Method and apparatus for reducing the peak-to-average power ratio in the transmission of physical layer protocol data units

Abstract

To provide a communication device that reduces the peak-to-average power ratio (PAPR) of a trigger-based (TB) PPDU, especially of a universal signal (U-SIG) field, and improves the transmission performance of the PPDU.SOLUTION: A communication device includes a processor that receives a trigger frame in a first PPDU and obtains a sequence of ignore bits in a U-SIG field in the first PPDU. The sequence of ignore bits includes at least one bit set to 0, which is copied to a U-SIG field of a second PPDU. The communication device also includes a transmitter for transmitting the second PPDU, and the second PPDU includes a sequence of ignore bits. Using the sequence of ignore bits including at least one bit set to 0 enables PAPR reduction, causes an STA to refrain from increasing power amplifier back-off, and makes it possible to transmit with greater efficiency.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] This disclosure relates to a wireless communication system, and more specifically, to a system and method for reducing the peak-to-average power ratio (PAPR) in the universal signal (U-SIG) field of a physical layer protocol data unit (PPDU).

Background Art

[0002] The U-SIG field is used to convey information about various important parameters, such as the standard version (after 802.11be), bandwidth, and the number of extremely high throughput (EHT) signal (EHT-SIG) symbols, to all receivers in the IEEE standard 802.11be (Standard for Information Technology - Telecommunications and Information Exchange between Systems Local and Metropolitan Area Networks - Specific Requirements - Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications Amendment 22: Enhancements for Very High Throughput). The receivers include both access points (APs) and / or stations (STAs). The U-SIG is composed of two orthogonal frequency division multiplexing (OFDM) symbols, and each OFDM symbol contains 26 information bits.

[0003] The standard 8**********e is divided into two releases, Release 1 and Release 2, with Release 2 still under study, and some bits within the U-SIG field are reserved. There is an agreement to divide these reserved bits into two types: - Verification bits - Used by the receiver to determine whether to continue receiving the packet or end the reception. For example, a Release 1 receiver may understand that the packet is intended for a Release 2 receiver and can thus end the reception. - Sequence of ignore bits - Defined as "don't care" and typically ignored by the receiver.

[0004] Both the verification bits and the sequence of ignore bits may be used for other purposes within Release 2. In a trigger-based (TB) PPDU, the sequence of ignore bits is copied from the trigger frame. This trigger frame is sent by the AP and instructs the STA that it can begin transmitting and provides information related to those transmissions (e.g., where to transmit, the modulation scheme to use, etc.).

[0005] The sequence of ignored bits can cause performance issues in TB PPDUs. For example, if all ignored bits are set to 1, it results in an unnecessarily high PAPR across the entire U-SIG field, which requires the transmitting STA to increase the power amplifier backoff, thus reducing the transmit power. If the STA does not increase the backoff, the high PAPR can introduce distortion into the transmitted signal (due to clipping of time-domain signals, etc.). [Overview of the project]

[0006] The purpose of this disclosure is to provide a method and apparatus for reducing PAPR for transmitting TB PPDUs, particularly PAPR in the U-SIG field, thereby improving PPDU transmission performance.

[0007] The aforementioned and other objectives are achieved by the features of the independent claims. Further implementations will become apparent from the dependent claims, specification and drawings.

[0008] According to a first aspect of this disclosure, a communication device is disclosed for transmitting a physical layer protocol data unit (PPDU) to one or more receiving devices. The communication device includes a processor configured to receive a trigger frame in the first PPDU and to obtain a sequence of ignore bits in the universal signal U-SIG field of the first PPDU. The sequence of ignore bits includes at least one bit set to 0 and is copied to the U-SIG field of a second PPDU. The communication device further includes a transmitter configured to transmit the second PPDU, which includes the sequence of ignore bits. By using a sequence of ignore bits including at least one bit set to 0, it is possible to achieve a reduced peak-to-average power ratio (PAPR), thereby preventing the STA from increasing the backoff of the power amplifier and enabling transmission at higher efficiency. Alternatively, it reduces the probability that the transmission of the STA, particularly the transmission of the U-SIG field, will suffer distortion caused by a high PAPR (e.g., due to clipping).

[0009] In a further implementation of the first embodiment, the U-SIG field includes at least a first U-SIG symbol and a second U-SIG symbol.

[0010] In a further implementation of the first embodiment, the processor is configured to obtain a sequence of ignore bits by obtaining one of the sequences in the set {11111111110,11111011110,01111111110}. Using any of the sequences in this set as the sequence of ignore bits makes it possible to achieve a further reduced peak-to-average power ratio (PAPR), thereby preventing the STA from increasing the power amplifier backoff and enabling transmission with higher efficiency. Alternatively, it reduces the probability that the STA transmission, particularly the U-SIG field transmission, will suffer distortion caused by a high PAPR (e.g., due to clipping).

[0011] A second aspect of this disclosure discloses an access point for transmitting a physical layer protocol data unit (PPDU) to one or more communication devices. The access point includes a processor configured to set the fields of a trigger frame into a sequence containing at least one zero. The access point further includes a transmitter configured to transmit a PPDU to one or more communication devices, the PPDU including the fields of a trigger frame, the fields of the trigger frame being configured to be copied by one or more communication devices into ignore bits of a universal signal (U-SIG) sequence.

[0012] In a further implementation of the second embodiment, the fields of the trigger frame may be, for example, special user information fields.

[0013] In a further implementation of the second embodiment, the access point processor is configured to set the field of the trigger frame by setting the field to one of the sequences in the set {11111111110,11111011110,01111111110}. Using one of the sequences in this set as a sequence of ignore bits makes it possible to achieve a further reduced peak-to-average power ratio (PAPR), thereby preventing the STA from increasing the backoff of the power amplifier and enabling transmission with higher efficiency. Alternatively, it reduces the probability that the STA's transmission, particularly the transmission of the U-SIG field, will suffer distortion caused by a high PAPR (e.g., due to clipping).

[0014] A third aspect of this disclosure discloses a method for transmitting a physical layer protocol data unit (PPDU) in a communication device. The method includes the steps of: receiving a trigger frame in a first PPDU; and obtaining a sequence of ignore bits in the universal signal U-SIG field of the first PPDU, wherein the sequence of ignore bits includes at least one bit set to 0. Furthermore, the method includes the steps of: copying the sequence of ignore bits to the U-SIG field of a second PPDU; and transmitting the second PPDU containing the sequence of ignore bits. By using a sequence of ignore bits containing at least one bit set to 0, it is possible to achieve a reduced peak-to-average power ratio (PAPR), thereby preventing the STA from increasing the backoff of the power amplifier and enabling transmission with higher efficiency. Alternatively, it reduces the probability that the transmission of the STA, particularly the transmission of the U-SIG field, will suffer distortion caused by a high PAPR (e.g., due to clipping).

[0015] In a further implementation of the third embodiment, the U-SIG field includes at least a first U-SIG symbol and a second U-SIG symbol.

[0016] In a further implementation of the third embodiment, the step of obtaining a sequence of ignore bits includes the step of obtaining one of the sequences in the set {11111111110,11111011110,01111111110}. By using one of the sequences in this set as the sequence of ignore bits, it is possible to achieve a further reduced peak-to-average power ratio (PAPR), thereby preventing the STA from increasing the backoff of the power amplifier and enabling transmission with higher efficiency. Alternatively, it reduces the probability that the STA transmission, particularly the U-SIG field transmission, will suffer distortion caused by a high PAPR (e.g., due to clipping).

[0017] A fourth aspect of this disclosure discloses a method for transmitting a physical layer protocol data unit (PPDU) at an access point. The method includes the steps of: setting the fields of a trigger frame into a sequence containing at least one zero; and transmitting the PPDU to one or more communication devices, wherein the PPDU includes the fields of a trigger frame, and the fields of the trigger frame are set to be copied by one or more communication devices into ignore bits of a universal signal U-SIG sequence. Using a sequence of ignore bits containing at least one bit set to zero makes it possible to achieve a reduced peak-to-average power ratio (PAPR), thereby preventing the STA from increasing the backoff of the power amplifier and enabling transmission with higher efficiency. Alternatively, it reduces the probability that the transmission of the STA, particularly the transmission of the U-SIG field, will suffer distortion caused by a high PAPR (e.g., due to clipping).

[0018] In a further implementation of the fourth aspect, the step of obtaining a sequence of ignore bits includes the step of obtaining one of the sequences in the set {11111111110,11111011110,01111111110}. By using one of the sequences in this set as the sequence of ignore bits, it is possible to achieve a further reduced peak-to-average power ratio (PAPR), thereby preventing the STA from increasing the power amplifier backoff and enabling transmission with higher efficiency. Alternatively, it reduces the probability that the STA transmission, particularly the U-SIG field transmission, will suffer distortion caused by a high PAPR (e.g., due to clipping).

[0019] A fifth aspect of this disclosure discloses a machine-readable storage medium storing processor-executable instructions. When executed by the processor of a device, the instructions cause the device to perform a method according to any of the disclosed methods.

[0020] According to a sixth aspect of the present disclosure, a computer program product is disclosed which includes a computer-readable storage medium storing computer-readable instructions, the computer-readable instructions being executable by a device including processing hardware to perform any of the disclosed methods. According to a seventh aspect of this disclosure, a computer storage medium or computer program product is disclosed that provides any method for reducing PAPR.

[0021] Other apparatus, methods, features, and advantages of the Disclosure will be apparent to those skilled in the art by examining the following drawings and detailed description. All such additional apparatus, methods, features, and advantages are included in this Description, are within the scope of the Disclosure, and are intended to be protected by the appended claims.

[0022] Unless otherwise specified, all technical and / or scientific terms used herein have the same meaning as those generally understood by those skilled in the art for the embodiments. Similar or equivalent methods and materials described herein may be used in the implementation or testing of the embodiments, although exemplary methods and / or materials are described below. In case of conflict, the patent specification, including definitions, will prevail. Furthermore, materials, methods and specific examples are illustrative only and are not necessarily intended to be limiting. [Brief explanation of the drawing]

[0023] In this case, several embodiments are described only as examples with reference to the accompanying drawings. Herein, a detailed reference to the drawings emphasizes that the illustrated details are illustrative and for illustrative purposes only. In this regard, the description accompanying the drawings will make it clear to those skilled in the art how the embodiments may be carried out. [Figure 1] Figure 1 shows a system for reducing PAPR in the field of PPDU according to some embodiments of this disclosure. [Figure 2] Figure 2 shows the U-SIG design for the TB PPDU of 802.11be Release 1. [Figure 3] Figure 3 shows the complementary cumulative distribution function (CCDF) of the PAPR of the U-SIG-1 and U-SIG-2 symbols using a 320 MHz BW. [Figure 4] Figure 7 shows the comparison between the CCDF of the PAPR using the ignore bit sequence '11111011110' and '01111011110' for U-SIG-2, and that using the ignore bit sequence '11111111111' assuming a 320 MHz BW without puncturing. [Figure 5] Figure 5 is a schematic diagram of a possible logical structure of a communication device according to some embodiments of the present disclosure. [Figure 6] Figure 6 shows the comparison between the CCDF of the PAPR using the ignore bit sequence '11111111110', and that using the ignore bit sequence '111111111' assuming a 320 MHz BW without puncturing. [Figure 7] Figure 7 shows the comparison between the CCDF of the PAPR using the ignore bit sequence '11111111110', and that using the ignore bit sequence '111111111' assuming a 320 MHz BW with the puncturing pattern 1111111100001111. [Figure 8] Figure 8 shows the comparison between the CCDF of the PAPR using the ignore bit sequences '11111011110' and '01111011110' for U-SIG-1, and that using the ignore bit sequence '11111111111' assuming a 320 MHz BW without puncturing. [Figure 9] Figure 9 shows the comparison between the CCDF of the PAPR using the ignore bit sequences '11111011110' and '01111011110' for U-SIG-2, and that using the ignore bit sequence '111111111' assuming a 320 MHz BW without puncturing. [Figure 10] Figure 10 shows the structure of the special user information field in the trigger frame regarding the situation of the present disclosure. [Figure 11] Figure 11 shows the “U-SIG ignore and verify” field used in the context of this disclosure to convey the ignored bit sequence. [Figure 12] Figure 12 shows the workflow for transmitting a Physical Layer Protocol Data Unit (PPDU) in a communication device. [Figure 13] Figure 13 shows the workflow for sending a Physical Layer Protocol Data Unit (PPDU) at an access point. [Modes for carrying out the invention]

[0024] Before describing at least one embodiment in detail, it should be understood that embodiments are not necessarily limited to the structural and arrangement details of the components and / or methods described in the following description and / or drawings and / or specific examples. The implementations described herein may have the capabilities of other embodiments or may be realized or performed in various ways.

[0025] Figure 1 shows a system for reducing PAPR in the field of a PPDU according to several embodiments of this disclosure. System 100 includes an access point (AP) 101 and one or more stations (STAs), such as STA 102, STA 103, STA 104, as shown in Figure 1. System 100 is also referred to in this disclosure as a Basic Service Set (BSS). In System 100, the AP and STA communicate both downlink and uplink. The arrows between the AP and STA shown in Figure 1 indicate downlink only, but should not be understood as a limitation of transmission.

[0026] System 100 shows only one AP within the system, but a system may contain multiple APs, and the APs within the system can perform coordinated transmission.

[0027] System 100 of this disclosure includes, but is not limited to, wireless fidelity (WIFI) communication systems, narrowband Internet of Things (NB-IoT) systems, long-term evolution (LTE) systems, fifth-generation mobile communication systems (5G) or later, and machine-to-machine (M2M) communication systems. LTE systems and 5G or later can integrate with WIFI systems.

[0028] In this disclosure, the communication device is AP 101 or STA, and STA may be, for example, a mobile phone, intelligent terminal, tablet computer, notebook computer (laptop), video game console, multimedia player, WIFI-supporting vehicle, device-to-device (D2D) equipment, or any smart device. AP and / or STA may be fixed or mobile devices.

[0029] The WIFI system is capable of supporting all IEEE 802.11 series standards, including but not limited to 802.11a / b / g, 802.11n, 802.11ac, 802.11ax, 802.11be, or later.

[0030] Figure 2 shows the U-SIG design for a TB PPDU in 802.11be Release 1. The bits in the first symbol of the TB PPDU's U-SIG transmit information about the PHY version (e.g., 802.11be or later version of the standard), BW (e.g., 20 MHz, 40 MHz, etc.), whether it is a DL or UL transmit, BSS color that distinguishes different possible adjacent BSS values, TXOP including the TXOP period, and / or how the transmitter is utilizing the channel resource. The bits in the second symbol of the U-SIG transmit information about the PPDU type (e.g., MU, TB) and spatial reuse (e.g., spatial reuse 1 and spatial reuse 2), which allows multiple transmitters to simultaneously transmit six 0-tail bits used for the CRC and convolutional code on the same resource.

[0031] As shown in both Figure 2, the sequence of ignore bits is located within the first and second U-SIG symbols; however, since the CRC is calculated as a function of all preceding bits, including both the first and second U-SIG symbols, the value of the CRC bit (located in the second U-SIG symbol) is also a function of the sequence of ignore bits located in the first U-SIG symbol.

[0032] In 802.11ax, the trigger frame contains nine reserved bits, all of which are set to '1'. The nine reserved bits are copied to the second symbol in the HE-SIG-A field of the TB PPDU. In the current development stage of 802.11be, for each TB PPDU, there are six sequences of ignored bits in the first U-SIG symbol and five sequences of ignored bits in the second U-SIG symbol. All sequences of ignored bits are currently (in the current development stage of 802.11be) defined to be copied from the trigger frame (similar to 802.11ax operation). In 11be, maintaining the same design as in 11ax, sequences of ignored bits copied from the trigger frame may be set to 1.

[0033] Although the structure of the trigger frame is not presented in this disclosure, the sequence of the trigger frame and the ignored bits of the TB PPDU contains consecutive binary bits '1', which may lead to a high PAPR, and as a result the performance of the U-SIG field on the TB PPDU will be affected (for example, using a lower PAPR can reduce the backoff of the power amplifier, thereby increasing efficiency).

[0034] Figure 3 shows the complementary cumulative distribution function (CCDF) of PAPR for both U-SIG symbols for a 320 MHz bandwidth (in Figure 3, U-SIG-1 refers to the first symbol in the U-SIG field, and U-SIG-2 refers to the second symbol in the U-SIG field). The sequence of ignored bits in the U-SIG symbols is assumed to be all 1. Figure 3 shows the complementary cumulative distribution function (CCDF) of PAPR for both U-SIG symbols, compared to that of the data portion (assuming MCS0 = BPSK rate 1 / 2) and the legacy SIG (L-SIG) field. As shown, the U-SIG PAPR is significantly higher than that of the data portion. It is also higher than that of the L-SIG field, especially the PAPR of the U-SIG-2 symbol.

[0035] Figure 4 shows the CCDF of PAPR for both U-SIG symbols against a 40 MHz BW. The effect shown in relation to Figure 5 is shown to be consistent for other BW values ​​and puncturing patterns. Figure 4 shows a similar comparison with a 40 MHz BW. As shown there, the PAPR for both U-SIG symbols also outperforms that of the L-SIG field and data payload.

[0036] Current standards stipulate that the pre-EHT field, which is replicated for each 20MHz portion (e.g., L-SIG, U-SIG), undergoes a phase rotation every 20MHz to reduce PAPR. However, as shown in Figures 3 and 4, the U-SIG PAPR is higher than both the data and L-SIG, which means it is a limiting factor from a performance standpoint (this may define the power amplifier backoff).

[0037] Therefore, based on the simulation results, Figures 3 and 4 show that reducing PAPR in the U-SIG field is important.

[0038] To address the above issues, this disclosure provides a method and / or apparatus for reducing PAPR of TB PPDU, particularly PAPR in the U-SIG field.

[0039] Embodiments presented in this disclosure may be systems, methods, and / or computer program products. A computer program product may include a computer-readable storage medium (or medium) having computer-readable program instructions for causing a processor to execute an aspect of the embodiment.

[0040] A computer-readable storage medium can be a tangible device capable of holding and storing instructions for use by an instruction execution device. A computer-readable storage medium can be, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination thereof.

[0041] A non-exclusive list of more specific examples of computer-readable storage media includes: portable computer diskettes, hard disks, random-access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random-access memory (SRAM), portable compact disk read-only memory (CD-ROM), digital multipurpose disks (DVDs), memory sticks, floppy disks, and any appropriate combination of the above.

[0042] The computer-readable storage media used herein are not to be interpreted as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through optical fiber cables), or electrical signals transmitted through wires.

[0043] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to each arithmetic / processing device, or downloaded to an external computer or external storage device via a network such as the Internet, local area network, wide area network, and / or wireless network. A network adapter card or network interface in each arithmetic / processing device can receive computer-readable program instructions from the network and transfer them for storage on computer-readable storage media within the respective arithmetic / processing device.

[0044] Computer-readable program instructions for performing the operation of the embodiment may be assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk and C++, or traditional procedural programming languages ​​such as the C programming language or similar programming languages.

[0045] Computer-readable program instructions can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be to an external computer (for example, via the Internet using an Internet service provider).

[0046] In some embodiments, for example, an electronic circuit including a programmable logic circuit, a field-programmable gate array (FPGA), or a programmable logic array (PLA) can execute computer-readable program instructions by utilizing computer-readable program instruction state information in order to personalize the electronic circuit and perform an aspect of the embodiment.

[0047] Figure 5 is a schematic diagram of a possible logical structure of a communication device in the present disclosure according to some embodiments. The communication device includes a processor 402. In some embodiments of the present disclosure, the processor 402 may be configured to control and manage one or more operations of the communication device, for example, to execute code that operates with respect to a sequence of ignore bits to reduce PAPR, and / or to process data transmitted and / or received at the AP. Optionally, the communication device may further include a memory 401 and a communication interface 403. The processor 402, the communication interface 403, and the memory 401 may be interconnected or interconnected using a bus 404. The communication interface 403 is configured to support the communication device when performing communication, and the memory 401 is configured to store program code and data for the communication device. The processor 402 invokes the code stored in the memory 401 to perform control and management. The memory 401 may or may not be coupled to the processor 402.

[0048] The processor 402 may be a central processing unit, a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field-programmable gate array or other programmable logic device, a transistor logic device, a hardware component, or any combination thereof. The processor 402 can implement or run various exemplary logic blocks, modules, and circuits described with reference to what is disclosed in this disclosure. Alternatively, the processor 402 may be a combination of processors implementing arithmetic functions, for example, a combination of one or more microprocessors, or a combination of a digital signal processor and a microprocessor. The bus 404 may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The bus may be classified as an address bus, a data bus, a control bus, etc.

[0049] According to the communication device provided above, in some embodiments, the U-SIG may include at least a first U-SIG symbol and a second U-SIG symbol.

[0050] The ignore bit sequences in this disclosure may be predefined bit sequences in the prior art, such as the current IEEE protocol. In some embodiments, the ignore bit sequences may be 5 or 6 bits, all of which are set as binary '1' in the TB PPDU. The ignore bit sequences may refer to a 6-bit sequence of ignore bits for a first U-SIG symbol in the TB PPDU, and / or a 5-bit sequence of ignore bits for a second U-SIG symbol in the TB PPDU. It should be noted that the ignore bit sequences may include any other number of binary bits, and 5 or 6 bits is not an limitation of this disclosure.

[0051] Figure 6 shows the CCDF of PAPR assuming a ignore bit sequence where all bits except a single '0' at either edge of U-SIG-1 or U-SIG-2 are set to '1', without puncture and assuming 320 MHz. In particular, the sequence '111111' in U-SIG-1 and the sequence '11110' in U-SIG-2 (totaling '11111111110') are shown, which yield the lowest PAPR. Figure 7 compares the CCDF of PAPR in the all-1 case with that of the '11111111110' sequence, which has a single '0' at the end of the sequence, without puncture and assuming 320 MHz. Since the first six values ​​are the same for both sequences, the CCDF curves for U-SIG-1 for both '11111111111' and '11111111110' are identical. For U-SIG-2, an improvement can be observed with a single '0'.

[0052] Figure 7 shows a comparison between the CCDF of PAPR for all 1 cases and that of a sequence with a single '0' at the end of the sequence, assuming 320MHz with the puncturing pattern 1111111100001111. Here again, the first six values ​​are the same in both sequences, so the CCDF curve for U-SIG-1 is located. For U-SIG-2, an improvement with a single '0' can be observed.

[0053] Figure 8 shows an example where all bits are set to '1' except for a single '0' at both the U-SIG-1 and U-SIG-2 edges. In other words, there are two values ​​of '0' used throughout the entire sequence: one '0' at U-SIG-1 and one '0' at U-SIG-2.

[0054] In particular, the following sequence is shown in Figure 8: - '111110' in U-SIG-1 and '11110' in U-SIG-2 (therefore, a total of '11111011110') - U-SIG-1 is '011111' and U-SIG-2 is '11110' (therefore, the total is '01111111110')

[0055] Figure 8 shows a comparison of the CCDF of the PAPR in the case of all 1s for U-SIG-1, assuming 320 MHz without puncture, with that of the sequence proposed above. As shown in Figure 8, there is an improvement in the PAPR.

[0056] Figure 9 shows a comparison of the CCDF of the PAPR for U-SIG-2 in the case of all 1s, assuming 320 MHz without puncture, with that of the same sequence as in Figure 8. As shown in Figure 9, there is an improvement in the PAPR.

[0057] Figure 10 shows a special user information field from an exemplary trigger frame of the present disclosure. In the example of the present disclosure, the field between B25 and B36 is a field in which a ignored bit sequence is transmitted from the access point and can be used as a field that is received by the communication device and used as a ignored bit sequence, thereby achieving reduced PAPR.

[0058] Figure 11 shows the definition of the "U-SIG ignore and verify" subfield and the copy of the ignore bit sequence to the U-SIG field.

[0059] Figure 12 shows a workflow for a method of transmitting a Physical Layer Protocol Data Unit (PPDU) in a communication device. The method includes step S1 of receiving a trigger frame in a first PPDU. Further, the method includes step S2 of obtaining a sequence of ignore bits in the Universal Signal U-SIG field of the first PPDU, where the sequence of ignore bits includes at least one bit set to 0. The method further includes step S3 of copying the sequence of ignore bits to the U-SIG field of a second PPDU, and step S4 of transmitting a second PPDU, where the second PPDU includes the sequence of ignore bits.

[0060] Figure 13 shows a workflow for transmitting a Physical Layer Protocol Data Unit (PPDU) at an access point. The method includes step S1 setting the fields of a trigger frame into a sequence containing at least one zero. The method further includes step S2 transmitting the PPDU to one or more communication devices, where the PPDU contains the fields of the trigger frame, where the fields of the trigger frame are set to be copied by one or more communication devices into the ignore bits of the Universal Signal U-SIG sequence.

[0061] The descriptions of various embodiments are presented for illustrative purposes only and are not intended to exhaust or limit the embodiments disclosed. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the embodiments described. The terms used herein have been selected to best describe the principles of the embodiments, practical applications or technical improvements beyond the art available on the market, or to enable those skilled in the art to understand the embodiments disclosed herein.

[0062] The terms "including," "containing," "encompassing," "containing," and "having," and their conjugations, all mean "including but not limited to."

[0063] As used here, the singular forms "aru," "aru," and "sono" include multiple references unless the context explicitly indicates otherwise. For example, the terms "compound" or "at least one compound" may include multiple compounds, including mixtures thereof.

[0064] The term “exemplary” is used in this context to mean “serving as a specific example, instance, or illustration.” Any embodiment described “exemplary” is not necessarily construed as being preferable or advantageous to other embodiments, and / or does not necessarily exclude the incorporation of features from other embodiments.

[0065] The phrase "optional" is used in this context to mean "provided in some embodiments but not in other embodiments." Any particular embodiment may include multiple "optional" features, provided that such features do not conflict.

[0066] Throughout this application, various embodiments may be presented in a certain scope. It should be understood that this scope-based description is merely for convenience and should not be interpreted as an inflexible limitation on the scope of the embodiments.

[0067] For clarity, it is acknowledged that certain features of embodiments described in the context of separate embodiments may be provided in combination in a single embodiment. Conversely, for brevity, various features of embodiments described in the context of a single embodiment may be provided separately, in any suitable sub-combination, or appropriately in any other described embodiment. Certain features described in the context of various embodiments should not be considered essential features of those embodiments unless the embodiment would not function without those elements.

[0068] While embodiments are described in relation to their specific embodiments, it is obvious that many alternatives, modifications, and variations will be apparent to those skilled in the art. Therefore, it is intended to encompass all such alternatives, modifications, and variations that fall within the spirit and broad scope of the appended claims.

[0069] While this disclosure describes solutions for reducing PAPR from an apparatus perspective, it will be apparent to those skilled in the art that the problems addressed in this disclosure can also be addressed by methods and / or systems. Methods for reducing PAPR to avoid redundancy are not detailed.

[0070] The applicant intends that all publications, patents, and patent applications referenced herein, when incorporated by reference, be incorporated in their entirety into the specification as if each individual publication, patent, or patent application were described specifically and individually. Furthermore, no citation or specification of any reference in this application shall be construed as an acknowledgment that such reference is available as prior art for embodiments. Section headings, to the extent used, should not be construed as necessary limitations.

Claims

1. A communication device that transmits a physical layer protocol data unit (PPDU) to one or more receiving devices, wherein the communication device is: Steps include receiving the trigger frame in the first PPDU; A step of obtaining a sequence of ignored bits in the universal signal U-SIG field of the first PPDU, wherein in the sequence of ignored bits, at least the most significant bit or the least significant bit is set to 0; and A processor configured to perform the step of copying the sequence of ignored bits to the U-SIG field of a second PPDU; and A transmitter configured to transmit the second PPDU, wherein the second PPDU includes the sequence of ignore bits; A communication device that includes a sequence of ignore bits in the second PPDU, the sequence of ignore bits in which the second PPDU includes two bits set to 0.

2. A communication device according to claim 1, wherein the U-SIG field includes at least a first U-SIG symbol and a second U-SIG symbol.

3. A communication device according to claim 1 or 2, wherein the processor is configured to obtain the sequence of ignore bits by obtaining one of the sequences in the set {11111011110,01111111110}.

4. An access point that transmits a physical layer protocol data unit (PPDU) to one or more communication devices, wherein the access point is: A processor configured to set the fields of a trigger frame to a sequence containing at least one zero; and A transmitter configured to transmit the PPDU to one or more communication devices, wherein the PPDU includes the field of the trigger frame, and the field of the trigger frame is configured to be copied by the one or more communication devices to the ignore bit of the universal signal U-SIG sequence; An access point that includes, and whose sequence of ignored bits includes two bits set to 0.

5. The access point according to claim 4, wherein the processor is configured to set the field of the trigger frame by setting the field to one of the sequences in the set {11111011110,01111111110}.

6. A method for transmitting a physical layer protocol data unit (PPDU) in a communication device, wherein the method is: Steps include receiving the trigger frame in the first PPDU; A step of obtaining a sequence of ignored bits in the universal signal U-SIG field of the first PPDU, wherein in the sequence of ignored bits, at least the most significant bit or the least significant bit is set to 0; The steps of copying the sequence of ignored bits to the U-SIG field of the second PPDU; and A step of transmitting the second PPDU, wherein the second PPDU includes the sequence of ignore bits; The method includes a sequence of ignore bits for the second PPDU, wherein the sequence of ignore bits for the second PPDU includes two bits set to 0.

7. The method according to claim 6, wherein the U-SIG field includes at least a first U-SIG symbol and a second U-SIG symbol.

8. A method by claim 6 or 7, wherein the step of obtaining the sequence of ignored bits includes the step of obtaining one of the sequences in the set {11111011110,01111111110}.

9. A method for transmitting a physical layer protocol data unit (PPDU) at an access point, the method being: The steps of setting the fields of the trigger frame to a sequence containing at least one zero; and A step of transmitting the PPDU to one or more communication devices, wherein the PPDU includes the field of the trigger frame, and the field of the trigger frame is configured to be copied by the one or more communication devices to the ignore bit of the universal signal U-SIG sequence; A method that includes, wherein the sequence of ignored bits includes two bits set to 0.

10. A method by claim 9, wherein the step of obtaining the sequence of ignored bits includes the step of obtaining one of the sequences in the set {11111011110,01111111110}.

11. A machine-readable storage medium storing processor-executable instructions, wherein, when executed by the processor of the device, the instructions cause the device to perform the method according to any one of claims 6 to 10.

12. A computer program comprising computer-readable instructions, wherein the computer-readable instructions can be executed by a device comprising processing hardware to perform the method according to any one of claims 6 to 10.