Techniques for assisted message decoding

Methods, systems, and devices for wireless communications are described. In some systems, a user equipment (UE) may transmit a first random access preamble to a base station and may transmit a payload associated with the first random access preamble via a first random access message as part of a two-step random access procedure. The base station may receive the first random access message and attempt to detect the first random access preamble. The base station may identify multiple random access preamble indices based on a detected random access preamble and may perform multiple decoding attempts on the payload portion of the first random access message using the multiple random access preamble indices. The base station may perform the multiple decoding attempts sequentially until one decoding attempt is successful or may perform the multiple decoding attempts in parallel.

FIELD OF DISCLOSURE

The following relates to wireless communications, including techniques for assisted message decoding.

BACKGROUND

In some systems, a UE may attempt to establish a connection with a base station via a random access procedure. Such a random access procedure may include a two-step random access procedure or a four-step random access procedure.

SUMMARY

The present disclosure relates to improved methods, systems, devices, and apparatuses that support techniques for assisted message decoding. In some implementations, the present disclosure provides for multiple decoding attempts, at a base station, on a payload portion of a first random access message using multiple different preamble indices. For example, a UE may transmit the first random access message, which may be an example of a message A (msgA), including a first random access preamble and a payload. The base station may receive the first random access message and, in some scenarios, may have a relatively high likelihood for detecting a different random access preamble than the first random access preamble transmitted by the UE. For example, although the UE transmits the first random access preamble, the base station may detect a second random access preamble. In some implementations, the base station may attempt to decode the payload using the detected second random access preamble and may additionally attempt to decode the payload using one or more random access preambles that are adjacent to the second random access preamble. In some aspects, such one or more adjacent random access preambles may include or refer to random access preambles having adjacent or nearby cyclic shifts or time shifts relative to a cyclic shift or time shift of the detected second random access preamble.

A method for wireless communication at a first device is described. The method may include receiving, from a second device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel, performing a first decoding attempt for the payload using a second random access preamble index, the first decoding attempt being performed in response to receiving the first random access message, performing a second decoding attempt for the payload using a first random access preamble index associated with the first random access preamble, and transmitting, to the second device, a random access response message that includes an indication of the first random access preamble index, the transmitting of the random access response message based on successfully performing the second decoding attempt.

An apparatus for wireless communication at a first device is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive, from a second device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel, perform a first decoding attempt for the payload using a second random access preamble index, the first decoding attempt being performed in response to receiving the first random access message, perform a second decoding attempt for the payload using a first random access preamble index associated with the first random access preamble, and transmit, to the second device, a random access response message that includes an indication of the first random access preamble index, the transmitting of the random access response message based on successfully performing the second decoding attempt.

Another apparatus for wireless communication at a first device is described. The apparatus may include means for receiving, from a second device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel, means for performing a first decoding attempt for the payload using a second random access preamble index, the first decoding attempt being performed in response to receiving the first random access message, means for performing a second decoding attempt for the payload using a first random access preamble index associated with the first random access preamble, and means for transmitting, to the second device, a random access response message that includes an indication of the first random access preamble index, the transmitting of the random access response message based on successfully performing the second decoding attempt.

A non-transitory computer-readable medium storing code for wireless communication at a first device is described. The code may include instructions executable by a processor to receive, from a second device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel, perform a first decoding attempt for the payload using a second random access preamble index, the first decoding attempt being performed in response to receiving the first random access message, perform a second decoding attempt for the payload using a first random access preamble index associated with the first random access preamble, and transmit, to the second device, a random access response message that includes an indication of the first random access preamble index, the transmitting of the random access response message based on successfully performing the second decoding attempt.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for detecting a second random access preamble based on a reception time associated with the first random access message, where performing the first decoding attempt for the payload using the second random access preamble index may be based on detecting the second random access preamble.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, at a Layer 1 (L1) entity of the first device from a Layer 2 (L2) entity of the first device, a set of multiple random access preamble indices including the first random access preamble index and the second random access preamble index, where performing the first decoding attempt and the second decoding attempt may be based on receiving the set of multiple random access preamble indices.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the set of multiple random access preamble indices include the second random access preamble index and one or more adjacent random access preamble indices from a set of available random access preamble indices that may be associated with a same root sequence index as the second random access preamble index.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the one or more adjacent random access preamble indices that may be associated with the same root sequence may be identified from the set of available random access preamble indices based on one or more of a zero correlation zone configuration, a length of a random access sequence, a random access channel format, and a random access channel sub-carrier spacing.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the set of multiple random access preamble indices include the second random access preamble index and one or more adjacent random access preamble indices from a set of available random access preamble indices that may be associated with different root sequence indices.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, from the L1 entity to the L2 entity, an indication of the second random access preamble index based on detecting a second random access preamble, where receiving the set of multiple random access preamble indices may be based on transmitting the indication of the second random access preamble index.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for selecting, at an L1 entity of the first device without signaling from an L2 entity of the first device, a set of multiple random access preamble indices including the first random access preamble index and the second random access preamble index, where performing the first decoding attempt and the second decoding attempt may be based on selecting the set of multiple random access preamble indices.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, from an L1 entity of the first device to an L2 entity of the first device, a payload decoding report indicating that the second decoding attempt for the payload using the first random access preamble index may be successful and storing, at the L2 entity of the first device, the first random access preamble based on the payload decoding report indicating that the second decoding attempt for the payload using the first random access preamble index may be successful.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a timing advance for the user equipment (UE) based on the first random access preamble index and the second random access preamble index, where the random access response message further includes an indication of the timing advance.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the timing advance may be based on a time offset between a first reception time associated with the first random access preamble and a second random access preamble associated with the second random access preamble index.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, performing the second decoding attempt may include operations, features, means, or instructions for performing the second decoding attempt subsequent to the first decoding attempt based on a result of the first decoding attempt being unsuccessful.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, performing the first decoding attempt and the second decoding attempt may include operations, features, means, or instructions for performing the first decoding attempt for the payload using the second random access preamble index and the second decoding attempt for the payload using the first random access preamble index in parallel.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for performing the first decoding attempt for the payload using the second random access preamble index includes using a second scrambling sequence generation based on the second random access preamble index and performing the second decoding attempt for the payload using the first random access preamble index includes using a first scrambling sequence generation based on the first random access preamble index.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first random access message includes a message A (msgA) of a two-step random access procedure and the random access response message includes a message B (msgB) of the two-step random access procedure.

A method for wireless communication at a second device is described. The method may include transmitting, to a first device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel, receiving, from the first device, a random access response message that includes an indication of the first random access preamble and a timing advance, determining whether the timing advance satisfies a threshold, and establishing a connection with the first device based on whether the timing advance satisfies the threshold.

An apparatus for wireless communication at a second device is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to transmit, to a first device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel, receive, from the first device, a random access response message that includes an indication of the first random access preamble and a timing advance, determine whether the timing advance satisfies a threshold, and establish a connection with the first device based on whether the timing advance satisfies the threshold.

Another apparatus for wireless communication at a second device is described. The apparatus may include means for transmitting, to a first device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel, means for receiving, from the first device, a random access response message that includes an indication of the first random access preamble and a timing advance, means for determining whether the timing advance satisfies a threshold, and means for establishing a connection with the first device based on whether the timing advance satisfies the threshold.

A non-transitory computer-readable medium storing code for wireless communication at a second device is described. The code may include instructions executable by a processor to transmit, to a first device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel, receive, from the first device, a random access response message that includes an indication of the first random access preamble and a timing advance, determine whether the timing advance satisfies a threshold, and establish a connection with the first device based on whether the timing advance satisfies the threshold.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining whether the timing advance satisfies the threshold may further include operations, features, means, or instructions for determining that the timing advance satisfies the threshold. In such examples of the method, apparatuses, and non-transitory computer-readable medium described herein, establishing the connection with the first device may further include operations, features, means, or instructions for establishing the connection based on the random access response message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining whether the timing advance satisfies the threshold may further include operations, features, means, or instructions for determining that the timing advance fails to satisfy the threshold. In such examples of the method, apparatuses, and non-transitory computer-readable medium described herein, establishing the connection with the first device may include operations, features, means, or instructions for establishing the connection based on different random access signaling.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first random access message includes a msgA of a two-step random access procedure and the random access response message includes a msgB of the two-step random access procedure.

DETAILED DESCRIPTION

In some wireless communications systems, a user equipment (UE) may attempt to establish a connection with a base station via a random access procedure. The random access procedure may be a two-step random access procedure or a four-step random access procedure. In examples in which the random access procedure is a two-step random access procedure, the UE may transmit a first random access message, which may be an example of a message A (msgA), including a first random access preamble on a physical random access channel (PRACH) and a payload on a physical uplink shared channel (PUSCH). The base station may receive the first random access message and may attempt to decode the payload on the PUSCH using a detected random access preamble. In some cases, the base station may detect a different random access preamble than the one transmitted by the UE due to timing alignment error. In such cases, the base station may be unable to successfully decode the payload on the PUSCH and the random access procedure may fail, resulting in the UE performing another random access procedure.

In some implementations of the present disclosure, the base station may attempt to decode the payload on the PUSCH using the detected random access preamble and one or more other random access preambles to increase a likelihood that the base station is able to successfully decode the payload. For example, the base station may detect a second random access preamble (even though the UE transmits the first random access preamble) due to a timing alignment error and, to increase the likelihood that the base station is able to successfully decode the payload, may select one or more other random access preambles for additional decoding attempts for the payload. In some examples, the base station may autonomously select the one or more other random access preambles at a Layer 1 (L1) entity of the base station. The one or more other random access preambles may be a configurable number from a Layer 2 (L2) entity of the base station during initial setup.

In some other examples, the L1 entity of the base station may receive an indication of or request for the one or more other random access preambles from the L2 entity of the base station. In some implementations, the L1 entity of the base station may receive the request for the one or more other random access preambles from the L2 entity of the base station based on transmitting an indication of the detected random access preamble to the L2 entity. In such implementations, for example, the L2 entity may provide the L1 entity with the one or more other random access preambles based on receiving the indication of which random access preamble the L1 entity detects. As such, the base station may attempt to decode the received payload using the detected random access preamble and one or more other random access preambles that may be adjacent to the detected random access preamble.

Some aspects of the subject matter described herein may be implemented to realize one or more of the following potential advantages. For example, as a result of achieving a greater likelihood for successfully decoding the payload on the PUSCH based on performing multiple decoding attempts for the payload using different random access preambles, the UE and the base station may experience a lower likelihood for random access procedure failures. As such, the UE and the base station may experience lower latency and greater reliability for connection establishment. Further, the UE and the base station may exchange less random access signaling, which may provide greater spectral efficiency, lower system congestion, and lower signaling overhead. Likewise, and as a result of such greater spectral efficiency, lower system congestion, and lower signaling overhead, the UE and the base station may experience greater data rates and greater system capacity.

Aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are additionally illustrated by and described with reference to a random access table and process flows. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to techniques for assisted message decoding.

In some systems, such as the wireless communications system100, a UE115may attempt to establish a connection (e.g., a wireless connection) with a base station105. The UE115may perform a random access procedure to establish the connection with the base station105. As part of the random access procedure, the UE115and the base station105may exchange one or more random access messages associated with the establishment of the connection between the UE115and the base station105. The UE115and the base station105may participate in a two-step random access procedure or a four-step random access procedure.

As part of a two-step random access procedure, the UE115may transmit a first random access message, which may include or otherwise be referred to as a msgA, including a first random access preamble on a PRACH and a payload on a PUSCH. The base station105may receive the first random access preamble, detect the transmitted random access preamble, and use the detected random access preamble to decode the payload portion of the first random access message on the PUSCH. In some cases, however, the base station105may detect a different random access preamble than the first random access preamble transmitted by the UE115. For example, the base station105may detect a second random access preamble instead of the first random access preamble (e.g., due to a timing alignment error).

In some implementations, to reduce the likelihood of a decoding failure for the payload on the PUSCH, the base station105may perform multiple decoding attempts on the payload using multiple random access preambles. For example, the base station105may perform a first decoding attempt using a second random access preamble index associated with the second random access preamble (e.g., the random access preamble that the base station105detects) and may perform one or more additional decoding attempts using random access preamble indices adjacent to the second random access preamble index. In some aspects, such one or more adjacent random access preamble indices may include indices associated with random access preambles having relatively proximate cyclic shifts or time shifts within a receiver window to the second random access preamble detected by the base station105.

FIG.2illustrates an example of a wireless communications system200that supports techniques for assisted message decoding in accordance with various aspects of the present disclosure. The wireless communications system200may implement or be implemented to realize aspects of the wireless communications system100. For example, the wireless communications system200illustrates communication between a UE115and a base station105, which may be examples of corresponding devices described herein, including with reference toFIG.1. In some examples, the base station105may receive a first random access message215, which may be an example of a msgA, from the UE115and may attempt to decode a payload portion of the first random access message215using multiple random access preamble indices.

For example, the UE115may attempt to establish a connection with the base station105and may initiate a random access procedure with the base station105based on transmitting the first random access message215to the base station105via a communication link205. In some aspects, the random access procedure may be an example of a two-step random access procedure and the UE115may include a first random access preamble on a PRACH and a payload on a PUSCH in the first random access message215. The UE115may monitor for a random access response220from the base station105via a communication link210.

In some systems, such as 5G NR systems, the UE115and the base station105may generate PRACH preamble sequences as Zadoff-Chu (ZC) sequences using a given root sequence. In some aspects, a quantity of different preamble sequences that the UE115and the base station105may generate for a given root sequence may be based on a configured parameter. For example, the base station105may configure a value for an NCSparameter to indicate how many cyclic shifts can be derived from a given root, and a quantity of cyclic shifts that can be derived from a given root may correspond to or otherwise correlate with the quantity of different preamble sequences that the UE115and the base station105can generate for that root. The base station105may transmit an indication of the NCSparameter to the UE115via control signaling, such as via RRC signaling. For example, the base station105may transmit the NCSparameter via a zeroCorrelationZoneConfig parameter.

In some aspects, the more preambles that may be generated (e.g., the lesser the configured value of the NCSparameter) for a given root, the lower the width capability of the system to accommodate (relatively higher) timing alignment error. The UE115and the base station105may experience timing alignment error (e.g., time error) because of, as a result of, or otherwise based on a round-trip-delay associated with a propagation delay, a frequency or time error, or both, at the base station105(e.g., a positive frequency error may cause a negative time shift and vice versa), a negative or positive window size of a PRACH receiver235at the base station105, or any combination thereof. Further, for decreasing values of NCS, the number of preambles per root increases and time limits between preambles becomes more stringent (e.g., smaller or narrower). In other words, a duration associated with each receiver window230becomes smaller with increasing number of preambles per root.

The base station105may detect a preamble index and a timing offset associated with the first random access message215based on a location of a peak, which may correspond to a specific cyclic shift, detected by the base station105at the PRACH receiver235of the base station105within a preamble window230. As such, for relatively small values of NCS, even a relatively small timing alignment error in the transmission or reception of the first random access message215(e.g., the first random access preamble of the first random access message215) may shift a detected peak from an intended preamble window230to a different preamble window230(e.g., an adjacent preamble window230).

For example, for some NCSvalues, such as NCS=2, a relatively small time error in the transmission or the reception (e.g., such as on the order of approximately 65 nanoseconds) may shift a peak of the first random access preamble to an adjacent preamble window230, resulting in the base station105(e.g., a receiver) reporting a different preamble than the one transmitted by the UE115. For example, the UE115may have intended for the peak (e.g., the cyclic shift) associated with the first random access preamble to be located in a preamble window230-aat225, but, due to some timing alignment error, the base station105may detect the peak (e.g., the cyclic shift) in a preamble window230-b. As such, for example, the base station105may detect or assume that the UE115transmitted a second random access preamble associated with a peak (e.g., a cyclic shift) being located in the preamble window230-b.

In some cases, such a reporting of a mis-detected random access preamble may result in a random access failure. For example, in a four-step random access procedure (e.g., a 5G NR four-step random access procedure), the UE115may declare a failure due to a message 2 (msg2) random access preamble identifier (RAPID) mismatch. In a two-step random access procedure (e.g., a 5G NR two-step random access procedure, the base station105may be unable to successfully decode msgA PUSCH (e.g., the payload portion of the first random access message215). In some scenarios, the base station105may be unable to determine or identify if the preamble that the base station105detects is different than the preamble transmitted by the UE115, while, in some other scenarios, the base station105may be able to determine or identify if the preamble that the base station105detects is different than the preamble transmitted by the UE115.

For example, in scenarios in which the UE115and the base station105perform a four-step random access procedure (e.g., either a 4G LTE or 5G NR four-step random access procedure), the base station105may be unable to determine if the preamble that the base station105detects is correct because the preamble identifier (ID) detected (e.g., in a message 1 (msg1) of the four-step random access procedure) is not associated with the decoding aspect of the msg2, a message 3 (msg3), or a message 4 (msg4) of the four-step random access procedure. As such, the preamble ID that the base station105includes in the msg2 that the base station105transmits to the UE115is based on the value detected by the base station105and may be different than the preamble transmitted by the UE115(e.g., because of a round-trip-time or one or both of a frequency or time error in the system). In scenarios in which the UE115and the base station105perform a two-step random access procedure (e.g., a 5G NR two-step random access procedure), however, the base station105may be able to determine if the preamble that the base station105detects is correct because the preamble ID detected by the base station105is directly applied in data scrambling of the msgA-PUSCH (e.g., the payload portion of the first random access message215). Thus, if the base station105is unable to successfully decode the msgA-PUSCH using a detected preamble ID from the same msgA, the base station105may determine or otherwise assume that the base station105detected an incorrect preamble.

For example, as part of PUSCH scrambling, the UE115may use a scrambling ID for the msgA-PUSCH that is based on a formula that takes the preamble ID as one of the inputs. For example, the UE115may initialize a scrambling sequence generator with a Cinitvalue, and the UE115may calculate, obtain, or otherwise determine the Cinitvalue in accordance with Equation 1.

As shown in Equation 1, nRAPIDmay correspond to or otherwise be an index or ID of a random access preamble that the UE115transmits via a msgA (e.g., the first random access message215). As such, the UE115may use a scrambling sequence generation or otherwise generate a scrambling sequence for the payload portion of the first random access message215based on the first random access preamble included also included in the first random access message215. Likewise, the base station105may use a same or similar procedure for decoding (e.g., de-scrambling) the payload of the first random access message215. For example, the base station105may similarly use Equation 1 to identify which scrambling sequence or scrambling sequence generation the UE115used based on inputting the detected random access preamble into Equation 1. As such, if the base station105detects a different random access preamble than the first random access preamble that the UE115transmits, the base station105may obtain a different or incompatible (de-)scrambling sequence for the payload and, accordingly, the base station105may fail to decode the payload.

In some implementations, and to increase the likelihood of the base station105to successfully decode the payload even in examples in which the base station105mis-detects the random access preamble of the first random access message215, the base station105may perform multiple decoding attempts on the payload (e.g., the msgA-PUSCH) using multiple preamble indices. The base station105may perform the multiple decoding sequentially, in parallel, or any combination thereof (e.g., via multiple sequential iterations of parallel decoding). In some examples, such as in examples in which the base station105performs the multiple decoding attempts sequentially, the base station105may attempt more than one decoding attempt if an initial decoding attempt (e.g., using a detected random access preamble index) fails.

In some aspects, the multiple preamble indices that the base station105uses may include preamble indices that are adjacent to the preamble index detected by the base station105. For example, in accordance with some timing alignment error being the reason for the mis-detection of the random access preamble, the base station105may perform decoding attempts using preamble indices that are adjacent to the preamble index detected by the base station105because the actual preamble index transmitted by the UE115may likely be one of such adjacent preamble indices. Such adjacent preamble indices may refer to preamble indices associated with cyclic shifts, time shifts, preamble windows230, or any other time-domain information associated with reception of the random access preamble at the PRACH receiver235that are similar or proximate to a cyclic shift, a time shift, a preamble window230, or other time-domain information of the detected random access preamble.

For example, the base station105may receive or otherwise detect the random access preamble transmitted by the UE115during the preamble window230-band, in examples in which the UE115actually intended the random access preamble to be received by the base station during the preamble window230-aat225, the base station105may use an incorrect random access preamble index in a decoding attempt on the payload of the first random access message215. In some implementations, to avoid a failure of the random access procedure, the base station105may perform the multiple decoding attempts for the payload of the first random access message215using random access preambles that are associated with preamble windows230that are adjacent to the preamble window230-b. For example, the base station105may perform a first decoding attempt using a second random access preamble index associated with the preamble window230-bbased on (mis-)detecting a second random access preamble, may perform a second decoding attempt using the first random access preamble index associated with the preamble window230-a, and may optionally perform a third decoding attempt using a third random access preamble index associated with a preamble window230-c.

As such, the base station105may fail the first decoding attempt and the third decoding attempt, but may pass the second decoding attempt and determine that the UE115actually transmitted the first random access preamble associated with the preamble window230-a. In some implementations, the base station105may compute a timing advance for the UE115using the correct preamble index with which the base station105is able to successfully decode the payload and the initially detected preamble and may return the correct preamble index and the computed timing advance to the UE115via the random access response220. The random access response220may be an example of a message B (msgB) and the base station105may transmit the random access response220over a physical downlink shared channel (PDSCH). As such, the random access response220may be equivalently referred to as a msgB-PUSCH.

In accordance with implementing aspects of the present disclosure, the UE115and the base station105may support identification and correction of a preamble index, which may avoid RAPID mismatch between the UE115and the base station105and avoid a resulting random access procedure (e.g., attach) failures. Further, as a result of the greater likelihood for successful decoding of the payload (e.g., the msgA-PUSCH) using one or more de-scrambling and decoding attempts, the UE115may perform fewer re-transmissions of the first random access message215, which would otherwise add latency and increase power consumption at the UE115. As such, as a result of implementing aspects of the present disclosure, the UE115may achieve lower latency and reduced power consumption, which may be beneficial for various use cases, including URLLC applications which are delay sensitive and for MTC or massive MTC (mMTC) devices which may be designed for low power consumption use.

Additionally, for URLLC cases for which a two-step random access procedure is designed, the UE115and the base station105may experience improved detection in a first attempt (e.g., a first attempt at transmission of the first random access message215), which may aid in maintaining or enhancing URLLC quality of service (QoS). Further, the base station105may achieve some implementations of the present disclosure via software functionality, which may avoid additional manufacturing costs or complex design changes. Further, the base station105may not only increase the likelihood for successful decoding of the payload (e.g., the msgA-PUSCH), but may also correct a detected preamble ID and compute a correct corresponding timing offset (e.g., the timing offset included in msg2 or msgB), which may facilitate more reliable communication between the UE115and the base station105.

FIG.3illustrates an example of a random access table300that supports techniques for assisted message decoding in accordance with various aspects of the present disclosure. The random access table300may be implemented to realize aspects of the wireless communications system100or the wireless communications system200. For example, the random access table300illustrates how many PRACH receiver windows a base station105may monitor for a transmission of a random access preamble from a UE115as part of a random access procedure, and further illustrates how a lower width capability or availability may arise for increasing numbers of preambles per root sequence.

For example, the random access table300may include a column305illustrating example zeroCorrelationZoneConfig parameters (which may be referred to or illustrated as ZcZ parameters), a column310illustrating example NCSvalues (which may be referred to or illustrated as NCS values), a column315illustrating example numbers of preambles per root sequence, and a column315illustrating example PRACH receiver windows per root sequence. In other words, the random access table300may illustrate mappings between zeroCorrelationZoneConfig parameters, NCSvalues, numbers of preambles per root sequence, and PRACH receiver windows per root sequence. In some aspects, the random access table300may illustrate an example associated with a 5G NR base station105supporting a mmW small cell, communication associated with a 120 kHz sub-carrier spacing (SCS), and a length of random access preamble sequence L_RA of139(which may be associated with a short format).

As an example, for a zeroCorrelationZoneConfig parameter value of 0, NCS=0, there may be one preamble per root sequence, and the base station105may likewise support a single PRACH receiver window (for detecting preamble #0). As another example, for a zeroCorrelationZoneConfig parameter value of 15, NCS=69, there may be two preambles per root sequence, and the base station105may likewise support two PRACH receiver windows (for detecting a preamble #0 and a preamble #1). As another example, for a zeroCorrelationZoneConfig parameter value of 13, NCS=34, there may be four preambles per root sequence, and the base station105may likewise support four PRACH receiver windows (for detecting a preamble #0, a preamble #1, a preamble #2, and a preamble #3). The random access table300further illustrates other examples in which the zeroCorrelationZoneConfig parameter has a value of 9 and 1 and, as NCSbecomes smaller, the number of preambles per root sequence, and likewise the number of PRACH receiver windows supported by the base station105, becomes larger.

As such, in scenarios in which there are a relatively large amount of preambles per root sequence, relatively small timing alignment errors between the UE115and the base station105may result in a mis-detection, at the base station105, of which random access preamble is transmitted by the UE115. Accordingly, in some implementations of the present disclosure, the base station105may perform multiple decoding attempts for an associated payload using various, potentially adjacent preamble indices to the preamble index detected by the base station105. As such, the base station105may still successfully decode the associated payload even if a timing alignment error resulted in the base station105detecting a random access preamble ID that is several (e.g., one or two) shifts away from the random access preamble ID that the UE115actually transmitted, regardless if the timing alignment error is associated with a negative time shift (pushing random access preambles toward higher preamble #) or a positive time shift (pushing random access preambles toward lower preamble #).

In some aspects, the adjacent preamble indices that the base station105may use for the decoding attempts on the associated payload may be associated with a same root sequence as the preamble index that the base station105detects. For example, for an NCSvalue of 2 and 64 preamble sequences per root sequence, if the base station105detects preamble #6, the base station105may limit or constrain its selection of other preamble indices to try for decoding such that the other preamble indices are associated with the same root sequence. In such an example, for instance, the base station105may perform decoding attempts on the associated payload using any one or more of preambles #0-5 and 7. Similarly, if the base station105detects a preamble #9, the base station105may perform decoding attempts on the associated payload using any one or more of preambles #8 and 10-15. In some examples, the one or more adjacent random access preamble indices (e.g., that are associated with a same root sequence) may be identified from a set of available random access preamble indices based on one or more of zeroCorrelationZoneConfig parameter, a length of a random access sequence L_RA, a random access channel format, and a random access channel SCS.

In some other aspects, the adjacent preamble indices that the base station105may use for the decoding attempts on the associated payload may be associated with different root sequences. For example, for an NCSvalue of 2 and 64 preamble sequences per root sequence, if the base station105detects preamble #6, the base station105may select other preamble indices to try for decoding such that the other preamble indices may include any one or more of preambles #0-5 and 7-15, or any other preamble # associated with an NCSvalue of 2. Similarly, if the base station105detects a preamble #9, the base station105may perform decoding attempts on the associated payload using any one or more of preambles #0-8 and 10-15, or any other preamble # associated with an NCSvalue of 2.

The base station105may perform multiple decoding attempts for a received payload for all NCSvalues or for a subset of NCSvalues. In some implementations, for example, the base station105may activate a setting for multiple decoding attempts for NCSvalues associated with a number of preambles per given root sequence that satisfies a threshold and may deactivate the setting for multiple decoding attempts for NCSvalues associated with a number of preambles per given root sequence that fails to satisfy the threshold. Alternatively, in some other implementations, the base station105may perform multiple decoding attempts for the received payload commonly or universally (e.g., regardless of NCSvalue).

FIG.4illustrates an example of a process flow400that supports techniques for assisted message decoding in accordance with various aspects of the present disclosure. The process flow400may implement or be implemented to realize aspects of the wireless communications system100or the wireless communications system200. For example, the process flow400illustrates communication between a UE115and a base station105, which may be examples of corresponding devices described herein, including with reference toFIGS.1and2. In some implementations, the base station105may detect a preamble index associated with a msgA transmission from the UE115and may perform multiple decoding attempts on a payload portion of the msgA transmission using one or more preamble indices that are adjacent to the preamble index detected by the base station105.

In the following description of the process flow400, the operations may be performed (such as reported or provided) in a different order than the order shown, or the operations performed by the example devices may be performed in different orders or at different times. Some operations also may be omitted from the process flow400, or other operations may be added to the process flow400. Further, although some operations or signaling may be shown to occur at different times for discussion purposes, these operations may actually occur at the same time or otherwise concurrently.

At405, the base station105may receive a first random access message including a first random access preamble on a random access channel (e.g., a PRACH) and a payload on an uplink shared channel (e.g., a PUSCH). For example, the UE115may initiate a two-step random access procedure based on transmitting a msgA (e.g., the first random access message) including the first preamble on the PRACH and the payload on the PUSCH.

At410, the base station105may detect a second random access preamble based on receiving the first random access message (e.g., the msgA) at405. For example, the UE115and the base station105may experience some timing alignment error and the base station105may detect the random access preamble transmitted by the UE115in a different preamble window or PRACH receive window than intended by the UE115, which may result in the base station105assuming that the UE115transmitted a different random access preamble (e.g., the base station105may assume a second random access preamble index instead of a correct first random access preamble index). In some aspects, an L1 entity of the base station105may detect the preamble (e.g., the msgA-preamble) and the L1 entity may forward the detected preamble to an L2 entity of the base station105(e.g., a MAC entity). In some aspects, the MAC entity of the base station105may compute a random access radio network temporary ID (RA-RNTI) using the detected preamble.

At415, the base station105may perform multiple decoding attempts on the PUSCH payload using multiple different random access preambles. In some implementations, for example, the L2 entity of the base station105may instruct the L1 entity to decode the payload based on specifying a list of preamble indices. In some aspects, the list of preamble indices may start with the originally detected preamble indices (e.g., as detected at410) followed by some adjacent preamble indices from a same root sequence index or from one or more different root sequence indices. In some implementations, the L1 entity may receive the list of random access preamble indices based on transmitting an indication of the detected preamble index to the L2 entity at410. In some other implementations, the L1 entity may autonomously select the list of random access indices (e.g., without signaling from the L2 entity) based on the detected preamble index. Additionally or alternatively the L2 entity may pre-configure the list of preamble indices at the L1 entity that the L1 entity may use for multiple decoding attempts for a given detected preamble index.

The L1 entity of the base station105may attempt decoding of the payload (e.g., the msgA-PUSCH) by initializing a scrambling sequence generator with the fir preamble index in the list provided by the L2 entity. If the decoding fails, the L1 entity may perform another de-scrambling and decoding attempt using a next preamble index in the list (e.g., an adjacent preamble index). In some aspects, the base station105may stop such a (sequential) de-scrambling and decoding if (e.g., as soon as) a cyclic redundancy check (CRC) correct or pass is achieved for an applied preamble index (e.g., if the decoding of the payload is successful for that applied preamble index). Additionally or alternatively, the base station105may perform the processing for all or multiple of the preamble indices provided by the L2 entity in parallel. For example, the base station105may perform a first decoding procedure using the second random access preamble index and may perform a second decoding procedure using the first random access preamble index (which may result in a successful decoding of the payload).

At420, the L1 entity may transmit a payload decoding report indicating that the second decoding attempt for the payload using the first random access preamble index is successful. For example, the L1 entity may send a msgA-PUSCH decoding reporting including the protocol data unit (PDU) index associated with a preamble index and a corresponding decoding status (e.g., a CRC status) to the L2 entity.

At425, the base station105may store, at the L2 entity, the first random access preamble index based on the payload decoding report indicating that the second decoding attempt for the payload using the first random access preamble index is successful. In other words, for example, the L2 entity may receive the msgA-PUSCH decoding report and, if the report indicates that the decoding was successful with a preamble other than the initial or top-most preamble from the list (e.g., the originally detected preamble), the L2 entity may identify or otherwise determine that the preamble detected by the L1 entity is different than the preamble index transmitted by the UE115and that the preamble index included in the payload decoding report actually corresponds to the preamble transmitted by the UE115.

At430, the base station105may determine a timing advance for the UE115based on the first random access preamble index and the second random access preamble index. For example, the timing advance may be based on a time offset between a first reception time associated with the first random access preamble (e.g., the preamble actually transmitted by the UE115) and a second random access preamble associated with the second random access preamble index (e.g., the originally detected preamble index). In other words, the L2 entity may store the correct preamble index and compute a timing advance by taking into consideration the time offset between a latest preamble index (e.g., the correct preamble index) and a previous preamble index (e.g., the originally detected preamble index). The base station105, at the L2 entity, may include the latest preamble index (e.g., the correct preamble index) and the determined timing advance in a random access response message, such as a msgB-PDSCH or contention resolution message.

At435, the base station105may transmit the contention resolution message to the UE115. In some examples, the base station105may include the contention resolution message in a random access response message (e.g., a msgB-PDSCH). The contention resolution message may include the first random access preamble index corresponding to the first random access preamble transmitted by the UE115and the timing advance.

At440, the UE115may, in some implementations, determine whether the timing advance satisfies a threshold and may establish a connection with the base station105based on whether the timing advance satisfies the threshold. For example, if the UE115determines that the timing advance satisfies the threshold, the UE115may establish a connection with the base station based on the contention resolution message sent at435. Alternatively, if the UE115determines that the timing advance fails to satisfy the threshold (e.g., is too big), the UE115may attempt to establish a connection with the base station105based on different random access signaling (e.g., via another random access procedure).

FIG.5illustrates an example of a process flow500that supports techniques for assisted message decoding in accordance with various aspects of the present disclosure. The process flow500may implement or be implemented to realize aspects of the wireless communications system100or the wireless communications system200. For example, the process flow500illustrates communication between a UE115and a base station105, which may be examples of corresponding devices described herein, including with reference toFIGS.1and2. In some implementations, the base station105may detect a preamble index associated with an initial random access transmission from the UE115and may perform multiple decoding attempts on a payload portion of the transmission using one or more preamble indices that are adjacent to the preamble index detected by the base station105. In some aspects, the process flow500illustrates an example of a contention-based random access (CBRA) four-step random access procedure.

In the following description of the process flow500, the operations may be performed (such as reported or provided) in a different order than the order shown, or the operations performed by the example devices may be performed in different orders or at different times. Some operations also may be omitted from the process flow500, or other operations may be added to the process flow500. Further, although some operations or signaling may be shown to occur at different times for discussion purposes, these operations may actually occur at the same time or otherwise concurrently.

At505, the UE115may transmit, to the base station105, a random access preamble. In some aspects, the UE115may transmit the random access preamble via a msg1.

At510, the base station105may transmit, to the UE115, a random access response associated with the random access preamble transmitted by the UE115at505. In some aspects, the base station105may transmit the random access response via a msg2.

At515, the UE115may perform, to the base station105, a scheduled transmission. For example, the random access response may allocate an uplink resource, such as a PUSCH resource, for the UE115to use for the scheduled transmission and the UE115may perform the scheduled transmission over the allocated uplink resource accordingly. In some aspects, the UE115may perform the scheduled transmission via a msg3.

At520, the base station105may transmit, to the UE115, a contention resolution message. In some aspects, the base station105may transmit the contention resolution message via a msg4 and the contention resolution message may include information for the UE115to use to establish a connection with the base station105.

FIG.6illustrates an example of a process flow600that supports techniques for assisted message decoding in accordance with various aspects of the present disclosure. The process flow600may implement or be implemented to realize aspects of the wireless communications system100or the wireless communications system200. For example, the process flow600illustrates communication between a UE115and a base station105, which may be examples of corresponding devices described herein, including with reference toFIGS.1and2. In some implementations, the base station105may detect a preamble index associated with an initial random access transmission from the UE115and may perform multiple decoding attempts on a payload portion of the transmission using one or more preamble indices that are adjacent to the preamble index detected by the base station105. In some aspects, the process flow600illustrates an example of a CBRA two-step random access procedure.

In the following description of the process flow600, the operations may be performed (such as reported or provided) in a different order than the order shown, or the operations performed by the example devices may be performed in different orders or at different times. Some operations also may be omitted from the process flow600, or other operations may be added to the process flow600. Further, although some operations or signaling may be shown to occur at different times for discussion purposes, these operations may actually occur at the same time or otherwise concurrently.

At605, the UE115may transmit, to the base station105, a random access message including a random access preamble on a PRACH and a payload on a PUSCH. In some aspects, the UE115may scramble and encode the payload based on the random access preamble. In some aspects, the UE115may transmit the random access message via a msgA.

At610, the base station105may transmit a contention resolution message. In some aspects, the base station105may transmit the contention resolution message via a msgB and the contention resolution message may include information for the UE115to use to establish a connection with the base station105.

FIG.7illustrates an example of a process flow700that supports techniques for assisted message decoding in accordance with various aspects of the present disclosure. The process flow700may implement or be implemented to realize aspects of the wireless communications system100or the wireless communications system200. For example, the process flow700illustrates communication between a UE115and a base station105, which may be examples of corresponding devices described herein, including with reference toFIGS.1and2. In some implementations, the base station105may detect a preamble index associated with an initial random access transmission from the UE115and may perform multiple decoding attempts on a payload portion of the transmission using one or more preamble indices that are adjacent to the preamble index detected by the base station105. In some aspects, the process flow700illustrates an example of a contention-free random access (CFRA) four-step random access procedure.

In the following description of the process flow700, the operations may be performed (such as reported or provided) in a different order than the order shown, or the operations performed by the example devices may be performed in different orders or at different times. Some operations also may be omitted from the process flow700, or other operations may be added to the process flow700. Further, although some operations or signaling may be shown to occur at different times for discussion purposes, these operations may actually occur at the same time or otherwise concurrently.

At705, the base station105may transmit, to the UE115, a random access preamble assignment. In some aspects, the random access preamble assignment may indicate which random access preamble the UE115may select to transmit as part of a random access procedure with the base station105.

At710, the UE115may transmit, to the base station105, a random access preamble. The UE115may transmit the same random access preamble as indicated by the random access preamble assignment transmitted by the base station105at705. In some aspects, the UE115may transmit the random access preamble via a msg1.

At715, the base station105may transmit, to the UE115, a random access response associated with the random access preamble transmitted by the UE115at710. In some aspects, the base station105may transmit the random access response via a msg2. As part of the CFRA four-step random access procedure, the UE115may establish a connection with the base station105based on receiving the random access response at715.

FIG.8illustrates an example of a process flow800that supports techniques for assisted message decoding in accordance with various aspects of the present disclosure. The process flow800may implement or be implemented to realize aspects of the wireless communications system100or the wireless communications system200. For example, the process flow800illustrates communication between a UE115and a base station105, which may be examples of corresponding devices described herein, including with reference toFIGS.1and2. In some implementations, the base station105may detect a preamble index associated with an initial random access transmission from the UE115and may perform multiple decoding attempts on a payload portion of the transmission using one or more preamble indices that are adjacent to the preamble index detected by the base station105. In some aspects, the process flow800illustrates an example of a CFRA two-step random access procedure.

In the following description of the process flow800, the operations may be performed (such as reported or provided) in a different order than the order shown, or the operations performed by the example devices may be performed in different orders or at different times. Some operations also may be omitted from the process flow800, or other operations may be added to the process flow800. Further, although some operations or signaling may be shown to occur at different times for discussion purposes, these operations may actually occur at the same time or otherwise concurrently.

At805, the base station105may transmit, to the UE115, a random access preamble and PUSCH assignment. In some aspects, the random access preamble assignment may indicate which random access preamble the UE115may select to transmit as part of the random access procedure with the base station105and the PUSCH assignment may indicate over which PUSCH resource the UE115is scheduled to transmit a payload associated with the random access preamble.

At810, the UE115may transmit, to the base station105, a random access message including the random access preamble on a PRACH and the payload on the PUSCH. In some aspects, the UE115may scramble and encode the payload based on the random access preamble. The UE115may transmit the same random access preamble as indicated by the random access preamble assignment transmitted by the base station105at805and may transmit the payload over the same PUSCH resource as indicated by the PUSCH assignment transmitted by the base station105at805. In some aspects, the UE115may transmit the random access message via a msgA.

At815, the base station105may transmit, to the UE115, a random access response associated with the random access preamble transmitted by the UE115at810. In some aspects, the base station105may transmit the random access response via a msgB. As part of the CFRA two-step random access procedure, the UE115may establish a connection with the base station105based on receiving the random access response at815.

The transmitter915may provide a means for transmitting signals generated by other components of the device905. For example, the transmitter915may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to techniques for assisted message decoding). In some examples, the transmitter915may be co-located with a receiver910in a transceiver component. The transmitter915may utilize a single antenna or a set of multiple antennas.

The communications manager920, the receiver910, the transmitter915, or various combinations thereof or various components thereof may be examples of means for performing various aspects of techniques for assisted message decoding as described herein. For example, the communications manager920, the receiver910, the transmitter915, or various combinations or components thereof may support a method for performing one or more of the functions described herein.

The communications manager920may support wireless communication at a first device in accordance with various aspects of the present disclosure. For example, the communications manager920may be configured as or otherwise support a means for receiving, from a second device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel. The communications manager920may be configured as or otherwise support a means for performing a first decoding attempt for the payload using a second random access preamble index, the first decoding attempt being performed in response to receiving the first random access message. The communications manager920may be configured as or otherwise support a means for performing a second decoding attempt for the payload using a first random access preamble index associated with the first random access preamble. The communications manager920may be configured as or otherwise support a means for transmitting, to the second device, a random access response message that includes an indication of the first random access preamble index, the transmitting of the random access response message based on successfully performing the second decoding attempt.

By including or configuring the communications manager920in accordance with examples as described herein, the device905(e.g., a processor controlling or otherwise coupled with the receiver910, the transmitter915, the communications manager920, or a combination thereof) may support techniques for reduced processing, reduced power consumption, and more efficient utilization of communication resources.

The device1005, or various components thereof, may be an example of means for performing various aspects of techniques for assisted message decoding as described herein. For example, the communications manager1020may include a random access component1025a decoding component1030, or any combination thereof. The communications manager1020may be an example of aspects of a communications manager920as described herein. In some examples, the communications manager1020, or various components thereof, may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver1010, the transmitter1015, or both. For example, the communications manager1020may receive information from the receiver1010, send information to the transmitter1015, or be integrated in combination with the receiver1010, the transmitter1015, or both to receive information, transmit information, or perform various other operations as described herein.

The communications manager1020may support wireless communication at a first device in accordance with various aspects of the present disclosure. The random access component1025may be configured as or otherwise support a means for receiving, from a second device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel. The decoding component1030may be configured as or otherwise support a means for performing a first decoding attempt for the payload using a second random access preamble index, the first decoding attempt being performed in response to receiving the first random access message. The decoding component1030may be configured as or otherwise support a means for performing a second decoding attempt for the payload using a first random access preamble index associated with the first random access preamble. The random access component1025may be configured as or otherwise support a means for transmitting, to the second device, a random access response message that includes an indication of the first random access preamble index, the transmitting of the random access response message based on successfully performing the second decoding attempt.

FIG.11shows a block diagram1100of a communications manager1120that supports techniques for assisted message decoding in accordance with various aspects of the present disclosure. The communications manager1120may be an example of aspects of a communications manager920, a communications manager1020, or both, as described herein. The communications manager1120, or various components thereof, may be an example of means for performing various aspects of techniques for assisted message decoding as described herein. For example, the communications manager1120may include a random access component1125, a decoding component1130, a detection component1135, an inter-layer communication component1140, an autonomous selection component1145, a timing advance component1150, or any combination thereof. Each of these components may communicate, directly or indirectly, with one another (e.g., via one or more buses).

The communications manager1120may support wireless communication at a first device in accordance with various aspects of the present disclosure. The random access component1125may be configured as or otherwise support a means for receiving, from a second device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel. The decoding component1130may be configured as or otherwise support a means for performing a first decoding attempt for the payload using a second random access preamble index, the first decoding attempt being performed in response to receiving the first random access message. In some examples, the decoding component1130may be configured as or otherwise support a means for performing a second decoding attempt for the payload using a first random access preamble index associated with the first random access preamble. In some examples, the random access component1125may be configured as or otherwise support a means for transmitting, to the second device, a random access response message that includes an indication of the first random access preamble index, the transmitting of the random access response message based on successfully performing the second decoding attempt.

In some examples, the detection component1135may be configured as or otherwise support a means for detecting a second random access preamble based on a reception time associated with the first random access message, where performing the first decoding attempt for the payload using the second random access preamble index is based on detecting the second random access preamble.

In some examples, the inter-layer communication component1140may be configured as or otherwise support a means for receiving, at a L1 entity of the first device from a L2 entity of the first device, a set of multiple random access preamble indices including the first random access preamble index and the second random access preamble index, where performing the first decoding attempt and the second decoding attempt is based on receiving the set of multiple random access preamble indices.

In some examples, the set of multiple random access preamble indices include the second random access preamble index and one or more adjacent random access preamble indices from a set of available random access preamble indices that are associated with a same root sequence index as the second random access preamble index.

In some examples, the one or more adjacent random access preamble indices that are associated with the same root sequence are identified from the set of available random access preamble indices based on one or more of a zero correlation zone configuration, a length of a random access sequence, a random access channel format, and a random access channel SCS.

In some examples, the set of multiple random access preamble indices include the second random access preamble index and one or more adjacent random access preamble indices from a set of available random access preamble indices that are associated with different root sequence indices.

In some examples, the inter-layer communication component1140may be configured as or otherwise support a means for transmitting, from the L1 entity to the L2 entity, an indication of the second random access preamble index based on detecting a second random access preamble, where receiving the set of multiple random access preamble indices is based on transmitting the indication of the second random access preamble index.

In some examples, the autonomous selection component1145may be configured as or otherwise support a means for selecting, at a L1 entity of the first device without signaling from a L2 entity of the first device, a set of multiple random access preamble indices including the first random access preamble index and the second random access preamble index, where performing the first decoding attempt and the second decoding attempt is based on selecting the set of multiple random access preamble indices.

In some examples, the inter-layer communication component1140may be configured as or otherwise support a means for transmitting, from a L1 entity of the first device to a L2 entity of the first device, a payload decoding report indicating that the second decoding attempt for the payload using the first random access preamble index is successful. In some examples, the random access component1125may be configured as or otherwise support a means for storing, at the L2 entity of the first device, the first random access preamble based on the payload decoding report indicating that the second decoding attempt for the payload using the first random access preamble index is successful.

In some examples, the timing advance component1150may be configured as or otherwise support a means for determining a timing advance for the UE based on the first random access preamble index and the second random access preamble index, where the random access response message further includes an indication of the timing advance.

In some examples, the timing advance is based on a time offset between a first reception time associated with the first random access preamble and a second random access preamble associated with the second random access preamble index.

In some examples, to support performing the second decoding attempt, the decoding component1130may be configured as or otherwise support a means for performing the second decoding attempt subsequent to the first decoding attempt based on a result of the first decoding attempt being unsuccessful.

In some examples, to support performing the first decoding attempt and the second decoding attempt, the decoding component1130may be configured as or otherwise support a means for performing the first decoding attempt for the payload using the second random access preamble index and the second decoding attempt for the payload using the first random access preamble index in parallel.

In some examples, performing the first decoding attempt for the payload using the second random access preamble index includes using a second scrambling sequence generation based on the second random access preamble index. In some examples, performing the second decoding attempt for the payload using the first random access preamble index includes using a first scrambling sequence generation based on the first random access preamble index.

In some examples, the first random access message includes a message A of a two-step random access procedure and the random access response message includes a message B of the two-step random access procedure.

The network communications manager1210may manage communications with a core network130(e.g., via one or more wired backhaul links). For example, the network communications manager1210may manage the transfer of data communications for client devices, such as one or more UEs115.

The communications manager1220may support wireless communication at a first device in accordance with various aspects of the present disclosure. For example, the communications manager1220may be configured as or otherwise support a means for receiving, from a second device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel. The communications manager1220may be configured as or otherwise support a means for performing a first decoding attempt for the payload using a second random access preamble index, the first decoding attempt being performed in response to receiving the first random access message. The communications manager1220may be configured as or otherwise support a means for performing a second decoding attempt for the payload using a first random access preamble index associated with the first random access preamble. The communications manager1220may be configured as or otherwise support a means for transmitting, to the second device, a random access response message that includes an indication of the first random access preamble index, the transmitting of the random access response message based on successfully performing the second decoding attempt.

By including or configuring the communications manager1220in accordance with examples as described herein, the device1205may support techniques for improved communication reliability, reduced latency, improved user experience related to reduced processing, reduced power consumption, more efficient utilization of communication resources, improved coordination between devices, longer battery life, and improved utilization of processing capability.

FIG.13shows a block diagram1300of a device1305that supports techniques for assisted message decoding in accordance with various aspects of the present disclosure. The device1305may be an example of aspects of a UE115as described herein. The device1305may include a receiver1310, a transmitter1315, and a communications manager1320. The device1305may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

The transmitter1315may provide a means for transmitting signals generated by other components of the device1305. For example, the transmitter1315may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to techniques for assisted message decoding). In some examples, the transmitter1315may be co-located with a receiver1310in a transceiver component. The transmitter1315may utilize a single antenna or a set of multiple antennas.

The communications manager1320, the receiver1310, the transmitter1315, or various combinations thereof or various components thereof may be examples of means for performing various aspects of techniques for assisted message decoding as described herein. For example, the communications manager1320, the receiver1310, the transmitter1315, or various combinations or components thereof may support a method for performing one or more of the functions described herein.

In some examples, the communications manager1320may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver1310, the transmitter1315, or both. For example, the communications manager1320may receive information from the receiver1310, send information to the transmitter1315, or be integrated in combination with the receiver1310, the transmitter1315, or both to receive information, transmit information, or perform various other operations as described herein.

The communications manager1320may support wireless communication at a second device in accordance with various aspects of the present disclosure. For example, the communications manager1320may be configured as or otherwise support a means for transmitting, to a first device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel. The communications manager1320may be configured as or otherwise support a means for receiving, from the first device, a random access response message that includes an indication of the first random access preamble and a timing advance. The communications manager1320may be configured as or otherwise support a means for determining whether the timing advance satisfies a threshold. The communications manager1320may be configured as or otherwise support a means for establishing a connection with the first device based on whether the timing advance satisfies the threshold.

By including or configuring the communications manager1320in accordance with examples as described herein, the device1305(e.g., a processor controlling or otherwise coupled with the receiver1310, the transmitter1315, the communications manager1320, or a combination thereof) may support techniques for reduced processing, reduced power consumption, and more efficient utilization of communication resources.

FIG.14shows a block diagram1400of a device1405that supports techniques for assisted message decoding in accordance with various aspects of the present disclosure. The device1405may be an example of aspects of a device1305or a UE115as described herein. The device1405may include a receiver1410, a transmitter1415, and a communications manager1420. The device1405may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

The transmitter1415may provide a means for transmitting signals generated by other components of the device1405. For example, the transmitter1415may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to techniques for assisted message decoding). In some examples, the transmitter1415may be co-located with a receiver1410in a transceiver component. The transmitter1415may utilize a single antenna or a set of multiple antennas.

The device1405, or various components thereof, may be an example of means for performing various aspects of techniques for assisted message decoding as described herein. For example, the communications manager1420may include a random access component1425, a timing advance component1430, a connection establishment component1435, or any combination thereof. The communications manager1420may be an example of aspects of a communications manager1320as described herein. In some examples, the communications manager1420, or various components thereof, may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver1410, the transmitter1415, or both. For example, the communications manager1420may receive information from the receiver1410, send information to the transmitter1415, or be integrated in combination with the receiver1410, the transmitter1415, or both to receive information, transmit information, or perform various other operations as described herein.

The communications manager1420may support wireless communication at a second device in accordance with various aspects of the present disclosure. The random access component1425may be configured as or otherwise support a means for transmitting, to a first device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel. The random access component1425may be configured as or otherwise support a means for receiving, from the first device, a random access response message that includes an indication of the first random access preamble and a timing advance. The timing advance component1430may be configured as or otherwise support a means for determining whether the timing advance satisfies a threshold. The connection establishment component1435may be configured as or otherwise support a means for establishing a connection with the first device based on whether the timing advance satisfies the threshold.

FIG.15shows a block diagram1500of a communications manager1520that supports techniques for assisted message decoding in accordance with various aspects of the present disclosure. The communications manager1520may be an example of aspects of a communications manager1320, a communications manager1420, or both, as described herein. The communications manager1520, or various components thereof, may be an example of means for performing various aspects of techniques for assisted message decoding as described herein. For example, the communications manager1520may include a random access component1525, a timing advance component1530, a connection establishment component1535, or any combination thereof. Each of these components may communicate, directly or indirectly, with one another (e.g., via one or more buses).

The communications manager1520may support wireless communication at a second device in accordance with various aspects of the present disclosure. The random access component1525may be configured as or otherwise support a means for transmitting, to a first device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel. In some examples, the random access component1525may be configured as or otherwise support a means for receiving, from the first device, a random access response message that includes an indication of the first random access preamble and a timing advance. The timing advance component1530may be configured as or otherwise support a means for determining whether the timing advance satisfies a threshold. The connection establishment component1535may be configured as or otherwise support a means for establishing a connection with the first device based on whether the timing advance satisfies the threshold.

In some examples, determining whether the timing advance satisfies the threshold includes determining that the timing advance satisfies the threshold. In some examples, establishing the connection with the first device includes establishing the connection based on the random access response message.

In some examples, determining whether the timing advance satisfies the threshold includes determining that the timing advance fails to satisfy the threshold. In some examples, establishing the connection with the first device includes establishing the connection based on different random access signaling.

In some examples, the first random access message includes a message A of a two-step random access procedure and the random access response message includes a message B of the two-step random access procedure.

FIG.16shows a diagram of a system1600including a device1605that supports techniques for assisted message decoding in accordance with various aspects of the present disclosure. The device1605may be an example of or include the components of a device1305, a device1405, or a UE115as described herein. The device1605may communicate wirelessly with one or more base stations105, UEs115, or any combination thereof. The device1605may include components for bi-directional voice and data communications including components for transmitting and receiving communications, such as a communications manager1620, an I/O controller1610, a transceiver1615, an antenna1625, a memory1630, code1635, and a processor1640. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., a bus1645).

The I/O controller1610may manage input and output signals for the device1605. The I/O controller1610may also manage peripherals not integrated into the device1605. In some cases, the I/O controller1610may represent a physical connection or port to an external peripheral. In some cases, the I/O controller1610may utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operating system. Additionally or alternatively, the I/O controller1610may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller1610may be implemented as part of a processor, such as the processor1640. In some cases, a user may interact with the device1605via the I/O controller1610or via hardware components controlled by the I/O controller1610.

In some cases, the device1605may include a single antenna1625. However, in some other cases, the device1605may have more than one antenna1625, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver1615may communicate bi-directionally, via the one or more antennas1625, wired, or wireless links as described herein. For example, the transceiver1615may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver1615may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas1625for transmission, and to demodulate packets received from the one or more antennas1625. The transceiver1615, or the transceiver1615and one or more antennas1625, may be an example of a transmitter1315, a transmitter1415, a receiver1310, a receiver1410, or any combination thereof or component thereof, as described herein.

The memory1630may include RAM and ROM. The memory1630may store computer-readable, computer-executable code1635including instructions that, when executed by the processor1640, cause the device1605to perform various functions described herein. The code1635may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, the code1635may not be directly executable by the processor1640but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some cases, the memory1630may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The processor1640may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor1640may be configured to operate a memory array using a memory controller. In some other cases, a memory controller may be integrated into the processor1640. The processor1640may be configured to execute computer-readable instructions stored in a memory (e.g., the memory1630) to cause the device1605to perform various functions (e.g., functions or tasks supporting techniques for assisted message decoding). For example, the device1605or a component of the device1605may include a processor1640and memory1630coupled with the processor1640, the processor1640and memory1630configured to perform various functions described herein.

The communications manager1620may support wireless communication at a second device in accordance with various aspects of the present disclosure. For example, the communications manager1620may be configured as or otherwise support a means for transmitting, to a first device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel. The communications manager1620may be configured as or otherwise support a means for receiving, from the first device, a random access response message that includes an indication of the first random access preamble and a timing advance. The communications manager1620may be configured as or otherwise support a means for determining whether the timing advance satisfies a threshold. The communications manager1620may be configured as or otherwise support a means for establishing a connection with the first device based on whether the timing advance satisfies the threshold.

By including or configuring the communications manager1620in accordance with examples as described herein, the device1605may support techniques for improved communication reliability, reduced latency, improved user experience related to reduced processing, reduced power consumption, more efficient utilization of communication resources, improved coordination between devices, longer battery life, and improved utilization of processing capability.

In some examples, the communications manager1620may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the transceiver1615, the one or more antennas1625, or any combination thereof. Although the communications manager1620is illustrated as a separate component, in some examples, one or more functions described with reference to the communications manager1620may be supported by or performed by the processor1640, the memory1630, the code1635, or any combination thereof. For example, the code1635may include instructions executable by the processor1640to cause the device1605to perform various aspects of techniques for assisted message decoding as described herein, or the processor1640and the memory1630may be otherwise configured to perform or support such operations.

FIG.17shows a flowchart illustrating a method1700that supports techniques for assisted message decoding in accordance with various aspects of the present disclosure. The operations of the method1700may be implemented by a base station or its components as described herein. For example, the operations of the method1700may be performed by a base station105as described with reference toFIGS.1through12. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the described functions. Additionally or alternatively, the base station may perform aspects of the described functions using special-purpose hardware.

At1705, the method may include receiving, from a second device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel. The operations of1705may be performed in accordance with various aspects of the present disclosure. In some examples, aspects of the operations of1705may be performed by a random access component1125as described with reference toFIG.11.

At1710, the method may include performing a first decoding attempt for the payload using a second random access preamble index, the first decoding attempt being performed in response to receiving the first random access message. The operations of1710may be performed in accordance with various aspects of the present disclosure. In some examples, aspects of the operations of1710may be performed by a decoding component1130as described with reference toFIG.11.

At1715, the method may include performing a second decoding attempt for the payload using a first random access preamble index associated with the first random access preamble. The operations of1715may be performed in accordance with various aspects of the present disclosure. In some examples, aspects of the operations of1715may be performed by a decoding component1130as described with reference toFIG.11.

At1720, the method may include transmitting, to the second device, a random access response message that includes an indication of the first random access preamble index, the transmitting of the random access response message based on successfully performing the second decoding attempt. The operations of1720may be performed in accordance with various aspects of the present disclosure. In some examples, aspects of the operations of1720may be performed by a random access component1125as described with reference toFIG.11.

FIG.18shows a flowchart illustrating a method1800that supports techniques for assisted message decoding in accordance with various aspects of the present disclosure. The operations of the method1800may be implemented by a base station or its components as described herein. For example, the operations of the method1800may be performed by a base station105as described with reference toFIGS.1through12. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the described functions. Additionally or alternatively, the base station may perform aspects of the described functions using special-purpose hardware.

At1805, the method may include receiving, from a second device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel. The operations of1805may be performed in accordance with various aspects of the present disclosure. In some examples, aspects of the operations of1805may be performed by a random access component1125as described with reference toFIG.11.

At1810, the method may include detecting a second random access preamble based on a reception time associated with the first random access message. The operations of1810may be performed in accordance with various aspects of the present disclosure. In some examples, aspects of the operations of1810may be performed by a detection component1135as described with reference toFIG.11.

At1815, the method may include performing a first decoding attempt for the payload using a second random access preamble index, the first decoding attempt being performed in response to receiving the first random access message. The operations of1815may be performed in accordance with various aspects of the present disclosure. In some examples, aspects of the operations of1815may be performed by a decoding component1130as described with reference toFIG.11.

At1820, the method may include performing a second decoding attempt for the payload using a first random access preamble index associated with the first random access preamble. The operations of1820may be performed in accordance with various aspects of the present disclosure. In some examples, aspects of the operations of1820may be performed by a decoding component1130as described with reference toFIG.11.

At1825, the method may include transmitting, to the second device, a random access response message that includes an indication of the first random access preamble index, the transmitting of the random access response message based on successfully performing the second decoding attempt. The operations of1825may be performed in accordance with various aspects of the present disclosure. In some examples, aspects of the operations of1825may be performed by a random access component1125as described with reference toFIG.11.

FIG.19shows a flowchart illustrating a method1900that supports techniques for assisted message decoding in accordance with various aspects of the present disclosure. The operations of the method1900may be implemented by a UE or its components as described herein. For example, the operations of the method1900may be performed by a UE115as described with reference toFIGS.1through7and13through16. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may perform aspects of the described functions using special-purpose hardware.

At1905, the method may include transmitting, to a first device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel. The operations of1905may be performed in accordance with various aspects of the present disclosure. In some examples, aspects of the operations of1905may be performed by a random access component1525as described with reference toFIG.15.

At1910, the method may include receiving, from the first device, a random access response message that includes an indication of the first random access preamble and a timing advance. The operations of1910may be performed in accordance with various aspects of the present disclosure. In some examples, aspects of the operations of1910may be performed by a random access component1525as described with reference toFIG.15.

At1915, the method may include determining whether the timing advance satisfies a threshold. The operations of1915may be performed in accordance with various aspects of the present disclosure. In some examples, aspects of the operations of1915may be performed by a timing advance component1530as described with reference toFIG.15.

At1920, the method may include establishing a connection with the first device based on whether the timing advance satisfies the threshold. The operations of1920may be performed in accordance with various aspects of the present disclosure. In some examples, aspects of the operations of1920may be performed by a connection establishment component1535as described with reference toFIG.15.

Aspect 1: A method for wireless communication at a first device, comprising: receiving, from a second device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel; performing a first decoding attempt for the payload using a second random access preamble index, the first decoding attempt being performed in response to receiving the first random access message; performing a second decoding attempt for the payload using a first random access preamble index associated with the first random access preamble; and transmitting, to the second device, a random access response message that includes an indication of the first random access preamble index, the transmitting of the random access response message based at least in part on successfully performing the second decoding attempt.

Aspect 2: The method of aspect 1, further comprising: detecting a second random access preamble based at least in part on a reception time associated with the first random access message, wherein performing the first decoding attempt for the payload using the second random access preamble index is based at least in part on detecting the second random access preamble.

Aspect 3: The method of any of aspects 1 or 2, further comprising: receiving, at an L1 entity of the first device from an L2 entity of the first device, a plurality of random access preamble indices including the first random access preamble index and the second random access preamble index, wherein performing the first decoding attempt and the second decoding attempt is based at least in part on receiving the plurality of random access preamble indices.

Aspect 4: The method of aspect 3, wherein the plurality of random access preamble indices include the second random access preamble index and one or more adjacent random access preamble indices from a set of available random access preamble indices that are associated with a same root sequence index as the second random access preamble index.

Aspect 5: The method of aspect 4, wherein the one or more adjacent random access preamble indices that are associated with the same root sequence are identified from the set of available random access preamble indices based at least in part on one or more of a zero correlation zone configuration, a length of a random access sequence, a random access channel format, and a random access channel sub-carrier spacing.

Aspect 6: The method of aspect 3, wherein the plurality of random access preamble indices include the second random access preamble index and one or more adjacent random access preamble indices from a set of available random access preamble indices that are associated with different root sequence indices.

Aspect 7: The method of any of aspects 3 through 6, further comprising: transmitting, from the L1 entity to the L2 entity, an indication of the second random access preamble index based at least in part on detecting a second random access preamble, wherein receiving the plurality of random access preamble indices is based at least in part on transmitting the indication of the second random access preamble index.

Aspect 8: The method of any of aspects 1 or 2, further comprising: selecting, at an L1 entity of the first device without signaling from an L2 entity of the first device, a plurality of random access preamble indices including the first random access preamble index and the second random access preamble index, wherein performing the first decoding attempt and the second decoding attempt is based at least in part on selecting the plurality of random access preamble indices.

Aspect 9: The method of any of aspects 1 through 8, further comprising: transmitting, from an L1 entity of the first device to an L2 entity of the first device, a payload decoding report indicating that the second decoding attempt for the payload using the first random access preamble index is successful; and storing, at the L2 entity of the first device, the first random access preamble based at least in part on the payload decoding report indicating that the second decoding attempt for the payload using the first random access preamble index is successful.

Aspect 10: The method of any of aspects 1 through 9, further comprising: determining a timing advance for the UE based at least in part on the first random access preamble index and the second random access preamble index, wherein the random access response message further includes an indication of the timing advance.

Aspect 11: The method of aspect 10, wherein the timing advance is based at least in part on a time offset between a first reception time associated with the first random access preamble and a second random access preamble associated with the second random access preamble index.

Aspect 12: The method of any of aspects 1 through 11, wherein performing the second decoding attempt further comprises: performing the second decoding attempt subsequent to the first decoding attempt based at least in part on a result of the first decoding attempt being unsuccessful.

Aspect 13: The method of any of aspects 1 through 11, wherein performing the first decoding attempt and the second decoding attempt further comprises: performing the first decoding attempt for the payload using the second random access preamble index and the second decoding attempt for the payload using the first random access preamble index in parallel.

Aspect 14: The method of any of aspects 1 through 13, wherein performing the first decoding attempt for the payload using the second random access preamble index comprises using a second scrambling sequence generation based at least in part on the second random access preamble index; and performing the second decoding attempt for the payload using the first random access preamble index comprises using a first scrambling sequence generation based at least in part on the first random access preamble index.

Aspect 15: The method of any of aspects 1 through 14, wherein the first random access message comprises a msgA of a two-step random access procedure and the random access response message comprises a msgB of the two-step random access procedure.

Aspect 16: A method for wireless communication at a second device, comprising: transmitting, to a first device, a first random access message including a first random access preamble on a random access channel and a payload on an uplink shared channel; receiving, from the first device, a random access response message that includes an indication of the first random access preamble and a timing advance; determining whether the timing advance satisfies a threshold; and establishing a connection with the first device based at least in part on whether the timing advance satisfies the threshold.

Aspect 17: The method of aspect 16, wherein determining whether the timing advance satisfies the threshold comprises determining that the timing advance satisfies the threshold; and establishing the connection with the first device comprises establishing the connection based at least in part on the random access response message.

Aspect 18: The method of aspect 16, wherein determining whether the timing advance satisfies the threshold comprises determining that the timing advance fails to satisfy the threshold; and establishing the connection with the first device comprises establishing the connection based at least in part on different random access signaling.

Aspect 19: The method of any of aspects 16 through 18, wherein the first random access message comprises a msgA of a two-step random access procedure and the random access response message comprises a msgB of the two-step random access procedure.

Aspect 21: An apparatus for wireless communication at a first device, comprising at least one means for performing a method of any of aspects 1 through 15.

Aspect 23: An apparatus for wireless communication at a second device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of aspects 16 through 19.

Aspect 24: An apparatus for wireless communication at a second device, comprising at least one means for performing a method of any of aspects 16 through 19.

Aspect 25: A non-transitory computer-readable medium storing code for wireless communication at a second device, the code comprising instructions executable by a processor to perform a method of any of aspects 16 through 19.