Patent Description:
In many countries, regulatory requirements may limit the number of <NUM> channels available or place additional restrictions on their use because the spectrum is shared with other technologies and services. For example, for parts of band <NUM>, there are regional requirements aiming at protecting radars from interference by other users of the spectrum.

DFS (Dynamic Frequency Selection) is a mechanism that allows a device to identify the radar presence in the channel. Depending on the regional regulatory requirements either we must seize the transmission, or we must stop transmission for an amount of the time in the channel radar is detected. The idea behind this is not to interfere with the radar.

Certain problems with previous systems exist. For example, once the radar is identified on the channel, the channel should be vacated within specified limits. This creates a breakage in the ongoing traffic. The overall throughput of the channel drops drastically. As devices tends to operate towards radar free channels, because of congestion on the channel, throughput may decline. When operating at large system channel bandwidths requiring DFS, a radar hit will take down the entire system channel bandwidth even though radar only is present within a limited part of the channel.

Prior art examples are: <CIT>; <CIT>; and <CIT>.

The aspects of the present invention are defined by the appended independent claims. To address the foregoing problems with existing solutions, disclosed are a network node and methods for adaptive bandwidth usage at radar congestion. Specifically, the concept of operating sub-channels is introduced for improved co-existence of evolving 3GPP <NUM>/<NUM> and IEEE <NUM> signals with frequency bands where active primary radar sources exist. The improvement achieves the key requirements of spectrum sharing with co-existing radar transceivers, while optimally maximizing network capacity through effective usage of spectrum, and not disturbing the ongoing traffic.

According to claim <NUM>, that is a first aspect, a method by a network node includes detecting a radar signal in at least one subchannel within a plurality of subchannels within an operating channel. In response to detecting the radar signal in the at least one subchannel, transmission of at least one signal is scheduled in at least one subchannel within the plurality of subchannels other than the at least one subchannel in which the radar signal was detected.

According to independent claim <NUM>, that is a second aspect, a network node includes processing circuitry configured to detect a radar signal in at least one subchannel within a plurality of subchannels within an operating channel. In response to detecting the radar signal in the at least one subchannel, the processing circuitry schedules transmission of at least one signal in at least one subchannel within the plurality of subchannels other than the at least one subchannel in which the radar signal was detected.

According to independent claim <NUM>, that is a third aspect, a method performed by a network node includes detecting a signature of a primary user in at least one subchannel within a plurality of subchannels within an operating channel. In response to detecting the signature of the primary user in the at least one subchannel, transmission of at least one signal is scheduled in at least one subchannel within the plurality of subchannels other than the at least one subchannel in which the signature of the primary user was detected.

Certain embodiments of the present disclosure may provide one or more technical advantages. For example, a technical advantage may be that certain embodiments may provide effective utilization of the unlicensed band, which is a critical task in modem communications. As another example, a technical advantage may be that certain embodiments optimize the bandwidth usage with Dynamic Frequency Selection.

As another example, a technical advantage may be that certain embodiments provide a mechanism to selectively shutdown the operating subchannels interfering with nearby radar transceivers, while non-interfering operating sub-channels remain in operation.

As still another example, a technical advantage may be that, depending on the regulatory requirements and the particular techniques uses, certain embodiments operate without any breakage in the connection. As such, certain embodiments eliminate outages due to the loss of a complete operating channel, while maximizing the achievable throughput on the remaining available operating sub-channels.

Other advantages may be readily apparent to one having skill in the art. Certain embodiments may have none, some, or all of the recited advantages.

Particular embodiments of the present disclosure may provide solutions providing adaptive bandwidth usage at radar congestion in Orthogonal Frequency Division Multiple Access (OFDMA) based systems.

In the world of modem communications, the effective utilization of the unlicensed band is a critical task. The FCC regulations define 'operating channels' as having <NUM> operating bandwidth selected to align to IEEE <NUM> channel bandwidths. The FCC defined these channels in the rules "<NUM> D06 <NUM><NUM> Channel Plans New Rules v02 " to address co-existence issues with the TDWR band from <NUM>-<NUM>, which spans full and partial <NUM> Wi-Fi channel boundaries. Additionally, non-TDWR radar signals such as the SpaceX Falcon Radar Transponder (as disclosed in Falcon User's Guide by SpaceX) exist both in DFS (<NUM>) and non-DFS (<NUM>) frequency bands which cross <NUM> channel bandwidths, or employ operating bandwidths less a <NUM> 3GPP <NUM> or <NUM> channel.

According to certain embodiments, two methods or use cases are disclosed herein for optimizing the bandwidth usage with DFS by performing operating subchannel shutdown after radar detection on DFS required channel.

The first method or use cases employs native 3GPP OFDM based technologies, for example <NUM> LTE and <NUM> NR, where OFDM carriers are grouped into resource blocks (RBs), and RB are grouped into a number of operating subchannels. This is similar, but not identical to the definition of CAT-M1 channels which appear as subchannel. As disclosed heroin, an operating subchannel utilizes a portion of an operating channel. The operating channel may be <NUM>, as depicted in FCC regulations, or larger and/or smaller than <NUM>, as describes in 3GPP <NUM> and <NUM> standards as well as current IEEE <NUM> standards.

By dividing each operating channel into a number of operating subchannels, where each operating subchannel is independently controlled, the 3GPP radio system introduces a finer granularity of control, and is able to only shut down the operating subchannel that is found to be interfering with radar, while continuing operation on the non-interfering operating subchannels. For example, according to certain embodiments, a radio scheduler may aggregate contiguous subchannels consisting of a defined number of physical resource blocks (in LTE) or resource units (in <NUM>) up to the system channel bandwidth. Since there are no guard bands between the PRBs/RUs constituting an operating subchannel in an OFDM system, there will be no gaps between contiguous operating sub-channels where the detection performance could be degraded.

The second method/use case enables the radio access technology to re-initialize and reconfigure the operating channel by removing operating subchannels where radar has been repeatedly detected from the candidate set of operating subchannels. As consequence, the maximum operating channel bandwidth may be reduced by the removed set of repeated offending operating sub-channels. This tradeoff mitigates the risk for hard shutdown of the complete operating channel, and yields a steady state operating condition which optimally utilizes the operating channel bandwidth, while meeting the intent of the DFS function, which guarantees spectrum sharing with active radar transceivers by forcing secondary users to not transmit on frequencies used by radar transceivers.

This second use case is IEEE <NUM>. 11ax, which describes Partial Bandwidth support for UL and DL MU-MIMO operation, but fails to align this concept with DFS operation and misses the concept of operating subchannels:.

According to certain embodiments, the time domain samples received over the system channel bandwidth are analyzed by the DFS algorithm in time and frequency domain. At a radar hit in DFS, the concerned operating subchannel(s) where the radar application is transmitting is identified by estimating the center frequency and bandwidth of the radar signal. When the DFS algorithm detects radar, the operating subchannel is immediately shutdown. The ongoing user data or control data on the operating subchannel may be lost until next RAT scheduling occasion on different operating subchannels, but the data could be decodable for the UE even though some parts of it is missing. The performance impact will depend on the code rate the user(s) operate at and the aggregation level. The radar interfering operating subchannels are notified to the RAT Scheduler by the DFS. The RAT Scheduler should not allocate any user or control data on these operating subchannels.

Note that shutdown of operating subchannels might contain sync and reference signals. In such a scenario, and according to particular embodiments, the information may be communicated to the user equipment or other slave device. This information may be used by the user equipment and or other slave device for the sync update and the channel estimation.

Thus, according to this method, reconfiguration of system bandwidth is enabled. In this approach, RAT will seize all ongoing transmissions and RAT system is reconfigured with the reduced system bandwidth. The new bandwidth of the RAT will not interfere the radar signal any more. This method uses bandwidth scalability of the native OFDM bases systems. The time taken to or reconfiguration of system channel bandwidth should be within limits of the local regulatory authorities.

Particular embodiments are described in <FIG> of the drawings, like numerals being used for like and corresponding parts of the various drawings. <FIG> illustrates an example context <NUM> for a dynamic frequency selection (DFS) algorithm in a Radio Access Technology (RAT) digital unit <NUM>, according to certain embodiments. In a particular embodiment, the RAT digital unit <NUM> is a RAT transceiver.

The Radar detector <NUM> performs an integral part of the DFS algorithm that is to be implemented in the RAT transceiver together with the native RAT channel estimation, modulator/demodulator and encoding/decoding modules. The radar detector operates on the digitalized complex radio frequency (RF) samples received over Common Public Radio Interface (CPRI) or an optical fiber link from the RF unit <NUM>. According to certain embodiments described herein, a detector is provided that detects whether an intercepted linear chirp is present in the RF samples. The detector <NUM> is preceded by a Pulse Detection block <NUM> that detects that energy has been detected for a short time duration. The short time duration of energy followed by a silent period that then repeat itself characterizes a potential intercepting radar signal in the RF samples.

Radar detection is a mandatory procedure to operate in the DFS bands. If radar is not detected, then the DFS channel may be acquired and channel may be used for data transmissions. During the service, the channel should be monitored continuously depending on the regulatory requirements. Once the radar is identified on the operating channel, in the "in-service" state, the RAT must cease transmissions following a Channel Move Time, where transmissions are limited to the Channel Closing Transmission Time procedure, as defined by the FCC in <NUM> D02 UNII DFS Compliance Procedures New Rules v02. According to certain embodiments described herein, the DFS channel is divided into contiguous operating subchannels, each of which performs independent DFS processing state machines.

According to certain embodiments, a bandwidth and approximate center frequency estimation module is introduced after detection of radar. This module calculates the <NUM> to <NUM>% bandwidth of the <NUM>% transmission of the radar, as defined in FCC DFS regulations. This module also provides the approximate center frequency of the transmission of radar. There several cognitive signal processing methods to detection bandwidth of the intercepted signal. The present invention will not discuss anything on the methods used for the estimation bandwidth and center frequency. The present invention uses the results of the bandwidth and center frequency results. The bandwidth and center frequency are used to define operating subchannels that are interfering with radar. With this information, only those operating subchannels which interfere with the detected radar signatures are "Closed" leaving remaining operating subchannels (a partial part of the total system bandwidth) for transmissions.

The embodiments described herein can be used any OFDM based systems.

LTE-LAA and IEEE <NUM>. 11ax have higher possibility deployment. The ideas of the present disclosure are explained with respect to LTE-LAA and IEEE <NUM>. RAT (LTE-LAA/ IEEE <NUM>. 11ax) cell of <NUM> started data transmission on a DFS channel after performing initial channel availability check (CAC). The subchannels where DFS detect radar will then be blocked for usage by the RAT scheduler already from the start. Once the transmission has started the subchannels in the LTE-LAA cell will operate in an in-service monitoring state for radar, as per the regulations shall be performed.

The particular embodiments of the two solutions will now be described in more detail.

According to certain embodiments providing selective subchannel shutdown, the DFS output may be continuously fed as input to the RAT scheduler and lower layers. With this information, the RAT scheduler will not allocate any data on the subchannels occupied by the radar and potential cell reference signals belonging to affected subchannel(s) are effectively removed at lower layers.

<FIG> illustrates the radar being received on the subchannel of the LTE-LAA. Specifically, <FIG> illustrates a <NUM> LTE-LAA signal at EARFCN <NUM> where the detected radar is not interfering with sync signals or system information. By contrast, <FIG> illustrates the interfering portion of the LTE-LAA signal with radar being removed using a subchannel shutdown technique. More specifically, <FIG> illustrates a <NUM> LTE-LAA signal at EARFCN <NUM> where subchannel shutdown is ON.

Subchannel shutdown is technique which enables LTE-LAA system, not to transmit anything on the PRBs belonging to the subchannel. The scheduler can easily omit scheduling of traffic in the radar effected subchannels and by this achieve a shutdown. If the radar signal is detected on the same subchannel as cell reference signals the shutdown of these signals must be done at the lower layers close to the OFDM modulator.

If only data traffic is affected the master device (eNodeB, LTE Pcell) need not to communicate the changes to the slave device(UE). This change in the transmission barely effect the decoding capability of the slave device. If the information is communicated through the Pcell it improves the decoding performance on the UE.

Subchannel shutdown will not work if the radar occupies the sync signal and broadcast channel subchannels of LTE-LAA. To overcome this situation, a bandwidth scalability feature of the LTE-LAA system can be used where the new configuration of the SCell is communicated over PCell, as described in more detail below.

<NUM> ax has adopted the LTE technology to serve more users by assigning parts of frequency band called subchannels. Each <NUM> (<NUM>, <NUM>, <NUM> and <NUM>) channel, which may inclue but are not limited to <NUM>, <NUM>, <NUM> and <NUM>, in one example, are small subchannels. The minimum sub channel size is of <NUM> sub carriers and is called as Resource Unit. 11ax has defined various size of Resource Units. The minimum size of each resource unit is <NUM>.

By finding the radar effected subchannels within the system bandwidth, scheduler can shut down the respective subchannels (Resource Units) interfering with radar alone. In case of <NUM> the shutdown of the transmission will be done in multiples of resource units. If the scheduler uses the small size Resource Unit, the bandwidth can be used effectively in case of radar hit due to that a higher granularity in shutdown is achieved.

According to certain embodiments, a method may include reconfiguring the LTE-LAA Scell with reduced bandwidth. For example, <FIG> illustrates that a radar signal occupies the sync and system information parts of LTE-LAA, according to certain embodiments. Thus, the LTE-LAA sync signal interferes with the radar signal. The LTE-LAA cell should then stop the transmission in the whole system channel bandwidth. In this case, by using the bandwidth scalability feature, so that the LTE-LAA signal will not interfere with radar. Depending on the radar occupied subchannels, LTE-LAA cells can be configured with reduced bandwidth where the concerned subchannels where DFS found radar are omitted permanently. An option here is to shutdown all subchannels within the system channel bandwidth according to the time limits in the regulations and then performing CAC for the same subchannels once the channels are available for CAC again. But if the radar repeatedly is found in the same subchannel(s) as sync and system information it might be better to use bandwidth scalability. As depicted in <FIG>, the radar signal is occupied approximately <NUM> around EARFCN <NUM> out of <NUM> of LTE-LAA bandwidth. There is around <NUM> bandwidth is available on the both sides of EARFCN <NUM> within <NUM>.

<FIG> illustrates a reduced bandwidth LTE-LAA signal transmission without interfering radar. For example, using information, two LTE-LAA cells with <NUM> bandwidth at EARFCN numbers and <NUM>, <NUM> can be configured as shown in <FIG>. These new LTE-LAA cells do not interfere with the radar anymore.

<FIG> is a block diagram a wireless network <NUM> for linear chirp detection, in accordance with certain embodiments. Although the subject matter described herein may be implemented in any appropriate type of system using any suitable components, the embodiments disclosed herein are described in relation to a wireless network, such as the example wireless network illustrated in <FIG>. For simplicity, the wireless network of <FIG> only depicts network <NUM>, network nodes <NUM> and 1360b, and WDs <NUM>, 1310b, and 1310c. In practice, a wireless network may further include any additional elements suitable to support communication between wireless devices or between a wireless device and another communication device, such as a landline telephone, a service provider, or any other network node or end device. Of the illustrated components, network node <NUM> and wireless device (WD) <NUM> are depicted with additional detail. The wireless network may provide communication and other types of services to one or more wireless devices to facilitate the wireless devices' access to and/or use of the services provided by, or via, the wireless network.

<FIG> illustrates an example network node <NUM> for linear chirp detection, according to certain embodiments.

<FIG> illustrates an example wireless device (WD) for linear chirp detection, according to certain embodiments. As used herein, WD refers to a device capable, configured, arranged and/or operable to communicate wirelessly with network nodes and/or other wireless devices. Unless otherwise noted, the term WD may be used interchangeably herein with user equipment (UE). Communicating wirelessly may involve transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information through air. In some embodiments, a WD may be configured to transmit and/or receive information without direct human interaction. For instance, a WD may be designed to transmit information to a network on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the network. Examples of a WD include, but are not limited to, a smart phone, a mobile phone, a cell phone, a voice over IP (VoIP) phone, a wireless local loop phone, a desktop computer, a personal digital assistant (PDA), a wireless cameras, a gaming console or device, a music storage device, a playback appliance, a wearable terminal device, a wireless endpoint, a mobile station, a tablet, a laptop, a laptop-embedded equipment (LEE), a laptop-mounted equipment (LME), a smart device, a wireless customer-premise equipment (CPE), a vehicle-mounted wireless terminal device, etc. A WD may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-everything (V2X) and may in this case be referred to as a D2D communication device. As yet another specific example, in an Internet of Things (IoT) scenario, a WD may represent a machine or other device that performs monitoring and/or measurements and transmits the results of such monitoring and/or measurements to another WD and/or a network node. The WD may in this case be a machine-to-machine (M2M) device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the WD may be a UE implementing the 3GPP narrow band internet of things (NB-IoT) standard. Particular examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances (e.g. refrigerators, televisions, etc.) personal wearables (e.g., watches, fitness trackers, etc.). In other scenarios, a WD may represent a vehicle or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation. A WD as described above may represent the endpoint of a wireless connection, in which case the device may be referred to as a wireless terminal. Furthermore, a WD as described above may be mobile, in which case it may also be referred to as a mobile device or a mobile terminal.

Radio front end circuitry <NUM> is connected to antenna <NUM> and processing circuitry <NUM> and is configured to condition signals communicated between antenna <NUM> and processing circuitry <NUM>.

The benefits provided by such functionality are not limited to processing circuitry <NUM> alone or to other components of WD <NUM>, but are enj oyed by WD <NUM> as a whole, and/or by end users and the wireless network generally.

User interface equipment <NUM> is configured to allow input of information into WD <NUM> and is connected to processing circuitry <NUM> to allow processing circuitry <NUM> to process the input information. Using one or more input and output interfaces, devices, and circuits, of user interface equipment <NUM>, WD <NUM> may communicate with end users and/or the wireless network and allow them to benefit from the functionality described herein.

Network connection interface <NUM> may be configured to provide a communication interface to network 1643a. Network 1643a may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network 1643a may comprise a Wi-Fi network.

In <FIG>, processing circuitry <NUM> may be configured to communicate with network 1643b using communication subsystem <NUM>. Network 1643a and network 1643b may be the same network or networks or different network or networks. Communication subsystem <NUM> may be configured to include one or more transceivers used to communicate with network 1643b.

Network 1643b may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network 1643b may be a cellular network, a Wi-Fi network, and/or a near-field network.

In some embodiments, some signaling can be affected with the use of control system <NUM> which may alternatively be used for communication between the hardware nodes <NUM> and radio units <NUM>.

<FIG> illustrates a telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments. Access network <NUM> comprises a plurality of base stations 1812a, 1812b, 1812c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 1813a, 1813b, 1813c. Each base station 1812a, 1812b, 1812c is connectable to core network <NUM> over a wired or wireless connection <NUM>. A first UE <NUM> located in coverage area 1813c is configured to wirelessly connect to, or be paged by, the corresponding base station 1812c. A second UE <NUM> in coverage area 1813a is wirelessly connectable to the corresponding base station 1812a.

Host computer <NUM> may be under the ownership or control of a service provider or may be operated by the service provider or on behalf of the service provider.

<FIG> illustrates a host computer communicating via a base station with a user equipment over a partially wireless connection in accordance with some embodiments.

It is noted that host computer <NUM>, base station <NUM> and UE <NUM> illustrated in <FIG> may be similar or identical to host computer <NUM>, one of base stations 1812a, 1812b, 1812c and one of UEs <NUM>, <NUM> of <FIG>, respectively.

Wireless connection <NUM> between UE <NUM> and base station <NUM> is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to UE <NUM> using OTT connection <NUM>, in which wireless connection <NUM> forms the last segment. More precisely, the teachings of these embodiments may improve the data rate, latency, and/or power consumption and thereby provide benefits such as reduced user waiting time, relaxed restriction on file size, better responsiveness, and/or extended battery lifetime.

In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which OTT connection <NUM> passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above or supplying values of other physical quantities from which software <NUM>, <NUM> may compute or estimate the monitored quantities.

<FIG> depicts a method <NUM> by a network node <NUM> for, according to certain embodiments. At step <NUM>, network node <NUM> detects a radar signal in at least one subchannel within a plurality of subchannels within an operating channel. At step <NUM>, in response to detecting the radar signal in the at least one subchannel, network node <NUM> schedules transmission of at least one signal in at least one subchannel within the plurality of subchannels other than the at least one subchannel in which the radar signal was detected.

In a particular embodiment, the operating channel comprises a total bandwidth, and the network node <NUM> divides the operating channel into the plurality of subchannels. Each subchannel is associated with a portion of the total bandwidth.

In a particular embodiment, detecting the radar signal in the at least one subchannel within the plurality of subchannels within the operating channel includes performing, by the network node, one DFS procedure on the total bandwidth of the operating channel.

In a particular embodiment, when detecting the radar signal in the at least one subchannel within the plurality of subchannels within the operating channel, the network node <NUM> performs one of a plurality of DFS procedures on each of the plurality of subchannels within the operating channel.

In a particular embodiment, the operating channel includes a total number of contiguous physical resource blocks, and network node <NUM> divides the total number of physical resource blocks into a plurality of groups of distinct physical resource block groups.

In a particular embodiment, the operating channel includes a total number of resource units, and network node <NUM> divides the total number of resource units into a plurality of groups of distinct resource unit groups.

In a particular embodiment, each resource unit comprises one or more OFDM tones.

In a particular embodiment, each of the plurality of subchannels are associated with a respective one of a plurality of subcarriers.

In a particular embodiment, network node <NUM> allocates at least one resource for the transmission of the at least one signal in the at least one subchannel other than the at least one subchannel in which the radar signal was detected.

In a particular embodiment, network node <NUM> transmits a message to a wireless device. The message indicates the at least one resource for the transmission of the at least one signal on the at least one subchannel other than the at least one subchannel in which the radar signal was detected.

In a particular embodiment, when scheduling the transmission of the at least one signal in the at least one subchannel other than the at least one subchannel in which the radar signal was detected, network node <NUM> replaces a previous allocation of at least one resource associated with the at least one subchannel in which the radar signal was detected with a new allocation of at least one resource associated with the at least one subchannel other than the at least one subchannel in which the radar signal was detected.

In a particular embodiment, network node <NUM> ceases transmission of at least one signal in the at least one subchannel in which the radar signal was detected in response to detecting the radar signal.

In a particular embodiment, the at least one signal comprises a network signal, and the network node <NUM> determines that the radar signal interferes with the network signal scheduled for transmission within the the at least one subchannel and transmits, to at least one wireless device, a message comprising a new configuration for the channel, the new configuration excluding the at least one subchannel in which the radar signal was detected.

In a particular embodiment, when transmitting the message including the new configuration for the channel to the at least one wireless device, network node <NUM> transmits the new configuration to all wireless devices in a cell.

In a particular embodiment, the at least one signal comprises a synchronization signal or system information signal.

In a particular embodiment, prior to transmitting the new configuration, network node <NUM> ceases transmission of all signals within the plurality of subchannels to eliminate interference with the radar signal and resumes transmission after the new configuration is transmitted to the wireless device. <FIG> illustrates a schematic block diagram of a virtual apparatus <NUM> in a wireless network (for example, the wireless network shown in <FIG>). The apparatus may be implemented in a wireless device or network node (e.g., wireless device <NUM> or network node <NUM> shown in <FIG>). Apparatus <NUM> is operable to carry out the example method described with reference to <FIG> and possibly any other processes or methods disclosed herein. It is also to be understood that the method of <FIG> is not necessarily carried out solely by apparatus <NUM>. At least some operations of the method can be performed by one or more other entities.

Virtual Apparatus <NUM> may comprise processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory, cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein, in several embodiments. In some implementations, the processing circuitry may be used to cause detecting module <NUM>, scheduling module <NUM>, and any other suitable units of apparatus <NUM> to perform corresponding functions according one or more embodiments of the present disclosure.

According to certain embodiments, detecting module <NUM> may perform certain of the detecting functions of the apparatus <NUM>. For example, detecting module <NUM> may detect a radar signal in at least one subchannel within a plurality of subchannels within an operating channel.

According to certain embodiments, scheduling module <NUM> may perform certain of the scheduling functions of the apparatus <NUM>. For example, scheduling module <NUM> may, in response to detecting the radar signal in the at least one subchannel, schedule transmission of at least one signal in at least one subchannel within the plurality of subchannels other than the at least one subchannel in which the radar signal was detected.

<FIG> depicts another method <NUM> by a network node <NUM>, according to certain embodiments. The method begins at step <NUM> when network node <NUM> detects a signature of a primary user in at least one subchannel within a plurality of subchannels within an operating channel. At step <NUM>, in response to detecting the signature of the primary user in the at least one subchannel, network node <NUM> schedules transmission of at least one signal in at least one subchannel within the plurality of subchannels other than the at least one subchannel in which the signature of the primary user was detected.

As used herein, the term 'signature' may include any In a particular embodiment, the signature may include an identification signal. The term `identification signal' as used herein may refer to an identification signal as used by the FCC. For example, at <NUM>, FCC rules define an 'identification signal' to permit other users experiencing interference from indoor wireless local area network (LAN) devices to more accurately identify the source of the interference. Thus, an 'identification signal' may include any valid signature causing the proposed subchannel muting operation. The FCC proposed similar requirements for white space devices which transmit an identification signal that can be used to not transmit on active channels. Accordingly, in a particular embodiment, the methods described herein may be used to detect WSD identification signals to subsequently mute sub-channels so as to not interfere with the incumbent WSD.

In a particular embodiment, the signature comprises at least one of a preamble, a level of burstiness, a bandwidth, at least one time or frequency parameter of the primary user.

In a particular embodiment, the operating channel includes a total bandwidth, and network node <NUM> divides the operating channel into the plurality of subchannels. Each subchannel is associated with a portion of the total bandwidth.

In a particular embodiment, network node <NUM> allocates at least one resource for the transmission of the at least one signal in the at least one subchannel other than the at least one subchannel in which the signature of the primary user was detected.

In a particular embodiment, network node <NUM> ceases transmission of at least one signal in the at least one subchannel in which the signature of the primary user was detected in response to detecting the signature.

<FIG> illustrates a schematic block diagram of another virtual apparatus <NUM> in a wireless network (for example, the wireless network shown in <FIG>). The apparatus may be implemented in a wireless device or network node (e.g., wireless device <NUM> or network node <NUM> shown in <FIG>). Apparatus <NUM> is operable to carry out the example method described with reference to <FIG> and possibly any other processes or methods disclosed herein. It is also to be understood that the method of <FIG> is not necessarily carried out solely by apparatus <NUM>. At least some operations of the method can be performed by one or more other entities.

According to certain embodiments, detecting module <NUM> may perform certain of the obtaining functions of the apparatus <NUM>. For example, detecting module <NUM> may detect a signature of a primary user in at least one subchannel within a plurality of subchannels within an operating channel.

According to certain embodiments, scheduling module <NUM> may perform certain of the scheduling functions of the apparatus <NUM>. For example, scheduling module <NUM> may, in response to detecting the signature of the primary user in the at least one subchannel, schedule transmission of at least one signal in at least one subchannel within the plurality of subchannels other than the at least one subchannel in which the signature of the primary user was detected.

Modifications, additions, or omissions may be made to the systems and apparatuses described herein without departing from the scope of the disclosure. The components of the systems and apparatuses may be integrated or separated. Moreover, the operations of the systems and apparatuses may be performed by more, fewer, or other components. Additionally, operations of the systems and apparatuses may be performed using any suitable logic comprising software, hardware, and/or other logic. As used in this document, "each" refers to each member of a set or each member of a subset of a set.

Modifications, additions, or omissions may be made to the methods described herein without departing from the scope of the following claims.

Claim 1:
A method (<NUM>) performed by a network node (<NUM>), the method comprising:
dividing an operating channel into a plurality of subchannels, wherein the operating channel comprises a total number of contiguous physical resource blocks, wherein each subchannel is associated with a distinct group of physical resource blocks,
detecting (<NUM>) a radar signal in at least a first subchannel within a plurality of subchannels within the plurality of subchannels; and
in response to detecting the radar signal in at least the first subchannel, scheduling (<NUM>) transmission of at least one signal in at least a second subchannel that is different from the at least first subchannel in which the radar signal was detected.