Method and apparatus for link adaptation based on interference recognition

Abstract

A method for link adaptation in a Wireless LAN (WLAN) system is disclosed. In one embodiment, the link adaptation method in a WLAN system may include the steps of receiving signals within a communication environment, classifying the signals and identifying each of the signals, analyzing the channel access characteristics of each of the signals, and adjusting the communication parameters of a target signal by channel based on the analysis results.

Description

Technology Field

[0001] The following embodiments relate to an interference-aware link adaptation method and apparatus, and more specifically, to an interference-aware link adaptation apparatus and method capable of improving communication quality by classifying interference sources within a communication environment and applying different link adaptation techniques in response to each classified interference source. Background Technology

[0002] Wireless communication devices adaptively adjust transmission parameters according to changes in channel conditions to improve communication quality. For example, in a WLAN based on the IEEE 802.11 standard, communication quality is managed by adjusting the modulation and coding scheme to increase the data rate when the wireless channel conditions are good and decrease the data rate when the channel conditions are poor.

[0003] Channel conditions change under the influence of the environment in which the wireless communication device is transmitting or receiving, and other wireless devices in the same environment also affect the channel conditions. In this case, the relevant other wireless devices can act as sources of interference, negatively impacting the communication quality during transmission and reception. In unlicensed bands (ISM bands), since various wireless devices (WiFi, Bluetooth, Zigbee, etc.) can communicate without separate permission, interference between devices can occur more frequently.

[0004] Existing link adaptation techniques regulate the data rate based on channel conditions (e.g., RSSI values) at the receiver without specifically considering these other sources of interference. However, since wireless standard devices using unlicensed bands access channels using different standard techniques, higher improvements in communication quality can be expected if link adaptation is performed by taking their different access methods into account.

[0005] This specification proposes a device and method for recognizing such interference signals (wireless communication devices) and performing link adaptation considering the channel access methods of the devices.

[0006] The background technology described above is possessed or acquired by the inventor in the process of deriving the content of the disclosure of the present application, and cannot necessarily be considered as prior art disclosed to the general public prior to the filing of this application. means of solving the problem

[0007] In one embodiment, a link adaptation method in a WLAN (Wireless LAN) system may include the steps of: receiving signals within a communication environment; classifying the signals and identifying each of the signals; analyzing the channel access characteristics of each of the signals; and adjusting the communication parameters of a target signal by channel based on the analysis results.

[0008] The step of analyzing the channel access characteristics may include the step of analyzing the channel usage pattern of each of the signals.

[0009] The step of analyzing the channel usage pattern may include: a step of analyzing the channel usage cycle of each of the signals; and a step of analyzing the channel usage distribution of each of the signals.

[0010] The step of adjusting the communication parameters may include the step of adjusting the transmission power of the target signal; and the step of adjusting the modulation and coding format (MCS; Modulation and Coding Scheme) of the target signal.

[0011] The step of identifying each of the above signals may include: determining whether the new signal uses a target band corresponding to the target signal of the WLAN system; determining whether the signals are signals attributed to a non-communication device based on the determination that the new signal uses the target band; determining whether the signals are signals attributed to a Bluetooth device based on the determination that the new signal uses the target band; and determining whether the signals are signals attributed to a Zigbee device based on the determination that the new signal uses the target band.

[0012] The step of adjusting the communication parameters may include the step of up-adjusting the transmission power, modulation, and coding format of the target signal based on the determination that the identified signal is a signal attributed to the non-communication device.

[0013] The step of adjusting the communication parameters may include not changing the transmission power, modulation, and coding format of the target signal when the identified signal is a signal attributed to the Bluetooth device and the Bluetooth device has Adaptive Frequency Hopping (AFH) characteristics.

[0014] The step of adjusting the communication parameters may include, based on the determination that the identified signal is a signal attributed to the Zigbee device, not changing the transmission power, modulation, and coding format of the target signal during a first time interval, and lowering the transmission power, modulation, and coding format of the target signal after the first time interval. Brief explanation of the drawing

[0015] FIG. 1 is a diagram illustrating a Wireless LAN (WLAN) system according to one embodiment. FIG. 2 is a block diagram of a link adaptation device according to one embodiment. FIG. 3 is a diagram illustrating a link adaptation method according to one embodiment. FIG. 4 is a diagram illustrating a link adaptation method when the interference source is a non-communication device according to one embodiment. FIGS. 5 and 6 are drawings for explaining a link adaptation method when the interference source is a Bluetooth device according to one embodiment. FIG. 7 is a diagram illustrating a link adaptation method when the interference source is a Zigbee device according to one embodiment. Specific details for implementing the invention

[0016] The specific structural or functional descriptions disclosed in this specification are illustrative of embodiments according to technical concepts only, and the actual implemented form may take various other forms and is not limited to the embodiments described in this specification.

[0017] Terms such as "first" or "second" may be used to describe various components, but these terms should be understood solely for the purpose of distinguishing one component from another. For example, the first component may be named the second component, and similarly, the second component may be named the first component.

[0018] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. Conversely, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between. Expressions describing the relationships between components, such as "between" and "directly between," or "adjacent to" and "directly adjacent to," should be interpreted in the same way.

[0019] The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, terms such as “comprising” or “having” are intended to specify the existence of the implemented features, numbers, steps, actions, components, parts, or combinations thereof, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0020] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this specification.

[0021] The embodiments can be implemented in various forms of products, such as personal computers, laptop computers, tablet computers, smartphones, televisions, smart home appliances, intelligent vehicles, kiosks, and wearable devices. The embodiments will be described in detail below with reference to the attached drawings. Identical reference numerals in each drawing indicate identical components.

[0022] FIG. 1 is a diagram illustrating a Wireless LAN (WLAN) system according to one embodiment.

[0023] Referring to FIG. 1, in a WLAN system according to one embodiment, an access point (AP) and stations (STAs) can transmit and receive through a plurality of channels (e.g., channels 1 to 4 shown in FIG. 1). A station may be referred to as a target device, etc., to distinguish it from a wireless communication device, a mobile device, or an interference source to be described later.

[0024] Wireless communication devices can adaptively adjust transmission parameters according to changes in channel conditions to improve communication quality. For example, in a WLAN based on the IEEE 802.11 standard, communication quality is managed by adjusting the modulation and coding scheme to increase the data rate when the wireless channel conditions are good and decrease the data rate when the channel conditions are poor.

[0025] The channel condition changes under the influence of the environment in which the wireless communication device is transmitting or receiving, and other wireless devices in the same environment can also affect the channel condition. In this case, the relevant other wireless devices can act as sources of interference, negatively impacting the communication quality when the wireless communication device transmits or receives.

[0026] For example, the environment in which an IEEE 802.11-based WiFi device communicates is a communication environment using the ISM (Industrial Scientific Medical) band, where Bluetooth, Zigbee, microwave ovens, etc., exist in addition to other target devices. More specifically, the ISM band used by WiFi can be used for industrial, scientific, medical, and home purposes in addition to telecommunications.

[0027] In unlicensed bands (e.g., ISM band), various wireless devices (e.g., WiFi, Bluetooth, Zigbee, etc.) can communicate without separate permission, so interference between devices can occur more frequently.

[0028] Some comparable existing link adaptation techniques adjust the data rate based on the channel status at the receiver (e.g., RSSI value) without specifically considering these other sources of interference. The ISM band is based on shared use that tolerates mutual interference and relies on low power output to minimize interference. Since wireless standard devices using the unlicensed band (hereinafter referred to as sources of interference) access the channel using different standard techniques, higher improvements in communication quality can be expected if link adaptation is performed by taking their different access methods into account.

[0029] As will be explained in detail below, a link adaptation method according to one embodiment can recognize these interference signals and perform link adaptation considering the channel access method of the devices.

[0030] Link adaptation according to one embodiment is a technology that adaptively adjusts communication parameters according to changes in channel conditions and may include power control, rate control, H-ARQ, etc. The purpose of link adaptation is to increase transmission speed, system capacity, and frequency efficiency, and key transmission parameters for link adaptation may include transmission power, modulation and coding format (MCS), spreading factor, etc. However, the scope of link adaptation technology is not limited to the aforementioned items.

[0031] In unlicensed bands such as the 2.4 GHz band, various wireless devices can cause cross-technology interference. This interference can have an adverse effect on the quality of wireless communication. When applying link adaptation technology, significant improvements in communication quality can be expected if interference caused by these other technologies is taken into account.

[0032] For example, the IEEE 802.11 standard-based wireless devices of Fig. 1 can perform communication based on OFDMA (Orthogonal frequency-division multiple access), and Bluetooth and Zigbee devices may coexist within this communication environment. In this case, the Zigbee device uses channel 1 and the Bluetooth device uses channel 3, but as channel 3 is frequently used, the channel used can be changed to channel 4 according to Adaptive Frequency Hopping (AFH) technology.

[0033] In such situations, if the relevant signals are identified to determine the type of device and their channel access characteristics are analyzed, communication quality can be improved by applying appropriate link adaptation.

[0034] FIG. 2 is a block diagram of a link adaptation device according to one embodiment.

[0035] Referring to FIG. 2, a link adaptation device (200) according to one embodiment may include a receiver (210), a processing unit (220), and a control unit (230). However, not all of the illustrated components are essential components. The link adaptation device (200) may be implemented with more components than those illustrated, or with fewer components. For example, in addition to the receiver (210), processing unit (220), and control unit (230) according to one embodiment of the present invention, a sensor unit and a memory may be further included. Terms such as 'unit' and 'unit' used below refer to a unit that processes at least one function or operation, and this may be implemented in hardware or software, or a combination of hardware and software.

[0036] In a receiving unit (210) according to one embodiment, signals within a communication environment can be received.

[0037] In a processing unit (220) according to one embodiment, signals of wireless devices in a communication environment can be identified and wireless channel access characteristics of the devices can be analyzed.

[0038] In a control unit (230) according to one embodiment, the link adaptation technique can be controlled.

[0039] A processing unit (220) and a control unit (230) according to one embodiment may be a device implemented in hardware having a circuit having a physical structure for executing desired operations. The desired operations may include code or instructions included in a program. The device implemented in hardware may include a microprocessor, a Central Processing Unit (CPU), a Graphic Processing Unit (GPU), a processor core, a multi-core processor, a multiprocessor, an Application-Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a Neural Processing Unit (NPU), etc.

[0040] The memory can store instructions that can be read by a computer. When the instructions stored in the memory are executed by the processing unit (220) and the control unit (230), the processing unit (220) and the control unit (230) can process operations defined by the instructions. The memory may include, for example, RAM (random access memories), DRAM (dynamic random access memories), SRAM (static random access memories), or other forms of non-volatile memory known in the art.

[0041] FIG. 3 is a diagram illustrating a link adaptation method according to one embodiment.

[0042] For convenience of explanation, steps (310 to 340) are described as being performed using the link adaptation device (200) illustrated in FIG. 3. However, these steps (310 to 340) may be used through any other suitable electronic device and within any suitable system.

[0043] Furthermore, the operations of FIG. 3 may be performed in the illustrated order and manner, but the order of some operations may be changed or some operations may be omitted without departing from the spirit and scope of the illustrated embodiment. Multiple operations illustrated in FIG. 3 may be performed in parallel or simultaneously.

[0044] In step (310), a link adaptation device according to one embodiment may receive signals within a communication environment. The link adaptation device may receive signals within a communication environment through a receiver (e.g., a receiver (210) of FIG. 2). The received signals may include a target signal and an interference signal. The target signal of a WLAN system according to one embodiment is a signal that is the target of the corresponding WLAN system, for example, in a WLAN system according to one embodiment, the target signal may be a signal using an 802.11ax frame. The interference signal according to one embodiment may be a signal caused by an interference source (e.g., a microwave oven, a Bluetooth device, a Zigbee device, etc.).

[0045] In step (320), a link adaptation device according to one embodiment can classify signals and identify each of the signals. The link adaptation device can identify signals of wireless devices in a communication environment through a processing unit (e.g., the processing unit (220) of FIG. 2).

[0046] In step (330), a link adaptation device according to one embodiment can analyze the channel access characteristics of each of the signals. The link adaptation device can identify the signals and identify the interference source corresponding to each of the signals.

[0047] The link adaptor can analyze the channel access characteristics of each of the signals. For example, the link adaptor can analyze the channel usage patterns of each signal. More specifically, the link adaptor can analyze the channel usage cycle and / or channel usage distribution of each signal. For example, the link adaptor can analyze the channel primarily used by the signal, determine whether interference between signals can be minimized through techniques such as adaptive frequency hopping, and identify the channel usage cycle.

[0048] In step (340), the link adapting device according to one embodiment can adjust the communication parameters of the target signal by channel based on the analysis results. The link adapting device can adjust the transmission power of the target signal based on the analysis results. For example, the link adapting device can increase, decrease, or leave the transmission power of the target signal by channel based on the analysis results. When increasing or decreasing the power, the link adapting device can also adjust the degree of increase or decrease according to the analysis results.

[0049] The link adaptor can adjust the Modulation and Coding Scheme (MCS) of the target signal. For example, based on the analysis results, the link adaptor can upscale, downscale, or leave the target signal's MCS unchanged for each channel. Similarly, the link adaptor can adjust the degree of upscalement and downscalement according to the analysis results.

[0050] As mentioned above, Bluetooth, Zigbee, microwave ovens, etc., can use the same ISM band as Wi-Fi.

[0051] A link adaptation device according to one embodiment can determine whether an identified signal is a signal attributable to a non-communication device. For example, a non-communication device may be a microwave oven using the ISM band, but the disclosure of the present invention is not limited thereto. A link adaptation method when the interference source is a non-communication device will be described in detail below with reference to FIG. 4.

[0052] A link adaptation device according to one embodiment can determine whether a new signal is a signal originating from a Bluetooth device based on the determination that the new signal uses a target band. Below, with reference to FIGS. 5 and 6, a link adaptation method when the interference source is a Bluetooth device is described in detail.

[0053] A link adaptation device according to one embodiment can determine whether a new signal is a signal originating from a Zigbee device based on the determination that the new signal uses a target band. Below, with reference to FIG. 7, a link adaptation method when the interference source is a Zigbee device is described in detail.

[0054] FIG. 4 is a diagram illustrating a link adaptation method when the interference source is a non-communication device according to one embodiment.

[0055] When communication devices exist on the same channel, transmission power cannot be indiscriminately increased for the purpose of fair channel usage. Since a microwave oven is not a device intended for communication, it may not malfunction even if it is subject to interference within the same frequency during operation. Therefore, if the source of interference is a non-communication device (e.g., a microwave oven), the link adaptor can increase the transmission power of the target signal. Furthermore, because the transmission power has been increased, the link adaptor can also increase the MCS of the target signal (of course, the MCS can also be left unchanged).

[0056] Referring to FIG. 4, if the link adaptor identifies that the microwave oven is using channels 2 and 3 during the time interval (t-1), the link adaptor can increase the transmission power and MCS of the target signal of channels 2 and 3 during the time interval t.

[0057] FIGS. 5 and 6 are drawings for explaining a link adaptation method when the interference source is a Bluetooth device according to one embodiment.

[0058] Bluetooth devices can use frequency hopping technology as an access method. Additionally, adaptive frequency hopping technology is applied to avoid interference with devices using the same channel, such as WiFi and Zigbee (it detects collisions during channel scanning and excludes the corresponding channel during dynamic hopping).

[0059] When a Bluetooth device uses adaptive frequency hopping technology, if another wireless device is communicating within the same channel, the Bluetooth device can be treated as non-existent because it does not use that channel. Therefore, in this case, the link adaptive device can leave the transmission power and MCS of the target signal unchanged.

[0060] Referring to the figure (510) of FIG. 5, if the link adaptor identifies that a Bluetooth device is using channels 1 and 2 during the time interval (t-1) and that the Bluetooth device has adaptive frequency hopping characteristics, the link adaptor can leave the transmission power and MCS of the target signal of channels 2 and 3 unchanged during the time interval t.

[0061] On the other hand, since Bluetooth devices that do not use adaptive frequency hopping technology can cause interference by using the same channel, the link adaptor can perform relatively robust communication by downsizing the target signal's MCS.

[0062] Referring to the figure (610) of FIG. 6, if the link adaptor identifies that a Bluetooth device is using channels 1 and 2 during the time interval (t-1) and that the Bluetooth device does not have adaptive frequency hopping characteristics, the link adaptor can lower the MCS of the target signal of channels 2 and 3 during the time interval t.

[0063] FIG. 7 is a diagram illustrating a link adaptation method when the interference source is a Zigbee device according to one embodiment.

[0064] Although Zigbee devices are not negligible signals like microwave ovens or Bluetooth devices with adaptive frequency hopping technology, interference with Zigbee devices may not occur if SR is attempted within a few seconds of identifying the Zigbee device because the communication interval is long by default (since Zigbee devices in the same channel are not transmitting communication signals).

[0065] In other words, the link adaptor can maintain the MCS as is for a few seconds after identifying the Zigbee device's signal (where no interference is expected), and then lower the MCS after a few seconds (where interference is expected) to perform robust communication.

[0066] Referring to the figure (710) in FIG. 7, if the link adaptor identifies that the Zigbee device is using channel 1 during the time interval (t-1), the link adaptor may leave the transmission power and MCS of the target signal of channel 1 unchanged during the time interval t, and may lower the MCS of the target signal of channel 1 during the time interval (t+1). The unit time in FIG. 7 can be determined based on the communication interval of Zigbee. For convenience of explanation, FIG. 4 to FIG. 7 are described based on the time interval (t-1) and the time interval t, but the unit times in FIG. 4 to FIG. 7 may differ from each other.

[0067] The embodiments described above may be implemented as hardware components, software components, and / or combinations of hardware and software components. For example, the devices, methods, and components described in the embodiments may be implemented using a general-purpose computer or a special-purpose computer, such as, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing unit may execute an operating system (OS) and software applications executed on said operating system. Additionally, the processing unit may access, store, manipulate, process, and generate data in response to the execution of the software. For ease of understanding, the processing unit may be described as being used as a single unit, but those skilled in the art will understand that the processing unit may include multiple processing elements and / or multiple types of processing elements. For example, the processing unit may include multiple processors or one processor and one controller. Additionally, other processing configurations, such as parallel processors, are also possible.

[0068] Software may include computer programs, code, instructions, or a combination thereof, and may configure a processing unit to operate as desired or command the processing unit independently or collectively. Software and / or data may be permanently or temporarily embodied in any type of machine, component, physical device, virtual equipment, computer storage medium or device, or transmitted signal wave in order to be interpreted by the processing unit or to provide instructions or data to the processing unit. Software may be distributed over networked computer systems and may be stored or executed in a distributed manner. Software and data may be stored on computer-readable recording media.

[0069] The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc., either alone or in combination. The program instructions recorded on the medium may be those specifically designed and configured for the embodiment, or they may be those known and available to those skilled in the art of computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes; optical recording media such as CD-ROMs and DVDs; magneto-optical media such as floptical disks; and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, and flash memory. Examples of program instructions include machine code, such as that generated by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc.

[0070] Although the embodiments have been described above with reference to the limited drawings, those skilled in the art can apply various technical modifications and variations based on the above. For example, suitable results may be achieved even if the described techniques are performed in a different order than described, and / or if the components of the described system, structure, device, circuit, etc. are combined or assembled in a form different from described, or replaced or substituted by other components or equivalents.

[0071] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims set forth below.

Claims

Claim 1 A method for link adaptation in a WLAN (Wireless LAN) system comprises: receiving signals within a communication environment; classifying the signals and identifying each of the signals; analyzing the channel access characteristics of each of the signals; and adjusting the communication parameters of a target signal by channel based on the analysis results, wherein the step of identifying each of the signals includes: determining whether a new signal uses a target band corresponding to a target signal of the WLAN system; determining whether the signals are signals originating from a non-communication device using an ISM band based on the determination that the new signal uses the target band; and determining whether the signals are signals originating from a Bluetooth device based on the determination that the new signal uses the target band. A link adaptation method comprising: a step of determining whether the signals are signals originating from a Zigbee device based on the determination that the new signal uses the target band; a step of analyzing channel access characteristics including a step of analyzing the channel usage pattern of each of the signals; and a step of adjusting communication parameters including a step of up-adjusting the transmission power, modulation, and coding format of the target signal based on the determination that the identified signal is a signal originating from a non-communication device. Claim 2 delete Claim 3 A link adaptation method according to claim 1, wherein the step of analyzing the channel usage pattern comprises: a step of analyzing the channel usage cycle of each of the signals; and a step of analyzing the channel usage distribution of each of the signals. Claim 4 A link adaptation method according to claim 1, wherein the step of adjusting the communication parameters comprises: a step of adjusting the transmission power of the target signal; and a step of adjusting the modulation and coding format (MCS; Modulation and Coding Scheme) of the target signal. Claim 5 delete

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