Patent Description:
Various communication environments utilize a common medium for communications transmitted and/or received at various communication nodes. For instance, in vehicle-to-vehicle or vehicle-to-everything (V2X) environments, multiple vehicles may communicate with one another and/or with other communication nodes such as traffic lights, pedestrian-carried devices and others. Under such conditions, communication nodes may inadvertently select the same subchannel, such as when re-scheduling is required. For instance, when two or more vehicles in close proximity select the same subchannel, conflicts and deleterious co-channel interference may occur.

These and other matters have presented challenges to communication efficiencies and quality, for a variety of applications.

<CIT> discloses a wireless communication device configured to perform resource allocation of device-to-device (D2D) communication.

<CIT> discloses an apparatus (e.g., first transmitter) that determines a transmission power of each of a plurality of neighboring transmitters respectively transmitting on a plurality of subchannels in a bandwidth, detects a pathloss to each of the plurality of neighboring transmitters respectively transmitting on the plurality of subchannels, and selects one of the plurality of subchannels for transmitting a signal based on the determined transmission power on each of the plurality of subchannels and the detected pathloss to each of the plurality of neighboring transmitters.

Various example embodiments are directed to issues such as those addressed above and/or others which may become apparent from the following disclosure concerning shared usage of communications mediums, and efficiently/accurately ensuring communications.

Aspects of the present disclosure are believed to be applicable to a variety of different types of apparatuses, systems and methods involving communications between respective circuits or vehicles located at disparate distances. In certain implementations, aspects of the present disclosure have been shown to be beneficial when used in the context of vehicle-to-everything (V2X) communications, in which a plurality of vehicles that communicate are in motion and share the V2X communication environment. In some embodiments, energy associated with communications as well as a location of the source of the communications are ascertained and used for sharing a communication environment. For instance, subchannels or resource blocks in a V2X communication environment can be selected and used for communication based on ascertained energy and transmitter locations, in a manner that facilitates sharing of communication resources and address issues such as those noted in the Background above. While not necessarily so limited, various aspects may be appreciated through the following discussion of non-limiting examples which use exemplary contexts.

Accordingly, in the following description various specific details are set forth to describe specific examples presented herein. It should be apparent to one skilled in the art, however, that one or more other examples and/or variations of these examples may be practiced without all the specific details given below. In other instances, well known features have not been described in detail so as not to obscure the description of the examples herein. For ease of illustration, the same reference numerals may be used in different diagrams to refer to the same elements or additional instances of the same element. Also, although aspects and features may in some cases be described in individual figures, it will be appreciated that features from one figure or embodiment can be combined with features of another figure or embodiment even though the combination is not explicitly shown or explicitly described as a combination.

Various aspects of the disclosure are directed to the use of latent information pertaining to transmitter location, which can be used to enhance the performance of communications such as V2X links, such as those utilized in centralized and/or distributed modes. More specifically, subchannels can be selected based on current subchannel use by other transmitters operating in a local environment, and using location information associated with the other transmitters. For instance, subchannel communications by transmitters located at greater distances, such as near an outer range of communications, can be weighted lower or otherwise ascertained in a manner that emphasizes or prioritizes avoidance of subchannels used by transmitters that are closer. When employed with V2X communications, this facilitates communications in a manner that mitigates collisions or other issues involving communications with vehicles that are near one another.

Various embodiments are directed to C-V2X (cellular V2X) mode-<NUM> communications, as defined in the 3rd Generation Partnership Project (3GPP) Release <NUM>, which expressly supports vehicular communications in scenarios without network coverage. Energy and source location of communications utilizing C-V2X are utilized to mitigate the inadvertent selection of the same subchannel by two vehicles, such as when re-scheduling is required. This mitigates conflicts and co-channel interference. For instance, by reusing subchannels utilized by vehicles at geographically distanced locations, conflicts with communications carried out by nearby vehicles can be mitigated. Accordingly, in connection with some embodiments a distributed subchannel scheduling scheme is based on unsupervised learning whereby vehicles can minimize the occurrence of conflicts and their impact by exploiting both geographical location and received power. The reliability of vehicle-to-vehicle links in the short range can be improved by efficiently utilizing sidelink subchannels.

In accordance with one or more embodiments herein, one or more transmitters may use each subchannel. For instance, each transmitter may utilize a resource block of the related communication medium as a time-frequency block in the subchannel.

Various embodiments are directed to implementation in communications environments in which each transmitter acts autonomously in selecting its own subchannel for communications. Such an approach may, for example, involve V2X communications such as C-V2X mode-<NUM> in scenarios without network coverage. A subchannel scheduling scheme is implemented in three stages: (<NUM>) a power monitoring stage, (<NUM>) a ranking stage, and (<NUM>) a selection stage. This scheduling may be carried out at each transmitter, and may be carried out autonomously. In the monitoring stage, received power intensities across monitorable subchannels are assessed. In the ranking stage, a list is created with the subchannels sorted in ascending order of power intensity. In the selection stage, a subchannel is selected based on the ranking and location information associated with transmitters utilizing the subchannels.

Randomization or pseudo-randomizaton may be utilized to select one of a multitude of subchannels identified in the selection stage, which can mitigate selection of the same subchannel for different transmitters. For instance, when vehicles at geographically proximate positions experience similar subchannel conditions, similar candidate subchannels may be identified such that randomization or pseudo-randomization can facilitate selection of different subchannels for the geographically proximate vehicles.

Vehicles located at geographically distant positions are less susceptible to prohibitively high co-channel interference when utilizing a common subchannel, and as such the location of related transmissions can be processed accordingly. More specifically, while conflicts may not be prevented due the scarceness of sidelink subchannels, the impact of co-channel interference can be mitigated if subchannels are reutilized at geographically distanced locations. In this context it has thus been recognized/discovered that utilizing location information along with subchannel energy can facilitate subchannel selection and use in a manner that mitigates conflicts. As a result, the reliability of vehicle-to-vehicle links, especially in the short range can be leveraged.

Certain embodiments are implemented with centralized communications, in which a particular node performs clustering based on information obtained from a multitude of transmitters (e.g., vehicles). This clustering may be utilized for selecting subchannels for each of the transmitters in a local environment.

In a more specific example embodiment, a method is carried out in a communications environment involving remote transmitters that communicate over respective subchannels, as follows. For each of the subchannels, energy characteristics of wireless transmissions received from one of the remote transmitters over the subchannel, and a location of the remote transmitter that communicates via the subchannel, are respectively ascertained (e.g., in a receiver). The location may, for example, be ascertained using location information in the collected transmissions, such as data indicative of GPS coordinates. One of the subchannels is selected based on the ascertained energy characteristics and locations of the remote transmitters, and data is generated for transmission over the selected one of the subchannels. These steps of ascertaining and selecting may be repeated, for example based on a time period from an initialization and/or a period after one of the subchannels is selected.

Subchannel selection may be carried out in a variety of manners, to suit particular embodiments. In some embodiments, subchannels are selected which have an energy value that is lower than an energy value of other ones of the subchannels, and that is collected from one of the remote transmitters located at a distance that is greater than a distance at which other ones of the remote transmitters are located. In certain embodiments, data indicative of energy and a distance value of the remote transmitter from which the wireless transmission was collected are grouped into clusters including data from other ones of the wireless transmissions, based on the energy and distance values of the data. One of the subchannels is pseudorandomly selected from subchannels in one of the clusters depicting low energy values and high distance values, relative to subchannels in other ones of the clusters.

In certain embodiments, data points are created for the subchannels, in which each data point indicates energy of the wireless transmissions collected on the subchannel, and a distance value of the remote transmitter from which the wireless transmissions are collected (e.g., as two-dimensional data points). The data points are grouped into clusters based on the energy and distance values of the respective data points. One of the clusters that depicts low energy values and high distance values, relative to other ones of the clusters, is selected. From that cluster, one of the subchannels corresponding to one of the data points in the selected cluster is chosen, such as by pseudorandomly selecting the data point.

Another embodiment is directed to an apparatus for use in a communications environment involving remote transmitters that communicate over respective subchannels. The apparatus includes respective circuits/circuitry, which may be combined in a single processor circuit, as follows. First circuitry (e.g., including receiver circuitry) ascertains, for each of the subchannels, energy characteristics of wireless transmissions received from one of the remote transmitters over the subchannel, and to further ascertain a location of the remote transmitter that communicates via the subchannel. For instance, location data placed in the collected transmissions by the remote transmitters may be utilized to identify each transmitter's physical location. Second circuitry selects one of the subchannels based on the ascertained energy characteristics and locations of the remote transmitters, and third circuitry generates data for transmission over the selected one of the subchannels. The first and second circuitry may repeat the steps of ascertaining and selecting for a time period as may begin after selection of one of the subchannels and/or initiation. The first, second and third circuitry may, for example, be part of or make up a common processor circuit that carries out the respective functions of the first, second and third circuitry.

The second circuitry selects one of the subchannels in one of more of a variety of manners. In some embodiments, a subchannel is selected that has an energy value that is lower than an energy value of other ones of the subchannels, and that is collected from one of the remote transmitters located at a distance that is greater than a distance at which other ones of the remote transmitters are located. Such an approach may, for example, involve forming clusters depicting subchannels having similar distance and energy characteristic, and selecting a subchannel from the cluster that exhibits subchannels having lower energy and located at a greater distance than all other clusters.

In some implementations, the second circuitry creates data points for the subchannels in which each data point indicates both energy of the wireless transmissions collected on the subchannel and a distance value of the remote transmitter from which the wireless transmissions are collected. The data points are grouped into clusters based on the energy and distance values of the respective data points, and one of the clusters depicting low energy values and high distance values, relative to other ones of the clusters, is selected. From that selected cluster, one of the subchannels therein corresponding to one of the data points is selected (e.g., pseudorandomly) for use.

Another embodiment is directed to a method in which a plurality of wireless communications from different transmitters are carried out over a cellular V2X communication network. The wireless communications may, for example, be distributed communications in which each of the transmitters autonomously selects its own subchannel. Energy characteristics of each of the wireless transmissions as well as location data in the wireless transmission, which is indicative of a location of the transmitter via which the wireless transmission was sent, are collected. A subchannel in the V2X communication network is selected based on the ascertained energy characteristics and location data for the respective wireless communications. Data is then transmitted in the V2X communication network using the selected subchannel. In various embodiments, the transmitters share the V2X communication network via a pool of time-frequency resource blocks, and the energy characteristics and location data are ascertained for each communication received from the different transmitters in a respective time-frequency resource block.

In some implementations, the subchannel in the V2X communication network is selected by creating data points for the subchannels, where each data point indicates energy of a wireless transmission collected on the subchannel and a distance value of the transmitter from which the wireless transmission is collected. The data points are grouped into clusters based on the energy and distance values of the respective data points, and one of the clusters that depicts low energy values and high distance values (relative to other ones of the clusters) is selected. From the selected cluster, one of the subchannels in the cluster, which corresponds to one of the data points in the selected cluster, is selected.

Turning now to the figures, <FIG> shows an apparatus <NUM> and system <NUM>, as may be implemented in accordance with one or more embodiments. By way of example, a plurality of vehicles <NUM>-<NUM> are shown participating in a wireless communication environment, along with an additional non-vehicle communication node <NUM> (e.g., a traffic structure or pedestrian-carried device). More or fewer communication nodes may be present, in a variety of applications. The apparatus <NUM> is shown as being implemented in connection with vehicle <NUM>, and includes blocks <NUM> and <NUM> for respectively determining distance and energy of signals received from remote transmitters, as may be in the other vehicles <NUM>-<NUM> and node <NUM>. A subchannel selection block <NUM> utilizes the distance and energy information at blocks <NUM> and <NUM> to select a subchannel for communication.

The apparatus <NUM> and respective blocks therein may be implemented in a variety of manners, as may the selection approach. For instance, the distance determination block <NUM>, energy determination block <NUM>, and subchannel selection block <NUM> may be implemented in a common processor circuit that receives signals from the remote transmitters and generates an output indicative of the selected subchannel. Further, subchannel selection at block <NUM> may, for example, be implemented using one or more approaches as discussed herein above and/or as shown in and described in connection with <FIG> and <NUM>.

In a particular implementation, the apparatus <NUM> operates as follows, with the various remote transmitters operating in the system <NUM> environment over a plurality of subchannels. For each of the subchannels via which communications are obtained, the distance block <NUM> ascertains the distance (e.g., location) of the transmitter in one of the other vehicles <NUM>-<NUM> or node <NUM> that is transmitting on the subchannel, relative to the vehicle <NUM>. The energy block <NUM> ascertains energy characteristics of transmissions received on the subchannel from the one of the transmitter. The subchannnel selection block <NUM> selects one of the subchannels based on the ascertained energy characteristics and locations of the remote transmitters. Data may then be generated for transmission over the selected one of the subchannels, from the vehicle <NUM>.

<FIG> shows an apparatus <NUM>, as may be implemented in accordance with one or more embodiments. The apparatus <NUM> is configured to communicate with a multitude of remote transmitters, including remote transmitter apparatus <NUM> which is depicted by way of example. The apparatus <NUM> includes transmitter and receiver circuits <NUM> and <NUM>, as well as an antenna <NUM> via which signals may be received and transmitted, respectively processed by a receiver processor <NUM> and a transmitter processor <NUM>. The apparatus <NUM> also includes controller/processor circuit <NUM>, which includes distance assessment block <NUM>, energy assessment block <NUM>, and subchannel selection block <NUM>. The distance and energy assessment blocks <NUM> and <NUM> operate to assess distance and energy of received communications carried out on various subchannels, and the subchannel selection block <NUM> utilizes this information to select a subchannel via which transmissions are to be sent. Memory <NUM> can be used to store information for subchannel selection (e.g., an algorithm) and other information used to facilitate operation of the apparatus <NUM>. Data indicative of the selected subchannel is used in generating transmissions that are sent via transmitter processor <NUM>, transmitter <NUM> and antenna <NUM>. Each of the components within the apparatus <NUM> may be implemented in a common circuit, as may be represented by the indicated dashed lines.

The remote transmitter apparatus <NUM> may be implemented in a variety of manners. By way of example, the remote transmitter apparatus <NUM> includes receiver and transmitter circuits <NUM> and <NUM>, antenna <NUM>, transmitter processor circuit <NUM> and receiver processor circuit <NUM>. A controller/processor circuit <NUM> operates with memory <NUM> for controlling the transmission and reception of signals, as well as related processing. In some instances, the controller/processor circuit <NUM> also includes distance and energy assessment blocks, and a subchannel selection block, as depicted with controller/processor circuit <NUM>.

Various embodiments may further be directed to systems including a combination of the apparatus <NUM> and the transmitter apparatus <NUM>, and/or multiple additional transmitter apparatuses such as that depicted for apparatus <NUM>. For instance, the apparatus <NUM> may be implemented in vehicle <NUM> of <FIG>, as the apparatus <NUM>, with the controller/processor circuit <NUM> employing distance assessment block <NUM> as block <NUM>, energy assessment block <NUM> as block <NUM>, and subchannel selection block <NUM> as block <NUM>.

Referring to <FIG>, an approach to channel selection is shown, as may be implemented in accordance with one or more embodiments. At block <NUM>, energy in respective subchannels via which communications are received is sensed, and the location at which each subchannel is being used is decoded from the received communications. This decoding may involve, for example, ascertaining data from the communications, which indicates a geographical location as included with by a remote transmitter from which the communications emanated. A 2D set of data points is generated at block <NUM>, in which the data points include energy and position information for the subchannels, and the data points are classified into clusters at block <NUM>. At block <NUM>, a cluster having data points with low energy and furthest locations (relative to a transmitter carrying out channel selection) is identified, and a subchannel from the selected cluster is randomly/pseudorandomly selected at block <NUM>. The selected subchannel is then used at block <NUM>, and can be carried on for a predetermined amount of time after which the process may be repeated (e.g., starting at block <NUM>) for selecting a new subchannel. Such an approach may, for example, be utilized with subchannel selection at block <NUM> or at block <NUM>.

Accordingly, the geographical position of the transmission source utilizing particular subchannels may be exploited when available, and may mitigate the severity of subchannel conflicts. For instance, subchannel reuse may be limited to those subchannels that are utilized by vehicles (or other transmitter sources) that are distant. In a particular embodiment, the 2D (bi-dimensional) set of points may be normalized to the range [<NUM><NUM>] (with respect to each dimension). The data points with normalized values are partitioned into a number of disjoint groups using a k-means clustering technique, in which each group is called a cluster. For instance, k-means clustering can be utilized by partitioning a number (n) of observations (distance, energy points) into a number (k) of clusters in which each observation belongs to the cluster with the nearest mean, serving as a prototype of the cluster. Subchannels may be grouped based on mutual similarities of their features: power and location. In this context, a cluster in which the subchannels have low energy and the corresponding locations are distant can be targeted for allocation and selection of a subchannel therefrom. Various specific clustering approaches may be implemented in connection with aspects characterized herein, as would be known and appreciated by the skilled artisan. See, e.g., <NPL>).

In a more particular embodiment, <FIG> shows an approach to selecting subchannels using transmitter location and energy information, as may be implemented in accordance with one or more embodiments. At block <NUM>, a subchannel assessment and selection process is initialized at time t = <NUM>, beginning with the assessment process that continues for communications received via respective subchannels, so long as the time t does not exceed a set time Tsps as noted at block <NUM>. Energy of a received communication is assessed beginning at block <NUM>, where for each monitorable subchannel sk, the received energy εk for a communication is recorded and stored at block <NUM>. The SINR (signal-to-interference-plus-noise ratio) is computed for each subchannel sk at block <NUM>. If this SINR is sufficiently high (e.g., γk> γT) at block <NUM>, the received signal (packet) is decoded at block <NUM> and the location information of the transmitter (e.g., vehicle) using the subchannel is obtained. If the SINR is not sufficiently high at block <NUM>, it may be assumed that the position of the vehicle pk is far as noted at block <NUM>, in which case the subchannel is noted at being at a distance ∞ from the receiver. Alternately, if the SINR is not sufficiently high at block <NUM>, the subchannel can simply be not used. The position data pk is stored at block <NUM>.

The process continues at block <NUM> until the sensing stage has expired (when t = TSPS), after which the values εk and pk are normalized to the range [<NUM><NUM>] at block <NUM>. At this time, the subchannels whose location was assigned a value of ∞ may have their locations updated to equal a furthest decoded distance among the subchannels from which location information was decoded. The normalized values are depicted by (ε̃, p̃). At block <NUM>, 2D data points including of energy and location (ε̃k, p̃k) are created, and are classified into clusters at block <NUM> using a k-means algorithm. The cluster that has subchannels with relatively low energy and far locations is selected at block <NUM>, and one of the subchannels in the selected cluster is randomly/pseudorandomly chosen at block <NUM> for transmission (e.g., semi-persistent transmission).

Aspects of the disclosure are directed to a communications environment involving a plurality of remote transmitters that communicate over respective subchannels. As may be implemented in accordance with one or more embodiments, energy characteristics of wireless transmissions received from one of the remote transmitters and a location that remote transmitter are respectively ascertained, for each of such subchannels. One of the subchannels is selected based on the ascertained energy characteristics and locations of the remote transmitters, and data is generated for transmission over the selected one of the subchannels.

The skilled artisan would recognize that various terminology as used in the Specification (including claims) connote a plain meaning in the art unless otherwise indicated. As examples, the Specification describes and/or illustrates aspects useful for implementing the claimed disclosure by way of various circuits or circuitry which may be illustrated as or using terms such as blocks, modules, device, system, unit, controller, transmitter, subchannel selector/collector, and/or other circuit-type depictions (e.g., reference numerals <NUM>-<NUM> of <FIG>, <NUM> and <NUM> of <FIG> may depict a block/module as described herein). Such circuits or circuitry are used together with other elements to exemplify how certain embodiments may be carried out in the form or structures, steps, functions, operations, activities, etc. For example, in certain of the above-discussed embodiments, one or more modules are discrete logic circuits or programmable logic circuits configured and arranged for implementing these operations/activities, as may be carried out in the approaches shown in <FIG>. In certain embodiments, such a programmable circuit is one or more computer circuits, including memory circuitry for storing and accessing a program to be executed as a set (or sets) of instructions (and/or to be used as configuration data to define how the programmable circuit is to perform), and an algorithm or process as shown in and described in connection with <FIG> and/or <NUM> is used by the programmable circuit to perform the related steps, functions, operations, activities, etc. Depending on the application, the instructions (and/or configuration data) can be configured for implementation in logic circuitry, with the instructions (whether characterized in the form of object code, firmware or software) stored in and accessible from a memory (circuit). As another example, where the Specification may make reference to a "first [type of structure]", a "second [type of structure]", etc., where the [type of structure] might be replaced with terms such as ["circuit", "circuitry" and others], the adjectives "first" and "second" are not used to connote any description of the structure or to provide any substantive meaning; rather, such adjectives are merely used for English-language antecedence to differentiate one such similarly-named structure from another similarly-named structure (e.g., "first circuit configured to convert. " is interpreted as "circuit configured to convert.

Claim 1:
A method for use in a communications environment involving a plurality of remote transmitters that communicate over respective subchannels, the method comprising:
ascertaining, for each of the subchannels,
energy characteristics of wireless transmissions received from one of the plurality of remote transmitters over the subchannel (<NUM>), and
a location of the remote transmitter that communicates via the subchannel (<NUM>) using location information from the wireless transmissions;
selecting one of the subchannels based on the ascertained energy characteristics and locations of the remote transmitters (<NUM>); and
generating data for transmission over the selected one of the subchannels;
wherein selecting the one of the subchannels includes:
creating data points for the subchannels, each data point indicating energy of the wireless transmissions collected on the subchannel, and a distance value of the remote transmitter from which the wireless transmissions are collected (<NUM>);
grouping the data points into clusters based on the energy and distance values of the respective data points (<NUM>);
selecting one of the clusters depicting low energy values and high distance values, relative to other ones of the clusters (<NUM>); and
selecting one of the subchannels corresponding to one of the data points in the selected cluster (<NUM>).