expected to perform blind decoding by considering that the downlink control channel may or may not be repeated. For example, the UE402may perform a first blind decoding operation for the downlink control channel based on an assumption that the downlink control channel will not be repeated, and may perform a second blind decoding operation for the downlink control channel based on an assumption that the downlink control channel will be repeated.

In some aspects of the disclosure, if the message510is the first message of a network access procedure (e.g., message 1 (Msg1)408of the 4-step random access procedure inFIG.4) and includes an indication for activating repetition of a downlink control channel, the base station404may repeat the downlink control channels for any of the subsequent messages (e.g., PDCCH for message 2 (Msg2)410, and PDCCH for message 4 (Msg4)414) of the network access procedure.

For example, if the indication in the message510includes a PRACH preamble from a preconfigured subset of PRACH preambles, the base station404may determine to repeat the PDCCH for the next message of the network access procedure (e.g., for the message 2 (Msg2)410of the 4-step random access procedure). Accordingly, the base station404may transmit the downlink control channel514for the next message of the network access procedure (e.g., for the message 2 (Msg2)410of the 4-step random access procedure), followed by a first repetition516of the downlink control channel. As shown inFIG.5, the base station404may send up to an Nth repetition518of the downlink control channel.

In some aspects of the disclosure, the configuration information may be structured in tabular form. For example,FIG.6illustrates an example configuration information table600including a row identifier field602, a downlink control channel field604, an indication field606, and a rules and/or parameters field608. In some examples, and as described in detail herein, the configuration information table600may describe the indication that the UE402may transmit to activate or deactivate repetition of a particular downlink control channel. Moreover, the configuration information table600may further describe any additional rules and/or parameters for controlling the repetition of a downlink control channel.

The row identifier field602may include a unique k-bit identifier for each row (e.g., first row610, second row612, eighth row614) of the configuration information table600. In the example ofFIG.6, the k-bit identifier is a 3-bit identifier. In other examples, the k-bit identifier may be less than a 3-bit identifier or greater than a 3-bit identifier.

The downlink control channel field604may include downlink control channels that may be repeated by a base station (e.g., the base station404), where the downlink control channels are associated with a network access procedure. The indication field606may include an indication for activating or deactivating repetition of a downlink control channel. The rules/parameters field608may include rules and/or parameters that may control the repetition of a downlink control channel.

In one example, the first row610of the configuration information table600having row identifier ‘000’ may indicate that repetition of the PDCCH for message 2 of a random access procedure (e.g., for the message 2 (Msg2)410of the 4-step random access procedure) may be activated by transmitting a PRACH preamble with Type A format.

In another example, the second row612of the configuration information table600having row identifier ‘001’ may indicate that repetition of the PDCCH for message 2 and the PDCCH for message 4 of a random access procedure (e.g., for message 2 (Msg2)410and message 4 (Msg4)414of the 4-step random access procedure inFIG.4) may be activated by transmitting a PRACH preamble with a Type B format. As indicated in the rules/parameters field608for row identifier ‘001’, beam reporting from the UE402in message 3 on PUSCH may deactivate repetition of the PDCCH for Message 4.

In another example, the eighth row614of the configuration information table600having row identifier ‘111’ may indicate that repetition of a unicast PDCCH before the UE402transmits a CSI report may be activated by transmitting a PRACH preamble with a Type C format.

In some aspects of the disclosure, the base station404may transmit a row identifier in RMSI to the UE402to indicate which downlink control channels may be repeated (e.g., to indicate a set of repeatable downlink control channels), the indication for activating or deactivating repetition of those downlink control channels, and any rules/parameters for controlling the repetition of those downlink control channels. For example, the base station404may transmit the bits ‘001’ (assigned to the second row612in the configuration information table600) to the UE402in RMSI. This may inform the UE402that transmission of a PRACH preamble with Type B format may serve as an indication for activating repetition of the PDCCH for message 2 and the PDCCH for message 4 of a random access procedure (e.g., for message 2 (Msg2)410and message 4 (Msg4)414of the 4-step random access procedure inFIG.4). Moreover, the UE402may be aware that beam reporting in message 3 (e.g., in the message 3 (Msg3)412of the 4-step random access procedure) on PUSCH deactivates repetition of PDCCH for message 4 (e.g., for the message 4 (Msg4)414of the 4-step random access procedure inFIG.4).

FIG.7is a flowchart700of a method of wireless communication. The method may be performed by a UE (e.g., the UE402; the apparatus902/902′; the processing system1014, which may include the memory360and which may be the entire UE402or a component of the UE402, such as the TX processor368, the RX processor356, and/or the controller/processor359).

At702, the UE determines to activate or deactivate repetition of a downlink control channel associated with a network access procedure. In some aspects of the disclosure, the UE determines to activate or deactivate repetition of a downlink control channel associated with a network access procedure by obtaining configuration information including a set of repeatable downlink control channels and a set of indications for activating or deactivating repetition of one or more downlink control channels in the set of repeatable downlink control channels. The UE may then select the downlink control channel from the set of repeatable downlink control channels and may select the indication configured to activate or deactivate repetition of the downlink control channel from the set of indications. In some examples, the configuration information may include the configuration information table600. In some examples, and as described with reference to506inFIG.5, the UE may determine to activate repetition of a downlink control channel based on channel conditions (e.g., based on one or more signal measurements).

In some aspects of the disclosure, the set of repeatable downlink control channels includes at least one of a physical downlink control channel (PDCCH) for remaining minimum system information (RMSI), a physical downlink control channel (PDCCH) for a random access response message, a physical downlink control channel (PDCCH) for a retransmission grant of a radio resource connection (RRC) connection setup message, a physical downlink control channel (PDCCH) for a contention resolution message, or a unicast physical downlink control channel (PDCCH) before a channel state information (CSI) report is transmitted from the UE.

In some aspects of the disclosure, the set of indications includes at least one of a physical random access channel (PRACH) preamble from a preconfigured subset of PRACH preambles, a PRACH preamble repeated over multiple random access channel (RACH) occasions, a PRACH preamble on a predefined subset of RACH occasions, a PRACH preamble using a designated resource allocation, a request or a predefined message in a radio resource connection (RRC) connection request message, or a first uplink transmission after reception of a contention resolution message. For example, the predefined message may include a beam report and may be configured to deactivate repetition of the downlink control channel.

In some aspects of the disclosure, the configuration information may include at least one rule for controlling repetition of the downlink control channel. For example, the at least one rule may be included in a rules and/or parameters field of a configuration information table (e.g., the rules and/or parameters field608of the configuration information table600described with reference toFIG.6).

Finally, at704, the UE transmits an indication configured to activate or deactivate repetition of the downlink control channel. In some aspects of the disclosure, the indication may be configured to activate or deactivate repetition of the downlink control channel for one or more subsequent messages of the network access procedure from the base station. For example, with reference toFIG.5, if the indication (e.g., in the message510) from the UE402includes a PRACH preamble from a preconfigured subset of PRACH preambles, the base station404may determine to repeat the PDCCH for the next message of the network access procedure (e.g., for the message 2 (Msg2)410of the 4-step random access procedure). Accordingly, the base station404may transmit the downlink control channel514for the next message of the network access procedure (e.g., for the message 2 (Msg2)410of the 4-step random access procedure), followed by a first repetition516of the downlink control channel. As shown inFIG.5, the base station404may send up to an Nth repetition518of the downlink control channel. In some aspects of the disclosure, the downlink control channel is automatically repeated for a predefined number of repetitions in response to the transmitted indication.

FIG.8is a flowchart800of a method of wireless communication. The method may be performed by a UE (e.g., the UE402; the apparatus902/902′; the processing system1014, which may include the memory360and which may be the entire UE402or a component of the UE402, such as the TX processor368, the RX processor356, and/or the controller/processor359).

At802, the UE receives a unique identifier associated with a set of repeatable downlink control channels and a set of indications for activating or deactivating repetition of the one or more downlink control channels in the set of repeatable downlink control channels. For example, the unique identifier may be the unique k-bit identifier for each row (e.g., first row610, second row612, eighth row614) of the configuration information table600.

At804, the UE determines to activate or deactivate repetition of a downlink control channel associated with a network access procedure. In some aspects of the disclosure, the UE determines to activate or deactivate repetition of a downlink control channel associated with a network access procedure by obtaining configuration information including a set of repeatable downlink control channels and a set of indications for activating or deactivating repetition of one or more downlink control channels in the set of repeatable downlink control channels. The UE may then select the downlink control channel from the set of repeatable downlink control channels and may select the indication configured to activate or deactivate repetition of the downlink control channel from the set of indications. In some examples, the configuration information may include the configuration information table600. In some examples, and as described with reference to506inFIG.5, the UE may determine to activate repetition of a downlink control channel based on channel conditions (e.g., based on one or more signal measurements).

In some aspects of the disclosure, the set of repeatable downlink control channels includes at least one of a physical downlink control channel (PDCCH) for remaining minimum system information (RMSI), a physical downlink control channel (PDCCH) for a random access response message, a physical downlink control channel (PDCCH) for a retransmission grant of a radio resource connection (RRC) connection setup message, a physical downlink control channel (PDCCH) for a contention resolution message, or a unicast physical downlink control channel (PDCCH) before a channel state information (CSI) report is transmitted from the UE.

In some aspects of the disclosure, the set of indications includes at least one of a physical random access channel (PRACH) preamble from a preconfigured subset of PRACH preambles, a PRACH preamble repeated over multiple random access channel (RACH) occasions, a PRACH preamble on a predefined subset of RACH occasions, a PRACH preamble using a designated resource allocation, a request or a predefined message in a radio resource connection (RRC) connection request message, or a first uplink transmission after reception of a contention resolution message. For example, the predefined message may include a beam report and may be configured to deactivate repetition of the downlink control channel.

In some aspects of the disclosure, the configuration information may include at least one rule for controlling repetition of the downlink control channel. For example, the at least one rule may be included in a rules and/or parameters field of a configuration information table (e.g., the rules and/or parameters field608of the configuration information table600described with reference toFIG.6).

At806, the UE transmits an indication configured to activate or deactivate repetition of the downlink control channel. In some aspects of the disclosure, the indication may be configured to activate or deactivate repetition of the downlink control channel for one or more subsequent messages of the network access procedure from the base station. For example, with reference toFIG.5, if the indication (e.g., in the message510) from the UE402includes a PRACH preamble from a preconfigured subset of PRACH preambles, the base station404may determine to repeat the PDCCH for the next message of the network access procedure (e.g., for the message 2 (Msg2)410of the 4-step random access procedure). Accordingly, the base station404may transmit the downlink control channel514for the next message of the network access procedure (e.g., for the message 2 (Msg2)410of the 4-step random access procedure), followed by a first repetition516of the downlink control channel. As shown inFIG.5, the base station404may send up to an Nth repetition518of the downlink control channel. In some aspects of the disclosure, the downlink control channel is automatically repeated for a predefined number of repetitions in response to the transmitted indication.

At808, the UE performs a first blind decoding operation for the downlink control channel based on an assumption that the downlink control channel will not be repeated. The UE may perform the first blind decoding operation to obtain control information included in the downlink control channel.

Finally, at810, the UE performs a second blind decoding operation for the downlink control channel based on an assumption that the downlink control channel will be repeated. The UE may perform the second blind decoding operation to obtain control information included in the downlink control channel.

FIG.9is a conceptual data flow diagram900illustrating the data flow between different means/components in an example apparatus902. The apparatus may be a UE. The apparatus includes a reception component904that receives (e.g., from the base station950) configuration information including a set of repeatable downlink control channels and a set of indications for activating or deactivating repetition of one or more downlink control channels in the set of repeatable downlink control channels. The reception component904further receives a unique identifier associated with the set of repeatable downlink control channels and the set of indications for activating or deactivating repetition of the one or more downlink control channels in the set of repeatable downlink control channels. The reception component904further receives a reference signal (e.g., a reference signal, such as an SSB, which allows the apparatus to perform a signal measurement, such as a reference signal received power (RSRP) measurement).

The apparatus further includes a downlink control channel repetition activation or deactivation determination component906that determines to activate or deactivate repetition of a downlink control channel associated with a network access procedure. In some examples, the downlink control channel repetition activation or deactivation determination component906may perform a signal measurement (e.g., an RSRP measurement) and may determine to activate repetition of a downlink control channel based on the signal measurement (e.g., an RSRP measurement). In this example, the UE402may determine to activate repetition of a downlink control channel if the RSRP measurement is less than a threshold. In some examples, the type of signal measurement and/or value of the threshold to applied by the UE402for the determination may be configured by the base station404or may be selected by the UE402.

In some aspects of the disclosure, the downlink control channel repetition activation or deactivation determination component906may be configured to obtain configuration information (e.g., via the reception component904). The configuration information may include a set of repeatable downlink control channels and a set of indications for activating or deactivating repetition of one or more downlink control channels in the set of repeatable downlink control channels. The downlink control channel repetition activation or deactivation determination component906may select the downlink control channel from the set of repeatable downlink control channels, and may select the indication configured to activate or deactivate repetition of the downlink control channel from the set of indications.

The apparatus further includes a blind decoding performance component908that performs a first blind decoding operation for the downlink control channel (e.g., PDCCH for a message of a network access procedure) based on an assumption that the downlink control channel will not be repeated, and that performs a second blind decoding operation for the downlink control channel based on an assumption that the downlink control channel will be repeated, and a transmission component910that transmits an indication configured to activate or deactivate repetition of the downlink control channel.

FIG.10is a diagram1000illustrating an example of a hardware implementation for an apparatus902′ employing a processing system1014. The processing system1014may be implemented with a bus architecture, represented generally by the bus1024. The bus1024may include any number of interconnecting buses and bridges depending on the specific application of the processing system1014and the overall design constraints. The bus1024links together various circuits including one or more processors and/or hardware components, represented by the processor1004, the components904,906,908,910and the computer-readable medium/memory1006. The bus1024may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

The processing system1014may be coupled to a transceiver1010. The transceiver1010is coupled to one or more antennas1020. The transceiver1010provides a means for communicating with various other apparatus over a transmission medium. The transceiver1010receives a signal from the one or more antennas1020, extracts information from the received signal, and provides the extracted information to the processing system1014, specifically the reception component904. In addition, the transceiver1010receives information from the processing system1014, specifically the transmission component910, and based on the received information, generates a signal to be applied to the one or more antennas1020. The processing system1014includes a processor1004coupled to a computer-readable medium/memory1006. The processor1004is responsible for general processing, including the execution of software stored on the computer-readable medium/memory1006. The software, when executed by the processor1004, causes the processing system1014to perform the various functions described supra for any particular apparatus. The computer-readable medium/memory1006may also be used for storing data that is manipulated by the processor1004when executing software. The processing system1014further includes at least one of the components904,906,908,910. The components may be software components running in the processor1004, resident/stored in the computer readable medium/memory1006, one or more hardware components coupled to the processor1004, or some combination thereof. The processing system1014may be a component of the UE350and may include the memory360and/or at least one of the TX processor368, the RX processor356, and the controller/processor359. Alternatively, the processing system1014may be the entire UE (e.g., see350ofFIG.3).

In one configuration, the apparatus902/902′ for wireless communication includes means for determining, at the UE, to activate or deactivate repetition of a downlink control channel associated with a network access procedure, means for transmitting an indication configured to activate or deactivate repetition of the downlink control channel, means for receiving a unique identifier associated with the set of repeatable downlink control channels and the set of indications for activating or deactivating repetition of the one or more downlink control channels in the set of repeatable downlink control channels, means for performing a first blind decoding operation for the downlink control channel based on an assumption that the downlink control channel will not be repeated, and means for performing a second blind decoding operation for the downlink control channel based on an assumption that the downlink control channel will be repeated. The aforementioned means may be one or more of the aforementioned components of the apparatus902and/or the processing system1014of the apparatus902′ configured to perform the functions recited by the aforementioned means. As described supra, the processing system1014may include the TX Processor368, the RX Processor356, and the controller/processor359. As such, in one configuration, the aforementioned means may be the TX Processor368, the RX Processor356, and the controller/processor359configured to perform the functions recited by the aforementioned means.

FIG.11is a flowchart1100of a method of wireless communication. The method may be performed by a base station (e.g., the base station404; the apparatus1302/1302′; the processing system1414, which may include the memory376and which may be the entire base station404or a component of the base station404, such as the TX processor316, the RX processor370, and/or the controller/processor375).

At1102, the base station receives, from a user equipment (UE), an indication configured to activate or deactivate repetition of the downlink control channel associated with a network access procedure. For example, with reference toFIG.5, the indication received from the UE may be the selected indication included in message510, and the network access procedure may be the 4-step random access procedure400shown inFIG.4.

In some examples, the indication may be from a set of indications including at least one of a physical random access channel (PRACH) preamble from a preconfigured subset of PRACH preambles, a PRACH preamble repeated over multiple random access channel (RACH) occasions, a PRACH preamble on a predefined subset of RACH occasions, a PRACH preamble using a designated resource allocation, a request or a predefined message in a radio resource connection (RRC) connection request message, or a first uplink transmission after reception of a contention resolution message.

In some examples, the downlink control channel may be from a set of repeatable downlink control channels including at least one of a physical downlink control channel (PDCCH) for remaining minimum system information (RMSI), a physical downlink control channel (PDCCH) for a random access response message, a physical downlink control channel (PDCCH) for a retransmission grant of a radio resource connection (RRC) connection setup message, a physical downlink control channel (PDCCH) for a contention resolution message, or a unicast physical downlink control channel (PDCCH) before a channel state information (CSI) report is transmitted from the UE.

Finally, at1104, the base station repeats the downlink control channel or does not repeat the downlink control channel based on the indication. For example, with reference to512,514,516inFIG.5, the base station404may automatically repeat the downlink control channel for the next message of the network access procedure after receiving the indication in the message510. In other aspects of the disclosure, the base station404may determine whether or not to repeat the downlink control channel for the next message of the network access procedure based on one or more conditions defined by the network.

FIG.12is a flowchart1200of a method of wireless communication. The method may be performed by a base station (e.g., the base station406; the apparatus1302/1302′; the processing system1414, which may include the memory376and which may be the entire base station406or a component of the base station406, such as the TX processor316, the RX processor370, and/or the controller/processor375).

At1202, the base station obtains configuration information including a set of repeatable downlink control channels and a set of indications for activating or deactivating repetition of one or more downlink control channels in the set of repeatable downlink control channels.

For example, with reference to502inFIG.5, the base station404may obtain configuration information including a set of indications for activating or deactivating repetition of a set of downlink control channels (also referred to as a set of repeatable downlink control channels). In some examples, the set of indications may include at least one indication for each different downlink control channel in the set of downlink control channels. In some aspects of the disclosure, the set of downlink control channels may be associated with a network access procedure (e.g., the previously described 4-step random access procedure inFIG.4) that may be performed with the UE402. In some examples, the configuration information may include the configuration information table600previously described with reference toFIG.6.

In some examples, the set of repeatable downlink control channels includes at least one of a physical downlink control channel (PDCCH) for remaining minimum system information (RMSI), a physical downlink control channel (PDCCH) for a random access response message, a physical downlink control channel (PDCCH) for a retransmission grant of a radio resource connection (RRC) connection setup message, a physical downlink control channel (PDCCH) for a contention resolution message, or a unicast physical downlink control channel (PDCCH) before a channel state information (CSI) report is transmitted from the UE.

In some examples, the set of indications includes at least one of a physical random access channel (PRACH) preamble from a preconfigured subset of PRACH preambles, a PRACH preamble repeated over multiple random access channel (RACH) occasions, a PRACH preamble on a predefined subset of RACH occasions, a PRACH preamble using a designated resource allocation, a request or a predefined message in a radio resource connection (RRC) connection request message, or a first uplink transmission after reception of a contention resolution message.

At1204, the base station transmits the configuration information to the UE.

At1206, the base station transmits a unique identifier associated with the set of repeatable downlink control channels and the set of indications for activating or deactivating repetition of the one or more downlink control channels in the set of repeatable downlink control channels. For example, the unique identifier may be one of the unique k-bit identifiers for each row (e.g., first row610, second row612, eighth row614) of the configuration information table600.

At1208, the base station receives, from a user equipment (UE), an indication configured to activate or deactivate repetition of the downlink control channel associated with a network access procedure. For example, with reference toFIG.5, the indication received from the UE may be the selected indication included in message510, and the network access procedure may be the 4-step random access procedure400shown inFIG.4.

Finally, at1210, the base station repeats the downlink control channel or does not repeat the downlink control channel based on the indication. For example, with reference toFIG.5, if the indication (e.g., in the message510) from the UE402includes a PRACH preamble from a preconfigured subset of PRACH preambles, the base station404may determine to repeat the PDCCH for the next message of the network access procedure (e.g., for the message 2 (Msg2)410of the 4-step random access procedure). Accordingly, the base station404may transmit the downlink control channel514for the next message of the network access procedure (e.g., for the message 2 (Msg2)410of the 4-step random access procedure), followed by a first repetition516of the downlink control channel. As shown inFIG.5, the base station404may send up to an Nth repetition518of the downlink control channel. In some aspects of the disclosure, the downlink control channel is automatically repeated for a predefined number of repetitions in response to the transmitted indication. In other aspects of the disclosure, the base station404may determine whether or not to repeat the downlink control channel for the next message of the network access procedure based on one or more conditions defined by the network.

FIG.13is a conceptual data flow diagram1300illustrating the data flow between different means/components in an example apparatus1302. The apparatus may be a base station.

The apparatus includes a reception component1304that receives (e.g., from the UE1350) an indication configured to activate or deactivate repetition of a downlink control channel associated with a network access procedure. The reception component1304may further receive configuration information (e.g., from a network) including a set of repeatable downlink control channels and a set of indications for activating or deactivating repetition of one or more downlink control channels in the set of repeatable downlink control channels.

The apparatus further includes a configuration information obtaining component1306that obtains the configuration information including a set of repeatable downlink control channels and a set of indications for activating or deactivating repetition of one or more downlink control channels in the set of repeatable downlink control channels. The configuration information obtaining component1306may output a unique identifier associated with the set of repeatable downlink control channels and the set of indications for activating or deactivating repetition of the one or more downlink control channels in the set of repeatable downlink control channels

The apparatus further includes a downlink control channel repetition component1308that repeats the downlink control channel (e.g., PDCCH for a message of a network access procedure) or does not repeat the downlink control channel based on the indication. In some aspects of the disclosure, the downlink control channel repetition component1308may use the indication from the UE1350and the configuration information to determine the downlink control channel and to determine whether the downlink control channel is to be repeated.

The apparatus further includes a transmission component1310that transmits the configuration information to the UE1350, transmits a unique identifier associated with the set of repeatable downlink control channels and the set of indications for activating or deactivating repetition of the one or more downlink control channels in the set of repeatable downlink control channels, and transmits the configuration information.

FIG.14is a diagram1400illustrating an example of a hardware implementation for an apparatus1302′ employing a processing system1414. The processing system1414may be implemented with a bus architecture, represented generally by the bus1424. The bus1424may include any number of interconnecting buses and bridges depending on the specific application of the processing system1414and the overall design constraints. The bus1424links together various circuits including one or more processors and/or hardware components, represented by the processor1404, the components1304,1306,1308,1310and the computer-readable medium/memory1406. The bus1424may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

The processing system1414may be coupled to a transceiver1410. The transceiver1410is coupled to one or more antennas1420. The transceiver1410provides a means for communicating with various other apparatus over a transmission medium. The transceiver1410receives a signal from the one or more antennas1420, extracts information from the received signal, and provides the extracted information to the processing system1414, specifically the reception component1304. In addition, the transceiver1410receives information from the processing system1414, specifically the transmission component1310, and based on the received information, generates a signal to be applied to the one or more antennas1420. The processing system1414includes a processor1404coupled to a computer-readable medium/memory1406. The processor1404is responsible for general processing, including the execution of software stored on the computer-readable medium/memory1406. The software, when executed by the processor1404, causes the processing system1414to perform the various functions described supra for any particular apparatus. The computer-readable medium/memory1406may also be used for storing data that is manipulated by the processor1404when executing software. The processing system1414further includes at least one of the components1304,1306,1308,1310. The components may be software components running in the processor1404, resident/stored in the computer readable medium/memory1406, one or more hardware components coupled to the processor1404, or some combination thereof. The processing system1414may be a component of the base station310and may include the memory376and/or at least one of the TX processor316, the RX processor370, and the controller/processor375. Alternatively, the processing system1414may be the entire base station (e.g., see310ofFIG.3).

In one configuration, the apparatus1302/1302′ for wireless communication includes means for receiving an indication configured to activate or deactivate repetition of the downlink control channel associated with a network access procedure, means for repeating the downlink control channel or not repeating the downlink control channel based on the indication, means for obtaining configuration information including a set of repeatable downlink control channels and a set of indications for activating or deactivating repetition of one or more downlink control channels in the set of repeatable downlink control channels, means for transmitting the configuration information to the UE, means for transmitting a unique identifier associated with the set of repeatable downlink control channels and the set of indications for activating or deactivating repetition of the one or more downlink control channels in the set of repeatable downlink control channels. The aforementioned means may be one or more of the aforementioned components of the apparatus1302and/or the processing system1414of the apparatus1302′ configured to perform the functions recited by the aforementioned means. As described supra, the processing system1414may include the TX Processor316, the RX Processor370, and the controller/processor375. As such, in one configuration, the aforementioned means may be the TX Processor316, the RX Processor370, and the controller/processor375configured to perform the functions recited by the aforementioned means.

Therefore, the aspects described herein may enable a base station to selectively repeat a downlink control channel associated with a message for a network access procedure based on one or more indications received from a UE. Accordingly, the base station may efficiently use network resources to enhance coverage of downlink control channels for different messages of a network access procedure as needed by a UE. Since a UE may activate or deactivate repetition of a downlink control channel using certain messages of a network access procedure (e.g., a physical random access channel (PRACH) preamble from a preconfigured subset of PRACH preambles, a request or a predefined message in a radio resource connection (RRC) connection request message (e.g., message 3 (Msg 3)412inFIG.4), etc.), the aspects described herein may be implemented with low complexity and without a significant increase in signaling overhead.

Broadcast PDCCHs for some messages, however, may need less repetition (e.g., due to an additional enhancement or required resources) than broadcast PDCCHs for other messages. The aspects described herein may enable a base station to It is understood that the specific order or hierarchy of blocks in the processes/flowcharts disclosed is an illustration of example approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes/flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

Example 1: A method of wireless communication for a user equipment (UE), comprising: determining, at the UE, to activate or deactivate repetition of a downlink control channel associated with a network access procedure; and transmitting an indication configured to activate or deactivate repetition of the downlink control channel.

Example 2: The method of example 1, wherein the determining to activate or deactivate repetition of the downlink control channel comprises: obtaining configuration information including a set of repeatable downlink control channels and a set of indications for activating or deactivating repetition of one or more downlink control channels in the set of repeatable downlink control channels; selecting the downlink control channel from the set of repeatable downlink control channels; and selecting the indication configured to activate or deactivate repetition of the downlink control channel from the set of indications.

Example 3: The method of example 2, wherein the set of repeatable downlink control channels includes at least one of a physical downlink control channel (PDCCH) for remaining minimum system information (RMSI), a physical downlink control channel (PDCCH) for a random access response message, a physical downlink control channel (PDCCH) for a retransmission grant of a radio resource connection (RRC) connection setup message, a physical downlink control channel (PDCCH) for a contention resolution message, or a unicast physical downlink control channel (PDCCH) before a channel state information (CSI) report is transmitted from the UE.

Example 4: The method of example 2 or 3, wherein the set of indications includes at least one of a physical random access channel (PRACH) preamble from a preconfigured subset of PRACH preambles, a PRACH preamble repeated over multiple random access channel (RACH) occasions, a PRACH preamble on a predefined subset of RACH occasions, a PRACH preamble using a designated resource allocation, a request or a predefined message in a radio resource connection (RRC) connection request message, or a first uplink transmission after reception of a contention resolution message.

Example 5: The method of example 4, wherein the predefined message includes a beam report, and wherein the predefined message is configured to deactivate repetition of the downlink control channel.

Example 6: The method of any of examples 2 through 4, further comprising: receiving a unique identifier associated with the set of repeatable downlink control channels and the set of indications for activating or deactivating repetition of the one or more downlink control channels in the set of repeatable downlink control channels.

Example 7: The method of any of examples 2 through 6, wherein the configuration information includes at least one rule for controlling repetition of the downlink control channel.

Example 8: The method of any of examples 1 through 7, wherein the downlink control channel is automatically repeated for a predefined number of repetitions in response to the transmitted indication.

Example 9: The method of any of examples 1 through 8, further comprising: performing a first blind decoding operation for the downlink control channel based on an assumption that the downlink control channel will not be repeated; and performing a second blind decoding operation for the downlink control channel based on an assumption that the downlink control channel will be repeated.

Example 10: The method of examples 1 through 9, wherein the indication is configured to activate or deactivate repetition of the downlink control channel for one or more subsequent messages of the network access procedure from the base station.

Example 11: An apparatus for wireless communication, comprising: a memory; and at least one processor coupled to the memory and configured to perform a method of any one of examples of 1 through 10.

Example 12: A method of wireless communication for a base station, comprising: receiving, from a user equipment (UE), an indication configured to activate or deactivate repetition of the downlink control channel associated with a network access procedure; and repeating the downlink control channel or not repeating the downlink control channel based on the indication.

Example 13: The method of example 12, further comprising: obtaining configuration information including a set of repeatable downlink control channels and a set of indications for activating or deactivating repetition of one or more downlink control channels in the set of repeatable downlink control channels; and transmitting the configuration information to the UE.

Example 14: The method of example 13, wherein the set of repeatable downlink control channels includes at least one of a physical downlink control channel (PDCCH) for remaining minimum system information (RMSI), a physical downlink control channel (PDCCH) for a random access response message, a physical downlink control channel (PDCCH) for a retransmission grant of a radio resource connection (RRC) connection setup message, a physical downlink control channel (PDCCH) for a contention resolution message, or a unicast physical downlink control channel (PDCCH) before a channel state information (CSI) report is transmitted from the UE.

Example 15: The method of example 13 or 14, wherein the set of indications includes at least one of a physical random access channel (PRACH) preamble from a preconfigured subset of PRACH preambles, a PRACH preamble repeated over multiple random access channel (RACH) occasions, a PRACH preamble on a predefined subset of RACH occasions, a PRACH preamble using a designated resource allocation, a request or a predefined message in a radio resource connection (RRC) connection request message, or a first uplink transmission after reception of a contention resolution message.

Example 16: The method of example 15, wherein the predefined message includes a beam report, and wherein the predefined message is configured to deactivate repetition of the downlink control channel.

Example 17: The method of any of examples 14 through 16, further comprising: transmitting a unique identifier associated with the set of repeatable downlink control channels and the set of indications for activating or deactivating repetition of the one or more downlink control channels in the set of repeatable downlink control channels.

Example 18: The method of any of examples 13 through 17, wherein the configuration information includes at least one rule for controlling repetition of the downlink control channel.

Example 19: The method of any of examples 12 through 18, wherein the downlink control channel is automatically repeated for a predefined number of repetitions in response to the transmitted indication.

Example 20: The method of any of examples 12 through 18, wherein the downlink control channel is repeated or not repeated for one or more subsequent messages of the network access procedure.

Example 21: An apparatus for wireless communication, comprising: a memory; and at least one processor coupled to the memory and configured to perform a method of any one of examples of 12 through 20.