Subchannel-based listen before talk for unlicensed channel access

Abstract

Certain aspects of the present disclosure provide techniques for subchannel-based listen before talk (LBT). An example method that can be performed by a user equipment (UE) includes receiving one or more transmissions indicating one or more allocated subchannels of a frequency band allocated during a first time period, the frequency band including one or more allocated subchannels and one or more unallocated subchannels during the first time period; sensing the one or more unallocated subchannels for at least a portion of the first time period prior to a second time period; and transmitting a signal within the frequency band during the second time period based on sensed energy for the one or more unallocated subchannels being less than a threshold.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit and priority of Greek Patent Application No. 20200100426, filed on July 20, 2020, the entire contents of which are incorporated herein by reference for all applicable purposes. Technical Field

[0003] Various aspects of this disclosure relate to wireless communications, and more specifically, various aspects of this disclosure relate to technologies for unlicensed channel access. Background Technology

[0004] Wireless communication systems are widely deployed to provide a variety of telecommunications services such as telephone, video, data, messaging, and broadcasting. These wireless communication systems can employ multiple access technologies that enable communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple access systems include the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) system, the improved LTE (LTE-A) system, Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier Frequency Division Multiple Access (SC-FDMA) systems, and Time Division Synchronous Code Division Multiple Access (TD-SCDMA) systems.

[0005] These multiple access technologies have been adopted in various telecommunications standards to provide a common protocol that enables different wireless devices to communicate at the city, country, region, and even global levels. New radios (e.g., 5G NR) are an example of an emerging telecommunications standard. NR is a set of enhancements to the LTE mobile standard released by 3GPP. NR is designed to better support mobile broadband internet access by improving spectrum efficiency, reducing costs, improving service, utilizing new spectrum, and using OFDMA with cyclic prefix (CP) on the downlink (DL) and uplink (UL). To this end, NR supports beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

[0006] However, with the continued growth in demand for mobile broadband access, there is a need for further improvements to NR and LTE technologies. Preferably, these improvements should be applicable to other multiple access technologies and telecommunications standards that employ these technologies. Summary of the Invention

[0007] The systems, methods, and apparatuses of this disclosure have several aspects, none of which individually assumes their desired properties. Without limiting the scope of this disclosure as expressed by the following claims, some features will now be briefly discussed.

[0008] Certain aspects of the subject matter described in this disclosure can be implemented in a method for wireless communication by a user equipment (UE). In general, the method includes: receiving one or more transmissions of one or more allocated sub-channels allocated during a first time period for an indicated frequency band, the frequency band including the one or more allocated sub-channels and one or more unallocated sub-channels during the first time period; sensing the one or more unallocated sub-channels for at least a portion of the first time period prior to a second time period; and transmitting a signal within the frequency band during the second time period based on the sensing energy for the one or more unallocated sub-channels being less than a threshold.

[0009] Certain aspects of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. In general, the apparatus includes a memory and a processor coupled to the memory. The memory and the processor are configured to: receive one or more transmissions of one or more allocated sub-channels allocated during a first time period, the frequency band including the one or more allocated sub-channels and one or more unallocated sub-channels during the first time period. The processor and the memory are also configured to: sense the one or more unallocated sub-channels for at least a portion of the first time period prior to a second time period; and transmit a signal within the frequency band during the second time period based on the sensed energy for the one or more unallocated sub-channels being less than a threshold.

[0010] Certain aspects of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. In general, the apparatus includes: units for receiving one or more transmissions of one or more allocated sub-channels allocated during a first time period, the frequency band including the one or more allocated sub-channels and one or more unallocated sub-channels during the first time period; units for sensing the one or more unallocated sub-channels for at least a portion of the first time period prior to a second time period; and units for transmitting a signal within the frequency band during the second time period based on the sensing energy for the one or more unallocated sub-channels being less than a threshold.

[0011] Certain aspects of the subject matter described in this disclosure can be implemented in a computer-readable storage medium. The computer-readable storage medium includes instructions that, when executed by a processing system of a device, cause the processing system to perform operations generally comprising: receiving one or more transmissions of one or more allocated sub-channels allocated during a first time period for an indicated frequency band, the frequency band including the one or more allocated sub-channels and one or more unallocated sub-channels during the first time period; sensing the one or more unallocated sub-channels for at least a portion of the first time period prior to a second time period; and transmitting a signal within the frequency band during the second time period based on the sensing energy for the one or more unallocated sub-channels being less than a threshold.

[0012] Certain aspects of the subject matter described in this disclosure can be implemented in a method for wireless communication by a first user equipment (UE). In general, the method includes: receiving one or more transmissions indicating that a device has acquired a frequency band for communication by one or more devices, including the first UE, during a Channel Occupied Time (COT), the one or more transmissions further indicating that the frequency band is allocated to one or more allocated sub-channels of at least one device other than the first UE during a first time period of the COT, the frequency band including the one or more allocated sub-channels and one or more unallocated sub-channels during the first time period; measuring the signal strength of only the one or more unallocated sub-channels for at least a portion of the first time period prior to a second time period of the COT; and transmitting a signal within the frequency band during the second time period when the measured signal strength is less than a threshold.

[0013] Certain aspects of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. In general, the apparatus includes: a unit for receiving one or more transmissions indicating that a device has acquired a frequency band for communication by one or more devices including the apparatus during a Channel Occupied Time (COT), the one or more transmissions also indicating that the frequency band has been allocated to one or more allocated sub-channels of at least one device other than the apparatus during a first time period of the COT, the frequency band including the one or more allocated sub-channels and one or more unallocated sub-channels during the first time period; a unit for measuring the signal strength of only the one or more unallocated sub-channels for at least a portion of the first time period prior to a second time period of the COT; and a unit for transmitting a signal in the frequency band during the second time period when the measured signal strength is less than a threshold.

[0014] Certain aspects of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. In general, the apparatus includes: a memory; and a processor coupled to the memory, the memory and the processor being configured to: receive one or more transmissions indicating that the device has acquired a frequency band for communication by one or more devices including the apparatus during a Channel Occupied Time (COT), the one or more transmissions also indicating that the frequency band has been allocated to one or more allocated sub-channels of at least one device other than the device during a first time period of the COT, the frequency band including the one or more allocated sub-channels and one or more unallocated sub-channels during the first time period; measure the signal strength of only the one or more unallocated sub-channels for at least a portion of the first time period prior to a second time period of the COT; and transmit a signal in the frequency band during the second time period when the measured signal strength is less than a threshold.

[0015] Certain aspects of the subject matter described in this disclosure can be implemented in a computer-readable storage medium. The computer-readable storage medium includes instructions that, when executed by a processing system of a first UE, cause the processing system to perform operations generally comprising: receiving one or more transmissions indicating that a device has acquired a frequency band for communication by one or more devices, including the first UE, during a Channel Occupied Time (COT), the one or more transmissions further indicating that the frequency band is allocated to one or more allocated sub-channels of at least one device other than the first UE during a first time period of the COT, the frequency band including the one or more allocated sub-channels and one or more unallocated sub-channels during the first time period; measuring the signal strength of only the one or more unallocated sub-channels for at least a portion of the first time period prior to a second time period of the COT; and transmitting a signal in the frequency band during the second time period when the measured signal strength is less than a threshold.

[0016] To achieve the foregoing and related objectives, one or more aspects include the features fully described below and specifically pointed out in the claims. The following description and drawings set forth certain illustrative features of one or more aspects in detail. However, these feature indications can be adopted in only a few of the various ways in which the principles of each aspect apply. Attached Figure Description

[0017] To gain a more detailed understanding of the features described above, reference can be made to various aspects (briefly outlined above), some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only certain typical aspects of this disclosure and are therefore not intended to limit its scope, as other equally valid aspects may be permitted by this description.

[0018] Figure 1 This is a block diagram conceptually illustrating an example wireless communication network according to certain aspects of this disclosure.

[0019] Figure 2 This is a block diagram conceptually illustrating the design of an example base station (BS) and user equipment (UE) according to certain aspects of this disclosure.

[0020] Figure 3 These are example frame formats for certain wireless communication systems (e.g., New Radio (NR)) based on certain aspects of this disclosure.

[0021] Figure 4A and Figure 4B A graphical representation of an example vehicle-to-everything (V2X) system is shown, based on certain aspects of this disclosure.

[0022] Figure 5 This is a schematic diagram illustrating an example network of multiple cellular V2X (CV2X) devices operating in unlicensed spectrum.

[0023] Figure 6 This is an exemplary transmission timeline illustrating Time Division Multiplexing (TDM) Channel Occupancy Time (COT) sharing and Frequency Division Multiplexing (FDM) COT sharing in accordance with certain aspects of this disclosure.

[0024] Figure 7 The COT, extended in space according to certain aspects of this disclosure, is shown.

[0025] Figure 8A and Figure 8B A device for determining whether to extend COT in space is shown, based on certain aspects of this disclosure.

[0026] Figure 9 This is an exemplary transmission timeline of a device in a CV2X communication system according to certain aspects of this disclosure.

[0027] Figure 10 This is an exemplary transmission timeline of a device in a CV2X communication system according to certain aspects of this disclosure.

[0028] Figure 11This is an exemplary transmission timeline of a device in a CV2X communication system according to certain aspects of this disclosure.

[0029] Figure 12 This is an exemplary transmission timeline of a device in a CV2X communication system according to certain aspects of this disclosure.

[0030] Figure 13 This is an example channel energy graph illustrating energy leakage from various aspects according to this disclosure.

[0031] Figure 14 This is an example channel energy graph showing an adaptively determined exclusion subband according to various aspects of this disclosure.

[0032] Figure 15 This is an example channel energy graph illustrating the use of filter banks according to various aspects of this disclosure.

[0033] Figure 16 This is a flowchart illustrating example operations for wireless communication by a UE in accordance with certain aspects of this disclosure.

[0034] Figure 17 This is a flowchart illustrating example operations for wireless communication by a UE in accordance with certain aspects of this disclosure.

[0035] Figure 18 A communication device according to various aspects of this disclosure is shown, which may include various components configured to perform operations for the techniques disclosed herein.

[0036] To aid understanding, the same reference numerals have been used where possible to designate common elements for the purposes of the figures. It is intended that elements disclosed in one aspect can be usefully applied to other aspects without requiring specific description. Detailed Implementation

[0037] This disclosure provides apparatus, methods, processing systems, and computer-readable media for devices to perform a subchannel-based listen-before-speak (LBT) process to transmit signals using subchannels of unlicensed spectrum. In some aspects, the signals may be, for example, sidelink signals used for cellular vehicle-to-everything (CV2X) communications. Although certain aspects are described with respect to sidelink communications in unlicensed spectrum (such as CV2X communications), it should be understood that the techniques described herein can be used for other suitable communications.

[0038] In some aspects, for wireless communication in unlicensed spectrum, wireless communication devices (e.g., UEs, Wi-Fi devices, etc.) can perform a channel access procedure called a Listen-Before-Speak (LBT) procedure, in which the device can transmit if it senses that the channel corresponding to the frequency band is idle (e.g., free) before transmission. The period during which the LBT procedure is performed before transmission can be referred to as the sensing timing. In some aspects, during the LBT procedure, the wireless communication device senses (e.g., measures) the energy in the frequency band and avoids transmitting on that band if it is busy, and determines that it can communicate on that band if it is idle. As used herein, the term "idle" for a frequency band means that the energy sensed by the device determining that it is idle is below a threshold level. As used herein, the term "busy" for a frequency band means that the energy sensed by the device determining that it is idle is above a threshold level. This energy may be due to noise or signals within the frequency band.

[0039] In some respects, wireless communication devices have the ability to share frequency bands (such as unlicensed frequency bands) used for transmission. For example, a frequency band can be divided into multiple sub-channels. Furthermore, wireless communication devices can use frequency division multiplexing (FDM), whereby each device uses one or more different sub-channels from the multiple sub-channels for transmission, so that a transmission performed by one device does not interfere with a transmission performed by another device.

[0040] However, in some respects, if a wireless communication device performs an LBT process and senses across the entire frequency band, the energy sensed from a transmission by another device in a first sub-channel of that band could cause the wireless communication device to determine that the band is busy. Therefore, even if the wireless communication device could transmit in a second sub-channel of that band, different from the first sub-channel, without causing interference, it might avoid transmitting in any sub-channel of that band. In other words, the transmission by the wireless communication device is "blocked" because a transmission by another device is sensed.

[0041] Therefore, in some aspects, a wireless communication device (e.g., a CV2X device) can perform an LBT process and determine whether to transmit based on energy measured by the device not across the entire frequency band, but only on one or more resources (e.g., one or more time-frequency resources, one or more sub-channels, etc.) not allocated to other (e.g., CV2X) devices. In some aspects, the device can sense only the energy on resources not allocated to other devices. In some aspects, the device can sense energy across the entire frequency band, but only use the energy measured on resources not allocated to other devices to determine whether to transmit.

[0042] For example, in some aspects, an acquisition device (e.g., a CV2X device) can acquire (e.g., reserve, acquire, hold, etc.) the use of a frequency band (e.g., an unlicensed band) for a period of time (e.g., referred to as Channel Occupancy Time (COT)) by performing an LBT process and sensing energy across the entire band. For example, in some aspects of this disclosure, the COT may specify a time interval during which one or more devices may continue to transmit through the band before relinquishing it (e.g., ceasing transmission through the band for a sufficiently long period to allow other devices to begin transmitting through the same band).

[0043] Depending on certain aspects, a device (e.g., a CV2X device) can utilize the current active COT initiated by another device (e.g., a CV2X device) by performing an LBT procedure that ignores channel activity caused by CV2X signals (e.g., CV2X signals from the COT initiating device or other CV2X devices sharing the COT).

[0044] In some aspects, each of one or more devices may use FDM and share a frequency band during a COT by performing LBT based on energy measured by the device not across the entire frequency band, but only on one or more resources (e.g., one or more time-frequency resources, one or more sub-channels, etc.) not allocated for transmissions by other devices during the COT. In some aspects, a device (e.g., a CV2X device) given information about which sub-channels and during what time periods (e.g., time slots) one or more other CV2X devices utilize in the current active COT and has data to transmit in one or more time periods within the same COT may perform LBT only on sub-channels not used (e.g., transmitted on) by other CV2X devices during the one or more time periods on which the device has data to transmit. By performing LBT only on sub-channels not used by other CV2X devices, the device can avoid sensing energy originating from other CV2X devices and claiming that energy as channel activity.

[0045] As described in more detail below, in some respects, COT sharing can be: (i) time division multiplexing (TDM) COT sharing, wherein the COT is shared by time division multiplexing of CV2X signal transmissions (e.g., the CV2X device uses continuous time resources to transmit signaling one at a time on the frequency band to which the COT is applied until the COT duration is exhausted), and / or (ii) frequency division multiplexing (FDM) COT sharing, wherein the COT is shared by frequency division multiplexing (e.g., the CV2X device transmits simultaneously on different sub-channels of the frequency band to which the COT is applied).

[0046] For example, a CV2X device performing a LBT procedure, determining that the band is free, and thus acquiring usage of the band within a COT can share the band usage within a COT with one or more additional CV2X devices (also known as shared COT). In some aspects, for these CV2X devices to share a COT, signals (e.g., data signals carrying data (referred to as data signals), reservation signals not carrying data and used only for reserving the band, etc.) may need to be continuously transmitted by the CV2X devices on one or more sub-channels of the band without time gaps. Therefore, at any given time during a COT, at least one of the CV2X devices sharing the band within the COT may be transmitting a signal on at least one sub-channel of that band. Any non-CV2X device that can perform an LBT during a COT can detect that the band is busy and therefore avoid transmitting on that band.

[0047] In some aspects, the acquisition device allocates the resources of a frequency band during a COT (Concurrent Opportunity Time) to one or more additional devices that share the COT. For example, for each time period within one or more time periods in the COT, the acquisition device allocates one or more different sub-channels to one or more different additional devices for the latter to transmit data, signals, control information, etc. The acquisition device may send control information to one or more additional devices, informing them of the allocation of the frequency band resources during the COT.

[0048] In some respects, before transmitting in the band during COT, the device may perform an LBT process and determine whether to transmit based on the energy measured by the device not across the entire band, but only on one or more sub-channels of the band that are not allocated to other devices during COT.

[0049] Certain aspects of this disclosure provide that a user equipment (e.g., operating as a CV2X device) transmits signals in a subchannel of a frequency band during at least a portion of a Channel Occupancy Time (COT) acquired by another UE for (e.g., an unlicensed frequency band, e.g., an unlicensed channel) based on a Listen-Before-Speak (LBT) procedure: the LBT procedure is performed on an unused subchannel (e.g., excluding a subchannel on which another UE is transmitting) within that portion of the COT. That is, a UE can share a COT acquired by another UE to transmit on a subchannel during a time period corresponding to at least a portion of the COT. The UE shares the COT by measuring the received signal strength (e.g., Received Signal Strength Indicator (RSSI) or Reference Received Power (RSRP)) of one or more subchannels not allocated to other UEs (e.g., on which other UEs are transmitting) before that time period, and transmitting on the measured subchannel when the received signal strength is less than or equal to a threshold.

[0050] The execution of the LBT process by a device sharing a COT can help reduce interference to other devices, such as non-CV2X devices. For example, in a first illustrative example, a first CV2X device (e.g., a UE) can share a COT acquired by a second CV2X device by transmitting signals in an unoccupied sub-channel (e.g., sub-band) of the corresponding frequency band during a first time period of the COT, without performing LBT before the first time period. Meanwhile, a third device (e.g., a non-CV2X device, such as a Wi-Fi device) may be close enough to the first CV2X device that transmissions from the first CV2X device will interfere with communications performed by the third device. Furthermore, the third device may not sense transmissions in the frequency band reserved by the second CV2X device before the first time period, as discussed, for example, because the second CV2X device is far from the third device. Therefore, the third device may determine that the entire frequency band is idle before the first time period and also transmit during the first time period. Accordingly, the third device may be in transmit mode at the same time that the first CV2X device is transmitting during COT, causing interference, for example, if the third device is also transmitting in an unoccupied subchannel.

[0051] As discussed, in one or more aspects, before transmitting in the band during COT, the CV2X device can perform an LBT process and determine whether to transmit based on the energy measured by the device not across the entire band, but only on one or more sub-channels of the band that are not allocated to other devices during COT. The CV2X device can then determine whether another device (a non-CV2X device, such as a third device) is occupying the band during COT. Therefore, if the CV2X device determines that another device is occupying the band during COT, the CV2X device can avoid interference with that other device by avoiding transmitting. Furthermore, the CV2X device can still share COT by avoiding sensing transmissions by other CV2X devices on allocated sub-channels as indicating that the entire band is busy, allowing the CV2X to still determine that the band is free for transmission on one or more unallocated sub-channels within that band. Therefore, the techniques discussed in this paper can reduce latency and increase throughput for CV2X devices to communicate by allowing CV2X devices to transmit even when transmissions are blocked by unallocated subchannels (e.g., those used by other CV2X devices sharing the same COT). Furthermore, such techniques reduce interference by adhering to the LBT process on unlicensed spectrum.

[0052] In some aspects of this disclosure, a device (e.g., the first CV2X device described above) can determine a threshold for a measurement (e.g., a signal strength measurement in an LBT) to determine whether a channel is busy or idle with respect to non-CV2X transmissions. In some aspects of this disclosure, techniques are described for the device to adjust the threshold based on the number of sub-channels or the bandwidth size measured. In one example, as part of an LBT, the device (e.g., the first CV2X device described above) can measure only the signal strength of sub-channels not used by another CV2X device, and the device (e.g., the first CV2X device) can determine a signal strength threshold for the LBT based on the number of sub-channels or the bandwidth size measured in the LBT.

[0053] In some aspects of this disclosure, CV2X transmissions from relatively nearby transmitters, as measured by a receiver, exhibit greater subchannel energy leakage (also known as the near-far transmission problem) compared to transmissions from relatively distant transmitters, and the impact of the near-far transmission problem on subchannel LBT measurements (e.g., LBT measurements performed by the receiver) is described. In some aspects of this disclosure, techniques for mitigating the described near-far transmission problem to achieve accurate LBT measurements are described. Techniques for adjusting thresholds used in LBTs as part of mitigating the described near-far transmission problem are also described.

[0054] Certain aspects of this disclosure can improve the frequency division multiplexing (FDM) capability of CV2X devices by enabling them to comply with LBT coexistence rules in unlicensed spectrum while utilizing the FDM capability of CV2X. This can benefit both CV2X and non-CV2X transmissions. In some aspects, non-CV2X transmissions can benefit from the FDM of CV2X transmissions because the multiplexing of CV2X transmissions can result in a smaller effective channel occupancy time for CV2X transmissions, and therefore, more time can be available for non-CV2X transmissions. This can increase throughput and reduce latency.

[0055] According to certain aspects of this disclosure, a first UE may perform the following operations: receive one or more transmissions indicating that a device has acquired a frequency band for communication by one or more devices, including the first UE, during a Channel Occupied Time (COT), the one or more transmissions also indicating one or more allocated sub-channels of the frequency band allocated to at least one device other than the first UE during a first time period of the COT, the frequency band including one or more allocated sub-channels and one or more unallocated sub-channels during the first time period; measure the signal strength of only the one or more unallocated sub-channels during at least a portion of the first time period prior to a second time period of the COT; and transmit a signal in the frequency band during the second time period when the measured signal strength is less than a threshold. In some aspects, it is possible to prevent a first UE, which operates according to certain aspects of this document and receives weak (e.g., due to path loss) signaling from a second UE, from sharing the COT acquired by the second UE, thereby preventing the first UE from unfairly occupying (e.g., unlicensed) the frequency band without performing LBT and potentially introducing interference to non-CV2X transmissions occurring near the first UE.

[0056] For example, such techniques can be used in sidelink communication between wireless communication devices. In other examples, wireless communication devices may include cellular vehicle-to-everything (CV2X) devices. It should be noted that although certain aspects have been described regarding CV2X devices, UEs, and communication in unlicensed frequency bands, it is understood that these aspects can be similarly applied to other scenarios, such as any communication in unlicensed frequency bands (e.g., sidelink communication), communication in licensed frequency bands, communication between other devices (e.g., sidelink communication), etc.

[0057] Unlicensed spectrum (often also referred to as "shared spectrum") refers to any frequency band that is not subject to licensed use under regulatory practices, making that band open for use by any device, not just those with a license to use that specific band. Example sidelink communication includes vehicle-to-everything (V2X) communication. While some aspects may be discussed in relation to V2X communication systems, it should be noted that these aspects are equally applicable to other suitable types of sidelink communication systems.

[0058] The following description provides examples of a UE performing a subchannel-based Listen-Before-Speak (LBT) procedure to transmit cellular vehicle-to-everything (CV2X) signals using subchannels of unlicensed spectrum. Changes may be made to the functionality and arrangement of the elements discussed without departing from this disclosure. Various processes or components may be omitted, substituted, or added as appropriate in the examples. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Furthermore, features described with respect to some examples may be combined with those in other examples. For example, an apparatus or a method may be implemented using any number of aspects set forth herein. Furthermore, the scope of this disclosure is intended to cover such apparatuses or methods practiced using structures, functions, or structures and functions other than or different from those set forth herein. It should be understood that any aspect of the disclosure herein may be embodied by one or more elements of the claims. The term “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects.

[0059] The electromagnetic spectrum (such as in licensed bands) is typically subdivided into various categories, bands, channels, etc., based on frequency / wavelength. In 5G NR, the two initial operating bands have been designated as frequency range names FR1 (410MHz-7.125GHz) and FR2 (24.25GHz-52.6GHz). It should be understood that although a portion of FR1 is greater than 6GHz, in various documents and articles, FR1 is generally (interchangeably) referred to as the "below 6GHz" band. Similar naming issues sometimes arise regarding FR2, although it differs from the extremely high frequency (EHF) band (30GHz-300GHz) designated as a "millimeter wave" band by the International Telecommunication Union (ITU), it is generally (interchangeably) referred to as the "millimeter wave" band in documents and articles.

[0060] The frequencies between FR1 and FR2 are generally referred to as intermediate frequency (IF) bands. Recent 5G NR studies have designated the operating bands used for these IF bands as the frequency range name FR3 (7.125GHz-24.25GHz). Bands falling within FR3 can inherit FR1 and / or FR2 characteristics, and thus can effectively extend the features of FR1 and / or FR2 into the IF band. Additionally, higher frequency bands are currently being explored to extend 5G NR operation beyond 52.6GHz. For example, three higher operating frequency bands have been designated as the frequency range names FR4a or FR4-1 (52.6GHz-71GHz), FR4 (52.6GHz-114.25GHz), and FR5 (114.25GHz-300GHz). Each of these higher frequency bands falls within the EHF band.

[0061] In light of the foregoing, unless otherwise specifically stated, it should be understood that when the term "below 6 GHz" is used herein, it can broadly refer to frequencies that are less than 6 GHz, within FR1, or may include intermediate frequency band frequencies. Furthermore, unless otherwise specifically stated, it should be understood that when the term "millimeter wave" is used herein, it can broadly refer to frequencies that may include intermediate frequency band frequencies, within FR2, FR4, FR4-a or FR4-1 and / or FR5, or within the EHF band.

[0062] Typically, any number of wireless networks can be deployed in a given geographical area. Each wireless network can support a specific Radio Access Technology (RAT) and can operate on one or more frequencies. A RAT can also be referred to as a radio technology, air interface, etc. A frequency can also be referred to as a carrier, subcarrier, frequency channel, tone, subband, etc. Each frequency can support a single RAT in a given geographical area to avoid interference between wireless networks with different RATs.

[0063] The techniques described herein can be used in a variety of wireless network and radio technologies. While this document may use terms commonly associated with 3G, 4G, and / or newer radio technologies (e.g., 5G NR) to describe aspects, aspects of this disclosure can be applied to communication systems based on other generations.

[0064] NR access can support a variety of wireless communication services, such as enhanced mobile broadband (eMBB) targeting wide bandwidth (e.g., 80 MHz or greater), millimeter wave (mmW) targeting high carrier frequencies (e.g., 24 GHz to 53 GHz or greater), massive machine-type communication (mMTC) targeting non-backward compatible MTC technologies, and / or mission-critical ultra-reliable low-latency communication (URLLC). These services can include latency and reliability requirements. These services can also have different transmission time intervals (TTIs) to meet corresponding quality of service (QoS) requirements. Furthermore, these services can coexist in the same subframe. NR supports beamforming and can dynamically configure beam direction. It can also support MIMO transmission with precoding. MIMO configurations in DL can support up to 8 transmit antennas, with up to 8 streams in multi-layer DL transmission and up to 2 streams per UE. Multi-layer transmission with up to 2 streams per UE can be supported. Aggregation of multiple cells with up to 8 serving cells can be supported.

[0065] Figure 1 An example wireless communication network 100 in which various aspects of this disclosure can be implemented is shown. For example, the wireless communication network 100 may be an NR system (e.g., a 5G NR network). Figure 1 As shown, the wireless communication network 100 can communicate with the core network 132. The core network 132 can communicate with one or more base stations (BS) 110 and / or user equipment (UE) 120 in the wireless communication network 100 via one or more interfaces.

[0066] Depending on certain aspects, UE 120 can be configured to: transmit signals in a frequency band during a COT (Confirmation of Time) acquired by another UE for (e.g., an unlicensed) frequency band (e.g., an unlicensed channel). Figure 1As shown, according to various aspects of this disclosure, UE 120a includes a subband LBT manager 112 that performs the following operations: receiving one or more transmissions 121 indicating that a device (e.g., UE 120b) has acquired a frequency band for communication by one or more devices including the UE during the Channel Occupied Time (COT), the one or more transmissions also indicating one or more allocated subchannels of the frequency band that are allocated to at least one device other than the UE during a first time period of the COT, the frequency band including one or more allocated subchannels and one or more unallocated subchannels during the first time period; measuring the signal strength of only the one or more unallocated subchannels during at least a portion of the first time period before a second time period of the COT; and transmitting a signal in the frequency band during the second time period when the measured signal strength is less than a threshold. According to various aspects of this disclosure, UE 120b also includes a subband LBT manager 124 that performs the following operations: receiving one or more transmissions 121 indicating that a device (e.g., UE 120a) has acquired a frequency band for communication by one or more devices including the UE during the Channel Occupied Time (COT), the one or more transmissions also indicating one or more allocated subchannels of the frequency band that are allocated to at least one device other than the UE during a first time period of the COT, the frequency band including one or more allocated subchannels and one or more unallocated subchannels during the first time period; measuring the signal strength of only the one or more unallocated subchannels during at least a portion of the first time period before a second time period of the COT; and transmitting a signal in the frequency band during the second time period when the measured signal strength is less than a threshold.

[0067] like Figure 1 As shown, the wireless communication network 100 may include multiple BSs 110a-z (each individually referred to herein as BS 110 or collectively as BS 110) and other network entities. BS 110 may provide communication coverage for a specific geographic area (sometimes referred to as a "cell"), which may be fixed or movable depending on the location of the mobile BS 110. In some examples, BS 110 may use any suitable transport network to interconnect with each other and / or with one or more other BSs or network nodes (not shown) in the wireless communication network 100 via various types of backhaul interfaces (e.g., direct physical connection, wireless connection, virtual network, etc.). Figure 1In the example shown, BS 110a, 110b, and 110c can be macro BSs for macro cells 102a, 102b, and 102c, respectively. BS 110x can be a pico BS for pico cell 102x. BS 110y and 110z can be femto BSs for femto cells 102y and 102z, respectively. A BS can support one or more cells.

[0068] BS 110 communicates with UEs 120a-y (each individually referred to herein as UE 120 or collectively as UE 120) in the wireless communication network 100. UEs 120 (e.g., 120x, 120y, etc.) may be distributed throughout the wireless communication network 100, and each UE 120 may be fixed or mobile. In one example, a quadcopter, drone, or any other unmanned aerial vehicle (UAV) or remotely piloted aviation system (RPAS) 120d may be configured to act as a UE. The wireless communication network 100 may also include relay stations (e.g., relay station 110r) (also referred to as repeaters, etc.) that receive transmissions of data and / or other information from upstream stations (e.g., BS 110a or UE 120r) and transmit transmissions of data and / or other information to downstream stations (e.g., UE 120 or BS 110), or relay transmissions between UEs 120 to facilitate communication between devices.

[0069] Network controller 130 can communicate with a group of BSs 110 and provide coordination and control for these BSs 110 (e.g., via backhaul). In various aspects, network controller 130 can communicate with core network 132 (e.g., 5G core network (5GC)), which provides various network functions such as access and mobility management, session management, user plane functions, policy control functions, authentication server functions, unified data management, application functions, network openness functions, network repository functions, network slice selection functions, etc.

[0070] Figure 2 BS 110a and UE 120a are shown (e.g., Figure 1 Example components of a wireless communication network 100, which can be used to implement various aspects of this disclosure.

[0071] At BS 110a, the transmitting processor 220 can receive data from the data source 212 and control information from the controller / processor 240. Control information can be used for the Physical Broadcast Channel (PBCH), Physical Control Format Indicator Channel (PCFICH), Physical Hybrid ARQ Indicator Channel (PHICH), Physical Downlink Control Channel (PDCCH), Group Common PDCCH (GC PDCCH), etc. Data can be used for the Physical Downlink Shared Channel (PDSCH), etc. The Media Access Control (MAC)-Control Element (MAC-CE) is a MAC layer communication structure that can be used for exchanging control commands between wireless nodes. The MAC-CE can be carried in shared channels (such as the Physical Downlink Shared Channel (PDSCH), Physical Uplink Shared Channel (PUSCH), or Physical Sidelink Shared Channel (PSSCH)).

[0072] Processor 220 can process (e.g., encode and symbol map) data and control information separately to obtain data symbols and control symbols. Processor 220 can also generate reference symbols such as those for the primary synchronization signal (PSS), secondary synchronization signal (SSS), PBCH demodulation reference signal (DMRS), and channel state information reference signal (CSI-RS). Transmit (TX) multiple-input multiple-output (MIMO) processor 230 can perform spatial processing (e.g., precoding, if applicable) on data symbols, control symbols, and / or reference symbols, and can provide output symbol streams to modulators (MODs) 232a-232t. Each modulator 232 can process its corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator can further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The downlink signal from modulators 232a-232t can be transmitted via antennas 234a-234t respectively.

[0073] At UE 120a, antennas 252a-252r can receive downlink signals from BS 110a and can provide the received signals to demodulators (DEMODs) 254a-254r in the transceiver. Each demodulator 254 can adjust (e.g., filter, amplify, down-convert, and digitize) the corresponding received signal to obtain an input sample. Each demodulator can further process the input sample (e.g., for OFDM, etc.) to obtain received symbols. MIMO detector 256 can obtain received symbols from all demodulators 254a-254r, perform MIMO detection on the received symbols (if applicable), and provide the detected symbols. Receiver processor 258 can process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for UE 120a to data sink 260, and provide decoded control information to controller / processor 280.

[0074] On the uplink, at UE 120a, the transmitting processor 264 can receive and process data from data source 262 (e.g., for the Physical Uplink Shared Channel (PUSCH)) and control information from controller / processor 280 (e.g., for the Physical Uplink Control Channel (PUCCH)). The transmitting processor 264 can also generate reference symbols for reference signals (e.g., for Sounding Reference Signals (SRS)). Symbols from the transmitting processor 264 can be pre-encoded (if applicable) by the TX MIMO processor 266, further processed by modulators 254a-254r in the transceiver (e.g., for SC-FDM, etc.), and transmitted to BS 110a. At BS 110a, the uplink signals from UE 120a can be received by antenna 234, processed by modulator 232, detected by MIMO detector 236 (if applicable), and further processed by receiving processor 238 to obtain decoded data and control information transmitted by UE 120a. The receiver processor 238 can provide decoded data to the data sink 239 and decoded control information to the controller / processor 240.

[0075] Memory 242 and 282 can store data and program code for BS 110a and UE 120a, respectively. Scheduler 244 can schedule the UE for data transmission on the downlink and / or uplink.

[0076] The antenna 252, processors 266, 258, 264, and / or controller / processor 280 of UE 120a and / or the antenna 234, processors 220, 230, 238, and / or controller / processor 240 of BS 110a can be used to perform the various techniques and methods described herein. For example, such as Figure 2As shown, according to the aspects described herein, the controller / processor 280 of UE 120a has a subband LBT manager 281 that performs the following operations: receiving one or more transmissions indicating that the device has acquired a frequency band for communication by one or more devices, including the UE, during the Channel Occupied Time (COT), the one or more transmissions also indicating one or more allocated subchannels of the frequency band allocated to at least one device other than the UE during a first time period of the COT, the frequency band including one or more allocated subchannels and one or more unallocated subchannels during the first time period; measuring the signal strength of only the one or more unallocated subchannels during at least a portion of the first time period before a second time period of the COT; and transmitting a signal in the frequency band during the second time period when the measured signal strength is less than a threshold. Although shown at the controller / processor, other components of UE 120a and BS 110a can be used to perform the operations described herein.

[0077] NR can utilize Orthogonal Frequency Division Multiplexing (OFDM) with a cyclic prefix (CP) on both the uplink and downlink. NR can support half-duplex operation using Time Division Duplex (TDD). OFDM and Single-Carrier Frequency Division Multiplexing (SC-FDM) divide the system bandwidth into multiple orthogonal subcarriers, which are often referred to as tones, frequency bands, etc. Data can be modulated onto each subcarrier. Modulation symbols can be transmitted using OFDM in the frequency domain and SC-FDM in the time domain. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers can depend on the system bandwidth. The minimum resource allocation, called a resource block (RB), can be 12 consecutive subcarriers. The system bandwidth can also be divided into subbands. For example, a subband can cover multiple RBs. NR can support a basic subcarrier spacing (SCS) of 15 kHz and can define other SCSs (e.g., 30 kHz, 60 kHz, 120 kHz, 240 kHz, etc.) relative to the basic SCS.

[0078] Figure 3This is a diagram illustrating an example of frame format 300 for NR. The transmission timeline for each of the downlink and uplink can be divided into units of radio frames. Each radio frame can have a predetermined duration (e.g., 10 ms) and can be divided into 10 subframes (each 1 ms long) with indices 0 to 9. Each subframe can include a variable number of time slots (e.g., 1, 2, 4, 8, 16... time slots), depending on the SCS. Each time slot can include a variable number of symbol periods (e.g., 7, 12, or 14 symbols), depending on the SCS. Indices can be assigned to the symbol periods in each time slot. Micro-slots (which may be referred to as sub-slot structures) refer to transmission time intervals with a duration less than a time slot (e.g., 2, 3, or 4 symbols). Each symbol in a time slot can indicate the link direction for data transmission (e.g., DL, UL, or flexible), and the link direction for each subframe can be dynamically switched. The link direction can be based on the time slot format. Each time slot can include DL / UL data and DL / UL control information.

[0079] In NR, a Synchronization Signal Block (SSB) is transmitted. In some aspects, SSBs can be transmitted in bursts, where each SSB in the burst corresponds to a different beam direction used for UE-side beam management (e.g., including beam selection and / or beam refinement). An SSB includes a PSS, an SSS, and a two-symbol PBCH. It can be transmitted at fixed time slot locations (such as in...). Figure 3 SSBs are transmitted in symbols 0-3 shown in the diagram. PSS and SSS can be used by the UE for cell search and acquisition. PSS can provide half-frame timing; SS can provide CP length and frame timing. PSS and SSS can provide cell identification. PBCH carries some basic system information, such as downlink system bandwidth, timing information within the radio frame, SS burst set period, system frame number, etc. SSBs can be organized into SS bursts to support beam scanning. Further system information, such as Residual Minimum System Information (RMSI), System Information Block (SIB), and Other System Information (OSI), can be transmitted on the Physical Downlink Shared Channel (PDSCH) in some subframes. For millimeter waves, SSBs can be transmitted up to sixty-four times, for example, using up to sixty-four different beam directions. Multiple transmissions of SSBs are called SS burst sets. SSBs in an SS burst set can be transmitted in the same frequency region, while SSBs in different SS burst sets can be transmitted in different frequency regions.

[0080] Figure 4A and Figure 4B A graphical representation of an example V2X system according to some aspects of this disclosure is shown. For example, in Figure 4A and Figure 4BThe vehicles shown can communicate via a side link channel and can relay side link transmissions as described herein.

[0081] exist Figure 4A and Figure 4B The V2X system provided in China offers two complementary transmission modes. The first transmission mode (also known as Mode 4) (in...) Figure 4A (As illustrated in the example) involves direct communication between participants who are close to each other in a local area (e.g., also known as side link communication). The second transmission mode (also known as mode 3) (in...) Figure 4B (As illustrated in the example) This involves network communication over a network, which can be implemented on a Uu interface (e.g., a wireless communication interface between a radio access network (RAN) and a UE).

[0082] refer to Figure 4A A V2X system 400 (e.g., including vehicle-to-vehicle (V2V) communication) is shown as having two vehicles 402 and 404. A first transmission mode allows direct communication between different participants in a given geographic location. As shown, the vehicles may have a wireless communication link 406 with a person (V2P) (e.g., via a UE) through a PC5 interface. Communication between vehicles 402 and 404 can also occur through PC5 interface 408. Similarly, communication from vehicle 402 to other highway components (e.g., highway component 410), such as traffic signals or signs (V2I), can occur through PC5 interface 412. Figure 4A Each communication link shown allows for bidirectional communication between components, thus each component can be both a sender and receiver of information. The V2X system 400 can be a self-managing system implemented without assistance from network entities. Since no network service interruption occurs during handover operations for mobile vehicles, the self-managing system can achieve improved spectral efficiency, reduced costs, and increased reliability. The V2X system can be configured to operate in licensed or unlicensed spectrum, so any vehicle equipped with the system can access public frequencies and share information. Such coordinated / public spectrum operation allows for secure and reliable operation.

[0083] Figure 4BA V2X system 450 is illustrated for communication between vehicles 452 and 454 via network entity 456. These network communications can occur via discrete nodes such as BSs (e.g., BS 110a) that send and receive information from vehicles 452 and 454 (e.g., relay information between them). For example, network communication via vehicle-to-network (V2N) links 458 and 460 can be used for long-distance communication between vehicles, such as for transmitting the presence of a traffic accident a distance ahead along a road or highway. Wireless nodes can send other types of communication to vehicles, such as traffic flow conditions, road hazard warnings, environmental / weather reports, and service station availability, among other examples. Such data may be obtained from cloud-based shared services.

[0084] Roadside Units (RSUs) can be utilized. RSUs can be used for V2I communication. In some examples, RSUs can act as forwarding nodes to extend coverage for UEs. In some examples, RSUs can be co-located with the Base Station (BS) or can be independent. RSUs can have different classifications. For example, RSUs can be classified as UE-type RSUs and MicroNode B-type RSUs. MicroNode B-type RSUs have similar functionality to macro eNBs or gNBs. MicroNode B-type RSUs can utilize the Uu interface. UE-type RSUs can be used to meet stringent Quality of Service (QoS) requirements by minimizing collisions and improving reliability. UE-type RSUs can use centralized resource allocation mechanisms to allow for efficient resource utilization. Critical information (e.g., traffic conditions, weather conditions, congestion statistics, sensor data, etc.) can be broadcast to UEs in the coverage area. Repeaters can rebroadcast critical information received from some UEs. UE-type RSUs can be reliable synchronization sources.

[0085] Figure 5 This is a schematic diagram illustrating an example network 500 of multiple CV2X devices operating in unlicensed spectrum. The unlicensed spectrum may be an example of a sidelink frequency band. Furthermore, network 500 may be an example of a sidelink communication system. CV2X devices 502 may be configured to communicate on sidelink frequency channels, as discussed herein. For example, any one of CV2X devices 502 may communicate with any other CV2X device 502.

[0086] In the example shown, seven CV2X devices (e.g., first CV2X device 502a, second CV2X device 502b, third CV2X device 502c, fourth CV2X device 502d, fifth CV2X device 502e, sixth CV2X device 502f, and seventh CV2X device 502g, collectively referred to as CV2X device 502) can operate in unlicensed spectrum alongside other non-CV2X devices (e.g., non-CV2X devices 504a-c, collectively referred to as non-CV2X device 504). In some examples, first CV2X device 502a, sixth CV2X device 502f, and third CV2X device 502c may be part of a convoy or platoon. In transportation, platooning or convoying is a method for driving a group of vehicles together. This is intended to increase road capacity via automated highway systems. Placing can reduce the distance between cars or trucks, such as with SL-based communication.

[0087] While the provided examples illustrate six vehicle CV2X devices in a traffic setting, as well as CV2X devices for drones or other aircraft, it is understood that CV2X devices and environments can be extended beyond these to include other wireless communication devices and environments. For example, CV2X device 502 may include a UE operated by a highway authority (e.g., Figure 1 The UE120 and / or roadside unit (RSU) may be implemented on a motorcycle or carried by a user (e.g., a pedestrian, cyclist, etc.), or may be implemented on another aircraft such as a helicopter.

[0088] CV2X device 502 may include UE (e.g., Figure 1 The UE 120 in the figure can be a device implemented on a motorcycle or carried by a user (e.g., a pedestrian, cyclist, etc.) or implemented as a roadside unit.

[0089] Figure 6 This is an example transmission timeline 600 illustrating TDM COT sharing and FDM COT sharing between CV2X devices according to various aspects of this disclosure. It should be noted that, for ease of explanation, four CV2X devices are discussed, and any suitable number of CV2X devices can perform COT sharing. In this example transmission timeline, the first UE (e.g., in...) Figure 1The UE 120a shown (which may be a CV2X device) acquires COT 601, which includes symbols 602, 604, 606, 608, 610, and 612 on sub-channels 620, 622, and 624 of an unlicensed frequency band. The first UE transmits transmission 630 on sub-channel 624 during symbol 602, transmission 630 including control information 632. For example, the control information may be transmitted in the physical-side link control channel (PSCCH). The first UE also transmits transmissions 634 and 636 on sub-channel 624 during symbols 604 and 606, respectively. Although COT 601 is shown as including six symbols, it should be understood that COT 601 may include any appropriate number of symbols or other types of time periods. Although the unlicensed frequency band is shown as including three sub-channels, it should be understood that the unlicensed frequency band may include any appropriate number of sub-channels.

[0090] In this example transmission timeline, the second UE (e.g., in) Figure 1 The UE 120b shown determines (e.g., based on decoding of control channel 632) that the second UE can transmit transmission 640 on subchannel 620 during symbol 604 without performing LBT; that is, the second UE determines that it can share the COT acquired by the first UE. By transmitting transmission 640 on a different subchannel 620 during symbol 604 while the first UE is transmitting transmission 634 on subchannel 624, the second UE is performing FDM COT sharing, or sharing COT in an FDM manner. The second UE also transmits transmissions 642 and 644 on subchannel 620 during symbols 606 and 608, respectively.

[0091] In this example transmission timeline, the third UE (e.g., in) Figure 1 The UE 120r shown determines (e.g., based on decoding of control channel 632) that a third UE can transmit transmission 650 on subchannel 622 during symbol 606 without performing LBT; that is, the third UE determines that it can share the COT acquired by the first UE. By transmitting transmission 650 on subchannel 622 during symbol 606 while the first UE is transmitting transmission 636 on subchannel 624 and the second UE is transmitting transmission 642 on subchannel 620, the third UE is performing FDM COT sharing, or sharing the COT with both the first and second UEs in an FDM manner. The third UE also transmits transmission 652 on subchannel 622 during symbol 610.

[0092] In this example transmission timeline, the fourth UE (e.g., in Figure 1The UE 120d shown determines (e.g., based on decoding of control channel 632) that a fourth UE can transmit transmission 660 on subchannel 624 during symbol 610 without performing LBT; that is, the fourth UE determines that it can share the COT acquired by the first UE. The fourth UE also transmits transmission 662 on subchannel 624 during symbol 612. By transmitting transmission 660 on subchannel 624 during symbol 610 while the third UE is transmitting transmission 652 on subchannel 622, the fourth UE is performing FDM COT sharing with the third UE, or sharing the COT with the third UE in an FDM manner. By transmitting transmissions 660 and 662 on subchannel 624 during symbols 610 and 612 after the first UE has transmitted transmissions 630, 634, and 636 on subchannel 624, the fourth UE is also performing TDM COT sharing, or sharing the COT with the first UE in a TDM manner.

[0093] Figure 7 An example wireless communication system 700 is shown, which includes an example CV2X system 400 having vehicles 402, 404a and 404b, as previously described. Figure 4A As shown in [the image]. Figure 4A The items shown are not described further. In some respects, communication between vehicles 402 and 404a can occur via PC5 interface 408a, and communication between vehicles 402 and 404b can occur via PC5 interface 408b. Figure 7 The issue of COT "expanding in space" is also illustrated. Figure 7 In this scenario, vehicle 402 acquires a COT for an unlicensed frequency band (e.g., by performing LBT). Vehicle 404a shares the COT acquired by vehicle 402 and transmits signaling on the unlicensed frequency band without performing LBT on it. This signaling is detected by BS 110b (e.g., a Wi-Fi access point that does not conform to CV2X), which may experience the signaling as interference 712 because the BS is far from vehicle 402 and therefore does not detect vehicle 402 performing LBT and acquiring COT.

[0094] Therefore, techniques and apparatus are provided for a user equipment (UE) to perform a listen-before-speak (LBT) process based on a subchannel before transmitting cellular vehicle-to-everything (CV2X) signals using a subchannel in an unlicensed spectrum.

[0095] Example of a subchannel-based listen-before-speak approach for unlicensed channel access

[0096] Certain aspects of this disclosure provide that a user equipment (e.g., a CV2X UE) transmits signals in a subchannel of a frequency band during at least a portion of a Channel Occupancy Time (COT) acquired by another UE for (e.g., an unlicensed frequency band, e.g., an unlicensed channel) based on a Listen-Before-Speak (LBT) procedure: the LBT procedure is performed on an unused subchannel (e.g., excluding a subchannel on which another UE is transmitting) within that portion of the COT. In other words, a UE can share a COT acquired by another UE to transmit on a subchannel for a time period corresponding to at least a portion of the COT. The UE shares the COT by measuring the received signal strength (e.g., Received Signal Strength Indicator (RSSI) or Reference Received Power (RSRP)) of one or more subchannels not allocated to other UEs (e.g., on which other UEs are transmitting) before that time period, and transmitting on the measured subchannel when the received signal strength is less than or equal to a threshold.

[0097] Figure 8A and Figure 8B Example wireless communication systems 800 and 850 are shown, which include previously... Figure 4A The projects described herein will not be described further. Figure 8A The expansion of COT in space is also shown. Figure 8A In this process, vehicle 402 acquires the COT for the unlicensed frequency band (e.g., by performing LBT). Vehicle 404 receives the transmission from vehicle 402 in a sub-channel (e.g., sub-band) and measures the signal strength (e.g., RSSI or RSRP) in other sub-channels that do not contain that transmission. Vehicle 404 determines that the signal strength is less than or equal to a threshold and shares the COT acquired by vehicle 402. After performing LBT on one or more sub-channels in the other sub-channels of the unlicensed frequency band, vehicle 404 transmits signaling 812 on those other sub-channels. This signaling is controlled by BS 110b (in... Figure 1 As shown in the diagram, BS 110b can detect that the signaling is signaling 812 of a device with COT for an unlicensed frequency because the BS is relatively close to vehicle 402 and therefore can detect that vehicle 402 has acquired COT.

[0098] exist Figure 8BIn this scenario, vehicle 402 acquires a Certificate of Operation (COT) for an unlicensed frequency band (e.g., by performing a Level Bypass Transmission). Vehicle 404 receives a transmission from vehicle 402 (e.g., a Physical Side Link Control Channel (PSCCH)) and measures the signal strength (e.g., RSSI or RSRP) in other sub-channels not containing that transmission. Vehicle 404 detects that the signal strength is greater than a threshold (e.g., because BS110b is transmitting on an unlicensed frequency) and does not share the COT acquired by vehicle 402. Vehicle 404 does not transmit signaling on the unlicensed frequency band because the LBT performed by the vehicle on a sub-channel of that unlicensed frequency band indicates that the unlicensed frequency band is occupied. Because vehicle 404 is relatively far from vehicle 402, other nearby devices (e.g., BS110b) may not have detected that vehicle 402 acquired a COT or that vehicle 402 is transmitting. Other devices may expect to be able to transmit on the unlicensed frequency band after performing an LBT. It should be noted that, for simplicity, vehicle 402 is described as both acquiring COT and transmitting in a sub-channel on which vehicle 404 does not measure signal strength. However, in some respects, other devices may have been allocated sub-channel resources, and vehicle 404 may or may not measure the signal strength on sub-channel resources allocated to other devices, as described in other examples herein.

[0099] Figure 9 This is an example transmission timeline 900 for devices in a CV2X communication system. This example transmission timeline includes four time slots: 904, 906, 908, and 909. In this example transmission timeline, the first UE (e.g., in...) Figure 8B The UE 402 shown has data to transmit in time slots 906 and 908. The UE performs LBT 910 before time slot 906. After successful LBT completion (e.g., LBT indicates the channel is idle), the UE initiates COT 940 starting at the beginning of time slot 906, which lasts for at least two time slots. As shown, the UE senses energy across the entire bandwidth of frequency band 920 during LBT 910. The UE transmits transmission 940 on subchannel 924, but not on subchannels 922, 926, and 928. Furthermore, transmission 940 continuously utilizes at least a portion of frequency band 920 during COT 940. At 930 and 932, the Wi-Fi AP accesses the channel when it becomes idle after performing LBT (not shown) on the Wi-Fi AP (e.g., BS 110a).

[0100] Figure 10This is an example transmission timeline 1000 for a device in a CV2X communication system. This example transmission timeline includes four time slots: 1004, 1006, 1008, and 1009. In this example transmission timeline, the first UE (e.g., in...) Figure 8B The UE 402 shown has data to be transmitted in time slots 1006 and 1008. The first UE performs LBT 1010 before time slot 1006. After successful LBT completion, the first UE initiates COT 1040 starting at the beginning of time slot 1006, which lasts for at least two time slots. As shown, the first UE senses energy across the entire bandwidth of frequency band 1020 during LBT 1010. The first UE transmits on subchannel 1024, but not on subchannels 1022, 1026, and 1028.

[0101] In this example transmission timeline, the second UE (e.g., in) Figure 8B The UE 404 shown (which may be a CV2X device) has data to transmit in time slot 1008. In some cases, the second UE performs LBT 1012 before transmitting on time slot 1008. Without the techniques discussed herein, the second UE could sense channel congestion due to transmissions from the first UE at 1042 and 1044. Using the techniques discussed herein, the second UE can select a different subchannel 1028 for transmission 1050. The second UE can decode the side link control information (SCI, e.g., in PSCCH) in transmission 1042 from the first UE at time slot 1006 and determine that the first UE will transmit on the same subchannel 1024 during time slot 1008. The second UE shares this in COT 1040 by transmitting signal 1050 on subchannel 1028 without performing LBT for channel 1020. At 1030 and 1032, the Wi-Fi AP (e.g., BS 110a) performs LBT (not shown) and accesses the channel when it is idle.

[0102] According to certain aspects, as referenced above Figure 10 The described COT sharing effectively extends spatially by the first UE (e.g., in Figure 8B The COT is initiated by UE 402 as shown in the diagram. However, in some aspects, the first UE initiating the COT may sense interference activity near the first UE during LBT (e.g., from...). Figure 8BWi-Fi transmissions of BS 102a or BS 102b shown in the diagram), without sensing interference activity that is relatively far from the first UE (the interference activity does not have sufficient power received at the first UE to determine the frequency band as busy). Furthermore, in some aspects, when LBT is performed, subsequent transmissions of the first UE that initiate COT (e.g., in...) Figure 10 The transmissions 1042 and 1044 shown can be sensed by a local Wi-Fi AP (e.g., BS 102a) near the first UE when performing LBT, but not by a Wi-Fi AP further away from the first UE. This could lead to two problems:

[0103] 1) Even if the first UE initiating COT senses that the frequency band near the first UE is idle, at that time (e.g., in Figure 10 Before and / or during time slots 1006 and 1008 in the second UE (e.g., in Figure 8B Interference activity may also exist near UE 404 shown; and

[0104] 2) Other non-CV2X devices (e.g., Wi-Fi APs) near the second UE may not detect the transmission from the first UE and may initiate the transmission during the first UE's COT.

[0105] Based on these two issues, if the second UE will share the first UE's COT and transmit in the frequency band without performing LBT, it may interfere with the transmission of non-CV2X devices near the second UE (which the first UE does not sense as transmission).

[0106] Figure 11 This is an example transmission timeline 1100 for devices in a CV2X communication system. This example transmission timeline includes four time slots: 1104, 1106, 1108, and 1109. In this example transmission timeline, the first UE (e.g., in...) Figure 8B The UE 402 shown has data to transmit in time slots 1106 and 1108. The first UE performs LBT 1110 before time slot 1106. After LBT 1110 is successfully completed, the first UE initiates COT 1140 starting at the beginning of time slot 1106, which lasts for at least two time slots. As shown, the first UE senses energy across the entire bandwidth of frequency band 1120 during LBT 1110. The first UE transmits on subchannel 1124, but not on subchannels 1122, 1126, and 1128. In this example transmission timeline, the second UE, as a CV2X device (e.g., in...), ... Figure 8BThe UE 404 shown has data to be transmitted in time slot 1108. Additionally, another non-CV2X device near the second UE (e.g., in...) Figure 8B The BS 110b shown has data to be transmitted. Another device completes LBT 1160 just before time slot 1108 and does not detect (e.g., due to path loss to the first UE) transmissions 1142 and 1144 performed by the first UE. Then, this other device initiates transmission 1162. Therefore, as shown in timeline 1100, at the beginning of time slot 1108, transmission 1162 performed by this other device overlaps with transmission 1144 performed by the first UE in subchannel 1124. The second UE shares COT 1140 initiated by the first UE without performing LBT and selects subchannel 1128 to avoid conflicts with transmissions from the first UE. Because the second UE does not perform LBT, the second UE does not sense transmission 1162 performed by this other device, thus causing a conflict with the transmission performed by this other device. Therefore, as shown in timeline 1100, at the beginning of time slot 1108, the transmission 1162 performed by the other device overlaps with the transmission 1150 of the second UE in subchannel 1128, resulting in interference. At 1130 and 1132, when the channel is idle after performing LBT (not shown), a Wi-Fi AP (e.g., BS 110a) accesses the channel.

[0107] Depending on certain aspects, a device (e.g., a UE) can utilize a current active COT initiated by another device (e.g., a CV2X device) by performing an LBT procedure that ignores channel activity caused by CV2X signals (e.g., CV2X signals from the device initiating the COT or other CV2X devices sharing the COT).

[0108] In some respects, a device (e.g., a CV2X device) given information about which subchannels and during what time periods (e.g., time slots) one or more other CV2X devices are using in the current active COT, and having data to transmit in the same COT during one or more time periods, can perform LBT only on subchannels not used (e.g., transmitted on) by other CV2X devices during the one or more time periods on which the device has data to transmit. By performing LBT only on subchannels not used by other CV2X devices, the device can avoid sensing energy originating from other CV2X devices and claiming that energy as channel activity.

[0109] According to some aspects, if the modified LBT is successfully terminated (that is, the device that performs LBT only on available (e.g., not used by CV2X devices) sub-channels does not detect sufficient energy to prevent transmission on the sub-channels), then the device (e.g., the CV2X device) can transmit on any of the available sub-channels during one or more time periods within the COT and avoid conflicts with ongoing CV2X transmissions.

[0110] Figure 12 This is an example transmission timeline 1200 of a device operating in a CV2X communication system according to various aspects of this disclosure. This example transmission timeline includes four time slots 1204, 1206, 1208, and 1209, but this disclosure is not limited thereto, and aspects can be applied to longer or shorter time periods. In this example transmission timeline, the first UE (e.g., in...) Figure 8B The UE 402 shown has data to transmit in time slots 1206 and 1208. The first UE performs LBT 1210 before time slot 1206. After LBT 1210 is successfully completed, the first UE initiates COT 1240 starting at the beginning of time slot 1206, which lasts for at least two time slots. As shown, the first UE senses energy across the entire bandwidth of frequency band 1220 during LBT 1210. The first UE transmits on subchannel 1224, but not on subchannels 1222, 1226, and 1228.

[0111] In this example transmission timeline, the second UE (e.g., in) Figure 8B The UE 404 shown (which could be a CV2X device) has data to transmit in time slot 1208. Additionally, another device (e.g., in...) Figure 8BThe BS 110b shown has data to be transmitted. The other device completes LBT (not shown) just before time slot 1208 and does not detect (e.g., due to path loss to the first UE) transmissions 1242 and 1244 performed by the first UE. Then, the other device initiates transmission 1262. Therefore, as shown in timeline 1200, at the beginning of time slot 1208, transmission 1262 performed by the other device overlaps with transmission 1244 of the first UE in subchannel 1224. The second UE decodes the SCI transmitted by the first UE (e.g., in transmission 1242) and performs subchannel-based LBTs 1260a and 1260b on subchannels 1222, 1226, and 1228 to avoid measuring transmissions from the first UE and detecting interference based on first UE transmissions. The second UE detects transmission 1262 performed by the other device during subchannel-based LBT and determines not to transmit on subchannel 1228 during time slot 1208, thereby avoiding conflicts with transmissions performed by the other device. At 1230 and 1232, the Wi-Fi AP (e.g., BS110a) performs LBT (not shown) and accesses the channel when it is idle.

[0112] In some respects, during LBT (e.g., wideband LBT or not as described herein, subchannel-based LBT), when a signal energy greater than a threshold (e.g., Received Signal Strength Indicator (RSSI)) is detected, the channel is declared busy (e.g., unavailable for transmission).

[0113] In some aspects, the threshold (e.g., signal strength or RSSI threshold) used (e.g., by a CV2X device) to declare a channel as busy when performing subchannel-based LBT may be proportional to the percentage of the threshold that would be applied if all subchannels were sensed as busy in the wideband LBT. For example, an unlicensed channel (e.g., the channel on which the device is performing subchannel-based LBT) may consist of N (e.g., one or more) subchannels. The device (e.g., a CV2X UE) may perform LBT only on a portion of the total bandwidth of a channel consisting of M not necessarily contiguous subchannels, where M ≤ N. If T is the LBT threshold value used to declare a busy channel for an LBT process that uses sensing across the entire bandwidth of the unlicensed channel, then each subchannel effectively contributes a portion of the threshold value T (e.g., 1 / N). Therefore, in some aspects, when the device measures M subchannels, then the device uses a threshold equal to M*(1 / N)*T.

[0114] According to certain aspects, the above proportionality rule is desirable when the subchannel energy sensing performed by the device is ideal; that is, the above proportionality rule is desirable when the energy of the CV2X active subchannel can be ideally filtered out by the device.

[0115] In some respects, energy sensing in the subchannel-based LBT process is performed within the same predefined time interval as in the broadband LBT process.

[0116] In some respects, subchannel energy measurements may not be perfect due to energy leakage effects.

[0117] Figure 13 This is an example channel energy diagram 1300 illustrating energy leakage according to various aspects of this disclosure. In this example diagram, the example channel has a total of four sub-channels 1302, 1304, 1306, and 1308. As discussed, a channel can have any suitable number of sub-channels. In this example, a device (e.g., a CV2X UE) detects CV2X activity within an initiated COT on sub-channels 1304 and 1308. To share the COT, the device performs sub-channel-based LBT sensing on sub-channels 1302 and 1306. Even if there is no interference activity or noise on sub-channels 1302 and 1306, energy leakage 1320, 1322, and 1324 from CV2X transmissions 1310 and 1312 may still be sensed by sub-channel-based LBT.

[0118] In some respects, energy leakage may be greater when the CV2X signal originates from a nearby device (e.g., due to the proximity effect).

[0119] According to some aspects, when a subchannel is not actually busy, it may be perceived as busy (e.g., by a device performing subchannel-based LBT) due to energy leakage from CV2X transmissions on other subchannels.

[0120] In some respects, the device can measure the energy on any sub-channel while excluding (e.g., not measuring) the frequencies in the sub-bands on either side of the sub-channel occupied by the CV2X (e.g., excluding the sub-bands).

[0121] Depending on certain aspects, the size of the aforementioned exclusion subband can be fixed (e.g., pre-configured). For example, the size of the exclusion subband can be pre-configured based on a worst-case scenario.

[0122] In some aspects, the device can adaptively determine the size of the aforementioned exclusion subband. For example, the device can determine the size of the exclusion subband based on the Reference Signal Received Power (RSRP) of the CV2X signal in adjacent sub-channels. According to some aspects, a larger RSRP may indicate greater leakage from the CV2X signal, and therefore a larger exclusion subband size (e.g., guard band size) may be desired. In some aspects of this disclosure, the size of the aforementioned exclusion subband can be determined based on the location of the CV2X transmitter. For example, an energy sensing device (e.g., a CV2X UE that intends to share a COT) can identify the location of the transmitting UE based on the SCI (e.g., a region identifier (ID) that may be included in the SCI), and if the transmitting UE is close to the energy sensing device, the energy sensing device determines to use a larger exclusion subband (e.g., guard band) size.

[0123] Figure 14 This is an example channel energy pattern 1400 illustrating adaptively determined exclusion subbands according to various aspects of this disclosure. In this example pattern, the channel has a total of four subchannels 1402, 1404, 1406, and 1408. As discussed, a channel can have any suitable number of subchannels. In this example, a device (e.g., a CV2X UE) detects CV2X activity within an initiated COT on subchannels 1404 and 1408. To share the COT, the device performs subchannel-based LBT sensing on subchannels 1402 and 1406. The device determines to use exclusion subbands 1420 and 1422 to exclude energy leakage from transmission 1410. The device also determines to use the larger exclusion subband 1424 to exclude energy leakage from higher-power transmission 1412. Therefore, subbands 1420, 1422 and 1424 are examples of one or more frequency subbands adjacent to one or more assigned subchannels 1404 and 1408 within one or more unassigned subchannels 1402 and 1406.

[0124] According to some aspects, the exclusion subbands that are useful for eliminating CV2X signal leakage as described above may also eliminate a portion of any interference energy present in the excluded subbands.

[0125] In some respects, the device can determine an energy detection threshold for a busy channel claim based on the size of one or more exclusion subbands applied to measure energy in a subchannel. Therefore, the larger the exclusion subband is relative to the subchannel, the smaller the contribution of that subchannel to determining the energy threshold. For example, when the device is performing energy sensing (e.g., subchannel-based LBT) on M=2 subchannels out of a total of N=4 subchannels, as previously described herein, the device can determine a basic threshold equal to 2*(1 / 4)*T. The first subchannel energy measurement excludes the subchannels respectively (e.g., see in...). Figure 14 The left and right edges of subchannel 1406 shown are 10% and 25%, respectively. A second subchannel energy measurement can exclude subchannels (e.g., see in...). Figure 14 The right edge of the sub-channel 1402 shown is 25%. The frequencies of 65% of the first sub-channel frequency and 75% of the second sub-channel frequency were measured, and therefore, the refined energy detection threshold can be 0.65*(1 / 4)*T+0.75*(1 / 4)*T.

[0126] According to some aspects, in a wideband LBT process, a device (e.g., a CV2X UE) can measure the total energy of the channel by summing all subcarriers of the channel at the output of the receiver's inverse fast Fourier transform (IFFT) module. In some aspects, in a subband-based LBT process, only subcarriers corresponding to the subband being measured (e.g., a subchannel) and not included in the corresponding excluded subband (e.g., a guard band) are measured.

[0127] Optionally, in some aspects of this disclosure, the input signal to the receiver's Fast Fourier Transform (FFT) module can first be applied to a filter bank that is tuned to filter out subchannels occupied by the CV2X signal. Since the CV2X energy contribution will tend to be smaller, these aspects can lead to better performance compared to summing the subcarriers at the output of the receiver's IFFT module as described above. Using a filter bank may incur costs in terms of implementation complexity and additional delay due to the filtering operations.

[0128] Figure 15 Example channel energy pattern 1500 illustrates the use of filter banks according to various aspects of this disclosure. In example pattern 1500, the channel has a total of four sub-channels 1502, 1504, 1506, and 1508. In this example, a device (e.g., a CV2X UE) detects CV2X activity within an initiated COT on sub-channels 1504 and 1508. To share the COT, the device applies filter banks 1520a and 1520b, excluding sub-channels 1504 and 1508, to input signals 1510 and 1512 before performing sub-channel-based LBT sensing on sub-channels 1502 and 1506.

[0129] Figure 16 This is a flowchart illustrating an example operation 1600 for wireless communication according to certain aspects of this disclosure. Operation 1600 can be performed, for example, by a UE (e.g., UE 120a in wireless communication network 100). Operation 1600 can be implemented in one or more processors (e.g., Figure 2Software components that execute and run on the controller / processor 280 (in the processor). Furthermore, they can be transmitted, for example, via one or more antennas (e.g., Figure 2 The UE transmits and receives signals in operation 1600 via antenna 252. In some aspects, the UE transmits and / or receives signals via a bus interface that acquires and / or outputs signals from one or more processors (e.g., controller / processor 280).

[0130] Operation 1600 may begin at block 1602, wherein the UE may receive one or more transmissions indicating that the device has acquired a frequency band for communication by one or more devices, including the UE, during the Channel Occupied Time (COT), and the one or more transmissions also indicating that one or more allocated sub-channels of the frequency band have been allocated to at least one device other than the UE during a first time period of the COT, the frequency band including one or more allocated sub-channels and one or more unallocated sub-channels during the first time period.

[0131] Operation 1600 can continue at box 1604, wherein the UE can measure the signal strength of only one or more unassigned sub-channels within at least a portion of the first time period prior to the second time period of COT.

[0132] Operation 1600 may optionally continue at block 1606, wherein the UE may calculate a threshold based on the ratio of a first bandwidth of one or more unallocated sub-channels to a second bandwidth of that frequency band.

[0133] Operation 1600 may optionally continue at block 1608, wherein the first UE may calculate a threshold based on the ratio of a first bandwidth of one or more unallocated frequency sub-bands to a second bandwidth of that band.

[0134] Operation 1600 can continue at box 1610: when the measured signal strength is less than a threshold (which may be one of the thresholds calculated at boxes 1606 and / or 1608), the UE may transmit a signal in the frequency band during the second time period.

[0135] Depending on certain aspects, the threshold of box 1606 may be based on the ratio of the first bandwidth of one or more unassigned sub-channels of box 1602 to the second bandwidth of that frequency band of box 1602.

[0136] In some aspects, such as measuring the signal strength of only one or more unassigned sub-channels as in block 1604, this may include measuring only the signal strength of one or more unassigned sub-channels that are excluded from one or more frequency sub-bands adjacent to one or more assigned sub-channels within the one or more unassigned sub-channels. In some such aspects, the threshold in block 1606 may be based on the ratio of a first bandwidth of the one or more unassigned sub-channels excluding one or more frequency sub-bands to a second bandwidth of that frequency band. In some other such aspects, one or more frequency sub-bands (e.g., as described herein with respect to...) Figure 14 The bandwidth of each frequency sub-band in the described excluded sub-bands can be fixed (e.g., pre-configured) or configured by another wireless communication device. In other such aspects, for each of one or more frequency sub-bands, the corresponding bandwidth of the corresponding frequency sub-band can be based on the corresponding signal strength of the corresponding signal received on the corresponding assigned sub-channel adjacent to the corresponding frequency sub-band. In other words, for sub-bands excluded from sensing (e.g., as described herein...), the bandwidth of each frequency sub-band can be fixed (e.g., pre-configured) or configured by another wireless communication device. Figure 14 The bandwidth determined for each subband in the described excluded subbands can be based on the signal strength of the signal received on an allocated subchannel adjacent to such a subband. For example, if a high RSRP is sensed on an allocated subchannel adjacent to the excluded subband, a larger bandwidth can be assigned to that excluded subband. As an example, if a low RSRP is sensed on an allocated subchannel adjacent to the excluded subband, a smaller bandwidth can be assigned to that excluded subband. In some other aspects, for each of one or more frequency subbands, the corresponding bandwidth of the corresponding frequency subband can be based on the corresponding distance between the UE and a corresponding device allocated a corresponding allocated subchannel adjacent to that corresponding frequency subband. That is, the bandwidth determined for each excluded subband can be based on the distance between the UE and other devices allocated subchannels. For example, if the UE and other devices are close to each other, a larger bandwidth can be assigned to the excluded subband. As an example, if the UE and other devices are not close to each other, a smaller bandwidth can be used for the excluded subband.

[0137] According to some aspects, such as measuring signal strength in block 1604, it may include: applying a filter bank to an input signal corresponding to the frequency band, the filter bank being configured to filter one or more assigned sub-channels of the input signal; and measuring the signal strength of the filtered input signal.

[0138] In some respects, the first time period of box 1602 and the second time period of box 1604 can each be a time slot.

[0139] Depending on some aspects, the communication performed by one or more devices in block 1602 may correspond to sidelink communication. In some such aspects, the one or more devices may be CV2X devices.

[0140] In all respects, the frequency band of frame 1602 may include unlicensed frequency bands.

[0141] Figure 17 This is a flowchart illustrating an example operation 1700 for wireless communication according to certain aspects of this disclosure. Operation 1700 can be performed, for example, by a first UE (e.g., UE 120a in wireless communication network 100). Operation 1700 can be implemented in one or more processors (e.g., Figure 2 Software components that execute and run on the controller / processor 280 (in the processor). Furthermore, they can be transmitted, for example, via one or more antennas (e.g., Figure 2 The UE transmits and receives signals in operation 1700 via antenna 252. In some aspects, the UE transmits and / or receives signals via a bus interface that acquires and / or outputs signals from one or more processors (e.g., controller / processor 280).

[0142] Operation 1700 can begin at block 1702, wherein a first UE can receive one or more transmissions on one or more allocated sub-channels indicating a frequency band, wherein the sub-channels were allocated during a first time period, and the frequency band includes the allocated sub-channels and one or more unallocated sub-channels during the first time period. For example, the first UE can perform an LBT procedure to determine whether a sub-channel is occupied by another wireless communication device. The first UE (e.g., in...) Figure 8A and 8B The vehicle 404 depicted in the image can be transmitted from a second UE (e.g., in an unlicensed frequency band) in an unlicensed frequency band. Figure 8A and 8B The vehicle 402 depicted in the image receives the transmission.

[0143] At box 1704, the first UE may sense unassigned sub-channels (e.g., only) for at least a portion of the first time period prior to the second time period. For example, the first UE may monitor any signals from other wireless communication devices in the unassigned sub-channels during a portion of the first time period.

[0144] Optionally, at block 1706, the first UE may calculate a threshold based on the ratio of the first bandwidth of one or more unallocated sub-channels to the second bandwidth of the frequency band.

[0145] Optionally, at block 1708, the first UE may calculate a threshold based on the ratio of the first bandwidth of one or more frequency sub-bands excluded from one or more unallocated sub-channels to the second bandwidth of that frequency band.

[0146] At box 1710, the first UE may transmit a signal in the frequency band during a second time period based on the sensed energy for one or more unallocated sub-channels being less than a threshold, which may be one of the thresholds calculated at boxes 1606 and / or 1608. The first UE may determine that the sensed energy for the unallocated sub-channels is less than the threshold, and the first UE may consider the unallocated sub-channels to be unoccupied and open during the second time period to share the COT with the second UE, for example, as described herein. Figure 8A Described. In some cases, the first UE can determine that the energy sensed for an unallocated subchannel is equal to or greater than a threshold, and the first UE can avoid transmitting on the unallocated subchannel during a second time period, for example, as described herein. Figure 8B Described.

[0147] In some respects, the first UE can perform actions as described in this article. Figures 8A-16 And operation 1700 as described in operation 1600. For example, sensing at block 1704 may involve the first UE sensing only unallocated subchannels that are excluded from one or more frequency subbands adjacent to allocated subchannels within the unallocated subchannels. In some cases, the first time period and the second time period may each include time slots. COT may include the first time period and the second time period.

[0148] Figure 18 A communication device 1800 is shown, which may include operations configured to perform the techniques disclosed herein (such as in...). Figure 16 and / or Figure 17 Various components (e.g., corresponding to unit plus functional components) are shown in the diagram. The communication device 1800 includes a processing system 1802 and circuits 1824, 1826, and 1828 coupled to a transceiver 1808 (e.g., a transmitter and / or receiver). The transceiver 1808 is configured to transmit and receive signals for the communication device 1800 via an antenna 1810, such as the various signals described herein. The processing system 1802 may be configured to perform processing functions for the communication device 1800, including processing signals received and / or to be transmitted by the communication device 1800.

[0149] Processing system 1802 includes processor 1804 coupled to computer-readable medium / memory 1812 via bus 1806. In some aspects, computer-readable medium / memory 1812 is configured to store instructions (e.g., computer-executable code) that, when executed by processor 1804, cause processor 1804 to perform actions... Figure 16 and / or Figure 17 The operations shown herein, or other operations used to perform the various techniques discussed herein for subchannel-based LBT, are described. In some aspects, the computer-readable medium / memory 1812 stores: code 1814 for receiving one or more transmissions indicating that the device has acquired a frequency band for communication by one or more devices, including communication device 1800, during the Channel Occupied Time (COT), the one or more transmissions also indicating one or more allocated subchannels of the frequency band allocated to at least one device other than the communication device during a first time period of the COT, the frequency band including one or more allocated subchannels and one or more unallocated subchannels during the first time period; code 1816 for measuring the signal strength of only the one or more unallocated subchannels during at least a portion of the first time period prior to a second time period of the COT; and code 1818 for transmitting a signal in the frequency band during the second time period when the measured signal strength is less than a threshold.

[0150] In some aspects, the processing system 1802 has circuitry configured to implement code stored in a computer-readable medium / memory 1812. The processing system 1802 includes: circuitry (e.g., an example of a unit for this operation) 1824 for receiving one or more transmissions indicating that a device has acquired a frequency band for communication by one or more devices, including the communication device 1800, during a Channel Occupancy Time (COT), the transmissions also indicating one or more allocated sub-channels of the frequency band allocated to at least one device other than the communication device during a first time period of the COT, the frequency band including one or more allocated sub-channels and one or more unallocated sub-channels during the first time period; circuitry (e.g., an example of a unit for this operation) 1826 for measuring the signal strength of only the one or more unallocated sub-channels during at least a portion of the first time period prior to a second time period of the COT; and circuitry (e.g., an example of a unit for this operation) 1828 for transmitting a signal within the frequency band during the second time period when the measured signal strength is less than a threshold. One or more of circuits 1824, 1826 and 1828 may be implemented by one or more of a digital signal processor (DSP), a circuit, an application-specific integrated circuit (ASIC) or a processor (e.g., a general-purpose or specially programmed processor).

[0151] The various components of the communication device 1800 can provide for the execution of this document (including those concerning...) Figure 16 and / or Figure 17 The unit described in the method. In some examples, the unit for transmission or sending (or the unit for output to transmit) may be included in Figure 2 The transceiver 254 and / or antenna 252 of the user equipment 120 shown are shown. Figure 18 The communication device 1800 includes a transceiver 1808 and an antenna 1810. In some examples, the unit for receiving (or the unit for receiving) may be included in... Figure 2 The transceiver 254 and / or antenna 252 of the user equipment 120 shown are shown. Figure 18 The communication device 1800 includes a transceiver 1808 and an antenna 1810. In some examples, the sensing unit may include various processing system components, such as: Figure 18 The processor 1804 and / or computer-readable medium / memory 1812, or in Figure 2 The user equipment 120 depicted includes various aspects such as MIMO detector 256, receive processor 258, transmit processor 264, TX MIMO processor 266, controller / processor 280 (including subband LBT manager 281) and / or memory 282.

[0152] Example

[0153] In addition to the aspects mentioned above, specific combinations of these aspects are also within the scope of this disclosure, and some of these specific combinations are described in detail below:

[0154] Aspect 1: A method for wireless communication by a first user equipment (UE), comprising: receiving one or more transmissions indicating that the device has acquired a frequency band for communication by one or more devices including the first UE during a channel occupied time (COT), the one or more transmissions further indicating that the frequency band is allocated to one or more allocated sub-channels of at least one device other than the first UE during a first time period of the COT, the frequency band including the one or more allocated sub-channels and one or more unallocated sub-channels during the first time period; measuring the signal strength of only the one or more unallocated sub-channels for at least a portion of the first time period prior to a second time period of the COT; and transmitting a signal in the frequency band during the second time period when the measured signal strength is less than a threshold.

[0155] Aspect 2: According to the method of aspect 1, wherein the threshold is based on the ratio of the first bandwidth of the one or more unallocated sub-channels to the second bandwidth of the frequency band.

[0156] Aspect 3: The method according to one of Aspects 1-2, wherein measuring the signal strength of only the one or more unassigned sub-channels comprises: measuring only the signal strength of the one or more unassigned sub-channels excluding one or more frequency sub-bands adjacent to the one or more assigned sub-channels within the one or more unassigned sub-channels.

[0157] Aspect 4: According to the method of aspect 3, wherein the threshold is based on the ratio of a first bandwidth of the one or more unallocated sub-channels excluding the one or more frequency sub-bands to a second bandwidth of the frequency band.

[0158] Aspect 5: According to the method of aspect 3, wherein the bandwidth of each frequency sub-band in the one or more frequency sub-bands is fixed.

[0159] Aspect 6: According to the method of aspect 3, wherein, for each of the one or more frequency sub-bands, the corresponding bandwidth of the corresponding frequency sub-band is based on the corresponding signal strength of the corresponding signal received on the corresponding allocated sub-channel adjacent to the corresponding frequency sub-band.

[0160] Aspect 7: According to the method of aspect 3, wherein, for each of the one or more frequency sub-bands, the corresponding bandwidth of the corresponding frequency sub-band is based on the corresponding distance between the first UE and the corresponding device that has been allocated a corresponding sub-channel adjacent to the corresponding frequency sub-band.

[0161] Aspect 8: The method according to one of aspects 1-7, wherein: measuring the signal strength comprises: applying a filter bank to an input signal corresponding to the frequency band, the filter bank being configured to filter one or more assigned sub-channels of the input signal; and measuring the signal strength of the filtered input signal.

[0162] Aspect 9: The method according to one of aspects 1-8, wherein the first time period and the second time period each include a time slot.

[0163] Aspect 10: The method according to one of aspects 1-9, wherein the communication performed by the one or more devices corresponds to side link communication.

[0164] Aspect 11: The method according to aspect 10, wherein the one or more devices include cellular vehicle-to-everything (CV2X) devices.

[0165] Aspect 12: The method according to one of aspects 1-11, wherein the frequency band includes an unlicensed frequency band.

[0166] Aspect 13: An apparatus for wireless communication, comprising a unit for performing one or more methods according to aspects 1-12 or 29-41.

[0167] Aspect 14: An apparatus for wireless communication, comprising: a memory; and a processor coupled to the memory, the memory and the processor being configured to perform the method according to one or more of aspects 1-12 or 29-41.

[0168] Aspect 15: A computer-readable medium comprising instructions that, when executed by a processing system, cause the processing system to perform the method according to one or more of aspects 1-12 or 29-41.

[0169] Aspect 16: An apparatus for wireless communication, comprising: a memory; a processor coupled to the memory, the processor and the memory being configured to: receive one or more transmissions of one or more allocated sub-channels allocated during a first time period of an indicated frequency band, the frequency band including the one or more allocated sub-channels and one or more unallocated sub-channels during the first time period; sense the one or more unallocated sub-channels for at least a portion of the first time period prior to a second time period; and transmit a signal within the frequency band during the second time period based on the sensing energy for the one or more unallocated sub-channels being less than a threshold.

[0170] Aspect 17: The apparatus according to aspect 16, wherein the threshold is based on the ratio of a first bandwidth of the one or more unallocated sub-channels to a second bandwidth of the frequency band.

[0171] Aspect 18: The apparatus according to any one of aspects 16 or 17, wherein the processor and the memory are further configured to sense only the one or more unallocated subchannels that are excluded from the one or more unallocated subchannels and are adjacent to the one or more allocated subchannels.

[0172] Aspect 19: The apparatus according to aspect 18, wherein the threshold is based on the ratio of a first bandwidth excluding the one or more frequency sub-bands to a second bandwidth of the frequency band of the one or more unassigned sub-channels.

[0173] Aspect 20: The apparatus according to any one of aspects 18 or 19, wherein the bandwidth of each of the one or more frequency sub-bands is fixed.

[0174] Aspect 21: The apparatus according to any one of aspects 18 or 19, wherein, for each of the one or more frequency sub-bands, the corresponding bandwidth of the corresponding frequency sub-band is based on the corresponding signal strength of the corresponding signal received on the corresponding assigned sub-channel adjacent to the corresponding frequency sub-band.

[0175] Aspect 22: The apparatus according to any one of aspects 18, 19 or 21, wherein, for each of the one or more frequency sub-bands, the corresponding bandwidth of the corresponding frequency sub-band is based on the corresponding distance between the first UE and the corresponding device that has been allocated a corresponding sub-channel adjacent to the corresponding frequency sub-band.

[0176] Aspect 23: The apparatus according to any one of aspects 16-22, wherein the processor and the memory are further configured to: apply a filter bank to an input signal corresponding to the frequency band, the filter bank being configured to filter one or more assigned sub-channels of the input signal; and sense the filtered input signal.

[0177] Aspect 24: The apparatus according to any one of aspects 16-23, wherein the first time period and the second time period each include a time slot.

[0178] Aspect 25: The apparatus according to any one of aspects 16-24, wherein the channel occupancy time (COT) includes the first time period and the second time period.

[0179] Aspect 26: The apparatus according to any one of aspects 16-25, wherein the processor and the memory are further configured to transmit the signal via a side link channel.

[0180] Aspect 27: The apparatus according to any one of aspects 16-26, wherein the apparatus includes a cellular vehicle-to-everything (CV2X) device.

[0181] Aspect 28: The apparatus according to any one of aspects 16-27, wherein the frequency band includes an unlicensed frequency band.

[0182] Aspect 29: A method for wireless communication performed by a user equipment (UE), comprising: receiving one or more transmissions of one or more allocated sub-channels allocated during a first time period of an indicated frequency band, the frequency band including the one or more allocated sub-channels and one or more unallocated sub-channels during the first time period; sensing the one or more unallocated sub-channels for at least a portion of the first time period prior to a second time period; and transmitting a signal in the frequency band during the second time period based on sensing energy less than a threshold for the one or more unallocated sub-channels.

[0183] Aspect 30: The method according to aspect 29, wherein the threshold is based on the ratio of the first bandwidth of the one or more unallocated sub-channels to the second bandwidth of the frequency band.

[0184] Aspect 31: The method according to any one of aspects 29 or 30, wherein sensing only the one or more unassigned subchannels comprises: sensing only the one or more unassigned subchannels that are excluded from one or more frequency subbands adjacent to the one or more assigned subchannels within the one or more unassigned subchannels.

[0185] Aspect 32: According to the method of aspect 31, wherein the threshold is based on the ratio of a first bandwidth of the one or more unallocated sub-channels excluding the one or more frequency sub-bands to a second bandwidth of the frequency band.

[0186] Aspect 33: The method according to any one of aspects 31 or 32, wherein the bandwidth of each frequency sub-band in the one or more frequency sub-bands is fixed.

[0187] Aspect 34: The method according to any one of aspects 31 or 32, wherein, for each of the one or more frequency sub-bands, the corresponding bandwidth of the corresponding frequency sub-band is based on the corresponding signal strength of the corresponding signal received on the corresponding assigned sub-channel adjacent to the corresponding frequency sub-band.

[0188] Aspect 35: The method according to any one of aspects 31, 32 or 34, wherein, for each of the one or more frequency sub-bands, the corresponding bandwidth of the corresponding frequency sub-band is based on the corresponding distance between the first UE and the corresponding device that has been allocated a corresponding sub-channel adjacent to the corresponding frequency sub-band.

[0189] Aspect 36: The method according to any one of aspects 29-35, wherein sensing includes: applying a filter bank to an input signal corresponding to the frequency band, the filter bank being configured to filter one or more assigned sub-channels of the input signal; and sensing the filtered input signal.

[0190] Aspect 37: The method according to any one of aspects 29-36, wherein the first time period and the second time period each include a time slot.

[0191] Aspect 38: The method according to any one of aspects 29-37, wherein the channel occupancy time (COT) includes the first time period and the second time period.

[0192] Aspect 39: The method according to any one of aspects 29-38, wherein transmitting the signal comprises: transmitting the signal via a side link channel.

[0193] Aspect 40: The method according to any one of aspects 29-39, wherein the UE includes a cellular vehicle-to-everything (CV2X) device.

[0194] Aspect 41: The method according to any one of aspects 29-40, wherein the frequency band includes an unlicensed frequency band.

[0195] Aspect 42: An apparatus for wireless communication, comprising: a unit for receiving one or more transmissions of one or more allocated sub-channels allocated during a first time period of an indicated frequency band, the frequency band including the one or more allocated sub-channels and one or more unallocated sub-channels during the first time period; a unit for sensing the one or more unallocated sub-channels for at least a portion of the first time period prior to a second time period; and a unit for transmitting a signal within the frequency band during the second time period based on the sensing energy for the one or more unallocated sub-channels being less than a threshold.

[0196] Aspect 43: The apparatus according to aspect 42, wherein the threshold is based on the ratio of a first bandwidth of the one or more unallocated sub-channels to a second bandwidth of the frequency band.

[0197] Aspect 44: A computer-readable medium having instructions stored thereon, which, when executed by a device, cause the device to perform the following operations: receive one or more transmissions of one or more allocated sub-channels allocated during a first time period of an indicated frequency band, the frequency band including the one or more allocated sub-channels and one or more unallocated sub-channels during the first time period; sense the one or more unallocated sub-channels for at least a portion of the first time period prior to a second time period; and transmit a signal within the frequency band during the second time period based on the sensing energy for the one or more unallocated sub-channels being less than a threshold.

[0198] Aspect 45: The computer-readable medium according to aspect 44, wherein the threshold is based on the ratio of a first bandwidth of the one or more unallocated sub-channels to a second bandwidth of the frequency band.

[0199] Additional considerations

[0200] The techniques described in this article can be used in various wireless communication technologies, such as NR (e.g., 5G NR), 3GPP Long Term Evolution (LTE), Improved LTE (LTE-A), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC FDMA), Time Division Synchronous Code Division Multiple Access (TD-SCDMA), and other networks. The terms "network" and "system" are often used interchangeably. CDMA networks can implement radio technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes Wideband CDMA (WCDMA) and other variations of CDMA. cdma2000 encompasses the IS-2000, IS-95, and IS-856 standards. TDMA networks can implement radio technologies such as Global System for Mobile Communications (GSM). OFDMA networks can implement radio technologies such as NR (e.g., 5G RA), evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and Flash-OFDMA. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). LTE and LTE-A are versions of UMTS using E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization called the 3rd Generation Partnership Project (3GPP). CDMA2000 and UMB are described in documents from an organization called the 3rd Generation Partnership Project 2 (3GPP2). NR is an emerging wireless communication technology currently being deployed.

[0201] In 3GPP, the term "cell" can refer to the coverage area of ​​a Node B (NB) and / or the NB subsystem serving that coverage area, depending on the context in which the term is used. In NR systems, the term "cell" is used interchangeably with BS, Next Generation Node B (gNB or gNodeB), Access Point (AP), Distributed Unit (DU), and Carrier or Transmitter / Receiver Point (TRP). A BS can provide communication coverage for macrocells, picocells, femtocells, and / or other types of cells. A macrocell can cover a relatively large geographic area (e.g., a radius of several kilometers) and can allow unrestricted access by UEs with service subscriptions. A picocell can cover a relatively small geographic area and can allow unrestricted access by UEs with service subscriptions. A femtocell can cover a relatively small geographic area (e.g., a residential area) and can allow restricted access by UEs associated with that femtocell (e.g., UEs in a Closed Subscriber Group (CSG), UEs for users in a residential area, etc.). A BS used for a macrocell can be called a macro BS. A BS used for a picocell can be called a pico BS. A BS used for a femtocell can be called a femtocell BS or a home BS.

[0202] In this document, the term “User Equipment (UE)” or “CV2X device” refers broadly to a variety of devices and technologies. UEs and CV2X devices may include multiple hardware structural components sized, shaped, and arranged to facilitate communication; such components may include antennas, antenna arrays, RF chains, amplifiers, one or more processors, etc., electrically coupled to each other. For example, some non-limiting examples of UEs or CV2X devices include mobile stations, cellular phones, smartphones, Session Initiation Protocol (SIP) phones, laptops, personal computers (PCs), notebooks, netbooks, smartbooks, tablet devices, personal digital assistants (PDAs), and a wide range of embedded systems, such as those corresponding to the “Internet of Things” (IoT). UE or CV2X devices can also be automobiles or other vehicles, remote sensors or actuators, robots or robotic devices, satellite radio units, Global Positioning System (GPS) devices, object tracking devices, drones, multi-rotor helicopters, quadcopter helicopters, remote control devices, consumer and / or wearable devices (such as glasses, wearable cameras, virtual reality devices, smartwatches, health or fitness trackers), digital audio players (e.g., MP3 players), cameras, game consoles, etc. UE or CV2X devices can also be digital home or smart home devices, such as home audio, video and / or multimedia devices, appliances, vending machines, smart lighting, home security systems, smart meters, etc. UE or CV2X devices can also be smart energy devices, security devices, solar panels or solar arrays, municipal infrastructure equipment (e.g., smart grids, public Wi-Fi, etc.), industrial automation and enterprise equipment, logistics controllers, agricultural equipment, military defense equipment: vehicles, aircraft, ships, and weapons, etc. Furthermore, UE or CV2X devices can provide connected medical or telemedicine support, such as telemedicine. Remote health devices may include remote health monitoring devices and remote health management devices, whose communications may be given priority processing or access relative to other types of information, for example, in terms of priority access for transmission of critical service data and / or in terms of relevant QoS for transmission of critical service data.

[0203] In some examples, access to the air interface can be scheduled. A scheduling entity (e.g., a BS) allocates resources for communication among some or all devices and apparatuses within its service area or cell. The scheduling entity may be responsible for scheduling, allocating, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communication, the subordinate entity utilizes the resources allocated by the scheduling entity. A base station is not the only entity that can act as a scheduling entity. In some examples, a UE can act as a scheduling entity and can schedule resources for one or more subordinate entities (e.g., one or more other UEs), and other UEs can utilize the resources scheduled by that UE for wireless communication. In some examples, a UE can act as a scheduling entity in a peer-to-peer (P2P) network and / or a mesh network. In the mesh network example, in addition to communicating with a scheduling entity, UEs can also communicate directly with each other.

[0204] The methods disclosed herein include one or more steps or actions for implementing the methods. These method steps and / or actions may be interchanged with each other without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of a particular step and / or action may be modified without departing from the scope of the claims.

[0205] As used in this article, the phrase “at least one of” in a list of items refers to any combination of those items, including a single member. For example, “at least one of a, b, or c” is intended to cover a, b, c, ab, ac, bc, and abc, as well as any combination with multiples of the same element (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other ordering of a, b, and c).

[0206] As used herein, the term "determine" encompasses a wide variety of actions. For example, "determine" can include calculation, operation, processing, derivation, investigation, lookup (e.g., searching in a table, database, or other data structure), ascertainment, and so on. Furthermore, "determine" can include receiving (e.g., receiving information), accessing (e.g., accessing data in memory), and so on. Additionally, "determine" can include parsing, selecting, choosing, establishing, and so on.

[0207] The foregoing description is provided to enable any person skilled in the art to implement the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Therefore, the claims are not intended to be limited to the aspects shown herein, but rather to be given the full scope consistent with the language of the claims, wherein references to elements in the singular form are not intended to mean “one and only one,” but rather “one or more,” unless specifically stated otherwise. Unless otherwise expressly stated, the term “some” refers to one or more. All structural and functional equivalents of the elements throughout the various aspects described in this disclosure are expressly incorporated herein by reference and intended to be included by the claims, such structural and functional equivalents being known or to be known by those skilled in the art. Furthermore, nothing disclosed herein is intended to be offered to the public, whether or not such disclosure is expressly stated in the claims. No claim element is to be interpreted pursuant to 35 U.SC §112(f) unless the element is expressly stated using the phrase “unit for…” or, in the case of a method claim, using the phrase “step for…”.

[0208] The various operations of the methods described above can be performed by any suitable unit capable of performing the corresponding function. These units may include various hardware and / or software components and / or modules, including but not limited to: circuits, application-specific integrated circuits (ASICs), or processors. Typically, in the presence of operations as shown in the figures, those operations may have corresponding paired units plus functional components with similar numbering.

[0209] The various illustrative logic blocks, modules, and circuits described in connection with this disclosure can be implemented or executed using a general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The processor may be a microprocessor, but alternatively, it may be any commercially available processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration.

[0210] If implemented in hardware, an example hardware configuration could include a processing system in a wireless node. The processing system could utilize a bus architecture. Depending on the specific application and overall design constraints of the processing system, the bus could include any number of interconnect buses and bridges. The bus could link together various circuits, including a processor, machine-readable media, and a bus interface. In addition, the bus interface could be used to connect a network adapter to the processing system via the bus. The network adapter could be used to implement signal processing functions at the PHY layer. In the user terminal (see...) Figure 1 In this case, a user interface (e.g., keypad, display, mouse, joystick, etc.) can also be connected to the bus. The bus can also link various other circuits such as timing sources, peripheral devices, voltage regulators, power management circuits, etc., which are well known in the art and therefore will not be described further. The processor can be implemented using one or more general-purpose and / or special-purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuits capable of executing software. Those skilled in the art will recognize how the functions described for the processing system can be optimally implemented based on the specific application and the overall design constraints imposed on the system as a whole.

[0211] If implemented in software, the functionality can be stored or transmitted as one or more instructions or code on or through a computer-readable medium. Whether referred to as software, firmware, middleware, microcode, hardware description language, or other terms, software should be broadly interpreted to mean instructions, data, or any combination thereof. Computer-readable media includes both computer storage media and communication media, with communication media encompassing any medium that facilitates the transfer of a computer program from one place to another. The processor may be responsible for managing the bus and general-purpose processing, including executing software modules stored on the machine-readable storage medium. The computer-readable storage medium may be coupled to the processor so that the processor can read information from and write information to the storage medium. Alternatively, the storage medium may be an integral part of the processor. For example, the machine-readable medium may include a transmission line, a carrier wave modulated by data, and / or a separate computer-readable storage medium containing instructions stored thereon, all accessible to the processor via a bus interface. Alternatively or additionally, the machine-readable medium or any portion thereof may be integrated into the processor; for example, this could be a cache and / or a general-purpose register file. For example, examples of machine-readable storage media may include RAM (random access memory), flash memory, ROM (read-only memory), PROM (programmable read-only memory), EPROM (erasable programmable read-only memory), EEPROM (electrically erasable programmable read-only memory), registers, disks, optical disks, hard drives, or any other suitable storage media, or any combination thereof. Machine-readable media may be embodied in a computer program product.

[0212] Software modules may include a single instruction or many instructions, and may be distributed across several different code segments, within different programs, and across multiple storage media. Computer-readable media may include multiple software modules. A software module includes instructions that, when executed by a device such as a processor, cause a processing system to perform various functions. A software module may include sending modules and receiving modules. Each software module may reside in a single storage device or be distributed across multiple storage devices. For example, when a triggering event occurs, a software module may be loaded from a hard drive into RAM. During the execution of a software module, the processor may load some of the instructions into a cache to increase access speed. One or more cache lines may then be loaded into a general-purpose register file for execution by the processor. It will be understood that when the functionality of a software module is referred to below, this functionality is implemented by the processor when executing the instructions from that software module.

[0213] Furthermore, any connection is appropriately referred to as computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technology (e.g., infrared (IR), radio, and microwave), then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technology (e.g., infrared, radio, and microwave) is included in the definition of medium. As used herein, disk and disc include compressed optical disc (CD), laser disc, optical disc, digital versatile optical disc (DVD), floppy disk, and Blu-ray. Optical discs, where magnetic disks typically copy data magnetically, use lasers to optically copy data. Therefore, in some aspects, computer-readable media can include non-transitory computer-readable media (e.g., tangible media). Furthermore, in other aspects, computer-readable media can include transient computer-readable media (e.g., signals). Combinations of the above should also be included within the scope of computer-readable media.

[0214] Therefore, certain aspects may include a computer program product for performing the operations described herein. For example, such a computer program product may include a computer-readable medium having instructions stored (and / or encoded thereon) thereon, which can be executed by one or more processors to perform the operations described herein. Figure 16 and / or Figure 17 The instructions for the operation are shown in the image.

[0215] Furthermore, it should be understood that modules and / or other suitable units for performing the methods and techniques described herein can be downloaded and / or otherwise obtained by the user terminal and / or base station, where applicable. For example, such a device can be coupled to a server to facilitate the transmission of units for performing the methods described herein. Alternatively, the various methods described herein can be provided via storage units (e.g., RAM, ROM, physical storage media such as compressed optical discs (CDs) or floppy disks, etc.) so that the user terminal and / or base station can obtain the various methods when the storage units are coupled to or provided to the device. Furthermore, any other suitable techniques for providing the methods and techniques described herein to the device can be used.

[0216] It should be understood that the claims are not limited to the precise configuration and components shown above. Various modifications, alterations, and variations may be made in the arrangement, operation, and details of the methods and apparatus described above without departing from the scope of the claims.

Claims

1. An apparatus for wireless communication, comprising: One or more memory units; as well as One or more processors coupled to the one or more memories are configured to cause the device to perform the following operations: Receive one or more transmissions of one or more allocated sub-channels of an indicated frequency band during a first time period, the frequency band including the one or more allocated sub-channels and one or more unallocated sub-channels during the first time period; Sensing the one or more unassigned sub-channels within at least a portion of the first time period prior to the second time period; as well as Based on the fact that the energy sensed for the one or more unassigned sub-channels is less than a threshold, a signal is transmitted in the frequency band during the second time period.

2. The apparatus according to claim 1, wherein, The threshold is based on the ratio of the first bandwidth of the one or more unallocated sub-channels to the second bandwidth of the frequency band.

3. The apparatus according to claim 1, wherein, The one or more processors are further configured to sense the one or more unassigned subchannels by excluding the sensing of one or more frequency subbands adjacent to the one or more assigned subchannels within the one or more unassigned subchannels.

4. The apparatus according to claim 3, wherein, The threshold is based on the ratio of the first bandwidth of the one or more unassigned sub-channels excluding the one or more frequency sub-bands to the second bandwidth of the frequency band.

5. The apparatus according to claim 3, wherein, The bandwidth of each frequency sub-band in the one or more frequency sub-bands is fixed.

6. The apparatus according to claim 3, wherein, For each of the one or more frequency sub-bands, the corresponding bandwidth of the corresponding frequency sub-band is based on the corresponding signal strength of the corresponding signal received on the corresponding assigned sub-channel adjacent to the corresponding frequency sub-band.

7. The apparatus according to claim 3, wherein, For each of the one or more frequency sub-bands, the corresponding bandwidth of the corresponding frequency sub-band is based on the corresponding distance between the device and the corresponding device that has been assigned a corresponding sub-channel adjacent to the corresponding frequency sub-band.

8. The apparatus according to claim 1, wherein, The one or more processors are further configured to: A filter bank is applied to an input signal corresponding to the frequency band, the filter bank being configured to filter one or more assigned sub-channels of the input signal; as well as Sensing the filtered input signal.

9. The apparatus according to claim 1, wherein, The first time period and the second time period each include time slots.

10. The apparatus according to claim 1, wherein, Channel Occupancy Time (COT) includes the first time period and the second time period.

11. The apparatus according to claim 1, wherein, The one or more processors are also configured to transmit the signal via a side link channel.

12. The apparatus according to claim 11, wherein, The device includes cellular vehicle-to-everything (CV2X) devices.

13. The apparatus according to claim 1, wherein, The frequency band includes unlicensed frequency bands.

14. A method for wireless communication performed by a user equipment (UE), comprising: Receive one or more transmissions of one or more allocated sub-channels of an indicated frequency band during a first time period, the frequency band including the one or more allocated sub-channels and one or more unallocated sub-channels during the first time period; Sensing the one or more unassigned sub-channels within at least a portion of the first time period prior to the second time period; as well as Based on the fact that the energy sensed for the one or more unassigned sub-channels is less than a threshold, a signal is transmitted in the frequency band during the second time period.

15. The method according to claim 14, wherein, The threshold is based on the ratio of the first bandwidth of the one or more unallocated sub-channels to the second bandwidth of the frequency band.

16. The method of claim 14, wherein, Sensing the one or more unassigned subchannels includes: sensing the one or more unassigned subchannels while excluding one or more frequency subbands adjacent to the one or more assigned subchannels within the one or more unassigned subchannels.

17. The method according to claim 16, wherein, The threshold is based on the ratio of the first bandwidth of the one or more unassigned sub-channels excluding the one or more frequency sub-bands to the second bandwidth of the frequency band.

18. The method according to claim 16, wherein, The bandwidth of each frequency sub-band in the one or more frequency sub-bands is fixed.

19. The method of claim 16, wherein, For each of the one or more frequency sub-bands, the corresponding bandwidth of the corresponding frequency sub-band is based on the corresponding signal strength of the corresponding signal received on the corresponding assigned sub-channel adjacent to the corresponding frequency sub-band.

20. The method of claim 16, wherein, For each of the one or more frequency sub-bands, the corresponding bandwidth of the corresponding frequency sub-band is based on the corresponding distance between the UE and the corresponding device that has been allocated a corresponding sub-channel adjacent to the corresponding frequency sub-band.

21. The method according to claim 14, wherein, The sensing includes: A filter bank is applied to an input signal corresponding to the frequency band, the filter bank being configured to filter one or more assigned sub-channels of the input signal; as well as Sensing the filtered input signal.

22. The method according to claim 14, wherein, The first time period and the second time period each include time slots.

23. The method according to claim 14, wherein, Channel Occupancy Time (COT) includes the first time period and the second time period.

24. The method according to claim 14, wherein, The signal is transmitted via a side link channel.

25. The method according to claim 24, wherein, The UE includes cellular vehicle-to-everything (CV2X) devices.

26. The method according to claim 14, wherein, The frequency band includes unlicensed frequency bands.

27. An apparatus for wireless communication, comprising a unit for performing the method according to any one of claims 14 to 26.

28. A computer-readable storage medium having instructions stored thereon, which, when executed by a device, cause the device to perform the method according to any one of claims 14 to 26.

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