EP4690607A1

EP4690607A1 - Correlation of carriers in communication

Info

Publication number: EP4690607A1
Application number: EP24712601.4A
Authority: EP
Inventors: Nuno PRATAS; Kai-Erik Sunell; Takayuki Shimizu; Claude Arzelier; Torsten WILDSCHEK; Renato BARBOSA ABREU
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 2023-04-05
Filing date: 2024-02-27
Publication date: 2026-02-11
Also published as: WO2024209839A1; CN120982059A

Abstract

Disclosed are methods, apparatuses, and systems for carrier aggregation in a sidelink communication. The method includes determining, at a first node, a set of candidate carriers for aggregation; selecting one or more candidate carriers from the set of candidate carriers as one or more component carriers for carrier aggregation based on correlation among carriers; and transmitting or receiving on the one or more component carriers.

Description

CORRELATION OF CARRIERS IN COMMUNICATION

Cross-Reference to Related Application

This application claims the benefit of priority of U.S. Provisional Patent Application No. 63/457,273, filed on April 5, 2023, entitled “CORRELATION OF CONGESTION AND CHANNEL CONDITIONS BETWEEN TWO CARRIERS FOR PACKET DUPLICATION IN SIDELINK COMMUNICATION,” the entirety of which is incorporated by reference herein.

Field

Apparatuses and methods consistent with the present disclosure relate generally to communications, more specifically, to methods, systems, and devices for performing carrier aggregation in sidelink communication in a communication network.

Background

Sidelink (SL) communication is used in 3GPP radio interfaces to allow two or more wireless devices, or user equipments (UEs), to communicate directly between them. This may happen under the coverage of a cellular network, out of coverage of the cellular network, or even in partial coverage of the cellular network where only one of the two UEs is under the network coverage. Direct device-to-device communication uses the PC5 interface.

Sidelink communication is used by vehicle-to-everything applications, also known as V2X. An SL device may use various radio access technologies (RATs) such as Long Term Evolution (LTE) SL, Next Radio (NR) SL, or both, for transmission and reception.

Many radio interface technologies use carrier aggregation. The main principle in carrier aggregation is to transfer multiple packets in parallel on different carriers. A “carrier” is a waveform conveying the physical channel. Carrier aggregation is widely deployed in radio communication systems, typically targeting to wireless broadband applications. Carrier aggregation may be implemented by transmitting or receiving on multiple carriers at the same time, thereby aggregating the bandwidth of each carrier together to permit a higher bandwidth transmission or reception. Each aggregated carrier may be referred to as a “component carrier.” Not all available carriers may be considered for aggregation; the carriers that may be considered for aggregation may be referred to as “candidate carriers.” Examples of such technologies in terrestrial radio systems are 3GPP High-Speed Packet Access (HSPA) and 3GPP Long-Term Evolution (LTE), where carrier aggregation increases data transfer throughput on the radio interface between infrastructure nodes and mobile nodes. 3GPP generally denotes this interface as the Uu interface.

Apart from throughput improvements, carrier aggregation may also be used for reliability and latency enhancements. The basic idea is to replicate (e.g., duplicate or n-plicate) packets on parallel carriers. Packet replication is useful for services and deployments requiring high reliability and low latency, or if reliability and latency is an issue.

One example of such a deployment is sidelink (SL) where ,as opposed to e.g., conventional cellular communication such as mobile telephony systems, nodes can communicate directly with each other without continuous connectivity to controlling entities at the infrastructure side. Upon the absence of continuous connectivity to central controlling entities, SL resource allocations cannot be performed in a coordinated or centralized manner. Therefore, nodes perform autonomous or local resource allocations based on sensing of resources independently of each other in a distributed manner. Such a distributed operation is generally less complex than centralized solutions, but it gives rise to uncertainties in communication reliability and latency.

To address these issues, 3GPP has specified carrier aggregation for SL communication in the LTE radio interface standard, such as in Technical Specification 36.213 and Technical Specification 36.321. 3GPP generally denotes this interface as the SL or PC5 interface. Discussions are currently on-going to address the same problem in the 3GPP NR radio interface by specifying SL carrier aggregation in the scope of 3GPP Release 18 work items.

Summary

According to some embodiments of the present disclosure, there is provided a method for carrier aggregation in a sidelink communication. The method includes determining, at a first node, a set of candidate carriers for aggregation; selecting one or more candidate carriers from the set of candidate carriers as one or more component carriers for carrier aggregation based on correlation among carriers; and transmitting or receiving on the one or more component carriers.

According to some embodiments of the present disclosure, there is provided a first node. The first node includes a memory configured to store instructions; and a processor configured to execute the instructions stored in the memory to: determine a set of candidate carriers for aggregation; select one or more candidate carriers from the set of candidate carriers as one or more component carriers for carrier aggregation based on correlation among carriers; and transmit or receive on the one or more component carriers.

According to some embodiments of the present disclosure, there is provided a non-transitory computer-readable medium storing instructions that are executable by one or more processors of a first node in a communication network to perform a method. The method includes determining, at the first node, a set of candidate carriers for aggregation; selecting one or more candidate carriers from the set of candidate carriers as one or more component carriers for carrier aggregation based on correlation among carriers; and transmitting or receiving on the one or more component carriers.

According to some embodiments of the present disclosure, there is provided a method for carrier correlation detection. The method includes determining correlation of signals across carriers in a set of carriers; creating a resource matrix for each carrier in the set of carriers; and obtaining a correlation metric based on the resource matrix.

According to some embodiments of the present disclosure, there is provided a first node. The first node includes a memory configured to store instructions; and a processor configured to execute the instructions stored in the memory to: determine correlation of signals across carriers in a set of carriers; create a resource matrix for each carrier in the set of carriers; and obtain a correlation metric based on the resource matrix.

According to some embodiments of the present disclosure, there is provided a non-transitory computer-readable medium storing instructions that are executable by one or more processors of a first node to perform a method. The method includes determining correlation of signals across carriers in a set of carriers; creating a resource matrix for each carrier in the set of carriers; and obtaining a correlation metric based on the resource matrix.

FIG. 1 is a schematic diagram illustrating device types for dynamic co-channel coexistence of a first sidelink communication and a second sidelink communication, consistent with some embodiments of the present disclosure.

FIG. 2 is a flowchart of a method for carrier aggregation in a sidelink communication, consistent with some embodiments of the present disclosure.

FIG. 3 is a flowchart of a method for carrier correlation detection, consistent with some embodiments of the present disclosure.

FIG. 4 is a block diagram of a node, consistent with some embodiments of the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings in which the same numbers in different drawings represent the same or similar elements unless otherwise represented. The implementations set forth in the following description of exemplary embodiments do not represent all implementations consistent with the present disclosure. Instead, they are merely examples of systems, apparatuses, and methods consistent with aspects related to the present disclosure as recited in the appended claims.
Interface between LTE SL module and NR SL module
As part of the 3GPP discussions, a device Type A is defined as a device that includes both an LTE SL module and an NR SL module, where the NR SL module can receive information from the LTE SL module. For studying the feasibility of dynamic resource sharing as a possible solution for co-channel coexistence, for device Type A, the NR SL module uses the sensing and resource reservation information shared by the LTE SL module.
FIG. 1 is a schematic diagram illustrating device types for dynamic co-channel coexistence of a first SL communication and a second SL communication, consistent with some embodiments of the present disclosure. Referring to FIG. 1, at least three types (Type A, Type B, and Type C) of devices are considered in this disclosure. A Type A device includes a module for the first SL communication and a module for the second SL communication. A Type B device only includes a module for the first SL communication. A Type C device only includes a module for the second SL communication. For example, in an embodiment, a Type A device includes both LTE SL and NR SL modules; a Type B device only includes an NR SL module; and a Type C device only includes an LTE SL module.
Current solutions select SL resources independently on each carrier (e.g., as described in Technical Specification 36.213 and Technical Specification 36.321). The resource selection procedure includes sensing procedures and rules for resource exclusions performed in carrier-specific manner. The resource selection procedures use reference signal received power (RSRP) measurements, received signal strength indicator (RSSI) measurements, channel busy ratio (CBR) estimates, and channel occupancy ratio (CR) estimates.
3GPP Release 15 LTE-V2X PC5 mode 4 supports SL carrier aggregation. Multiple sidelink carriers (i.e., multiple V2X channels) may be used to increase the throughput and/or improve the reliability. To increase the throughput, multiple medium access control (MAC) protocol data units (PDUs) may be transmitted on multiple sidelink carriers. To improve the reliability, packet data convergence protocol (PDCP) duplication may be supported, in which the same PDCP packet is transmitted on multiple sidelink carriers. For example, 3GPP Technical Specification 36.321 Clause 5.14.1.5 specifies the transmission carrier selection or carrier reselection procedure to select or reselect sidelink carriers for transmission based on the measured CBR for each sidelink carrier. In the transmission carrier selection/reselection procedure, the transmitting UE considers sidelink carriers as candidate sidelink carriers if the measured CBR of the sidelink carrier is below a configured or pre-configured CBR threshold (associated with a priority). Then, the transmitting UE selects one or more sidelink carriers among the candidate sidelink carriers with an increasing order of CBR from the lowest CBR. It is left to UE implementation how many sidelink carriers the transmitting UE selects based on UE capability. For each selected sidelink carrier, LTE SL carrier aggregation reuses the sensing and resource selection procedure from 3GPP Release 14 LTE-V2X PC5 mode 4. That is, the UE selects resources independently on each involved carrier based on the Release 14 sensing and resource selection procedure. The Release 15 resource selection procedure considers the transmitting UE’s capability on whether it can transmit on multiple carriers at a time or not, such that the resource selection procedure will not select resources for transmission that violate the transmitting UE’s capabilities. The same sidelink carriers are used at least until the process triggers transmission carrier reselection.
A shortcoming of the current solution is that two or more carriers may be correlated because allocations for different carriers are performed independently of each other with possible negative impacts on carrier aggregation gains. For example, if two carriers are experiencing the same type of congestion, then any transmission on two or more carriers will be affected by the same congestion. In that case, the gains of carrier aggregation, e.g., packet replication, will be lower than in the case where carriers are experiencing uncorrelated congestion.
Disclosed embodiments improve the current solutions by identifying correlation between two or more carriers and using the information in resource allocation and selection. One benefit is the higher gains of carrier aggregation in terms of packet replication gains, such as higher reliability and lower latency, and in terms of throughput gains, because channel conditions, e.g., congestion, propagation, etc., are either not correlated or they are less correlated.
Some embodiments described herein provide a method and apparatus for identifying correlation between two or more carriers in carrier aggregation deployments, exchange of the correlation information with nodes, and selection of resources based on the correlation information. The method may be applied to any wireless communication system that uses carrier aggregation but, in the rest of the disclosure, the method is exemplified with, but not limited to, terrestrial mobile radio communication systems, such as 3GPP LTE and/or NR radio access technology, where SL communication is supported.
For the sake of brevity, the method is herein exemplified with two nodes, but any application of the method is not limited to the simplified use case. It is understood that a skilled person in the art may generalize the disclosed embodiments to apply to multiple nodes. Likewise, the method is exemplified with, but not limited to, one-directional communication between nodes, but it may be applied for bi-directional communication, i.e., both communication directions between two nodes, or there may be separate procedures taking place, e.g., the method may be applied to one direction but not to the other direction.
In an embodiment, a first node, also referred to herein as a transmitting node (although such a node may include both transmitting and receiving capabilities), indicates a start of a carrier correlation detection procedure to a second node, also referred to herein as a receiving node (although such a node may include both receiving and transmitting capabilities). The indication may be conveyed over the air from the transmitting node to the receiving node, e.g., by means of populating radio parameters, indicators, or fields in, e.g., a radio interface message, radio protocol data unit header, or physical layer field/control information. The indication may convey information about a set of two or more carriers, e.g., their identities and/or frequencies, to allow the receiving node to perform correlation of, e.g., propagation paths and traffic conditions/activity on the carriers.
In another embodiment, the receiving node may indicate the start of a carrier correlation detection procedure to the transmitting node. The indication may be conveyed over the air from the receiving node to the transmitting node in the same manner and with similar data and formats as in the embodiment above.
In another embodiment, a node, either the transmitting node or the receiving node, may restart the carrier correlation detection procedure. Restarting the carrier correlation detection procedure may resolve a use case where propagation and traffic conditions are time-varying. For example, a timer may be started when a carrier correlation detection procedure is indicated and the carrier correlation detection procedure may be restarted upon expiry of the timer. The timer value may be, e.g., given as a stored configuration in the node and provided by a controlling network entity, given as a stored configuration in the node and provided by another node, pre-configured in a Subscriber Identity Unit (SIM/USIM), pre-configured in a Universal Integrated Circuit Card (UICC), or hard coded in the node’s software. In another example, restarting the carrier correlation detection procedure may be triggered based on events detected by either the transmitting node or the receiving node. Example events may include the change of one or multiple propagation or traffic metrics (e.g., RSSI, CBR) between two or more time instances that exceed one or more configured or pre-configured thresholds. In an example, detecting the events may be performed within a time duration starting when the carrier correlation detection procedure is started. In another example, a configured timer value may be scaled depending on the speeds of the nodes involved or the observed rate at which the radio environment changes.
Upon starting or restarting of the carrier correlation detection procedure and reception of associated information thereof, the transmitting node transmits signals on the above-mentioned set of carriers to be used for correlation detection in the receiving node. Such transmitted signals may be, e.g., SL transmissions with a predetermined payload and/or reference signals such as the channel state information reference signal (CSI-RS). Another alternative may use the demodulation reference signals (DM-RS) transmitted along with the physical sidelink control channel (PSCCH) or the physical sidelink shared channel (PSSCH) for the correlation detection (RSRP measurements are based on DM-RS). The predetermined payload and its format may be, e.g., given as a stored configuration in the node and provided by a controlling network entity, given as a stored configuration in the node and provided by another node, pre-configured in a SIM/USIM, pre-configured in a UICC, or hard coded in the node’s software. The choice of transmitted signals, e.g., to use either the predetermined payload or the CSI-RS, may also be decided by the transmitting node and/or the receiving node, and the choice may be conveyed upon the indication of carrier correlation detection procedure starting and restarting.
Upon starting or restarting of the carrier correlation detection procedure and reception of associated information thereof, the receiving node receives signals, e.g., the predetermined payload or the CSI-RS, on the carriers. The receiving node evaluates the correlation of the signals across the different carriers used by the transmitting node. The correlation may be evaluated in terms of, for example, received energy, channel impulse response, history of CBR measurements, history of RSSI measurements, history of reserved resources, other physical layer measurements, history of channel occupancy ratio (CR) measurements, history of CSI report values, history of L3-filtered SL-RSRP (used for transmission power determination), history of acknowledgement (ACK)/negative acknowledgement (NACK) ratio, listen-before talk (LBT) failure rate (e.g., if it is an unlicensed band), history of consistent LBT failures, history of radio link failure, history of beam recovery/realignment (e.g., if operating with narrow beams in FR2 carriers). For each carrier, the receiving node creates a time and frequency resource matrix as an output of its own sensing procedure and then obtains a correlation metric representing the correlation between carriers. The generated matrix may be one or a combination of the embodiments described below. It is noted that the term “matrix” is used herein as a general term, without implying any restriction in terms of specific storage or graphical representation. While some examples below refer to the term “matrix” or “binary matrix,” the examples may also be described by use of direct computations or formulas, for example, without necessarily referring to the term “matrix” or “binary matrix.”
In another embodiment, the correlation information may be calculated using binary matrices where each matrix element includes binary information (e.g., a “0” value or a “1” value) if activity was detected or not at the receiving node in each time/frequency resource, e.g., each slot or sub-channel. The activity detection may be based on, e.g., RSRP, RSSI, signal to noise and interference ratio (SINR), or energy detection. In an embodiment, the activity detection may use one or more thresholds. For example, the receiving node may compare measurement values in slots, sub-channels, or other type of frequency and time resource against a threshold value. The threshold value may be, e.g., given as a stored configuration in the node and provided by a controlling network entity, given as a stored configuration in the node and provided by another node, pre-configured in a SIM/USIM, pre-configured in a UICC, or hard coded in the node’s software. If an obtained measurement value, e.g., RSRP or RSSI, in a slot or sub-channel is below the threshold value, then the matrix element of the corresponding slot or sub-channel is populated with a “0” value, otherwise it is populated with a “1” value.
In another embodiment, the correlation information may be calculated using binary matrices where each matrix element includes identification information to indicate whether the identities activated in carriers match in time and frequency. Each matrix element may provide information about time and frequency resources where the receiving node can receive signals from the transmitting node and identify its carriers. The identification information may be used to resolve a use case where carriers may be subject to, e.g., severe frequency-selective fading or co-channel interference (i.e., contamination of a received signal by another similar kind of information bearing signal from a node other than the first node) or other undesirable events, such as jamming (i.e., intentional interference), impacting the propagation path and signal transfer.
In another embodiment, the correlation information may be calculated using numerical matrices where each matrix element is, e.g., an integer value or a floating-point number. The matrix element may be represented as a code point in a fixed-size bit combination, to identify the correlation of the signals being transmitted in a time and frequency resource. An example of this embodiment is computation of a cross-correlation function of sampled channel impulse responses from two carriers. The outcome of the cross-correlation computation is a general metric that may describe the similarity between data sequences and signals; in this case, channel impulse responses of different carriers. It may be used as a metric to identify how strongly the propagation paths on the different carrier, are correlated. The matrix element corresponding to the carriers may be populated with the obtained correlation value.
In another embodiment, the correlation information may be calculated based on the outcome of decoding data that have been duplicated by the transmitting UE across the multiple carriers (PDCP duplication). If the same data is sent across multiple carriers at about the same time, then the correlation of decoding outcomes across the carriers may be determined. For example, if a recurring interfering signal affects all carriers equally, then it is likely that high correlation of decoding outcomes will be observed. If, on the other hand, the interfering signal affects only a proper subset of the carriers, then correlation of decoding outcomes between a carrier affected by the interference and a carrier not affected by the interference is likely to be low. These decoding outcomes may be determined by the receiving UE. If hybrid automatic repeat request (HARQ) feedback is used, then the decoding outcomes also become visible to the transmitting UE.
In the case of two carriers, the diagonal of the matrix, i.e., elements (1,1) and (2,2), represent auto-correlation, i.e., correlation of the signal by itself with the outcome of perfect correlation, whereas the elements (2,1) and (1,2) represent the cross-correlation between two different carriers and result in the same numerical value in both elements. A high correlation value indicates high correlation between carriers whereas a low integer value indicates low correlation between carriers.
In another embodiment, after obtaining the cross correlation between carriers, the receiving node may share the correlation information with the transmitting node. The correlation information may be conveyed over the air from the receiving node to the transmitting node, e.g., by populating radio parameters, indicators, or fields in, e.g., a radio interface message, a radio protocol data unit header, physical layer fields, or transferred as a contained octet string in a radio protocol, e.g., as a transparent container.
The conveyed correlation information may be either the entire matrix representation, e.g., the receiving node’s internal representation of the data, or a compressed version of the matrix to reduce overhead. For example, in the case of cross-correlation of channel impulse responses between two carriers, the correlation matrix is a symmetric 2×2 matrix since elements (1,2) and (2,1) have the same value because the correlation values are computed in the same manner, and values on the diagonal, i.e., elements (1,1) and (2,2), are of no interest to the transmitting node because they are outcomes of auto-correlation and not cross-correlation. It means that the matrix values on the diagonal can be removed and only one of the elements (1,2) or (2,1) may be transferred.
The correlation value may be conveyed e.g., as an integer value or a floating-point number represented as a code point in a fixed-size bit combination. The correlation value may also be compressed into one bit to indicate if carriers are correlated or not. For example, the correlation value may be compared to a threshold value. If the correlation value is above the threshold value, the bit may be set to “1,” otherwise the bit may be set to “0.” One possible interpretation is that a bit value of “1” indicates correlated carriers and a bit value of “0” indicates uncorrelated or sufficiently uncorrelated carriers.
In another embodiment, the transmitting node may use the correlation information in resource selection, resource reselection, carrier selection, or carrier reselection. For example, if two carriers are strongly correlated, one of them may be excluded from a transmission occasion, e.g., until correlation between carriers is sufficiently low.
In another embodiment, the receiving node may provide a report containing the raw version or a filtered version of the physical layer measurements which are then used by the transmitting node for computing the correlation information. This option may require more signaling, but may be preferable in case the transmitting node has greater computing and decision capability than the receiving node (e.g., if the transmitting node is an access point which considers the measurements from multiple other nodes for deciding the carrier selection or carrier reselection).
In another embodiment, the receiving node may share recommended carrier information with the transmitting node based on the cross correlation between carriers. For example, the receiving node may share one or multiple carrier indices that have cross-correlation values that are below a threshold.
In another embodiment, the transmitting node may use its sensing information and the information shared from the receiving node in resource selection, resource reselection, carrier selection, or carrier reselection.
In another embodiment, other functions to calculate a similarity and/or difference of two matrices may be used instead of the cross-correlation function. For example, cosine similarity and/or a distance between two matrices (e.g., L-0 norm, L-1 norm, L-2 norm, etc.), may be used. One or multiple similarity functions may be used.
In another embodiment, whether a different RAT can be detected may be used to enable any embodiment described herein. For example, whether LTE can be detected may be used to enable this process for LTE NR carrier aggregation.
In another embodiment, a priority may be used to assess whether to enable any embodiment described herein. One or more priority thresholds may also be used. Examples of priority may include 5G quality of service identifier (5QI) priority, quality of service class indicator (QCI) priority (used in LTE), proximity service (ProSe) per-packet priority (PPPP), L1/L2 priority, or any other priority related to quality of service or application priority.
In another embodiment, any information provided, measured, and/or calculated may be forwarded by an additional node to perform any embodiment described herein.
FIG. 2 is a flowchart of a method 200 for carrier aggregation in a sidelink communication, consistent with some embodiments of the present disclosure. The method 200 may be performed by a node in a communication system, for example, by a UE in a sidelink communication. For the purposes of explanation, it is assumed that the method 200 is performed in a node that includes an LTE SL module and an NR SL module.
The method 200 includes a step 202 of determining, at a first node, a set of candidate carriers for aggregation. In some embodiments, the first node may consider carriers as candidate carriers if the measured CBR of the carrier is below a configured or pre-configured CBR threshold. The first node may then select one or more carriers among the candidate carriers based on an increasing order of CBR starting from a lowest CBR.
The method 200 includes a step 204 of selecting one or more candidate carriers from the set of candidate carriers as one or more component carriers for carrier aggregation. In some embodiments, selecting the one or more candidate carriers may be based on excluding one or more carriers having high correlation with another one or more carriers. In some embodiments, determining the correlation among carriers may be based on correlation information received at the first node. In some embodiments, the method 200 may further include receiving, from a second node, a communication including the correlation information, wherein the communication includes any one of a radio interface message, a radio protocol data unit header, a physical layer field, or physical layer control information.
The method 200 includes a step 206 of transmitting or receiving on the one or more component carriers. Once the component carriers are selected, the first node may perform carrier aggregation by transmitting or receiving on the selected component carriers. Transmitting data on the one or more selected carriers involves scheduling, where the node decides which carrier is used for transmitting data units arriving in the node’s transmitter buffer. The decision can be made, for example, randomly and uniformly or in a circular order considering all carriers within the selected set without any priority to obtain even sharing of traffic load among the carriers. The decision may also involve determining the transmission sequence, for example, based on data unit priorities. Receiving on the one or more carriers within the selected set includes receiving control information, such as channel state information and data unit priority, conveyed in the data unit header and/or on a separate physical layer control field, and receiving the data unit payload. Transmitting and receiving data may further include retransmissions requested by the receiver if a transmission attempt fails.
In some embodiments, the method 200 may further include performing a carrier correlation detection procedure. In some embodiments, the carrier correlation detection procedure may be performed upon receipt of an indication of a start of the carrier correlation detection procedure by the first node. In some embodiments, the indication may include information relating to a second set of carriers allowing the first node to perform carrier correlation detection on the second set of carriers. In some embodiments, the method 200 may further include receiving, from a second node, a communication including the indication of the start of the carrier correlation detection procedure, wherein the communication includes any one of a radio interface message, a radio protocol data unit header, a physical layer field, or physical layer control information.
In some embodiments, the method 200 may further include restarting the carrier correlation detection procedure. In some embodiments, the restarting may be triggered based on an event detected by the first node. In some embodiments, the event may include one or more of: a change in a traffic metric, a change in the traffic metric over a predetermined period of time, a change in the traffic metric over the predetermined period of time that exceeds a configured or pre-configured threshold, a change in multiple traffic metrics, a change in the multiple traffic metrics over the predetermined period of time, or a change in the multiple traffic metrics over the predetermined period of time that each exceeds the pre-configured threshold. In some embodiments, the traffic metric may include one or more of received signal strength indicator or channel busy ratio. In some embodiments, the predetermined period of time may start when the carrier correlation detection procedure is started. In some embodiments, the predetermined period of time may be scaled depending on a speed of the first node or an observed rate at which a radio environment changes.
In some embodiments, the method 200 may further include starting a timer when the carrier correlation detection procedure is started and restarting the carrier correlation detection procedure when the timer expires. In some embodiments, a duration of the timer may be based on any one of: a stored configuration in the first node provided by a controlling network entity, a stored configuration in the first node provided by another node, a pre-configuration in a subscriber identity unit, a pre-configuration in a universal integrated circuit card, or a hard coding in the first node.
FIG. 3 is a flowchart of a method 300 for carrier correlation detection, consistent with some embodiments of the present disclosure. The method 300 may be performed by a node in a communication system, for example, by a UE in a sidelink communication. For the purposes of explanation, it is assumed that the method 300 is performed in a node that includes an LTE SL module and an NR SL module, although the node may include any other module(s).
The method 300 includes a step 302 of determining correlation of signals across carriers in a set of carriers. In some embodiments, the method 300 may further include receiving one or more signals in the set of carriers, wherein the one or more signals include a predetermined payload or a reference signal. In some embodiments, the predetermined payload may include any one of: a stored configuration in a first node provided by a controlling network entity, a stored configuration in the first node provided by another node, a pre-configuration in a subscriber identity unit, a pre-configuration in a universal integrated circuit card, or hard coding in the first node. In some embodiments, the reference signal may include any one of: a channel state information reference signal or a demodulation reference signal along with one of a physical sidelink control channel or a physical sidelink shared channel.
In some embodiments, determining correlation of the signals may be based on any one of: received energy, channel impulse response, history of channel busy ratio measurements, history of received signal strength indicator measurements, history of reserved resources, history of channel occupancy ratio measurements, history of channel status information report values, history of L3-filtered sidelink received signal reference power measurements, history of one or more of acknowledgement ratio or negative acknowledgement ratio, listen-before talk (LBT) failure rate, history of consistent LBT failures, history of radio link failure, or history of one or more of beam recovery or beam realignment.
The method 300 includes a step 304 of creating a resource matrix for each carrier in the set of carriers. In some embodiments, creating the resource matrix may include creating a time and frequency resource matrix based on sensing information determined by a first node.
The method 300 includes a step 306 of obtaining a correlation metric based on the resource matrix. In some embodiments, obtaining the correlation metric may include calculating the correlation metric using binary matrices and each matrix element of the resource matrix may be composed of binary information if activity was detected or not at a first node in each of one or more of time resource or frequency resource. In some embodiments, whether activity was detected or not at the first node may be based on any one or more of: received signal reference power, received signal strength indicator, signal to noise and interference ratio, or energy detection.
In some embodiments, the method 300 may further include comparing a measurement value of each of the one or more of time resource or frequency resource to a threshold value. If the measurement value is below the threshold value, the matrix element of a corresponding resource may be a “0” value. If the measurement value is equal to or above the threshold value, the matrix element of the corresponding resource may be a “1” value. In some embodiments, the threshold value may include any one of: a stored configuration in the first node provided by a controlling network entity, a stored configuration in the first node provided by another node, a pre-configuration in a subscriber identity unit, a pre-configuration in a universal integrated circuit card, or hard coding in the first node.
In some embodiments, obtaining the correlation metric may include calculating the correlation metric using binary matrices and each matrix element of the resource matrix may be composed of identification information to provide information about time and frequency resources where a first node can receive signals from a second node and identify its carriers.
In some embodiments, obtaining the correlation metric may include calculating the correlation metric using numerical matrices and each matrix element of the resource matrix may identify the correlation of signals transmitted in a time and frequency resource. In some embodiments, each matrix element may be an integer value or a floating point value. In some embodiments, each matrix element may be an obtained correlation value based on a similarity of channel impulse responses of different carriers.
In some embodiments, obtaining the correlation metric may include calculating the correlation metric based on an outcome of decoding data that has been duplicated across multiple carriers in the set of carriers. In some embodiments, a high value in the matrix may indicate a high correlation between carriers and a low value in the matrix may indicate a low correlation between carriers.
In some embodiments, the method 300 may further include receiving the correlation metric at a first node from a second node. In some embodiments, the method 300 may further include sharing the correlation metric from a first node to a second node. In some embodiments, the receiving or sharing may include any one of: populating radio parameters, indicators, or fields in a radio interface message; populating fields in a radio protocol data unit header; populating physical layer fields; or receiving a contained octet string in a radio protocol. In some embodiments, the receiving or sharing may include receiving the correlation metric as a matrix or a compressed matrix. In some embodiments, the receiving or sharing may include receiving the correlation metric as an integer value or a floating-point number represented as a code point in a fixed sized bit combination. In some embodiments, the receiving or sharing may include receiving the correlation metric as a single bit to indicate if carriers are correlated or not. In some embodiments, the method 300 may further include comparing the correlation metric to a threshold value to determine a value of the single bit and if the correlation is above the threshold value, the value of the single bit may be set to “1”.
In some embodiments, the method 300 may further include indicating one or more of the carriers as being excluded from a transmission occasion if the correlation metric indicates that another one or more carriers are strongly correlated. In some embodiments, the method 300 may further include determining carriers with a correlation value below a threshold and sharing the determined carriers with a second node.
Node
FIG. 4 is a block diagram of a node 400, consistent with some embodiments of the present disclosure. The node 400 can be a Type A, Type B, Type C, or any other type of UE. Node 400 may be mounted in a moving vehicle or in a fixed position. Node 400 may take any form, including but not limited to, a vehicle, a component mounted in a vehicle, a roadside unit, a laptop computer, a wireless terminal including a mobile phone, a wireless handheld device, or wireless personal device, or any other form. In the preceding description, any mention of a UE performing certain functionality may be replaced with a node performing the same functionality without changing the operation or functionality of any of the elements described herein.
Referring to FIG. 4, the node 400 may include antenna 402 that may be used for transmission or reception of electromagnetic signals to/from a base station or other UEs. The antenna 402 may include one or more antenna elements and may enable different input-output antenna configurations, for example, multiple input multiple output (MIMO) configuration, multiple input single output (MISO) configuration, and single input multiple output (SIMO) configuration. In some embodiments, the antenna 402 may include multiple (e.g., tens or hundreds) antenna elements and may enable multi-antenna functions such as beamforming. In some embodiments, the antenna 402 is a single antenna.
The node 400 may include a transceiver 404 that is coupled to the antenna 402. The transceiver 404 may be a wireless transceiver at the node 400 and may communicate bi-directionally with a base station or other UEs. For example, the transceiver 404 may receive/transmit wireless signals from/to a base station via downlink/uplink communication. The transceiver 404 may also receive/transmit wireless signals from/to another UE via sidelink communication. The transceiver 404 may include a modem to modulate the packets and provide the modulated packets to the antenna 402 for transmission, and to demodulate packets received from the antenna 402.
The node 400 may include a memory 406. The memory 406 may be any type of computer-readable storage medium including volatile or non-volatile memory devices, or a combination thereof. The computer-readable storage medium includes, but is not limited to, non-transitory computer storage media. A non-transitory storage medium may be accessed by a general purpose or special purpose computer. Examples of non-transitory storage medium include, but are not limited to, a portable computer diskette, a hard disk, random access memory (RAM), read-only memory (ROM), an erasable programmable read-only memory (EPROM), electrically erasable programmable ROM (EEPROM), a digital versatile disk (DVD), flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, etc. A non-transitory medium may be used to carry or store desired program code means (e.g., instructions and/or data structures) and may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. In some examples, the software/program code may be transmitted from a remote source (e.g., a website, a server, etc.) using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave. In such examples, the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are within the scope of the definition of medium. Combinations of the above examples are also within the scope of computer-readable medium.
The memory 406 may store information related to identities of node 400 and the signals and/or data received by antenna 402. The memory 406 may also store post-processing signals and/or data. The memory 406 may also store computer-readable program instructions, mathematical models, and algorithms that are used in signal processing in transceiver 404 and computations in processor 408. The memory 406 may further store computer-readable program instructions for execution by processor 408 to operate node 400 to perform various functions described in this disclosure. In some examples, the memory 406 may include a basic input/output system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices. In some embodiments, the node 400 is a Type A UE and the memory 406 includes both LTE SL and NR SL modules. In some embodiments, the node 400 is a Type B UE and the memory 406 includes an NR SL module only. In some embodiments, the node 400 is a Type C UE and the memory 406 includes an LTE SL module only.
The computer-readable program instructions of the present disclosure may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state-setting data, or source code or object code written in any combination of one or more programming languages, including an object-oriented programming language, and conventional procedural programming languages. The computer-readable program instructions may execute entirely on a computing device as a stand-alone software package, or partly on a first computing device and partly on a second computing device remote from the first computing device. In the latter scenario, the second, remote computing device may be connected to the first computing device through any type of network, including a local area network (LAN) or a wide area network (WAN).
The node 400 may include a processor 408 that may include a hardware device with processing capabilities. The processor 408 may include at least one of a general-purpose processor, a digital signal processor (DSP), a central processing unit (CPU), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or other programmable logic device. Examples of the general-purpose processor include, but are not limited to, a microprocessor, any conventional processor, a controller, a microcontroller, or a state machine. In some embodiments, the processor 408 may be implemented using a combination of devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration). The processor 408 may receive, from transceiver 404, downlink signals or sidelink signals and further process the signals. The processor 408 may also receive, from transceiver 404, data packets and further process the packets. In some embodiments, the processor 408 may be configured to operate a memory using a memory controller. In some embodiments, a memory controller may be integrated into the processor 408. The processor 408 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 406) to cause the node 400 to perform various functions.
The node 400 may include a global positioning system (GPS) 410. The GPS 410 may be used for enabling location-based services or other services based on a geographical position of the node 400 and/or synchronization among UEs. The GPS 410 may receive global navigation satellite systems (GNSS) signals from a single satellite or a plurality of satellite signals via the antenna 402 and provide a geographical position of the node 400 (e.g., coordinates of the node 400).
The node 400 may include an input/output (I/O) device 412 that may be used to communicate a result of signal processing and computation to a user or another device. The I/O device 412 may include a user interface including a display and an input device to transmit a user command to processor 408. The display may be configured to display a status of signal reception at the node 400, the data stored at memory 406, a status of signal processing, and a result of computation, etc. The display may include, but is not limited to, a cathode ray tube (CRT), a liquid crystal display (LCD), a light-emitting diode (LED), a gas plasma display, a touch screen, or other image projection devices for displaying information to a user. The input device may be any type of computer hardware equipment used to receive data and control signals from a user. The input device may include, but is not limited to, a keyboard, a mouse, a scanner, a digital camera, a joystick, a trackball, cursor direction keys, a touchscreen monitor, or audio/video commanders, etc.
The node 400 may further include a bus 414, such as an electrical bus that connects the transceiver 404, the memory 406, the processor 408, the GPS 410, and the I/O device 412.
In some embodiments, the node 400 may be configured to or programmed for sidelink communications. The processor 408 may be configured to execute the instructions stored in the memory 406 to perform carrier aggregation in a sidelink communication, consistent with the method 200 described in connection with FIG. 2 or perform carrier correlation detection, consistent with the method 300 described in connection with FIG. 3.
In an embodiment where the node 400 is a Type A UE, the node 400 may include a first radio access technology (RAT 1) module 420 in communication with the bus 414 and a second radio access technology (RAT 2) module 422 in communication with the bus 414. In some embodiments, RAT 1 module 420 may be configured to implement a first RAT, for example, LTE. In some embodiments, RAT 2 module 422 may be configured to implement a second RAT, different from the first RAT, for example, NR. It is noted that the types of RATs implemented by the RAT modules 420, 422 are not limited to LTE and NR. The RAT modules 420, 422 may implement any type of RAT without changing the principles of operation of the embodiments described herein.
In an embodiment where the node 400 is a Type B UE or a Type C UE, the node 400 may include only one RAT module (e.g., RAT 1 module 420). RAT 1 module 420 may implement any type of RAT, e.g., LTE, NR, or other type of RAT. In Fig. 4, RAT 2 module 422 is shown in dashed outline to indicate that it may not be included in some embodiments.
Any of the embodiments described in this disclosure may apply to 3GPP sidelink. This may, for example, apply to Release 18 NR Sidelink and/or Release 18 LTE-NR Sidelink co-existence (for example, for sidelink in unlicensed access). However, the embodiments described in the present disclosure are not restricted to this technology and may apply to other wireless communication technologies, for example and not limited to, Digital Enhanced Cordless Telecommunications / Digital European Cordless Telecommunications (DECT) or IEEE 802.11, for example, Wi-Fi.
As used in this disclosure, use of the term “or” in a list of items indicates an inclusive list. The list of items may be prefaced by a phrase such as “at least one of” or “one or more of.” For example, a list of at least one of A, B, or C includes A or B or C or AB (i.e., A and B) or AC or BC or ABC (i.e., A and B and C). Also, as used in this disclosure, prefacing a list of conditions with the phrase “based on” shall not be construed as “based only on” the set of conditions and rather shall be construed as “based at least in part on” the set of conditions. For example, an outcome described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of this disclosure.
In this specification, the terms “comprise,” “include,” or “contain” may be used interchangeably and have the same meaning and are to be construed as inclusive and open-ended. The terms “comprise,” “include,” or “contain” may be used before a list of elements and indicate that at least all of the listed elements within the list exist but other elements that are not in the list may also be present. For example, if A comprises B and C, both {B, C} and {B, C, D} are within the scope of A.
The present disclosure, in connection with the accompanied drawings, describes example configurations that are not representative of all the examples that may be implemented or all configurations that are within the scope of this disclosure. The term “exemplary” should not be construed as “preferred” or “advantageous compared to other examples” but rather “an illustration, an instance or an example.” By reading this disclosure, including the description of the embodiments and the drawings, it will be appreciated by a person of ordinary skills in the art that the technology disclosed herein may be implemented using alternative embodiments. The person of ordinary skill in the art would appreciate that the embodiments, or certain features of the embodiments described herein, may be combined to arrive at yet other embodiments for practicing the technology described in the present disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.
The flowcharts and block diagrams in the figures illustrate examples of the architecture, functionality, and operation of possible implementations of systems, methods, and devices according to various embodiments. It should be noted that, in some alternative implementations, the functions noted in blocks may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. Likewise, additional steps may be included in such methods, and certain steps may be omitted or combined, in methods consistent with various embodiments.
It is understood that the described embodiments are not mutually exclusive, and elements, components, materials, or steps described in connection with one example embodiment may be combined with, or eliminated from, other embodiments in suitable ways to accomplish desired design objectives.
Reference herein to “some embodiments” or “some exemplary embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment. The appearance of the phrases “one embodiment” “some embodiments” or “another embodiment” in various places in the present disclosure do not all necessarily refer to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments.
Additionally, the articles “a” and “an” as used in the present disclosure and the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from context to be directed to a singular form.
Unless explicitly stated otherwise, each numerical value and range should be interpreted as being approximate as if the word “about” or “approximately” preceded the value of the value or range.
Although the elements in the following method claims, if any, are recited in a particular sequence, unless the claim recitations otherwise imply a particular sequence for implementing some or all of those elements, those elements are not necessarily intended to be limited to being implemented in that particular sequence.
It is appreciated that certain features of the present disclosure, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the specification, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the specification. Certain features described in the context of various embodiments are not essential features of those embodiments, unless noted as such.
It will be further understood that various modifications, alternatives, and variations in the details, materials, and arrangements of the parts which have been described and illustrated in order to explain the nature of described embodiments may be made by those skilled in the art without departing from the scope. Accordingly, the following claims embrace all such alternatives, modifications, and variations that fall within the terms of the claims.
Clause 1: A method for carrier aggregation in a sidelink communication, comprising:
determining, at a first node, a set of candidate carriers for aggregation;
selecting one or more candidate carriers from the set of candidate carriers as one or more component carriers for carrier aggregation based on correlation among carriers; and
transmitting or receiving on the one or more component carriers.
Clause 2: The method of clause 1, further comprising:
performing the selection based on excluding one or more carriers having high correlation with another one or more carriers.
Clause 3: The method of clause 2, further comprising:
determining the correlation among carriers based on correlation information received at the first node.
Clause 4: The method of clause 3, further comprising:
receiving, from a second node, a communication including the correlation information, wherein the communication includes any one of a radio interface message, a radio protocol data unit header, a physical layer field, or physical layer control information.
Clause 5: The method of clause 1, further comprising:
performing a carrier correlation detection procedure.
Clause 6: The method of clause 5, wherein the carrier correlation detection procedure is performed upon receipt of an indication of a start of the carrier correlation detection procedure by the first node.
Clause 7: The method of clause 6, wherein the indication includes information relating to a second set of carriers allowing the first node to perform carrier correlation detection on the second set of carriers.
Clause 8: The method of clause 6, further comprising:
receiving, from a second node, a communication including the indication of the start of the carrier correlation detection procedure, wherein the communication includes any one of a radio interface message, a radio protocol data unit header, a physical layer field, or physical layer control information.
Clause 9: The method of clause 5, further comprising:
restarting the carrier correlation detection procedure.
Clause 10: The method of clause 9, wherein the restarting is triggered based on an event detected by the first node.
Clause 11: The method of clause 10, wherein the event includes one or more of:
a change in a traffic metric;
a change in the traffic metric over a predetermined period of time;
a change in the traffic metric over the predetermined period of time that exceeds a configured or pre-configured threshold;
a change in multiple traffic metrics;
a change in the multiple traffic metrics over the predetermined period of time; or
a change in the multiple traffic metrics over the predetermined period of time that each exceeds the configured or pre-configured threshold.
Clause 12: The method of clause 11, wherein the traffic metric includes one or more of received signal strength indicator or channel busy ratio.
Clause 13: The method of clause 11, wherein the predetermined period of time starts when the carrier correlation detection procedure is started.
Clause 14: The method of clause 11, wherein the predetermined period of time is scaled depending on a speed of the first node or an observed rate at which a radio environment changes.
Clause 15: The method of clause 5, further comprising:
starting a timer when the carrier correlation detection procedure is started; and
restarting the carrier correlation detection procedure when the timer expires.
Clause 16: The method of clause 15, wherein a duration of the timer is based on any one of:
a stored configuration in the first node provided by a controlling network entity;
a stored configuration in the first node provided by another node;
a pre-configuration in a subscriber identity unit;
a pre-configuration in a universal integrated circuit card; or
a hard coding in the first node.
Clause 17: A first node for performing carrier aggregation in a sidelink communication, comprising:
a memory configured to store instructions; and
a processor configured to execute the instructions stored in the memory to:
determine a set of candidate carriers for aggregation;
select one or more candidate carriers from the set of candidate carriers as one or more component carriers for carrier aggregation based on correlation among carriers; and
transmit or receive on the one or more component carriers.
Clause 18: The first node of clause 17, wherein the processor is further configured to:
perform the selection based on excluding one or more carriers having high correlation with another one or more carriers.
Clause 19: The first node of clause 18, wherein the processor is further configured to:
determine the correlation among carriers based on correlation information received at the first node.
Clause 20: The first node of clause 19, wherein the processor is further configured to:
receive, from a second node, a communication including the correlation information, wherein the communication includes any one of a radio interface message, a radio protocol data unit header, a physical layer field, or physical layer control information.
Clause 21: The first node of clause 17, wherein the processor is further configured to:
perform a carrier correlation detection procedure.
Clause 22: The first node of clause 21, wherein the carrier correlation detection procedure is performed upon receipt of an indication of a start of a carrier correlation detection procedure by the first node.
Clause 23: The first node of clause 22, wherein the indication includes information relating to a second set of carriers allowing the first node to perform carrier correlation detection on the second set of carriers.
Clause 24: The first node of clause 22, wherein:
the processor is further configured to receive the indication as a communication from a second node; and
the communication includes any one of a radio interface message, a radio protocol data unit header, a physical layer field, or physical layer control information.
Clause 25: The first node of clause 21, wherein the processor is further configured to:
restart the carrier correlation detection procedure.
Clause 26: The first node of clause 25, wherein the restarting is triggered based on an event detected by the first node.
Clause 27: The first node of clause 26, wherein the event includes one or more of:
a change in a traffic metric;
a change in the traffic metric over a predetermined period of time;
a change in the traffic metric over the predetermined period of time that exceeds a configured or pre-configured threshold;
a change in multiple traffic metrics;
a change in the multiple traffic metrics over the predetermined period of time; or
a change in the multiple traffic metrics over the predetermined period of time that each exceeds the configured or pre-configured threshold.
Clause 28: The first node of clause 27, wherein the traffic metric includes one or more of received signal strength indicator or channel busy ratio.
Clause 29: The first node of clause 27, wherein the predetermined period of time starts when the carrier correlation detection procedure is started.
Clause 30: The first node of clause 27, wherein the predetermined period of time is scaled depending on a speed of the first node or an observed rate at which a radio environment changes.
Clause 31: The first node of clause 21, wherein the processor is further configured to:
start a timer when the carrier correlation detection procedure is started; and
restart the carrier correlation detection procedure when the timer expires.
Clause 32: The first node of clause 31, wherein a duration of the timer is based on any one of:
a stored configuration in the first node provided by a controlling network entity;
a stored configuration in the first node provided by another node;
a pre-configuration in a subscriber identity unit;
a pre-configuration in a universal integrated circuit card; or
a hard coding in the first node.
Clause 33: A non-transitory computer-readable medium storing instructions that are executable by one or more processors of a first node in a communication network to perform a method, the method comprising:
determining, at the first node, a set of candidate carriers for aggregation;
selecting one or more candidate carriers from the set of candidate carriers as one or more component carriers for carrier aggregation based on correlation among carriers; and
transmitting or receiving on the one or more component carriers.
Clause 34: A method for carrier correlation detection, comprising:
determining correlation of signals across carriers in a set of carriers;
creating a resource matrix for each carrier in the set of carriers; and
obtaining a correlation metric based on the resource matrix.
Clause 35: The method of clause 34, further comprising:
receiving one or more signals in the set of carriers, wherein the one or more signals include a predetermined payload or a reference signal.
Clause 36: The method of clause 35, wherein the predetermined payload includes any one of:
a stored configuration in a first node provided by a controlling network entity;
a stored configuration in the first node provided by another node;
a pre-configuration in a subscriber identity unit;
a pre-configuration in a universal integrated circuit card; or
hard coding in the first node.
Clause 37: The method of clause 35, wherein the reference signal includes any one of:
a channel state information reference signal; or
a demodulation reference signal along with one of a physical sidelink control channel or a physical sidelink shared channel.
Clause 38: The method of clause 34, wherein determining correlation of the signals is based on any one of:
received energy;
channel impulse response;
history of channel busy ratio measurements;
history of received signal strength indicator measurements;
history of reserved resources;
history of channel occupancy ratio measurements;
history of channel status information report values;
history of L3-filtered sidelink received signal reference power measurements;
history of one or more of acknowledgement ratio or negative acknowledgement ratio;
listen-before talk (LBT) failure rate;
history of consistent LBT failures;
history of radio link failure; or
history of one or more of beam recovery or beam realignment.
Clause 39: The method of clause 34, wherein creating the resource matrix includes creating a time and frequency resource matrix based on sensing information determined by a first node.
Clause 40: The method of clause 34, wherein:
obtaining the correlation metric includes calculating the correlation metric using binary matrices; and
each matrix element of the resource matrix is composed of binary information if activity was detected or not at a first node in each of one or more of time resource or frequency resource.
Clause 41: The method of clause 40, wherein whether activity was detected or not at the first node is based on any one or more of:
received signal reference power;
received signal strength indicator;
signal to noise and interference ratio; or
energy detection.
Clause 42: The method of clause 41, further comprising:
comparing a measurement value of each of the one or more of time resource or frequency resource to a threshold value, wherein:
if the measurement value is below the threshold value, the matrix element of a corresponding resource is a “0” value; and
if the measurement value is equal to or above the threshold value, the matrix element of the corresponding resource is a “1” value.
Clause 43: The method of clause 42, wherein the threshold value includes any one of:
a stored configuration in the first node provided by a controlling network entity;
a stored configuration in the first node provided by another node;
a pre-configuration in a subscriber identity unit;
a pre-configuration in a universal integrated circuit card; or
hard coding in the first node.
Clause 44: The method of clause 34, wherein:
obtaining the correlation metric includes calculating the correlation metric using binary matrices, and
each matrix element of the resource matrix is composed of identification information to provide information about time and frequency resources where a first node can receive signals from a second node and identify its carriers.
Clause 45: The method of clause 34, wherein:
obtaining the correlation metric includes calculating the correlation metric using numerical matrices, and
each matrix element of the resource matrix identifies the correlation of signals transmitted in a time and frequency resource.
Clause 46: The method of clause 45, wherein each matrix element is an integer value or a floating point value.
Clause 47: The method of clause 45, wherein each matrix element is an obtained correlation value based on a similarity of channel impulse responses of different carriers.
Clause 48: The method of clause 34, wherein obtaining the correlation metric includes calculating the correlation metric based on an outcome of decoding data that has been duplicated across multiple carriers in the set of carriers.
Clause 49: The method of clause 48, wherein:
a high value in the matrix indicates a high correlation between carriers; and
a low value in the matrix indicates a low correlation between carriers.
Clause 50: The method of clause 34, further comprising:
receiving the correlation metric at a first node from a second node.
Clause 51: The method of clause 50, wherein the receiving includes any one of:
populating radio parameters, indicators, or fields in a radio interface message;
populating fields in a radio protocol data unit header;
populating physical layer fields; or
receiving a contained octet string in a radio protocol.
Clause 52: The method of clause 50, wherein the receiving includes receiving the correlation metric as a matrix or a compressed matrix.
Clause 53: The method of clause 50, wherein the receiving includes receiving the correlation metric as an integer value or a floating-point number represented as a code point in a fixed sized bit combination.
Clause 54: The method of clause 50, wherein the receiving includes receiving the correlation metric as a single bit to indicate if carriers are correlated or not.
Clause 55: The method of clause 54, further comprising:
comparing the correlation metric to a threshold value to determine a value of the single bit; and
if the correlation is above the threshold value, setting the value of the single bit to “1”.
Clause 56: The method of clause 34, further comprising:
sharing the correlation metric from a first node to a second node.
Clause 57: The method of clause 56, wherein the sharing includes any one of:
populating radio parameters, indicators, or fields in a radio interface message;
populating fields in a radio protocol data unit header;
populating physical layer fields; or
sending a contained octet string in a radio protocol.
Clause 58: The method of clause 56, wherein the sharing includes sharing the correlation metric as a matrix or a compressed matrix.
Clause 59: The method of clause 56, wherein the sharing includes sharing the correlation metric as an integer value or a floating-point number represented as a code point in a fixed sized bit combination.
Clause 60: The method of clause 56, wherein the sharing includes sharing the correlation metric as a single bit to indicate if carriers are correlated or not.
Clause 61: The method of clause 60, further comprising:
comparing the correlation metric to a threshold value to determine a value of the single bit; and
if the correlation is above the threshold value, setting the value of the single bit to “1”.
Clause 62: The method of clause 34, further comprising:
indicating one or more of the carriers as being excluded from a transmission occasion if the correlation metric indicates that another one or more carriers are strongly correlated.
Clause 63: The method of clause 34, further comprising:
determining carriers with a correlation value below a threshold; and
sharing the determined carriers with a second node.
Clause 64: A first node for performing carrier correlation detection, comprising:
a memory configured to store instructions; and
a processor configured to execute the instructions stored in the memory to:
determine correlation of signals across carriers in a set of carriers;
create a resource matrix for each carrier in the set of carriers; and
obtain a correlation metric based on the resource matrix.
Clause 65: The first node of clause 64, wherein:
the processor is further configured to receive one or more signals in the set of carriers; and
the signals include a predetermined payload or a reference signal.
Clause 66: The first node of clause 65, wherein the predetermined payload includes any one of:
a stored configuration in the first node provided by a controlling network entity;
a stored configuration in the first node provided by another node;
a pre-configured in a subscriber identity unit;
a pre-configured in a universal integrated circuit card; or
hard coding in the first node.
Clause 67: The first node of clause 65, wherein the reference signal includes any one of:
a channel state information reference signal; or
a demodulation reference signal along with a physical sidelink control channel or a physical sidelink shared channel.
Clause 68: The first node of clause 64, wherein determining correlation of the signals is based on any one of:
received energy;
channel impulse response;
history of channel busy ratio measurements;
history of received signal strength indicator measurements;
history of reserved resources;
history of channel occupancy ratio measurements;
history of channel status information report values;
history of L3-filtered sidelink received signal reference power measurements;
history of acknowledgement/negative acknowledgement ratio;
listen-before talk (LBT) failure rate;
history of consistent LBT failures;
history of radio link failure; or
history of beam recovery/realignment.
Clause 69: The first node of clause 64, wherein the processor is further configured to create the resource matrix by creating a time and frequency resource matrix based on sensing information determined by the first node.
Clause 70: The first node of clause 64, wherein:
the processor is further configured to obtain the correlation metric by calculating the correlation metric using binary matrices; and
each matrix element of the resource matrix is composed of binary information if activity was detected or not at the first node in each of the one or more of time or frequency resource.
Clause 71: The first node of clause 70, wherein whether activity was detected or not at the first node is based on any one or more of:
received signal reference power;
received signal strength indicator;
signal to noise and interference ratio; or
energy detection.
Clause 72: The first node of clause 71, wherein the processor is further configured to:
compare a measurement value of each of the one or more of time resource or frequency resource to a threshold value, wherein:
if the measurement value is below the threshold value, the matrix element of a corresponding resource is a “0” value; and
if the measurement value is equal to or above the threshold value, the matrix element of the corresponding resource is a “1” value.
Clause 73: The first node of clause 72, wherein the threshold value includes any one of:
a stored configuration in the first node provided by a controlling network entity;
a stored configuration in the first node provided by another node;
a pre-configuration in a subscriber identity unit;
a pre-configuration in a universal integrated circuit card; or
hard coding in the first node.
Clause 74: The first node of clause 64, wherein:
the processor is further configured to obtain the correlation metric by calculating the correlation metric using binary matrices; and
each matrix element of the resource matrix is composed of identification information to provide information about time and frequency resources where the first node can receive signals from a second node and identify its carriers.
Clause 75: The first node of clause 64, wherein:
the processor is further configured to obtain the correlation metric by calculating the correlation metric using numerical matrices; and
each matrix element or the resource matrix identifies the correlation of signals transmitted in a time and frequency resource.
Clause 76: The first node of clause 75, wherein each matrix element is an integer value or a floating point value.
Clause 77: The first node of clause 75, wherein each matrix element is an obtained correlation value based on a similarity of channel impulse responses of different carriers.
Clause 78: The first node of clause 64, wherein the processor is further configured to:
obtain the correlation metric by calculating the correlation metric based on an outcome of decoding data that has been duplicated across multiple carriers in the set of carriers.
Clause 79: The first node of clause 78, wherein:
a high value in the matrix indicates a high correlation between carriers; and
a low value in the matrix indicates a low correlation between carriers.
Clause 80: The first node of clause 64, wherein the processor is further configured to:
receive the correlation metric from a second node.
Clause 81: The first node of clause 80, wherein the processor is further configured to receive the correlation metric by any one of:
populating radio parameters, indicators, or fields in a radio interface message;
populating fields in a radio protocol data unit header;
populating physical layer fields; or
receiving a contained octet string in a radio protocol.
Clause 82: The first node of clause 80, wherein the processor is further configured to receive the correlation metric as a matrix or a compressed matrix.
Clause 83: The first node of clause 80, wherein the processor is further configured to receive the correlation metric as an integer value or a floating-point number represented as a code point in a fixed sized bit combination.
Clause 84: The first node of clause 80, wherein the processor is further configured to receive the correlation metric as a single bit to indicate if carriers are correlated or not.
Clause 85: The first node of clause 84, wherein the processor is further configured to:
compare the correlation metric to a threshold value to determine a value of the single bit; and
if the correlation is above the threshold value, set the value of the single bit to “1”.
Clause 86: The first node of clause 64, wherein the processor is further configured to:
share the correlation metric with a second node.
Clause 87: The first node of clause 86, wherein the processor is further configured to share the correlation metric by any one of:
populating radio parameters, indicators, or fields in a radio interface message;
populating fields in a radio protocol data unit header;
populating physical layer fields; or
sending a contained octet string in a radio protocol.
Clause 88: The first node of clause 86, wherein the processor is further configured to share the correlation metric as a matrix or a compressed matrix.
Clause 89: The first node of clause 86, wherein the processor is further configured to share the correlation metric as an integer value or a floating-point number represented as a code point in a fixed sized bit combination.
Clause 90: The first node of clause 86, wherein the processor is further configured to share the correlation metric as a single bit to indicate if carriers are correlated or not.
Clause 91: The first node of clause 90, wherein the processor is further configured to:
compare the correlation metric to a threshold value to determine a value of the single bit; and
if the correlation is above the threshold value, set the value of the single bit to “1”.
Clause 92: The first node of clause 64, wherein the processor is further configured to:
indicate one or more of the carriers as being excluded from a transmission occasion if the correlation metric indicates that another one or more carriers are strongly correlated.
Clause 93: The first node of clause 64, wherein the processor is further configured to:
determine carriers with a correlation value below a threshold; and
share the determined carriers with a second node.
Clause 94: A non-transitory computer-readable medium storing instructions that are executable by one or more processors of a first node in a communication network to perform a method, the method comprising:
determining correlation of signals across carriers in a set of carriers;
creating a resource matrix for each carrier in the set of carriers; and
obtaining a correlation metric based on the resource matrix.

Claims

A method for carrier aggregation in a sidelink communication, comprising:
determining, at a first node, a set of candidate carriers for aggregation;
selecting one or more candidate carriers from the set of candidate carriers as one or more component carriers for carrier aggregation based on correlation among carriers; and
transmitting or receiving on the one or more component carriers.
The method of claim 1, further comprising:
performing the selection based on excluding one or more carriers having high correlation with another one or more carriers.
The method of claim 1, further comprising:
performing a carrier correlation detection procedure.
The method of claim 3, wherein the carrier correlation detection procedure is performed upon receipt of an indication of a start of the carrier correlation detection procedure by the first node.
The method of claim 4, wherein the indication includes information relating to a second set of carriers allowing the first node to perform carrier correlation detection on the second set of carriers.
The method of claim 3, further comprising:
starting a timer when the carrier correlation detection procedure is started; and
restarting the carrier correlation detection procedure when the timer expires.
The method of claim 6, wherein a duration of the timer is based on any one of:
a stored configuration in the first node provided by a controlling network entity;
a stored configuration in the first node provided by another node;
a pre-configuration in a subscriber identity unit;
a pre-configuration in a universal integrated circuit card; or
a hard coding in the first node.
A method for carrier correlation detection, comprising:
determining correlation of signals across carriers in a set of carriers;
creating a resource matrix for each carrier in the set of carriers; and
obtaining a correlation metric based on the resource matrix.
The method of claim 8, further comprising:
receiving one or more signals in the set of carriers, wherein the one or more signals include a predetermined payload or a reference signal.
The method of claim 8, wherein determining correlation of the signals is based on any one of:
received energy;
channel impulse response;
history of channel busy ratio measurements;
history of received signal strength indicator measurements;
history of reserved resources;
history of channel occupancy ratio measurements;
history of channel status information report values;
history of L3-filtered sidelink received signal reference power measurements;
history of one or more of acknowledgement ratio or negative acknowledgement ratio;
listen-before talk (LBT) failure rate;
history of consistent LBT failures;
history of radio link failure; or
history of one or more of beam recovery or beam realignment.
The method of claim 8, wherein creating the resource matrix includes creating a time and frequency resource matrix based on sensing information determined by a first node.
The method of claim 8, wherein:
obtaining the correlation metric includes calculating the correlation metric using binary matrices; and
each matrix element of the resource matrix is composed of binary information if activity was detected or not at a first node in each of one or more of time resource or frequency resource.
The method of claim 8, wherein:
obtaining the correlation metric includes calculating the correlation metric using binary matrices, and
each matrix element of the resource matrix is composed of identification information to provide information about time and frequency resources where a first node can receive signals from a second node and identify its carriers.
The method of claim 8, wherein:
obtaining the correlation metric includes calculating the correlation metric using numerical matrices, and
each matrix element of the resource matrix identifies the correlation of signals transmitted in a time and frequency resource.
The method of claim 14, wherein each matrix element is an obtained correlation value based on a similarity of channel impulse responses of different carriers.
The method of claim 8, wherein obtaining the correlation metric includes calculating the correlation metric based on an outcome of decoding data that has been duplicated across multiple carriers in the set of carriers.
The method of claim 8, further comprising:
receiving the correlation metric at a first node from a second node.
The method of claim 8, further comprising:
sharing the correlation metric from a first node to a second node.
The method of claim 8, further comprising:
indicating one or more of the carriers as being excluded from a transmission occasion if the correlation metric indicates that another one or more carriers are strongly correlated.
The method of claim 8, further comprising:
determining carriers with a correlation value below a threshold; and
sharing the determined carriers with a second node.