Physical layer preamble design

Abstract

The invention provides a method, equipment and a system for generating a packet preamble. Some implementations more specifically relate to preamble designs that support an IEEE 802.11 be modified version according to the IEEE 802.11 standard and data throughput gains achievable in the future several generations. In other examples, the preamble design of this implementation may allow for more reliable packet detection, more accurate channel estimation, and more robust decoding of signal field (SIG) symbols. Additionally or alternatively, preamble designs of the present disclosure may be implemented with different lengths, modulation schemes, or transmit powers compared to existing versions of preamble designs that follow the IEEE 802.11 standard.

Description

[0001] This application is a divisional application of the application with the filing date of May 19, 2021, application number 202180035385.3 (international application number PCT / US2021 / 033092), and title "Physical Layer Preamble Design".

[0002] Cross - reference to related applications

[0003] This patent application claims the priority of U.S. Provisional Patent Application No. 63 / 027,337, entitled "PHYSICAL LAYER PREAMBLE DESIGN", filed on May 19, 2020; U.S. Provisional Patent Application No. 63 / 033,810, entitled "PHYSICAL LAYER PREAMBLE FOR EXTENDED RANGE (ER) PACKET FORMAT", filed on June 2, 2020; and U.S. Non - provisional Application No. 17 / 323,563, entitled "PHYSICAL LAYER PREAMBLE DESIGN", filed on May 18, 2021. All of the above applications are assigned to the assignee of this application. The disclosures of all prior applications are considered to be a part of this patent application and are incorporated herein by reference. Technical field

[0004] This disclosure generally relates to wireless communication, and more particularly to physical layer preambles and signaling for wireless transmission.

[0005] Description of related technology

[0006] A wireless local area network (WLAN) can be formed by one or more access points (APs) that provide a shared wireless communication medium for use by several client devices (also referred to as stations (STAs)). The basic building block of a WLAN that follows the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard family is a basic service set (BSS) managed by an AP. Each BSS is identified by a basic service set identifier (BSSID) announced by the AP. The AP periodically broadcasts beacon frames so that any STA within the wireless range of the AP can establish or maintain a communication link with the WLAN.

[0007] New WLAN communication protocols are being developed to enable enhanced WLAN communication features. Since new WLAN communication protocols implement enhanced features, new preamble designs are needed to support signaling related to the new features and packet formats. Additionally, new preamble designs may be needed to ensure that such signaling can be reliably communicated over an extended range, such as, for example, in an outdoor environment.

[0008] Overview

[0009] The systems, methods, and devices of the present disclosure each have several innovative aspects, and no single aspect is solely responsible for the desired attributes disclosed herein.

[0010] One innovative aspect of the subject matter described in the present disclosure may be implemented as a wireless communication method. The method may be performed by a wireless communication device and may include: receiving a packet including a physical layer preamble that includes a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signal field (L-SIG), a repetition of the L-SIG (RL-SIG) following the L-SIG, and a universal signal field (U-SIG) following the RL-SIG and including information for decoding one or more subsequent fields of the packet, where the L-SIG includes a length field having a value (L_LEN) that satisfies L_LEN % 3 = 0; detecting one or more modulation schemes associated with the U-SIG; and determining the format of the packet based on the detected modulation scheme associated with the U-SIG. In some implementations, the detection of one or more modulation schemes may include determining that a first symbol of the U-SIG is modulated according to a binary phase shift keying (BPSK) modulation scheme; and determining that a second symbol of the U-SIG is modulated according to a quadrature BPSK (QBPSK) modulation scheme.

[0011] In some implementations, the determination of the format of the packet may include: determining that the U-SIG further includes at least a third symbol and a fourth symbol based on determining that the second symbol of the U-SIG is modulated according to the QBPSK modulation scheme, where the first symbol of the U-SIG carries the same decoded bits as the second symbol of the U-SIG, and the third symbol of the U-SIG carries the same decoded bits as the fourth symbol of the U-SIG. In some aspects, each of the first symbol and the second symbol may be transmitted on a plurality of subcarriers, where the decoded bits of the first symbol are modulated on the plurality of subcarriers in an order different from the order of the decoded bits of the second symbol. In some aspects, each of the third symbol and the fourth symbol may be transmitted on a plurality of subcarriers, where the decoded bits of the third symbol are modulated on the plurality of subcarriers in an order different from the order of the decoded bits of the fourth symbol.

[0012] In some implementations, the method may further include: determining a timing of a non-legacy short training field (STF) of the physical layer preamble relative to the U-SIG based on the format of the packet; and initiating an automatic gain control (AGC) based on the timing of the non-legacy STF. In some aspects, the packet may include one or more padding symbols between the U-SIG and the non-legacy STF.

[0013] In some implementations, determining the format of the packet may include: determining that the packet follows a non-legacy extended range (ER) packet format based on a value of a version identifier subfield of the U-SIG and a determination that the second symbol of the U-SIG is modulated according to the QPSK modulation scheme. In some aspects, the preamble may further include a non-legacy signal field immediately following the U-SIG, where the non-legacy signal field includes a single user field and one or more overflow bits from the U-SIG. In some aspects, the U-SIG may include a user field carrying user-specific information for a single user, where the preamble further includes a non-legacy STF immediately following the U-SIG.

[0014] Another innovative aspect of the subject matter described in this disclosure may be implemented in a wireless communication device. In some implementations, the wireless communication device may include at least one modem, at least one processor communicatively coupled to the at least one modem, and at least one memory communicatively coupled to the at least one processor and storing processor-readable code. In some implementations, execution of the processor-readable code by the at least one processor causes the wireless communication device to perform operations that include: receiving a packet including a physical layer preamble, the physical layer preamble including an L-STF, an L-LTF, an L-SIG, an RL-SIG immediately following the L-SIG, and a U-SIG immediately following the RL-SIG and including information for interpreting one or more subsequent fields of the packet, where the L-SIG includes a length field having a value (L_LEN) that satisfies L_LEN % 3 = 0; detecting one or more modulation schemes associated with the U-SIG; and determining the format of the packet based on the detected modulation schemes associated with the U-SIG. In some implementations, detecting the one or more modulation schemes may include determining that a first symbol of the U-SIG is modulated according to the BPSK modulation scheme; and determining that a second symbol of the U-SIG is modulated according to the QPSK modulation scheme.

[0015] Another innovative aspect of the subject matter described in this disclosure can be implemented as a wireless communication method. The method can be performed by a wireless communication device and can include: generating a packet including a physical layer preamble, the physical layer preamble including an L-STF, an L-LTF, an L-SIG, an RL-SIG following immediately after the L-SIG, and a U-SIG following immediately after the RL-SIG and including information for interpreting one or more subsequent fields of the packet, where the L-SIG includes a length field having a value (L_LEN) that satisfies L_LEN % 3 = 0; modulating a first symbol of the U-SIG according to a BPSK modulation scheme; modulating a second symbol of the U-SIG according to a QBPSK modulation scheme; and transmitting the packet over a wireless channel.

[0016] In some implementations, the U-SIG can further include at least a third symbol and a fourth symbol, where the first symbol of the U-SIG carries the same decoded bits as the second symbol of the U-SIG, and the third symbol of the U-SIG carries the same decoded bits as the fourth symbol of the U-SIG. In some aspects, the decoded bits of the first symbol can be modulated on multiple subcarriers in an order different from that of the decoded bits of the second symbol. In some aspects, the decoded bits of the third symbol can be modulated on multiple subcarriers in an order different from that of the decoded bits of the fourth symbol. In some aspects, the packet can include one or more padding symbols between the U-SIG of the physical layer preamble and a non-legacy STF.

[0017] In some implementations, the packet can follow a non-legacy ER packet format having a bandwidth equal to 20 MHz. In some aspects, the preamble can further include a non-legacy signal field following immediately after the U-SIG, where the non-legacy signal field includes a single-user field and one or more overflow bits from the U-SIG. In some aspects, the U-SIG can further include a user field carrying user-specific information for a single user, where the preamble further includes a non-legacy STF following immediately after the U-SIG.

[0018] Another innovative aspect of the subject matter described in this disclosure can be implemented in a wireless communication device. In some implementations, the wireless communication device may include at least one modem, at least one processor communicatively coupled to the at least one modem, and at least one memory communicatively coupled to the at least one processor and storing processor-readable code. In some implementations, the execution of the processor-readable code by the at least one processor causes the wireless communication device to perform operations, which include: generating a packet including a physical layer preamble, the physical layer preamble including L-STF, L-LTF, L-SIG, RL-SIG following immediately after L-SIG, and U-SIG following immediately after RL-SIG and including information for interpreting one or more subsequent fields of the packet, where L-SIG includes a length field having a value (L_LEN) that satisfies L_LEN % 3 = 0; modulating a first symbol of U-SIG according to a BPSK modulation scheme; modulating a second symbol of U-SIG according to a QBPSK modulation scheme; and transmitting the packet over a wireless channel. Brief Description of the Drawings

[0020] Details of one or more implementations of the subject matter described in this disclosure are set forth in the drawings and the following description. Other features, aspects, and advantages will become apparent from the description, the drawings, and the claims. It should be noted that the relative dimensions of the following drawings may not be drawn to scale.

[0021] Figure 1 A schematic diagram of an example wireless communication network is shown.

[0022] Figure 2A An example protocol data unit (PDU) that can be used for communication between an access point (AP) and one or more wireless stations (STA) is shown.

[0023] Figure 2B Shows Figure 2A example fields in the PDU of

[0024] Figure 3 An example physical layer (PHY) protocol data unit (PPDU) that can be used for communication between an AP and one or more STAs is shown.

[0025] Figure 4 A block diagram of an example wireless communication device is shown.

[0026] Figure 5A A block diagram of an example AP is shown.

[0027] Figure 5B A block diagram of an example STA is shown.

[0028] Figure 6Shows an example PPDU that can be used for communication between an AP and several STAs according to some implementations.

[0029] Figure 7A Shows an example frame structure for a trigger-based (TB) PPDU according to some implementations.

[0030] Figure 7B Shows an example frame structure for a multi-user (MU) PPDU according to some implementations.

[0031] Figure 8 Shows an example frame structure of a non-legacy PPDU allocated on multiple sub-channels of a wireless channel according to some implementations.

[0032] Figure 9A Shows an example PHY preamble for a non-legacy PPDU according to some implementations.

[0033] Figure 9B Shows another example PHY preamble for a non-legacy PPDU according to some implementations.

[0034] Figure 10A Shows an example PHY preamble for a non-legacy PPDU according to some implementations.

[0035] Figure 10B Shows another example PHY preamble for a non-legacy PPDU according to some implementations.

[0036] Figure 11 Shows an example extended range (ER) single-user (SU) PPDU according to some implementations.

[0037] Figure 12 Shows an example frame structure for an ER SU PPDU according to some implementations.

[0038] Figure 13A Shows a flowchart illustrating an example process for wireless communication supporting PHY preamble design according to some implementations.

[0039] Figure 13B Shows a flowchart illustrating an example process for wireless communication supporting PHY preamble design according to some other implementations.

[0040] Figure 13C Shows a flowchart illustrating an example process for wireless communication supporting PHY preamble design according to some other implementations.

[0041] Figure 14 Shows a flowchart illustrating an example process for wireless communication supporting PHY preamble design according to some other implementations.

[0042] Figure 15 A flowchart illustrating an example process of wireless communication for supporting increasing the transmit power of a training field of a PHY preamble according to some implementations.

[0043] Figure 16 A flowchart illustrating an example process of wireless communication for supporting increasing the transmit power of a training field of a PHY preamble according to some other implementations.

[0044] Figure 17 A flowchart illustrating an example process of wireless communication for supporting increasing the transmit power of a training field of a PHY preamble according to some other implementations.

[0045] Figure 18 A block diagram of an example wireless communication device according to some implementations.

[0046] Figure 19 A block diagram of an example wireless communication device according to some implementations.

[0047] Like reference numerals and designations in the various figures indicate like elements.

[0048] Detailed Description

[0049] The following description is directed to certain implementations with the intent of describing innovative aspects of the present disclosure. However, one of ordinary skill in the art will readily recognize that the teachings herein can be applied in many different ways. The described implementations can be implemented in any device, system, or network capable of transmitting and receiving radio frequency (RF) signals according to one or more of the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards, IEEE 802.15 standards, standards defined by the Bluetooth Special Interest Group (SIG), standards, or Long Term Evolution (LTE), 3G, 4G, or 5G (New Radio (NR)) standards released by the Third Generation Partnership Project (3GPP), etc. The described implementations can be implemented in any device, system, or network capable of transmitting and receiving RF signals according to one or more of the following technologies or techniques: Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal FDMA (OFDMA), Single Carrier FDMA (SC-FDMA), Single User (SU) Multiple Input Multiple Output (MIMO), and Multi-User (MU) MIMO. The described implementations can also be implemented using other wireless communication protocols or RF signals suitable for use in one or more of Wireless Personal Area Networks (WPANs), Wireless Local Area Networks (WLANs), Wireless Wide Area Networks (WWANs), or Internet of Things (IoT) networks.

[0050] A new WLAN communication protocol is being developed to achieve enhanced WLAN communication features. Since the new WLAN communication protocol implements enhanced features, a new preamble design is needed to support signaling related to the new features and packet formats. Additionally, a new preamble design may be needed to ensure that such signaling can be reliably conveyed over an extended range, such as, for example, in an outdoor environment. Signaling refers to a control field or information that can be used by a wireless communication device to interpret another field or portion of a packet. Such information can be encoded in the physical layer (PHY) preamble of a packet. However, decoding and processing signaling information consumes time and resources, which may delay the processing of other information carried in the packet.

[0051] Generally speaking, various aspects relate to signaling included in a PHY preamble that supports a new wireless communication protocol, and more specifically, to preamble designs that support extended range communication or data throughput gains achievable with IEEE 802.11be amendment to the IEEE 802.11 standard and future generations. In some aspects, compared to preamble designs that follow existing versions of the IEEE 802.11 standard, the preamble designs of the present disclosure can be implemented using different lengths, modulation schemes, or frame structures. For example, information carried in one or more fields of the PHY preamble can be repeated (in time) to provide increased signaling gain at the receiving device. In some implementations, such information can be carried in the Universal Signal field (U-SIG) of the PHY preamble. In some other implementations, such information can be carried in a non-legacy signal field of the PHY preamble. As used herein, the term "non-legacy" can refer to the packet formats and communication protocols of IEEE 802.11be amendment to the IEEE 802.11 standard and future generations that follow the IEEE 802.11 standard.

[0052] Specific implementations that can implement the subject matter described in the present disclosure can achieve one or more of the following potential advantages. The preamble design of this implementation can allow for more reliable packet detection, more accurate channel estimation, and more robust decoding of signaling information in non-legacy packets. By adjusting the length, modulation scheme, or frame structure associated with the physical layer preamble, aspects of the present disclosure can also enable earlier detection of various contents (or the absence of such contents) in the PHY preamble and provide more time for the receiving device to process such contents.

[0053] Figure 1FIG. 0 shows a block diagram of an example wireless communication network 100. According to some aspects, wireless communication network 100 may be an example of a wireless local area network (WLAN) (such as a Wi-Fi network) (and will be referred to hereinafter as WLAN 100). For example, WLAN 100 may be a network that implements at least one of the IEEE 802.11 wireless communication protocol standards family (such as the standards defined by the IEEE 802.11-2016 specification or its amendments, including but not limited to 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be). WLAN 100 may include a number of wireless communication devices, such as access point (AP) 102 and multiple stations (STA) 104. Although only one AP 102 is shown, WLAN network 100 may also include multiple APs 102.

[0054] Each STA 104 may also be referred to as a mobile station (MS), mobile device, mobile handset, wireless handset, access terminal (AT), user equipment (UE), subscriber station (SS), or subscriber unit, among other possibilities. STA 104 may represent various devices, such as a mobile phone, personal digital assistant (PDA), other handheld devices, netbook, notebook computer, tablet computer, laptop device, display device (e.g., TV, computer monitor, navigation system, etc.), music or other audio or stereo device, remote control device (“remote control”), printer, kitchen or other household appliance, remote key fob (e.g., for a passive keyless entry and start (PKES) system), among other possibilities.

[0055] A single AP 102 and the associated set of STAs 104 may be referred to as a basic service set (BSS), which is managed by the corresponding AP 102. Figure 1Additionally shown is an example coverage area 106 of the AP 102, which may represent the basic service area (BSA) of the WLAN 100. A BSS can be identified to users by a service set identifier (SSID) and can also be identified to other devices by a basic service set identifier (BSSID), which can be the media access control (MAC) address of the AP 102. The AP 102 periodically broadcasts beacon frames ("beacons") including the BSSID so that any STA 104 within the wireless range of the AP 102 can "associate" or re-associate with the AP 102 to establish a corresponding communication link 108 (also hereinafter referred to as a "Wi-Fi link") with the AP 102 or maintain the communication link 108 with the AP 102. For example, the beacon may include an identification of the primary channel used by the corresponding AP 102 and a timing synchronization function for establishing or maintaining timing synchronization with the AP 102. The AP 102 can provide access to an external network to each STA 104 in the WLAN via the corresponding communication link 108.

[0056] The AP 102 and the STA 104 can operate and communicate (via the corresponding communication link 108) according to the IEEE 802.11 family of wireless communication protocol standards (such as the standards defined by the IEEE 802.11-2016 specification or its amendments, including but not limited to 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be). These standards define the WLAN radio and baseband protocols for the PHY and media access control (MAC) layers. The AP 102 and the STA 104 transmit and receive wireless communications (also hereinafter referred to as "Wi-Fi communications") with each other in the form of physical layer convergence protocol (PLCP) protocol data units (PPDUs). The AP 102 and the STA 104 in the WLAN 100 can transmit PPDUs in an unlicensed spectrum, which can be a part of the spectrum including the bands traditionally used by Wi-Fi technology (such as the 2.4 GHz band, the 5 GHz band, the 60 GHz band, the 3.6 GHz band, and the 700 MHz band). Some implementations of the AP 102 and the STA 104 described herein can also communicate in other bands (such as the 6 GHz band) that support both licensed and unlicensed communications. The AP 102 and the STA 104 can also be configured to communicate on other bands (such as shared licensed bands) where multiple operators may have licenses to operate in one or more identical or overlapping bands.

[0057] Figure 2AAn example protocol data unit (PDU) 200 that can be used for wireless communication between an AP 102 and one or more STAs 104 is shown. For example, PDU 200 can be configured as a PPDU. As shown, PDU 200 includes a PHY preamble 202 and a PHY payload 204. For example, preamble 202 may include a legacy portion that itself includes a legacy short training field (L-STF) 206 that can consist of two BPSK symbols, a legacy long training field (L-LTF) 208 that can consist of two BPSK symbols, and a legacy signal field (L-SIG) 210 that can consist of two BPSK symbols. The legacy portion of preamble 202 can be configured according to the IEEE 802.11a wireless communication protocol standard. Preamble 202 may also include a non-legacy portion that includes one or more non-legacy fields 212 that follow an IEEE wireless communication protocol such as IEEE 802.11ac, 802.11ax, 802.11be, or a future wireless communication protocol.

[0058] L-STF 206 generally enables a receiving device to perform automatic gain control (AGC) and coarse timing as well as frequency estimation. L-LTF 208 generally enables a receiving device to perform fine timing and frequency estimation and also to perform an initial estimation of the wireless channel. L-SIG 210 generally enables a receiving device to determine the duration of the PDU and use the determined duration to avoid transmitting over the PDU. For example, L-STF 206, L-LTF 208, and L-SIG 210 can be modulated according to a binary phase shift keying (BPSK) modulation scheme. Payload 204 can be modulated according to a BPSK modulation scheme, an orthogonal BPSK (Q-BPSK) modulation scheme, a quadrature amplitude modulation (QAM) modulation scheme, or another suitable modulation scheme. Payload 204 can include a PSDU that contains a data field (DATA) 214 that in turn can carry higher layer data in the form of, for example, a media access control (MAC) protocol data unit (MPDU) or an aggregated MPDU (A-MPDU).

[0059] Figure 2B is shown Figure 2AAn example L-SIG 210 in the PDU 200. The L-SIG 210 includes a data rate field 222, reserved bits 224, a length field 226, parity bits 228, and a tail field 230. The data rate field 222 indicates the data rate (note that the data rate indicated in the data rate field 212 may not be the actual data rate of the data carried in the payload 204). The length field 226 indicates the packet length, for example, in symbols or bytes. The parity bits 228 can be used to detect bit errors. The tail field 230 includes tail bits that can be used by the receiving device to terminate the operation of a decoder (e.g., a Viterbi decoder). The receiving device can utilize the data rate and length indicated in the data rate field 222 and the length field 226 to determine the packet duration, for example, in microseconds (μs) or other time units.

[0060] Figure 3 An example PPDU 300 that can be used for communication between the AP 102 and one or more STAs 104 is shown. As described above, each PPDU 300 includes a PHY preamble 302 and a PSDU 304. Each PSDU 304 can represent (or “carry”) one or more MAC protocol data units (MPDUs) 316. For example, each PSDU 304 can carry an aggregated MPDU (A-MPDU) 306, which includes an aggregation of multiple A-MPDU subframes 308. Each A-MPDU subframe 306 can include an MPDU frame 310, which includes a MAC delimiter 312 and a MAC header 314 before the accompanying MPDU 316 (which includes the data portion (“payload” or “frame body”) of the MPDU frame 310). Each MPDU frame 310 can also include a frame check sequence (FCS) field 318 for error detection (e.g., the FCS field can include a cyclic redundancy check (CRC)) and padding bits 320. The MPDU 316 can carry one or more MAC service data units (MSDUs) 330. For example, the MPDU 316 can carry an aggregated MSDU (A-MSDU) 322, which includes an aggregation of multiple A-MSDU subframes 324. Each A-MSDU subframe 324 contains a corresponding MSDU 330, which is preceded by a subframe header 328 and, in some cases, followed by padding bits 332.

[0061] Returning to reference MPDU frame 310, the MAC delimiter 312 can be used as a marker for the start of the associated MPDU 316 and indicates the length of the associated MPDU 316. The MAC header 314 can include multiple fields that contain information defining or indicating the characteristics or attributes of the data encapsulated within the frame body 316. The MAC header 314 includes a duration field that indicates the duration extending from at least the end of the PPDU to the end of the acknowledgment (ACK) or block acknowledgment (BA) of the PPDU to be transmitted by the receiving wireless communication device. The use of the duration field is for reserving the wireless medium for the indicated duration and enabling the receiving device to establish its network allocation vector (NAV). The MAC header 314 also includes one or more fields indicating the addresses of the data encapsulated within the frame body 316. For example, the MAC header 314 can include a combination of a source address, a transmitter address, a receiver address, or a destination address. The MAC header 314 can further include a frame control field containing control information. The frame control field can specify the frame type, such as a data frame, a control frame, or a management frame.

[0062] Figure 4 A block diagram of an example wireless communication device 400 is shown. In some implementations, the wireless communication device 400 can be an example of a device for a STA (such as one of the STAs 104 described with reference to Figure 1 ). In some implementations, the wireless communication device 400 can be an example of a device for an AP (such as the AP 102 described with reference to Figure 1 ). The wireless communication device 400 is capable of transmitting (or outputting for transmission) and receiving wireless communications (e.g., in the form of wireless packets). For example, the wireless communication device can be configured to transmit and receive physical layer convergence protocol (PLCP) protocol data units (PPDUs) and media access control (MAC) protocol data units (MPDUs) in the form of packets that comply with the IEEE 802.11 wireless communication protocol standard (such as the standard defined by the IEEE 802.11-2016 specification or its amendments, including but not limited to 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be).

[0063] The wireless communication device 400 can be or can include a chip, a system-on-chip (SoC), a chipset, a package, or a device that includes one or more modems 402 (e.g., a Wi-Fi (compliant with IEEE 802.11) modem). In some implementations, one or more modems 402 (collectively referred to as "modems 402") additionally include a WWAN modem (e.g., a 3GPP 4G LTE or 5G compliant modem). In some implementations, the wireless communication device 400 also includes one or more radios 404 (collectively referred to as "radios 404"). In some implementations, the wireless communication device 406 further includes one or more processors, processing blocks, or processing elements 406 (collectively referred to as "processors 406") and one or more memory blocks or elements 408 (collectively referred to as "memory 408").

[0064] The modem 402 can include intelligent hardware blocks or devices, such as, for example, an application-specific integrated circuit (ASIC), etc. The modem 402 is generally configured to implement the PHY layer. For example, the modem 402 is configured to modulate packets and output the modulated packets to the radio 404 for transmission over the wireless medium. Similarly, the modem 402 is configured to obtain the modulated packets received by the radio 404 and demodulate these packets to provide demodulated packets. In addition to the modulator and demodulator, the modem 402 may further include digital signal processing (DSP) circuitry, automatic gain control (AGC), an encoder, a decoder, a multiplexer, and a demultiplexer. For example, when in the transmission mode, the data obtained from the processor 406 is provided to an encoder, which encodes the data to provide encoded bits. The encoded bits are then mapped to points in the modulation constellation (using the selected MCS) to provide modulated symbols. Subsequently, the modulated symbols can be mapped to several (N SS number) spatial streams or several (N STS number) space-time streams. Subsequently, the modulated symbols in the corresponding spatial or space-time streams can be multiplexed, transformed via an inverse fast Fourier transform (IFFT) block, and then provided to the DSP circuitry for Tx windowing and filtering. The digital signal can then be provided to a digital-to-analog converter (DAC). The resulting analog signal can then be provided to an upconverter and ultimately to the radio 404. In implementations involving beamforming, the modulated symbols in the corresponding spatial streams are precoded via a steering matrix before being provided to the IFFT block.

[0065] When in the receive mode, the digital signal received from radio 404 is provided to the DSP circuitry, which is configured to acquire the received signal, e.g., by detecting the presence of the signal and estimating the initial timing and frequency offset. The DSP circuitry is further configured to digitally condition the digital signal, e.g., using channel (narrowband) filtering, analog impairment conditioning (such as correcting I / Q imbalance), and applying digital gain to ultimately obtain a narrowband signal. Subsequently, the output of the DSP circuitry can be fed to the AGC, which is configured to use the information extracted from the digital signal (e.g., in one or more received training fields) to determine the appropriate gain. The output of the DSP circuitry is also coupled to a demodulator, which is configured to extract the modulated symbols from the signal and, e.g., compute the log-likelihood ratio (LLR) for each bit position of each subcarrier in each spatial stream. The demodulator is coupled to a decoder, which can be configured to process the LLRs to provide the decoded bits. Subsequently, the decoded bits from all spatial streams are fed to a demultiplexer for demultiplexing. The demultiplexed bits can then be descrambled and provided to the MAC layer (processor 406) for processing, evaluation, or interpretation.

[0066] Radio 404 generally includes at least one radio frequency (RF) transmitter (or “transmitter chain”) and at least one RF receiver (or “receiver chain”), which may be combined into one or more transceivers. For example, the RF transmitter and receiver may include various DSP circuitry, respectively including at least one power amplifier (PA) and at least one low noise amplifier (LNA). The RF transmitter and receiver may in turn be coupled to one or more antennas. For example, in some implementations, wireless communication device 400 may include or be coupled to multiple transmit antennas (each having a corresponding transmit chain) and multiple receive antennas (each having a corresponding receive chain). The symbols output from the modem 402 are provided to radio 404, which then transmits these symbols via the coupled antennas. Similarly, the symbols received via the antennas are acquired by radio 404, which then provides these symbols to the modem 402.

[0067] Processor 406 may include intelligent hardware blocks or devices designed to perform the functions described herein, such as, by way of example, processing cores, processing blocks, central processing units (CPUs), microprocessors, microcontrollers, digital signal processors (DSPs), application specific integrated circuits (ASICs), programmable logic devices (PLDs) (such as field programmable gate arrays (FPGAs)), discrete gate or transistor logic, discrete hardware components, or any combination thereof. Processor 406 processes information received via radio 404 and modem 402 and processes information to be output via modem 402 and radio 404 for transmission over a wireless medium. For example, processor 406 may implement a control plane and MAC layer configured to perform various operations related to the generation and transmission of MPDUs, frames, or packets. The MAC layer is configured to perform or facilitate the decoding and encoding of frames, spatial multiplexing, space-time block coding (STBC), beamforming, and OFDMA resource allocation, and other operations or techniques. In some implementations, processor 406 may generally control modem 402 to cause the modem to perform the various operations described above.

[0068] Memory 408 may include tangible storage media such as random access memory (RAM) or read only memory (ROM) or a combination thereof. Memory 408 may also store non-transitory processor or computer executable software (SW) code containing instructions that, when executed by processor 406, cause the processor to perform the various operations for wireless communication described herein, including the generation, transmission, reception, and interpretation of MPDUs, frames, or packets. For example, the various functions of the components disclosed herein or the various blocks or steps of the methods, operations, processes, or algorithms disclosed herein may be implemented as one or more modules of one or more computer programs.

[0069] Figure 5A A block diagram of an example AP 502 is shown. For example, AP 502 may be an example implementation of AP 102 described with reference to Figure 1 AP 502 includes a wireless communication device (WCD) 510 (although AP 502 itself may generally also be referred to as a wireless communication device as used herein). For example, wireless communication device 510 may be the one described with reference to Figure 4Example implementation of the wireless communication device 400 described. The AP 502 also includes a plurality of antennas 520 coupled to the wireless communication device 510 to transmit and receive wireless communications. In some implementations, the AP 502 additionally includes an application processor 530 coupled to the wireless communication device 510, and a memory 540 coupled to the application processor 530. The AP 502 further includes at least one external network interface 550 that enables the AP 502 to communicate with a core network or a backhaul network to obtain access to an external network including the Internet. For example, the external network interface 550 may include one or both of a wired (e.g., Ethernet) network interface and a wireless network interface (such as a WWAN interface). Components among the foregoing components can communicate directly or indirectly with other components among these components over at least one bus. The AP 502 further includes a housing that encloses the wireless communication device 510, the application processor 530, the memory 540 and encloses at least portions of the antennas 520 and the external network interface 550.

[0070] Figure 5B A block diagram of an example STA 504 is shown. For example, the STA 504 may be an example implementation of the STA 104 described with reference to Figure 1 The example implementation of the STA 104 described. The STA 504 includes a wireless communication device 515 (although the STA 504 itself may generally also be referred to as a wireless communication device, as used herein). For example, the wireless communication device 515 may be an example implementation of the wireless communication device 400 described with reference to Figure 4 The example implementation of the wireless communication device 400 described. The STA 504 also includes one or more antennas 525 coupled to the wireless communication device 515 to transmit and receive wireless communications. The STA 504 additionally includes an application processor 535 coupled to the wireless communication device 515, and a memory 545 coupled to the application processor 535. In some implementations, the STA 504 further includes a user interface (UI) 555 (such as a touch screen or a keyboard) and a display 565, which may be integrated with the UI 555 to form a touch screen display. In some implementations, the STA 504 may further include one or more sensors 575 (by way of example, such as one or more inertial sensors, accelerometers, temperature sensors, pressure sensors, or altitude sensors). Components among the foregoing components can communicate directly or indirectly with other components among these components over at least one bus. The STA 504 further includes a housing that encloses the wireless communication device 515, the application processor 535, the memory 545 and encloses at least respective portions of the antennas 525, the UI 555 and the display 565.

[0071] Figure 6FIG. 600 shows an example PPDU that can be used for wireless communication between an AP and several STAs according to some implementations. The PPDU 600 can be used for transmissions to a single user, MU-OFDMA, or non-OFDMA MU-MIMO transmissions. The PPDU 600 includes a PHY preamble, which includes a first part 602 and a second part 604. The PPDU 600 can further include a PHY payload 606 (e.g., in the form of a PSDU including a data field 626) after the preamble.

[0072] The first part 602 includes an L-STF 608, an L-LTF 610, and an L-SIG 612. The second part 604 of the preamble and the data field 626 can be respectively formatted as a non-legacy or very high throughput (EHT) WLAN preamble and frame according to the IEEE 802.11be amendment to the IEEE 802.11 wireless communication protocol standard, or can be respectively formatted as a preamble and frame of any later (post-HE) version that follows a new wireless communication protocol (following a future IEEE 802.11 wireless communication protocol standard or other standard). In some implementations, the PPDU 600 can be logically divided into an EHT pre-modulation part 650 (including PPDU fields 608-618) and an EHT modulation part 660 (including PPDU fields 622-626).

[0073] The second part 604 of the preamble includes a repeated legacy signal field (RL-SIG) 614 and a plurality of wireless communication protocol version-related signal fields after the RL-SIG 614. For example, in some aspects, the second part can include a universal signal field (U-SIG) 616 and an EHT signal field (EHT-SIG) 618. The second part 604 further includes an EHT short training field (EHT-STF) 622 and several EHT long training fields (EHT-LTF) 624.

[0074] In some implementations, the U-SIG 616 may include one or more version-agnostic fields 632 and one or more version-dependent fields 634. The information in the version-agnostic fields 632 may include, for example, a version identifier (starting from and including IEEE 802.11be amendments) and channel occupancy and coexistence information (such as PPDU bandwidth). The version-dependent fields 634 may include format information fields for interpreting the formats of other fields in the U-SIG 616 and the EHT-SIG 618. In some implementations, the version-dependent fields 634 may at least include a PPDU type and compression mode field 636. The PPDU type and compression mode field 636 may indicate the general PPDU format and compression mode for the PPDU 600. Example suitable PPDU formats include a trigger-based (TB) PPDU format, a MU PPDU format for DL OFDMA transmissions, a MU PPDU format for transmissions to a single user or for the transmission of null data packets (NDPs), and a MU PPDU format for DL non-OFDMA MU-MIMO transmissions.

[0075] In some implementations, the EHT-SIG 618 may include a common field 642 and user-specific fields 644. The common field 642 includes one or more bits or fields 646 that overflow from the U-SIG 616 and RU allocation information 648 for the intended recipient(s) of the PPDU 600. The user-specific fields 644 may include one or more user fields carrying per-user information for one or more intended recipients of the PPDU 600. In some implementations, the RU allocation information 648 may be replaced by a non-OFDMA user count field in a MU PPDU for DL non-OFDMA transmissions or transmissions to a single user. Further still, in some implementations, the EHT-SIG 618 may not be present in the TB PPDU format.

[0076] As previously described, in IEEE 802.11be and future generations, new fields can be used to carry signaling information. For example, the new fields and signaling information can be included in U-SIG 616. Additionally, the new fields and signaling information can be included in EHT-SIG 618 (or can overflow from U-SIG 616 into EHT-SIG 618). In some implementations, U-SIG 616 can include signaling regarding the type or format of additional signal fields (such as EHT-SIG 618) that follow U-SIG 616. The AP can use EHT-SIG 618 to identify that the AP has scheduled UL or DL resources and notify one or more STAs 104. EHT-SIG 618 can be decoded by each compatible STA 104 served by AP 102. EHT-SIG 618 can generally be used by the receiving device to interpret the bits in data field 626. In the context of DL MU-OFDMA, such information enables the corresponding STA 104 to identify and decode the corresponding RU in associated data field 626.

[0077] Figure 7A An example frame structure for a TB PPDU 700 according to some implementations is shown. In some implementations, the TB PPDU 700 can be Figure 6 an example of the PPDU 600. For simplicity, Figure 7A only the EHT preamble portion of the TB PPDU 700 (corresponding to portion 650 of the PPDU 600) is shown. The TB PPDU 700 includes an L-STF 701, an L-LTF 702, an L-SIG 703, an RL-SIG 704, and a U-SIG 705, which can correspond to the L-STF 608, L-LTF 610, L-SIG 612, RL-SIG 614, and U-SIG 616 of the PPDU 600, respectively. In the example TB PPDU format, the TB PPDU 700 may not include an EHT-SIG. Referring, for example, to Figure 6 , the TB PPDU 700 may not include any U-SIG overflow 646, RU allocation information 648, or other user-specific information (such as that provided in user-specific field 644).

[0078] Figure 7B An example frame structure for a MU PPDU 720 according to some implementations is shown. In some implementations, the MU PPDU 720 can be Figure 6 an example of the PPDU 600. For simplicity, Figure 7BOnly the EHT pre - modulation part of the MU PPDU 720 (corresponding to part 650 of the PPDU 600) is shown. The MU PPDU 720 includes L - STF 721, L - LTF 722, L - SIG 723, RL - SIG 724, U - SIG 725, and EHT - SIG 726, which can respectively correspond to the L - STF 608, L - LTF 610, L - SIG 612, RL - SIG 614, U - SIG 616, and EHT - SIG 616 of the PPDU 600. In the example MU PPDU format, the EHT - SIG 726 can include a common field 727 and a user - specific field 728. For example, referring to Figure 6 , the common field 642 can further include a U - SIG overflow 646 and RU allocation information 648. The user - specific field 728 can include per - user information for one or more intended receivers of the MU PPDU 720.

[0079] In some implementations, the MU PPDU format can be used for transmission to a single user or non - OFDMA MU - MIMO transmission. More specifically, transmission to a single user (when the PPDU type and compression mode fields of the U - SIG are set to 1) and non - OFDMA MU - MIMO transmission (when the PPDU type and compression mode fields of the U - SIG are set to 2) can be achieved by compressing (reducing or eliminating) one or more fields or sub - fields of the MU PPDU 720. For example, the RU allocation information can be omitted, and a non - OFDMA user number field can be present in the EHT - SIG 726. The user - specific field 728 includes several user fields (not shown for simplicity). The number of user fields can depend on the total number of users associated with the PPDU 720. When configured for transmission to a single user, the single - user field can be formatted according to a non - MU - MIMO allocation format. The user field for non - MU - MIMO allocation can include one or more sub - fields (such as NSS and beamforming sub - fields) that are not present in the user fields for MU - MIMO allocation. When the PPDU is configured for non - OFDMA MU - MIMO communication or the RU is configured for MU - MIMO transmission, the multiple user fields can be formatted according to a MU - MIMO allocation format. The user field for MU - MIMO allocation can include a spatial configuration sub - field (indicating the number of spatial streams for the STA) that is not present in the user fields for non - MU - MIMO allocation.

[0080] Because the new WLAN communication protocol implements enhanced features, a new preamble design is needed to support signaling related to the new features and packet formats. Generally speaking, each implementation involves signaling included in the PHY preamble that supports the new wireless communication protocol, and more specifically, involves a preamble design that supports extended range communication or data throughput gain achievable with the IEEE 802.11be amendment to the IEEE 802.11 standard and future generations. In some implementations, compared to the preamble design that follows the existing versions of the IEEE 802.11 standard, the preamble design of the present disclosure can be implemented using different lengths, modulation schemes, or frame structures. For example, the information carried in one or more fields of the PHY preamble can be repeated (in time) to provide increased signaling gain at the receiving device. In some aspects, such information can be carried in the U-SIG of the PHY preamble. In some other aspects, such information can be carried in the non-legacy signal field of the PHY preamble.

[0081] Specific implementations that can realize the subject matter described in the present disclosure can achieve one or more of the following potential advantages. The preamble design of this implementation can allow for more reliable packet detection, more accurate channel estimation, and more robust decoding of signaling information in non-legacy packets. Signaling refers to a control field or information that can be used by a wireless communication device to interpret another field or part of a packet. Such information can be encoded in the PHY preamble of the packet. However, decoding and processing signaling information consume time and resources, which may delay the processing of other information carried in the packet. Through adjusting the length, modulation scheme, or frame structure associated with the physical layer preamble, aspects of the present disclosure can allow for earlier detection of various contents (or the absence of such contents) in the physical layer preamble and provide more time for the receiving device to process such contents.

[0082] Figure 8 An example frame structure of a non-legacy (e.g., EHT) PPDU 800 allocated on multiple sub-channels of a wireless channel is shown. In some implementations, the EHT PPDU 800 can be Figure 6 an example of the PPDU 600. In Figure 8 the example, the EHT PPDU 800 is shown as including L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and EHT-SIG signaled or transmitted on multiple 20MHz sub-channels (or frequency segments) of a 320MHz wireless channel. In some other implementations, the wireless channel can cover any frequency range, including but not limited to 160MHz spectrum, 240MHz spectrum, 480MHz spectrum, or 640MHz spectrum. As Figure 8As shown, the 320 MHz spectrum includes 16 20 MHz sub-channels indexed from lowest to highest (such as from 1 to 16).

[0083] In Figure 8 the example of, the L-STF, L-LTF, L-SIG, and RL-SIG are replicated or repeated in each 20 MHz sub-channel across the entire 320 MHz spectrum. In some implementations, the U-SIG can be replicated or repeated in each 20 MHz sub-channel of a respective bin of four consecutive 20 MHz sub-channels, where each bin of four consecutive 20 MHz sub-channels corresponds to an 80 MHz sub-block within the PPDU bandwidth. For example, the first four sub-channels (1 to 4) can share the same U-SIG field and value. The next four sub-channels (5 to 8) can share the same U-SIG field and value, which can be different from the U-SIG field or value of the first four sub-channels. The next four sub-channels (9 to 12) can share the same U-SIG field and value, which in turn can be different from the U-SIG field or value in any of the first eight sub-channels. The next four sub-channels (13 to 16) can share the same U-SIG field and value, which in turn can be different from the U-SIG field or value in any of the first twelve sub-channels. In other words, the U-SIG field or value can change every 80 MHz. This can allow for greater parallelization of U-SIG information across various sub-channels.

[0084] In some implementations, the EHT-SIG can be signaled on a number of content channels. Each content channel can be defined by a particular bin of sub-channels. For example, a first content channel can carry signaling information for all odd-numbered sub-channels (such as the 1st, 3rd, 5th, 7th, 9th, 11th, 13th, and 15th 20 MHz sub-channels), while a second content channel can carry signaling information for all even-numbered sub-channels (such as the 2nd, 4th, 6th, 8th, 10th, 12th, 14th, and 16th 20 MHz sub-channels). In some implementations, the EHT-SIG can be replicated or repeated per content channel. For example, the (odd-numbered) sub-channels associated with the first content channel can share the same EHT-SIG field and value. The (even-numbered) sub-channels associated with the second content channel can share the same EHT-SIG field and value, which can be different from the EHT-SIG field or value of the first content channel.

[0085] Similar to U-SIG, the signaling content of the same content channel of EHT-SIG in different 80 MHz sub-blocks may be different. The signaling content of the two content channels of EHT-SIG within each 80 MHz sub-block is mainly used by the receiving device that processes the non-legacy preamble in that specific 80 MHz sub-block. Signaling information specific to other receiving devices that do not process the non-legacy preamble in an 80 MHz sub-block may not be carried in the EHT-SIG in that specific 80 MHz sub-block.

[0086] In some aspects, the L-STF can be used for packet detection. In other words, the receiving device can detect the presence of a PPDU on the wireless channel in response to detecting the L-STF. Additionally, a short training field (such as the L-STF) can be used by the receiving device to perform automatic gain control (AGC) in the receiver. Via the AGC, the receiver can be configured to receive the subsequent portions of the PPDU. To ensure that most of the L-STF can be used for AGC, it is desirable for the receiving device to detect the L-STF early in the transmission of the PPDU. Aspects of the present disclosure recognize that the receiving device can achieve more reliable packet detection (or detection of the L-STF) by opening its detection bandwidth to more than 20 MHz.

[0087] Referring to, for example Figure 8 , the L-STF is replicated or repeated on each of the 20 MHz sub-channels spanning the bandwidth of the EHT PPDU 800. Specifically, the EHT PPDU 800 includes 16 repetitions (in frequency) of the L-STF spanning 16 20 MHz sub-channels respectively. In some implementations, the receiving device can listen for the L-STF on multiple 20 MHz sub-channels. In this way, the receiving device can utilize the repetition of the L-STF in the EHT PPDU to achieve greater gain in L-STF detection. In other words, compared to what would likely be achieved by listening for the L-STF on any single 20 MHz sub-channel, the receiving device can detect the EHT PPDU earlier or more reliably by listening for the L-STF on multiple 20 MHz sub-channels.

[0088] In contrast to the L-STF, the U-SIG and EHT-SIG may not be replicated or repeated on each 20 MHz sub-channel of the EHT PPDU. Referring to, for example Figure 8, the information in the U-SIG can change every 80 MHz, while the information in the EHT-SIG can be different for each content channel and can change every 80 MHz. Due to the content changes in the U-SIG and EHT-SIG, the achievable gain resulting from repetition in the frequency domain may be significantly reduced. In some implementations, to compensate for the limited number of repetitions in the frequency domain, the U-SIG or EHT-SIG can be repeated in the time domain. For example, the information in the U-SIG can be carried on two unique U-SIG symbols in the time domain. Via repetition, the same information can be replicated or repeated on two additional U-SIG symbols. Thus, the U-SIG field can have an overall symbol duration equal to four U-SIG symbols (sequentially referred to as "U-SIG-1", "U-SIG-2", "U-SIG-3", and "U-SIG-4" in time).

[0089] In some implementations, U-SIG-2 can be a copy or repetition of U-SIG-1, and U-SIG-4 can be a copy or repetition of U-SIG-3. In other words, U-SIG-1 and U-SIG-2 can carry the same decoded bits, and U-SIG-3 and U-SIG-4 can carry the same decoded bits. To indicate the presence of repetition to the receiving device, the second U-SIG symbol (U-SIG-2) can be modulated according to a modulation scheme different from that of the first U-SIG symbol (U-SIG-1). For example, BPSK can be used to modulate U-SIG-1. In some implementations, quadrature BPSK (QBPSK) can be used to modulate U-SIG-2. In response to detecting a change in the modulation scheme from U-SIG-1 to U-SIG-2 (or detecting the modulation scheme associated with U-SIG-2), the receiving device can continue to listen for two additional U-SIG symbols (U-SIG-3 and U-SIG-4).

[0090] In some aspects, the ordering of the decoded bits carried on U-SIG-1 can be different from the ordering of the decoded bits carried on U-SIG-2. In some other aspects, the ordering of the decoded bits carried on U-SIG-3 can be different from the ordering of the decoded bits carried on U-SIG-4. For example, a known modulation scheme (such as BPSK or QBPSK) can be used to map the sequence of decoded bits associated with each U-SIG symbol to a corresponding modulated symbol sequence. Each modulated symbol can be modulated on different tones or subcarriers within a given 20 MHz subchannel. In some instances, interference in the wireless channel (such as deep fading) can prevent the transmission of the modulated symbols on one or more of the subcarriers. Thus, by varying the order in which the modulated symbols are modulated on different subcarriers (between two consecutive or replicated U-SIG symbols), aspects of the present disclosure can increase transmit diversity and further improve the signaling gain that can be achieved via the repetition of U-SIG symbols. In some implementations, the decoded bits carried on U-SIG-1 and U-SIG-3 can be interleaved, while the decoded bits carried on U-SIG-2 and U-SIG-4 can be non-interleaved.

[0091] The information in the EHT-SIG can be carried on one or more unique EHT-SIG symbols (without repetition in the time domain) in a PPDU configured for transmission to a single user, DL OFDMA, or non-OFDMA MU-MIMO. Via repetition, the same information can be replicated or repeated on one or more additional EHT-SIG symbols. Thus, the EHT-SIG field can have an overall symbol duration equal to twice the number of non-repeated EHT-SIG symbols. In some implementations, each unique EHT-SIG symbol can be followed by its repetition. For example, if the EHT-SIG has an overall symbol duration equal to four EHT-SIG symbols, the first EHT-SIG symbol (EHT-SIG-1) can be a unique EHT-SIG symbol, the second EHT-SIG symbol (EHT-SIG-2) can be a repetition of EHT-SIG-1, the third EHT-SIG symbol (EHT-SIG-3) can be another unique EHT-SIG symbol, and the fourth EHT-SIG symbol (EHT-SIG-4) can be a repetition of EHT-SIG-3. Thus, EHT-SIG-2 and EHT-SIG-4 can carry the same decoded bits as EHT-SIG-1 and EHT-SIG-3, respectively. In some other implementations, all unique EHT-SIG symbols can be before any repetition of the EHT-SIG symbols. For example, if the EHT-SIG has an overall symbol duration equal to four EHT-SIG symbols, the first and second EHT-SIG symbols (EHT-SIG-1 and EHT-SIG-2) can be unique EHT-SIG symbols, while the third and fourth EHT-SIG symbols (EHT-SIG-3 and EHT-SIG-4) can be repetitions of the first and second EHT-SIG symbols, respectively. Thus, EHT-SIG-3 and EHT-SIG4 can carry the same decoded bits as EHT-SIG-1 and EHT-SIG-2, respectively.

[0092] The receiving device can detect the presence of repetition in the EHT-SIG based on the modulation scheme associated with U-SIG-2 (or the change in the modulation scheme between U-SIG-1 and U-SIG-2). In some aspects, the ordering of the decoded bits carried on each unique EHT-SIG symbol can be different from the ordering of the decoded bits carried on the repetition of that EHT-SIG symbol, e.g., to increase transmit diversity and further improve the signaling gain achievable via repetition of the EHT-SIG symbols. In some implementations, the decoded bits carried on a unique EHT-SIG symbol can be interleaved, while the decoded bits carried on the repetition of the EHT-SIG symbol can not be interleaved.

[0093] Aspects of the present disclosure recognize that in some PPDU formats (such as Figure 7A the TB PPDU 700), there may be no EHT-SIG. The presence (or absence) of the EHT-SIG may affect the timing of one or more subsequent fields of the EHT PPDU. Referring to, for example, Figure 6 , a non-legacy STF (such as the EHT-STF) can follow the EHT-SIG immediately in SU and MU PPDU formats (such as Figure 7B shown), and can follow the U-SIG immediately in the TB PPDU format. Similar to the L-STF, a receiving device can use the EHT-STF to perform AGC in the receiver. More specifically, the receiving device can use the EHT-STF to reconfigure its receiver to receive the EHT modulation portion of the PPDU. Therefore, it is desirable for the receiving device to detect the EHT-STF early so that most of the EHT-STF can be used for AGC. Specifically, it may be desirable for the receiving device to know whether the EHT-STF follows the U-SIG or the EHT-SIG immediately.

[0094] As described above, the presence of the EHT-SIG depends on the PPDU format implemented for a particular transmission. The PPDU format can be indicated in a particular field or subfield of the U-SIG (such as Figure 6 the PPDU type and compression mode field 636). However, decoding and processing the information in the U-SIG consumes time and resources, which may delay the detection or processing of the EHT-STF. In some implementations, the presence (or absence) of the EHT-SIG in the EHT PPDU preamble can be indicated by changing the modulation scheme associated with one or more U-SIG symbols. For example, the third symbol of the U-SIG (U-SIG-3) can be modulated according to QBPSK or BPSK to indicate the presence or absence of the EHT-SIG in the preamble, respectively. In response to detecting that U-SIG-3 is modulated using QBPSK, the receiving device can expect the EHT-STF to occur at least two symbols after the U-SIG (depending on the duration of the EHT-SIG). In response to detecting that U-SIG-3 is modulated using BPSK, the receiving device can expect the EHT-STF to occur immediately after the U-SIG.

[0095] Aspects of the present disclosure further recognize that the presence of the EHT-SIG can provide a buffer (or additional time) for the receiving device to decode and process the information in the U-SIG, and thus determine the start of the EHT-STF. In other words, when the EHT-SIG is present in the preamble, the receiving device can determine the presence of the EHT-SIG (based on the PPDU format indicated in the U-SIG) before it starts receiving the EHT-STF. However, when the EHT-SIG is not present in the preamble, the receiving device may not be able to determine the absence of the EHT-SIG (based on the PPDU format indicated in the U-SIG) before it starts receiving the EHT-STF. In some implementations, in the absence of the EHT-SIG (such as in a TB PPDU), one or more padding symbols can be inserted between the U-SIG and the EHT-STF to provide a buffer (similar to the EHT-SIG) for the receiving device to decode and process the information in the U-SIG, and thus determine the start of the EHT-STF.

[0096] Figure 9A An example PHY preamble 900 for a non-legacy PPDU according to some implementations is shown. In some implementations, the PHY preamble 900 can be an example of a PHY preamble that includes Figure 6 portions 602 and 604. The PHY preamble 900 includes an L-STF 901, an L-LTF 902, an L-SIG 903, an RL-SIG 904, a U-SIG 905, an EHT-SIG 906, an EHT-STF 907, and an EHT-LTF 908. In Figure 9A the example, the U-SIG 905 includes four U-SIG symbols (U-SIG-1, U-SIG-2, U-SIG-3, and U-SIG-4), and the EHT-SIG 906 includes two EHT-SIG symbols (EHT-SIG-1 and EHT-SIG-2). More specifically, U-SIG-2 can be a replica of U-SIG-1, U-SIG-4 can be a replica of U-SIG-3, and EHT-SIG-2 can be a replica of EHT-SIG-1. In some implementations, QBPSK can be used to modulate U-SIG-2 to indicate the repetition of the PHY preamble 900 in the U-SIG 905 and the EHT-SIG 906. In some other implementations, further, QBPSK can be used to modulate U-SIG-3 to indicate the presence of the EHT-SIG 906 (at the PHY level).

[0097] The receiving device can detect the PHY preamble 900 based on the L-STF 901. In some implementations, the receiving device can detect the L-STF 901 on multiple 20 MHz sub-channels. The receiving device can further detect the presence of the U-SIG 905 in the PHY preamble 900 based on a combination of the L-SIG 903 and the RL-SIG 904. For example, the receiving device can determine that the PPDU follows the IEEE 802.11ax amendment or later generations of the IEEE 802.11 standard based on the presence of the RL-SIG 904. The receiving device can further determine that the PPDU further follows the IEEE 802.11be amendment to the IEEE 802.11 standard (where L_LEN % 3 == 0) based on the length field (L_LEN) of the L-SIG 903

[0098] The receiving device can further determine that the U-SIG-2 is modulated using QBPSK. Based on this determination, the receiving device can determine that the U-SIG 905 includes two additional U-SIG symbols (U-SIG-3 and U-SIG-4). In some implementations, the receiving device can further determine that the EHT-SIG 906 includes one or more additional EHT-SIG symbols (EHT-SIG-2) based on the determination that the U-SIG-2 is modulated using QBPSK. The receiving device can further determine that the U-SIG-3 is further modulated using QBPSK. In response to this determination, the receiving device can determine that one or more additional fields or sub-fields (such as the EHT-SIG 906) follow the U-SIG 905 before the EHT-STF 907. Thus, the receiving device can prepare to initiate or perform AGC starting from two symbol durations after the U-SIG 905

[0099] Figure 9B Another example PHY preamble 910 for a non-legacy PPDU is shown according to some implementations. In some implementations, the PHY preamble 910 can be an example of a PHY preamble that includes Figure 6 portions 602 and 604. The PHY preamble 910 includes an L-STF 911, an L-LTF 912, an L-SIG 913, an RL-SIG 914, a U-SIG 915, an EHT-STF 917, and an EHT-LTF 918. In Figure 9BIn the example of, U-SIG 915 includes four U-SIG symbols (U-SIG-1, U-SIG-2, U-SIG-3, and U-SIG-4). More specifically, U-SIG-2 can be a replica of U-SIG-1, and U-SIG-4 can be a replica of U-SIG-3. In some implementations, QBPSK can be used to modulate U-SIG-2 to indicate that the PHY preamble 910 includes repetitions in U-SIG 915. In some other implementations, BPSK can be used to modulate U-SIG-3 to indicate the absence of the EHT-SIG (at the PHY level).

[0100] The receiving device can detect the PHY preamble 910 based on the L-STF 911. In some implementations, the receiving device can detect the L-STF 911 on multiple 20 MHz sub-channels. The receiving device can further detect the presence of U-SIG 915 in the PHY preamble 910 based on a combination of the L-SIG 913 and the RL-SIG 914. For example, the receiving device can determine that the PPDU follows the 1EEE 802.11ax amendment or later generations of the IEEE802.11 standard based on the presence of the RL-SIG 914. The receiving device can further determine that the PPDU further follows the IEEE 802.11be amendment to the IEEE802.11 standard (where L_LEN % 3 == 0) based on the length field (L_LEN) of the L-SIG 913

[0101] The receiving device can further determine that U-SIG-2 is modulated using QBPSK. Based on this determination, the receiving device can determine that U-SIG 915 includes two additional U-SIG symbols (U-SIG-3 and U-SIG-4). The receiving device can further determine that U-SIG-3 is modulated using BPSK. In response to this determination, the receiving device can determine that the EHT-STF 917 follows immediately after U-SIG 915. Thus, the receiving device can be prepared to initiate or perform AGC immediately after U-SIG 915.

[0102] Figure 10A An example PHY preamble 1000 for a non-legacy PPDU according to some implementations is shown. In some implementations, the PHY preamble 1000 can be an example of a PHY preamble that includes Figure 6 parts 602 and 604 of. The PHY preamble 1000 includes L-STF 1001, L-LTF 1002, L-SIG 1003, RL-SIG 1004, U-SIG 1005, EHT-SIG 1006, EHT-STF 1007, and EHT-LTF 1008. InFigure 10A In the example of, U-SIG 1005 includes four U-SIG symbols (U-SIG-1, U-SIG-2, U-SIG-3, and U-SIG-4), and EHT-SIG 1006 includes two EHT-SIG symbols (EHT-SIG-1 and EHT-SIG-2). More specifically, U-SIG-2 can be a replica of U-SIG-1, U-SIG-4 can be a replica of U-SIG-3, and EHT-SIG-2 can be a replica of EHT-SIG-1. In some implementations, QBPSK can be used to modulate U-SIG-2 to indicate the repetition of PHY preamble 1000 in U-SIG 1005 and EHT-SIG 1006. However, different from the implementations described with reference to Figure 9A and Figure 9B QBPSK is not used to modulate U-SIG-3 to indicate the presence of EHT-SIG 1006.

[0103] The receiving device can detect PHY preamble 1000 based on L-STF 1001. In some implementations, the receiving device can detect L-STF 1001 on multiple 20 MHz subchannels. The receiving device can further detect the presence of U-SIG 1005 in PHY preamble 1000 based on the combination of L-SIG 1003 and RL-SIG 1004. For example, the receiving device can determine that the PPDU follows the 1EEE 802.11ax amendment or later generations of the IEEE 802.11 standard based on the presence of RL-SIG 1004. The receiving device can further determine that the PPDU further follows the IEEE 802.11be amendment to the IEEE 802.11 standard (where L_LEN % 3 == 0) based on the length field (L_LEN) of L-SIG 1003

[0104] The receiving device may further determine that U-SIG-2 is modulated using QBPSK. Based on this determination, the receiving device may determine that U-SIG 1005 includes two additional U-SIG symbols (U-SIG-3 and U-SIG-4). In some implementations, the receiving device may further determine that EHT-SIG 1006 includes one or more additional EHT-SIG symbols (EHT-SIG-2) based on the determination that U-SIG-2 is modulated using QBPSK. After decoding and processing U-SIG 1005, the receiving device may further determine that PHY preamble 1000 includes EHT-SIG 1006. For example, the receiving device may determine that PHY preamble 1000 is implemented according to the MU PPDU format (based on the PPDU type and compression mode fields in U-SIG 1005) and knows the length of the EHT-SIG field based on the number of EHT-SIG symbol field in U-SIG 1005. In some implementations, the receiving device may detect the PPDU format when receiving at least a portion of EHT-SIG 1006. Thus, the receiving device may be prepared to initiate or perform AGC immediately after EHT-SIG 1006.

[0105] Figure 10B Another example PHY preamble 1010 for a non-legacy PPDU according to some implementations is shown. In some implementations, PHY preamble 1010 may be an example of a PHY preamble that includes Figure 6 portions 602 and 604. PHY preamble 1010 includes L-STF 1011, L-LTF 1012, L-SIG 1013, RL-SIG 1014, U-SIG 1015, padding 1016, EHT-STF 1017, and EHT-LTF 1018. In Figure 10B the example, U-SIG 1015 includes four U-SIG symbols (U-SIG-1, U-SIG-2, U-SIG-3, and U-SIG-4). More specifically, U-SIG-2 may be a replica of U-SIG-1, and U-SIG-4 may be a replica of U-SIG-3. In some implementations, QBPSK may be used to modulate U-SIG-2 to indicate that PHY preamble 1010 includes the repetition in U-SIG 1015.

[0106] The receiving device can detect the PHY preamble 1010 based on the L-STF 1011. In some implementations, the receiving device can detect the L-STF 1011 on multiple 20 MHz sub-channels. The receiving device can further detect the presence of the U-SIG 1015 in the PHY preamble 1010 based on a combination of the L-SIG 1013 and the RL-SIG 1014. For example, the receiving device can determine that the PPDU follows the IEEE 802.11ax amendment or later generations of the IEEE 802.11 standard based on the presence of the RL-SIG 1014. The receiving device can further determine that the PPDU further follows the IEEE 802.11be amendment to the IEEE 802.11 standard (where L_LEN % 3 == 0) based on the length field (L_LEN) of the L-SIG 1013

[0107] The receiving device can further determine that the U-SIG-2 is modulated using QBPSK. Based on this determination, the receiving device can determine that the U-SIG 1015 includes two additional U-SIG symbols (U-SIG-3 and U-SIG-4). After decoding and processing the U-SIG 1015, the receiving device can further determine that the PHY preamble 1010 does not include an EHT-SIG. For example, the receiving device can determine that the PHY preamble 1010 is implemented according to the TB PPDU format (based on the PPDU type and compression mode fields in the U-SIG 1015). In some implementations, the receiving device can detect the PPDU format when receiving the padding symbol 1016. Thus, the receiving device can be prepared to initiate or perform AGC immediately after processing the U-SIG 1015

[0108] Aspects of the present disclosure recognize that the packet formats described above with reference to Figure 9A - Figure 10B can further facilitate communication over an extended range. For example, existing versions of the IEEE 802.11 standard support an Extended Range (ER) packet format suitable for wireless communication over greater distances (e.g., in an outdoor environment). Specifically, the IEEE 802.11ax amendment to the IEEE 802.11 standard defines a HE ER SU PPDU format that includes a repeated HE signal field (HE-SIG-A). In other words, the information carried on the HE-SIG-A is transmitted twice in the PHY preamble. Since the HE-SIG-A carries the signaling required to decode or interpret subsequent fields or portions of the HE PPDU, the repetition of the HE-SIG-A enables more robust and reliable transmission of the HE ER SU PPDU over greater distances. Similarly, the packet formats described above with reference to Figure 9A - Figure 10BThe repetition of U-SIG (and EHT-SIG) in the described packet format to extend the communication range of an EHT PPDU.

[0109] Figure 11 An example ER PPDU 1100 according to some implementations is shown. In some implementations, the ER PPDU 1100 can be Figure 6 an example of the PPDU 600. More specifically, the ER PPDU 1100 can be used for wireless communication over an extended range, such as, for example, in an outdoor environment. The ER PPDU 1100 includes an L-STF 1101, an L-LTF 1102, an L-SIG 1103, an RL-SIG 1104, a U-SIG 1105, an EHT-STF 1107, an EHT-LTF 1108, and a data field 1109, which can respectively correspond to the L-STF 608, L-LTF 610, L-SIG 612, RL-SIG 614, U-SIG 616, EHT-STF 622, EHT-LTF 624, and data field 626 of the PPDU 600. In some implementations, the ER PPDU 1100 can further include an EHT-SIG 1106, which can correspond to the EHT-SIG 618 of the PPDU 600.

[0110] In some implementations, to improve the reliability and robustness of the ER PPDU 1100 over longer distances, the U-SIG 1105 can be repeated (in the time domain). For example, the information in the U-SIG 1105 can be carried on two unique U-SIG symbols. However, via repetition, the same information can be replicated or repeated on two additional U-SIG symbols. Thus, the U-SIG 1105 can have an overall symbol duration equal to four U-SIG symbols, U-SIG-1, U-SIG-2, U-SIG-3, and U-SIG-4. In some implementations, U-SIG-2 can be a replication or repetition of U-SIG-1, and U-SIG-4 can be a replication or repetition of U-SIG-3. In other words, U-SIG-1 and U-SIG-2 can carry the same decoded bits (decoded bits A), and U-SIG-3 and U-SIG-4 can carry the same decoded bits (decoded bits B).

[0111] In some aspects, an interleaving technique can be used to reorder the decoded bits carried on each of U-SIG-1 and U-SIG-3. Thus, the order of the decoded bits carried on U-SIG-1 can be different from the order of the decoded bits carried on U-SIG-2, and the order of the decoded bits carried on U-SIG-3 can be different from the order of the decoded bits carried on U-SIG-4. For example, a known modulation scheme (such as BPSK) can be used to map the sequence of decoded bits associated with each U-SIG symbol to the corresponding sequence of modulation symbols. Each modulation symbol can be modulated on different tones or subcarriers within a 20 MHz subchannel. In some cases, interference in the wireless channel (such as deep fading) can prevent the transmission of modulation symbols on one or more of the subcarriers. Thus, by changing the order in which modulation symbols are modulated on different subcarriers (between replicated U-SIG symbols), aspects of the present disclosure can increase transmit diversity and further improve the signaling gain that can be achieved via the repetition of U-SIG symbols. In some implementations, the decoded bits carried on U-SIG-1 and U-SIG-3 can be interleaved, while the decoded bits carried on U-SIG-2 and U-SIG-4 can be non-interleaved.

[0112] In some implementations, U-SIG-2 can be modulated according to a modulation scheme different from U-SIG-1 to indicate the presence of repetition in U-SIG1105. For example, BPSK can be used to modulate U-SIG-1, and quadrature BPSK (QBPSK) can be used to modulate U-SIG-2. In response to detecting a change in the modulation scheme from U-SIG-1 to U-SIG-2 (or detecting that U-SIG-2 is modulated according to QBPSK), the receiving device can continue to listen for two additional U-SIG symbols (U-SIG-3 and U-SIG-4). In some implementations, the repetition in U-SIG 1105 can be present in other non-legacy PPDU formats (in addition to the ERP PPDU format). Thus, changing the modulation scheme associated with U-SIG-2 alone may not be sufficient to classify PPDU 1100 as an ERP PPDU.

[0113] In some implementations, the PHY version identifier in U-SIG 1105 can further distinguish the ERP PPDU 1100 from other non-legacy PPDU formats. The PHY version identifier can indicate the version of the wireless communication protocol associated with PPDU 1100. Referring to, for example Figure 6, the version identifier can be provided as a subfield of the version - independent field 632 of U - SIG 616. In some implementations, when the PHY version identifier subfield of U - SIG 1105 indicates the IEEE 802.11be amendment of the IEEE 802.11 standard, the PPDU 1100 can be classified as an ER PPDU. In other words, the receiving device can determine that the PPDU 1100 is formatted as an ER PPDU by detecting the repetition in U - SIG 1105 (based on the modulation scheme associated with U - SIG - 2) and determining that the PPDU 1100 is transmitted according to the IEEE 802.11be amendment of the IEEE 802.11 standard (based on the version identifier subfield of U - SIG 1105).

[0114] In some implementations, the ER PPDU 1100 can further include an EHT - SIG 1106. In some aspects, the EHT - SIG 1106 can carry one or more overflow bits from U - SIG 1105. In some other aspects, the EHT - SIG 1106 can carry user - specific information for one or more receivers of the ER PPDU 1100. For example, if the ER PPDU is for transmission to a single user, the EHT - SIG 1106 can include a user - specific field with a single - user field. In some implementations, for a single user, such as described with reference to Figure 8 , the ER PPDU 1100 can be formatted according to the MU PPDU format. Additionally, the EHT - SIG 1106 can be transmitted using a fixed code rate and a fixed modulation scheme that are optimized for ER communication. For example, in some aspects, the information carried on the EHT - SIG 1106 can be encoded at a rate equal to 1 / 2 and can be modulated according to the BPSK modulation scheme. In some implementations, the information carried on the EHT - SIG 1106 can be encoded at a rate equal to 1 / 2 and can be modulated according to the BPSK modulation and dual - carrier modulation (DCM) scheme.

[0115] In some implementations, the EHT - SIG 1106 can be repeated (in time). In Figure 11In an example, the information in EHT-SIG 1106 can be carried on a single unique EHT-SIG symbol. However, via repetition, the same information can be replicated or repeated on additional EHT-SIG symbols. Thus, EHT-SIG 1106 can have an overall symbol duration equal to two EHT-SIG symbols, EHT-SIG-1 and EHT-SIG-2. In some implementations, EHT-SIG-2 can be a replication or repetition of EHT-SIG-1. In other words, EHT-SIG-1 and EHT-SIG-2 can carry the same decoded bits (decoded bits C). In some aspects, an interleaving technique can be used to reorder the decoded bits carried on EHT-SIG-1, e.g., to increase transmit diversity and further improve the signaling gain achievable via repetition of the EHT-SIG symbols. In some implementations, the decoded bits carried on EHT-SIG-1 can be interleaved, while the decoded bits carried on EHT-SIG-2 can be non-interleaved. The receiving device can detect the presence of repetition in the EHT-SIG based on the modulation scheme associated with U-SIG-2 (or the change in the modulation scheme between U-SIG-1 and U-SIG-2).

[0116] In some other implementations, when the ER PPDU is only used for transmission to a single user, EHT-SIG 1106 can be omitted from the ER PPDU 1100 for transmission to a single user (further referred to as ER SU PPDU). Thus, one or more fields or sub-fields (such as the user field or U-SIG overflow) that would otherwise be included in EHT-SIG 1106 can instead be combined with U-SIG 1105. To support additional signaling in U-SIG 1105 without increasing the overhead, some fields or sub-fields associated with U-SIG 1105 or EHT-SIG 1106 can be omitted, and some fields or sub-fields of U-SIG 1105 or EHT-SIG 1106 can be shortened or compressed. For example, since the ER PPDU 1100 is intended for only a single receiving device, the STA ID sub-field can be omitted from the user field. More specifically, the receiving device can determine the STA ID based on the MAC header of the ER PPDU 1100. By eliminating EHT-SIG 1106, multiple fields or sub-fields (such as EHT-SIG compression, EHT-SIG MCS, and EHT-SIG symbol count) that carry signaling for EHT-SIG 1106 can be omitted from U-SIG 1105. Further, the PPDU format (or PPDU type) sub-field can be omitted from U-SIG 1105 because the classification of the ER PPDU is based on the modulation scheme associated with the U-SIG-2 and PHY version identifier sub-fields.

[0117] Aspects of the present disclosure further recognize that to support extended range communication, an ERP PPDU 1100 may be transmitted at a relatively low data rate (such as MCS0 - MSC3) on a limited number of spatial streams (such as 1 or 2 spatial streams) within a single 20 MHz subchannel (and the data portion 1109 may be transmitted on an even smaller subset of tones or subcarriers within the 20 MHz subchannel). Given such limitations on the ERP PPDU format, the number of fields or subfields of the U - SIG 1105 (such as bandwidth, MCS, number of LTFs, and medium - order signal period) may be shortened or compressed, and multiple additional fields or subfields (such as punctured channel information) may be omitted from the U - SIG 1105. In some implementations, two or more fields or subfields of the U - SIG 1105 may be jointly encoded to further reduce signaling overhead. For example, a single set of CRC and tail bits may be associated with multiple fields of the U - SIG 1105. By omitting, shortening, and combining fields in the U - SIG 1105, information that would otherwise be transmitted in the EHT - SIG 1106 may instead be transmitted in the U - SIG 1105 without increasing the size or length of the U - SIG 1105.

[0118] Figure 12 An example frame structure for an ERP PPDU 1200 according to some implementations is shown. In some implementations, the ERP PPDU 1200 may be Figure 11 an example of the ERP PPDU 1100. The ERP PPDU 1100 includes an L - STF 1201, an L - LTF 1202, an L - SIG 1203, an RL - SIG 1204, a U - SIG 1205, an EHT - STF 1207, an EHT - LTF 1208, and a data field 1209, which may respectively correspond to the L - STF 1101, the L - LTF 1102, the L - SIG 1103, the RL - SIG 1104, the U - SIG 1105, the EHT - STF 1107, the EHT - LTF 1108, and the data field 1109 of the ERP PPDU 1100. In Figure 12 the example, the ERP PPDU 1200 does not include an EHT - SIG. In fact, the U - SIG 1205 includes a set of version - independent fields 1210, a set of version - dependent fields 1211, and user fields 1212.

[0119] In some implementations, the version - agnostic field 1210 may include a PHY version identifier sub - field (3 bits), an uplink or downlink sub - field (1 bit), a Transmission Opportunity (TXOP) duration sub - field (7 bits), a BSS color sub - field (6 bits), and a PPDU bandwidth sub - field (3 bits). Thus, the length of the version - agnostic field 1210 can be 20 bits. In some implementations, the version - dependent field 1211 may include a spatial reuse sub - field (4 bits), a Guard Interval (GI) and LTF size sub - field (2 bits), an LDPC extra symbol sub - field (1 bit), a number of spatial streams (NSS) and mid - order signal period sub - field (2 bits), a Doppler sub - field (1 bit), an STBC sub - field (1 bit), a beam change sub - field (1 bit), an FEC pre - padding factor sub - field (2 bits), and a Packet Extension (PE) disambiguation sub - field (1 bit). Thus, the length of the version - dependent field 1211 can be 15 bits. In some implementations, the user field 1212 may include a beamforming sub - field (1 bit), an encoding sub - field (1 bit), and an MCS sub - field (2 bits), and the MCS sub - field may indicate whether DCM is used (along with BPSK). Thus, the length of the user field 1212 can be 4 bits.

[0120] In Figure 12 the example of, the version - agnostic field 1210, the version - dependent field 1211, and the user field 1212 represent a combined 39 - bit signaling information. In some implementations, the version - agnostic field 1210, the version - dependent field 1211, and the user field 1212 may be jointly encoded with a single CRC (4 bits) and tail bits (6 bits). Thus, the signaling information in U - SIG 1205 represents a total overhead of 49 bits. In contrast, 2 U - SIG symbols can carry a combined 52 bits. Thus, in Figure 12 the example of, U - SIG 1205 can carry any relevant user - specific information (otherwise to be carried on the EHT - SIG), where 3 unused bits are reserved.

[0121] Aspects of the present disclosure recognize that in some PPDU formats (such as Figure 7A the TB PPDU 700 of Figure 12 or the ERPPDU 1200 of Figure 11, EHT-STF 1107 can follow immediately after EHT-SIG 1106 (in an implementation of ER PPDU 1100 that includes EHT-SIG 1106) or immediately after U-SIG 1105 (in an implementation of ER PPDU 1100 that does not include EHT-SIG 1106). As described above, the receiving device can use the EHT-STF to perform AGC in the receiver. More specifically, the receiving device can use the EHT-STF to configure (or reconfigure) its receiver to receive the EHT modulation portion of the EHT PPDU. Thus, it is desirable for the receiving device to detect the EHT-STF early so that most of the EHT-STF can be used for AGC. More specifically, the receiving device may need to know whether the EHT-STF follows immediately after the U-SIG or immediately after the EHT-SIG.

[0122] As described above, the presence (or absence) of the EHT-SIG depends on the PPDU format for a particular transmission implementation. In this implementation, the ER PPDU format is classified in part based on the version identifier carried on the U-SIG. However, decoding and processing the information in the U-SIG consumes time and resources, which may delay the detection or processing of the EHT-STF. In some implementations, the presence (or absence) of the EHT-SIG in the ER PPDU preamble can be indicated by changing the modulation scheme associated with one or more U-SIG symbols. For example, the third symbol of the U-SIG (U-SIG-3) can be modulated according to QBPSK or BPSK to indicate the presence or absence of the EHT-SIG in the preamble, respectively. In response to detecting that U-SIG-3 is modulated using QBPSK, the receiving device can expect the EHT-STF to occur at least two symbol durations (corresponding to the duration of the EHT-SIG) after the U-SIG (as described in reference Figure 9A ). In response to detecting that U-SIG-3 is modulated using BPSK, the receiving device can expect the EHT-STF to occur immediately after the U-SIG (as described in reference Figure 9B ).

[0123] As described above, the presence of the EHT-SIG can also provide the receiving device with a buffer (or additional time) to decode and process the information in the U-SIG and thus determine the start of the EHT-STF. In other words, when the EHT-SIG is present in the preamble, the receiving device can determine the presence of the EHT-SIG based on the PPDU format indicated in the U-SIG before it starts receiving the EHT-STF (as described in reference Figure 10AHowever, when there is no EHT-SIG in the preamble, the receiving device may not be able to determine the absence of the EHT-SIG (based on the PPDU format indicated in the U-SIG) before it starts receiving the EHT-STF. In some implementations, in the absence of an EHT-SIG, one or more padding symbols can be inserted between the U-SIG and the EHT-STF to provide a buffer for the receiving device to decode and process the information in the U-SIG and thus determine the start of the EHT-STF (such as with reference to Figure 10B described).

[0124] Figure 13A FIG. 1300 is a flow chart illustrating an example process for supporting wireless communication for PHY preamble design according to some implementations. In some implementations, process 1300 can be performed by a wireless communication device operating as a STA (such as one of STAs 104 or 504, respectively, Figure 1 and 5B ), or operating within the STA. In some other implementations, process 1300 can be performed by a wireless communication device operating as an AP (such as one of APs 102 or 502, respectively, Figure 1 and 5A ), or operating within the AP.

[0125] In some implementations, at block 1301, process 1300 begins by receiving a packet including a physical layer preamble, the physical layer preamble including an L-STF, an L-LTF, an L-SIG, an RL-SIG following the L-SIG, and a U-SIG following the RL-SIG and including information for interpreting one or more subsequent fields of the packet, where the L-SIG includes a length field having a value (L_LEN) that satisfies L_LEN % 3 = 0. At block 1302, process 1300 continues by detecting one or more modulation schemes associated with the U-SIG. At block 1303, process 1300 continues by determining the format of the packet based on the detected modulation scheme associated with the U-SIG.

[0126] Figure 13B FIG. 1310 is a flow chart illustrating an example process for supporting wireless communication for PHY preamble design according to some implementations. In some implementations, process 1310 can be performed by a wireless communication device operating as a STA (such as one of STAs 104 or 504, respectively, Figure 1 and 5B ), or operating within the STA. In some other implementations, process 1310 can be performed by a wireless communication device operating as an AP (such as one of APs 102 or 502, respectively, Figure 1 and 5Aperformed by a wireless communication device that operates on or within one of the APs 102 or 502).

[0127] Refer to, for example Figure 13A , process 1310 can be a more detailed implementation of the operation of detecting one or more modulation schemes associated with U-SIG in block 1302 of process 1300. For example, process 1310 can start in block 1311 after receiving a packet in block 1301 and before determining the format of the packet in block 1303. In block 1311, process 1310 starts by determining that the first symbol of U-SIG is modulated according to the BPSK modulation scheme. In block 1312, process 1310 continues by determining that the second symbol of U-SIG is modulated according to the QBPSK modulation scheme. In some implementations, process 1310 can continue to block 1313 to determine that U-SIG further includes at least a third symbol and a fourth symbol based on determining that the second symbol of U-SIG is modulated according to the QBPSK modulation scheme, where the first symbol of U-SIG carries the same decoded bits as the second symbol of U-SIG, and the third symbol of U-SIG carries the same decoded bits as the fourth symbol of U-SIG.

[0128] In some implementations, each of the first symbol and the second symbol can be transmitted on multiple subcarriers, where the decoded bits of the first symbol are modulated on the multiple subcarriers in an order different from the order of the decoded bits of the second symbol. In some implementations, each of the third symbol and the fourth symbol can be transmitted on multiple subcarriers, where the decoded bits of the third symbol are modulated on the multiple subcarriers in an order different from the order of the decoded bits of the fourth symbol.

[0129] In some implementations, it can be determined that the packet follows a non-legacy ER packet format based on the value of the version identifier subfield of U-SIG and the determination that the second symbol of U-SIG is modulated according to the QBPSK modulation scheme. In some aspects, the preamble can further include a non-legacy signal field immediately following U-SIG, where the non-legacy signal field includes a single-user field and one or more overflow bits from U-SIG. In some aspects, U-SIG can include a user field carrying user-specific information for a single user, where the preamble further includes a non-legacy STF immediately following U-SIG.

[0130] Figure 13C A flowchart illustrating an example process 1320 for supporting wireless communication for PHY preamble design according to some implementations is shown. In some implementations, process 1320 can be performed by a STA (such as, respectively, Figure 1and 5B One of the STAs 104 or 504) or a wireless communication device operating within the STA. In some other implementations, process 1320 may be performed by a wireless communication device operating as an AP (such as one of the APs 102 or 502, respectively Figure 1 and 5A One of the APs 102 or 502) or a wireless communication device operating within the AP.

[0131] Referring to, for example Figure 13A , process 1320 may start in block 1321 after determining the format of the packet in block 1303 of process 1300. In block 1321, process 1320 starts by determining the timing of the non - legacy STF of the physical layer preamble relative to the U - SIG based on the format of the packet. In block 1322, process 1320 continues by initiating AGC based on the timing of the non - legacy STF. In some implementations, the packet may include one or more padding symbols between the U - SIG and the non - legacy STF.

[0132] Figure 14 FIG. shows a flowchart of an example process 1400 for supporting wireless communication for PHY preamble design according to some implementations. In some implementations, process 1400 may be performed by a wireless communication device operating as an STA (such as one of the STAs 104 or 504, respectively Figure 1 and 5B One of the STAs 104 or 504) or a wireless communication device operating within the STA. In some other implementations, process 1400 may be performed by a wireless communication device operating as an AP (such as one of the APs 102 or 502, respectively Figure 1 and 5A One of the APs 102 or 502) or a wireless communication device operating within the AP.

[0133] In some implementations, in block 1401, process 1400 starts by generating a packet including a physical layer preamble that includes an L - STF, an L - LTF, an L - SIG, an RL - SIG following immediately after the L - SIG, and a U - SIG following immediately after the RL - SIG and including information for interpreting one or more subsequent fields of the packet, where the L - SIG includes a length field having a value (L_LEN) that satisfies L_LEN % 3 = 0. In block 1402, process 1400 continues by modulating the first symbol of the U - SIG according to a BPSK modulation scheme. In block 1403, process 1400 continues by modulating the second symbol of the U - SIG according to a QBPSK modulation scheme. In block 1404, process 1400 continues by transmitting the packet over a wireless channel.

[0134] In some implementations, the U-SIG may further include at least a third symbol and a fourth symbol, where the first symbol of the U-SIG carries the same decoded bits as the second symbol of the U-SIG, and the third symbol of the U-SIG carries the same decoded bits as the fourth symbol of the U-SIG. In some aspects, the decoded bits of the first symbol may be modulated on multiple subcarriers in an order different from that of the decoded bits of the second symbol. In some aspects, the decoded bits of the third symbol may be modulated on multiple subcarriers in an order different from that of the decoded bits of the fourth symbol. In some aspects, the packet may include one or more padding symbols between the U-SIG of the physical layer preamble and the non-legacy STF.

[0135] In some implementations, the packet may follow a non-legacy ER packet format with a bandwidth equal to 20 MHz. In some aspects, the preamble may further include a non-legacy signal field following the U-SIG, where the non-legacy signal field includes a single-user field and one or more overflow bits from the U-SIG. In some aspects, the U-SIG may further include a user field carrying user-specific information for a single user, where the preamble further includes a non-legacy STF following the U-SIG.

[0136] The wireless range of a wireless communication device may be related to its transmit power level. For example, a wireless signal transmitted at a higher power level generally travels farther than a wireless signal transmitted at a lower power level. Many government agencies and regulations impose power spectral density (PSD) limits on the transmit power of wireless communication devices. The PSD limits may restrict the total transmit power of the wireless communication device as well as the energy of out-of-band transmissions. For example, a transmitting device may use a relatively low transmit power level to minimize signal distortion caused by its power amplifier, such that a receiving device can receive and successfully decode the information modulated onto the transmitted wireless signal. The transmitting device may further maintain its transmit power at a level that ensures its power amplifier operates mainly in the linear region, for example, to minimize signal distortion.

[0137] In some implementations, a wireless communication device disclosed herein can increase the accuracy of channel estimation by increasing the power level employed for one or more long training fields (LTFs) that are transmitted in a packet preamble. Specifically, increasing the transmit power level of one or more LTFs that can be used for channel estimation can increase the SINR of the one or more LTFs, which can result in a more accurate channel estimate. Although allowing for a more accurate channel estimate, increasing the power level employed for transmitting one or more LTFs can cause the total output power level of the wireless communication device to violate applicable PSD limits. Additionally, increasing the power level employed for transmitting one or more LTFs can increase the amount of signal distortion caused by non - linearities in power amplifiers provided in the transmission chain of the wireless communication device.

[0138] Accordingly, implementations of the subject matter disclosed herein can allow a wireless communication device to transmit one or more LTFs of a packet preamble at a greater power level to achieve a more accurate channel estimate without violating applicable PSD limits and without signal distortion. In some implementations, the wireless communication device can apply an additional amount of transmit power to one or more LTFs and can adjust the transmit power level applied to other portions of the packet based on the additional amount of transmit power, the duration of the one or more LTFs, and the PSD limits to maintain the total output power level of the wireless communication device over a frequency bandwidth below the PSD limits. PSD limits are typically defined on a per - frequency - band basis (such as, in certain spectrums, 5 dBm / MHz for an AP and - 1 dBm / MHz for a non - AP STA). Thus, a wireless communication device that transmits a wireless packet over a relatively large frequency bandwidth can use a greater transmit power level compared to a wireless communication device that transmits a wireless packet over a relatively small frequency bandwidth.

[0139] Additionally, PSD limits are typically based on the total output power of the wireless communication device measured over a period of time rather than on the instantaneous transmit power level. Thus, the wireless communication device can increase the transmit power level of one or more LTFs (to increase the accuracy of channel estimation) and comply with applicable PSD limits by reducing the transmit power level of one or more other portions of the packet by an amount and for a duration that compensates for the increased transmit power level applied to the LTFs.

[0140] Figure 15 A flowchart illustrates an example process 1500 for supporting wireless communication that increases the transmit power of training fields of a PHY preamble according to some implementations. In some implementations, process 1500 can be performed by a STA (such as Figure 1 and 5BOne of the STAs 104 or 504) or by a wireless communication device operating within the STA. In some other implementations, process 1500 may be performed by a wireless communication device operating as an AP (such as one of the APs 102 or 502, respectively, Figure 1 and 5A One of the APs 102 or 502) or by a wireless communication device operating within the AP.

[0141] In some implementations, in block 1502, process 1500 begins by formatting a packet for wireless transmission over a frequency bandwidth, the packet including a physical layer (PHY) preamble that includes one or more long training fields (LTFs). In block 1504, process 1500 continues by determining a transmit power level for the wireless transmission of the packet based at least in part on a power spectral density (PSD) limit corresponding to the frequency bandwidth. In block 1506, process 1500 continues by determining an additional transmit power amount for at least one of the LTFs in the PHY preamble. In block 1508, process 1500 continues by adjusting the transmit power level based on the additional transmit power amount, the duration of at least one LTF, and the PSD limit to maintain the total output power level of the wireless communication device below the PSD limit over the frequency bandwidth. In block 1510, process 1500 continues by transmitting the packet based on the adjusted transmit power level, the transmission including transmitting at least one LTF at the sum of the adjusted transmit power and the additional transmit power amount, and including transmitting one or more other fields of the PHY preamble at the adjusted transmit power level. In some implementations, at least one LTF may be one or more of the following: legacy LTF (L-LTF), high throughput (HT) LTF (HT-LTF), high efficiency (HE) LTF (HE-LTF), or extremely high throughput (EHT) LTF (EHT-LTF).

[0142] In some implementations, the determination of the increased transmit power amount for at least one LTF may further be based on the signal-to-interference-plus-noise ratio (SINR) associated with the transmission of the packet. In some other implementations, the determination of the increased transmit power amount for at least one LTF may further be based on a signal-to-interference-plus-noise ratio (SINR) threshold for channel estimation.

[0143] In some implementations, the determination of the transmit power level may further be based on the number of tones used to transmit the preamble. In some other implementations, the determination of the transmit power level may further be based on the distribution of the number of tones across the frequency bandwidth.

[0144] In some implementations, the adjustment of the transmit power level can further be based on an Output Power Backoff (OBO) value. In some instances, the OBO value can be selected to reduce signal distortion caused by one or more power amplifiers of a wireless communication device while maintaining the total transmit power of the wireless communication device within the corresponding PSD limit.

[0145] Figure 16 FIG. 1600 is a flow chart illustrating an example process for supporting the transmission power of a training field that increases a PHY preamble. In some implementations, process 1600 can be performed by a wireless communication device operating as a STA (such as one of STAs 104 or 504, respectively, being Figure 1 and 5B ), or operating within a STA. In some other implementations, process 1600 can be performed by a wireless communication device operating as an AP (such as one of APs 102 or 502, respectively, being Figure 1 and 5A ), or operating within an AP.

[0146] Referring to, for example, Figure 15 , process 1600 can be a more detailed implementation of the operation for adjusting the transmit power level in block 1508 of process 1500. For example, in block 1602, process 1600 begins with the operation of a wireless communication device adjusting the transmit power level by reducing the transmit power level by an amount that compensates for increasing the transmit power level by an additional amount over the duration of at least one LTF. In this way, a wireless communication device configured to implement one or more aspects of the subject matter disclosed herein can transmit the LTF at a higher power level compared to other parts of the packet without violating the applicable PSD limit. The ability to increase the transmit power level of the LTF can increase the SINR of the transmitted packet, for example, to achieve better channel estimation (such as compared to transmitting the packet without increasing the transmit power level of the LTF).

[0147] Figure 17 FIG. 1700 is a flow chart illustrating an example process for supporting the transmission power of a training field that increases a PHY preamble. In some implementations, process 1700 can be performed by a wireless communication device operating as a STA (such as one of STAs 104 or 504, respectively, being Figure 1 and 5B ), or operating within a STA. In some other implementations, process 1700 can be performed by a wireless communication device operating as an AP (such as one of APs 102 or 502, respectively, being Figure 1 and 5A ), or operating within an AP.

[0148] In some implementations, in block 1702, process 1700 begins by selecting an OBO value to reduce signal distortion caused by one or more power amplifiers of a wireless communication device while maintaining the total transmit power of the wireless communication device within a corresponding PSD limit.

[0149] Figure 18 A block diagram of an example wireless communication device 1800 is shown in accordance with some implementations. In some implementations, wireless communication device 1800 is configured to perform any one of processes 1300, 1310, or 1320 described above with reference to Figure 13A , Figure 13B or Figure 13C respectively. In some implementations, wireless communication device 1800 may be an example implementation of wireless communication device 400 described above with reference to Figure 4 . For example, wireless communication device 1800 may be a chip, SoC, chipset, package, or device that includes at least one processor and at least one modem (e.g., a Wi-Fi (IEEE 802.11) modem or a cellular modem).

[0150] Wireless communication device 1800 includes a receiving component 1810, a communication manager 1820, and a transmitting component 1830. Communication manager 1820 may further include a modulation detection component 1822 and a packet format detection component 1824. Portions of one or more of components 1822 and 1824 may be implemented at least in part in hardware or firmware. In some implementations, at least some of components 1822 or 1824 are implemented at least in part as software stored in a memory (such as memory 408). For example, portions of one or more of components 1822 and 1824 may be implemented as non-transitory instructions (or “code”) executable by a processor (such as processor 406) to perform the functions or operations of the corresponding components.

[0151] The receiving component 1810 is configured to receive an RX signal from one or more other wireless communication devices. In some implementations, the receiving component 1810 may receive a packet or PPDU including a PHY preamble, the PHY preamble including an L-STF, an L-LTF, an L-SIG, an RL-SIG following immediately after the L-SIG, and a U-SIG following immediately after the RL-SIG and including information for interpreting one or more subsequent fields of the packet or PPDU, where the L-SIG includes a length field having a value (L_LEN) that satisfies L_LEN % 3 = 0. The communication manager 1820 is configured to manage communication with other wireless communication devices. In some implementations, the modulation detection component 1822 may detect one or more modulation schemes associated with the U-SIG; and the packet format detection component 1824 may determine the format of the packet or PPDU based on the detected modulation scheme and the information in the U-SIG. The transmitting component 1830 is configured to transmit a TX signal to one or more other wireless communication devices.

[0152] Figure 19 A block diagram of an example wireless communication device 1900 is shown in accordance with some implementations. In some implementations, the wireless communication device 1900 is configured to perform the process 1400 described above with reference to Figure 14 as described. In some implementations, the wireless communication device 1900 may be an example implementation of the wireless communication device 400 described above with reference to Figure 4 as described. For example, the wireless communication device 1900 may be a chip, an SoC, a chipset, a package, or a device that includes at least one processor and at least one modem (e.g., a Wi-Fi (IEEE 802.11) modem or a cellular modem).

[0153] The wireless communication device 1900 includes a receiving component 1910, a communication manager 1920, and a transmitting component 1930. The communication manager 1920 may further include a packet generation component 1922 and a preamble modulation component 1924. Portions of one or more of the components 1922 and 1924 may be implemented at least in part in hardware or firmware. In some implementations, at least some of the components 1922 or 1924 are implemented at least in part as software stored in a memory (such as the memory 408). For example, portions of one or more of the components 1922 and 1924 may be implemented as non-transitory instructions (or “code”) executable by a processor (such as the processor 406) to perform the functions or operations of the corresponding components.

[0154] The receiving component 1910 is configured to receive an RX signal from one or more wireless communication devices. The communication manager 1920 is configured to manage communication with other wireless communication devices. In some implementations, the packet generation component 1922 may generate a packet or PPDU including a PHY preamble, the PHY preamble including an L-STF, an L-LTF, an L-SIG, an RL-SIG following the L-SIG, and a U-SIG following the RL-SIG and including information for interpreting one or more subsequent fields of the packet or PPDU, where the L-SIG includes a length field having a value (L_LEN) that satisfies L_LEN % 3 = 0; and the preamble modulation component 1924 may modulate the first symbol of the U-SIG according to a first modulation scheme and modulate the second symbol of the U-SIG according to a second modulation scheme different from the first modulation scheme. The transmission component 1930 is configured to transmit a TX signal to one or more other wireless communication devices. In some implementations, the transmission component 1930 may transmit a packet or PPDU over a wireless channel.

[0155] Example implementations are described in the following numbered clauses.

[0156] 1. A method for wireless communication by a wireless communication device, comprising:

[0157] Receiving a packet including a physical layer preamble, the physical layer preamble including a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signal field (L-SIG), a repetition of the L-SIG (RL-SIG) following the L-SIG, and a universal signal field (U-SIG) following the RL-SIG and including information for interpreting one or more subsequent fields of the packet, the L-SIG including a length field having a value (L_LEN) that satisfies L_LEN % 3 = 0;

[0158] Detecting one or more modulation schemes associated with the U-SIG; and

[0159] Determining a format of the packet based on the detected modulation schemes associated with the U-SIG.

[0160] 2. The method of clause 1, wherein the detecting of the one or more modulation schemes comprises:

[0161] Determining that a first symbol of the U-SIG is modulated according to a binary phase shift keying (BPSK) modulation scheme; and

[0162] Determining that a second symbol of the U-SIG is modulated according to a quadrature BPSK (QBPSK) modulation scheme.

[0163] 3. The method according to any one of clauses 1 or 2, wherein the determination of the format of the packet includes:

[0164] Determining that the U-SIG further includes at least a third symbol and a fourth symbol based on determining that the second symbol of the U-SIG is modulated according to the QPSK modulation scheme, wherein the first symbol of the U-SIG carries the same decoded bits as the second symbol of the U-SIG, and the third symbol of the U-SIG carries the same decoded bits as the fourth symbol of the U-SIG.

[0165] 4. The method according to any one of clauses 1-3, wherein each of the first symbol and the second symbol is transmitted on a plurality of subcarriers, and the decoded bits of the first symbol are modulated on the plurality of subcarriers in an order different from the order of the decoded bits of the second symbol.

[0166] 5. The method according to any one of clauses 1-4, wherein each of the third symbol and the fourth symbol is transmitted on a plurality of subcarriers, and the decoded bits of the third symbol are modulated on the plurality of subcarriers in an order different from the order of the decoded bits of the fourth symbol.

[0167] 6. The method according to any one of clauses 1-5, further comprising:

[0168] Determining the timing of the non-legacy short training field (STF) of the physical layer preamble relative to the U-SIG based on the format of the packet; and

[0169] Initiating automatic gain control (AGC) based on the timing of the non-legacy STF.

[0170] 7. The method according to any one of clauses 1-6, wherein the packet includes one or more padding symbols between the U-SIG and the non-legacy STF.

[0171] 8. The method according to any one of clauses 1-7, wherein the determination of the format of the packet includes:

[0172] Determining that the packet follows a non-legacy extended range (ER) packet format based on the value of the version identifier subfield of the U-SIG and the determination that the second symbol of the U-SIG is modulated according to the QPSK modulation scheme.

[0173] 9. The method according to any one of clauses 1-8, wherein the preamble further includes a non-legacy signal field immediately following the U-SIG, the non-legacy signal field including a single user field and one or more overflow bits from the U-SIG.

[0174] 10. The method according to any one of clauses 1-8, wherein the U-SIG includes a user field carrying user-specific information for a single user, and the preamble further includes a non-legacy STF following the U-SIG.

[0175] 11. A wireless communication device, comprising:

[0176] At least one modem;

[0177] At least one processor communicatively coupled to the at least one modem; and

[0178] At least one memory communicatively coupled to the at least one processor and storing processor-readable code, the processor-readable code being configured to perform the method according to any one or more of clauses 1-10 when executed by the at least one processor in combination with the at least one modem.

[0179] 12. A method for wireless communication to be performed by a wireless communication device, comprising:

[0180] Generating a packet including a physical layer preamble, the physical layer preamble including a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signal field (L-SIG), a repetition of the L-SIG (RL-SIG) following the L-SIG, and a universal signal field (U-SIG) following the RL-SIG and including information for interpreting one or more subsequent fields of the packet, the L-SIG including a length field having a value (L_LEN) that satisfies L_LEN % 3 = 0;

[0181] Modulating a first symbol of the U-SIG according to a binary phase shift keying (BPSK) modulation scheme;

[0182] Modulating a second symbol of the U-SIG according to a quadrature BPSK (QBPSK) modulation scheme; and

[0183] Transmitting the packet over a wireless channel.

[0184] 13. The method according to clause 12, wherein the U-SIG further includes at least a third symbol and a fourth symbol, the first symbol of the U-SIG carrying the same decoded bits as the second symbol of the U-SIG, and the third symbol of the U-SIG carrying the same decoded bits as the fourth symbol of the U-SIG.

[0185] 14. The method according to any one of clauses 12 or 13, wherein the decoded bits of the first symbol are modulated on multiple subcarriers in an order different from the decoded bits of the second symbol.

[0186] 15. A method as described in any one of clauses 12 - 14, wherein the decoded bits of the third symbol are modulated on the plurality of subcarriers in an order different from the decoded bits of the fourth symbol.

[0187] 16. A method as described in any one of clauses 12 - 15, wherein the packet includes one or more padding symbols between the U - SIG of the physical layer preamble and the non - legacy short training field (STF).

[0188] 17. A method as described in any one of clauses 12 - 16, wherein the packet follows a non - legacy extended range (ER) packet format having a bandwidth equal to 20 MHz.

[0189] 18. A method as described in any one of clauses 12 - 17, wherein the preamble further includes a non - legacy signal field immediately following the U - SIG, the non - legacy signal field including a single - user field and one or more overflow bits from the U - SIG.

[0190] 19. A method as described in any one of clauses 12 - 17, wherein the U - SIG includes a user field carrying user - specific information for a single user, and the preamble further includes a non - legacy STF immediately following the U - SIG.

[0191] 20. A wireless communication device, comprising:

[0192] At least one modem;

[0193] At least one processor communicatively coupled to the at least one modem; and

[0194] At least one memory communicatively coupled to the at least one processor and storing processor - readable code, the processor - readable code being configured to perform the method as described in any one or more of clauses 12 - 19 when executed by the at least one processor in combination with the at least one modem.

[0195] As used herein, a phrase that recites "at least one of" or "one or more of" a list of items means any combination of those items, including a single member. For example, "at least one of a, b, or c" is intended to cover the possibilities: only a, only b, only c, a combination of a and b, a combination of a and c, a combination of b and c, and a combination of a, b, and c.

[0196] The various illustrative components, logics, logical blocks, modules, circuits, operations, and algorithmic processes described in connection with the implementations disclosed herein can be implemented as electronic hardware, firmware, software, or any combination of hardware, firmware, or software, including the structures disclosed in this specification and their structural equivalents. This interchangeability of hardware, firmware, and software has been described generally in terms of their functionality and illustrated in the various illustrative components, blocks, modules, circuits, and processes described above. Whether such functionality is implemented in hardware, firmware, or software depends upon the particular application and design constraints imposed on the overall system.

[0197] Various modifications to the implementations described in this disclosure may be apparent to those of ordinary skill in the art, and the generic principles defined herein may be applied to other implementations without departing from the spirit or scope of the disclosure. Thus, the claims are not intended to be limited to the implementations shown herein but are to be accorded the widest scope consistent with the disclosure, the principles disclosed herein, and the novel features.

[0198] In addition, the various features described in the context of separate implementations herein can also be implemented in combination in a single implementation. Conversely, the various features described in the context of a single implementation can also be implemented separately or in any suitable sub-combination in multiple implementations. Thus, although the features may have been described above as acting in a particular combination and even initially claimed as such, one or more features from the claimed combination may in some cases be excluded from the combination, and the claimed combination may be directed to a sub-combination or a variant of a sub-combination.

[0199] Similarly, although the operations are depicted in the drawings in a particular order, this should not be understood to require that such operations be performed in the particular order shown or in sequential order, or that all of the illustrated operations be performed to achieve the desired result. Additionally, the drawings may schematically depict one or more example processes in the form of a flowchart or a flow diagram. However, other operations not depicted may be incorporated into the example processes schematically illustrated. For example, one or more additional operations may be performed before, after, concurrently with, or between any of the illustrated operations. In some environments, multitasking and parallel processing may be advantageous. Further, the separation of the various system components described above in the implementations should not be understood to require such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

Claims

1. A method for wireless communication by a wireless communication device, comprising: receiving a packet including a physical layer preamble, the physical layer preamble including a legacy short training field L-STF, a legacy long training field L-LTF, a legacy signal field L-SIG, a repetition RL-SIG of L-SIG following L-SIG, and a universal signal field U-SIG following RL-SIG and including information of one or more subsequent fields for interpreting the packet, L-SIG including a length field having a value L_LEN satisfying L_LEN modulo 3 equals 0, wherein U-SIG further includes at least one of one or more version-independent fields or one or more version-dependent fields; detecting one or more modulation schemes associated with U-SIG; and determining a format of the packet based on the one or more modulation schemes associated with U-SIG.

2. The method according to claim 1, wherein the one or more version-independent fields include a physical layer PHY version identifier subfield, an uplink or downlink subfield, a transmission opportunity duration subfield, a basic service set color subfield, a physical protocol data unit bandwidth subfield, or any combination thereof.

3. The method according to claim 1, wherein the one or more version-dependent fields include a spatial reuse subfield, a physical protocol data unit type and compression mode subfield, a modulation and coding scheme subfield, or any combination thereof.

4. The method according to claim 1, wherein the packet further includes an additional SIG field following U-SIG, and wherein U-SIG, the additional SIG field, or both include one or more additional version-dependent fields.

5. The method according to claim 4, wherein the one or more additional version-dependent fields include a guard interval and LTF size subfield, a low density parity check extra symbol subfield, a spatial stream number and midamble period subfield, a Doppler subfield, a space-time block coding subfield, a beam change subfield, a forward error correction pre-padding factor subfield, a packet extension disambiguation subfield, or any combination thereof.

6. The method according to claim 1, wherein the packet further includes a user field, and wherein the user field includes a beamforming subfield, a decoding subfield, a modulation and coding scheme subfield, or any combination thereof.

7. The method according to claim 6, wherein the modulation and coding scheme subfield indicates whether the one or more modulation schemes include a dual carrier modulation scheme.

8. The method according to claim 1, wherein at least one of the one or more version-independent fields, the one or more version-dependent fields, or the user field is jointly encoded using a single cyclic redundancy check.

9. A wireless communication device, comprising: at least one modem; at least one processor communicatively coupled to the at least one modem; and At least one memory communicatively coupled to the at least one processor and storing processor-readable code that, when executed by the at least one processor in combination with the at least one modem, is configured to: Receive a packet including a physical layer preamble that includes a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signal field (L-SIG), a repetition of the L-SIG (RL-SIG) following the L-SIG, and a universal signal field (U-SIG) following the RL-SIG and including information for interpreting one or more subsequent fields of the packet, the L-SIG including a length field having a value L_LEN such that L_LEN modulo 3 equals 0, wherein the U-SIG further includes at least one of one or more version-independent fields or one or more version-dependent fields; Detect one or more modulation schemes associated with the U-SIG; and Determine a format of the packet based on the one or more modulation schemes associated with the U-SIG.

10. The wireless communication device of claim 9, wherein the one or more version-independent fields include a physical layer (PHY) version identifier subfield, an uplink or downlink subfield, a transmission opportunity duration subfield, a basic service set color subfield, a physical protocol data unit bandwidth subfield, or any combination thereof.

11. The wireless communication device of claim 9, wherein the one or more version-dependent fields include a spatial reuse subfield, a physical protocol data unit type and compression mode subfield, a modulation and coding scheme subfield, or any combination thereof.

12. The wireless communication device of claim 9, wherein the packet further includes an additional SIG field following the U-SIG, and wherein the U-SIG, the additional SIG field, or both include one or more additional version-dependent fields.

13. The wireless communication device of claim 12, wherein the one or more additional version-dependent fields include a guard interval and LTF size subfield, a low density parity check extra symbol subfield, a spatial stream number and midamble signal period subfield, a Doppler subfield, a space-time block coding subfield, a beam change subfield, a forward error correction pre-padding factor subfield, a packet extension disambiguation subfield, or any combination thereof.

14. The wireless communication device of claim 9, wherein the packet further includes a user field, and wherein the user field includes a beamforming subfield, a decoding subfield, a modulation and coding scheme subfield, or any combination thereof.

15. The wireless communication device of claim 14, wherein the modulation and coding scheme subfield indicates whether the one or more modulation schemes include a dual carrier modulation scheme.

16. A method for wireless communication by a wireless communication device, comprising: Generate a packet including a physical layer preamble, the physical layer preamble including a legacy short training field L-STF, a legacy long training field L-LTF, a legacy signal field L-SIG, a repetition RL-SIG of L-SIG following L-SIG, and a universal signal field U-SIG following RL-SIG and including information of one or more subsequent fields for interpreting the packet, L-SIG including a length field having a value L_LEN satisfying L_LEN modulo 3 equals 0, wherein U-SIG further includes at least one of one or more version-independent fields or one or more version-dependent fields; Modulate a first symbol of U-SIG according to a binary phase shift keying BPSK modulation scheme; Modulate a second symbol of U-SIG according to an orthogonal BPSK QBPSK modulation scheme; And Transmit the packet over a wireless channel.

17. The method according to claim 16, wherein the one or more version-independent fields include a physical layer PHY version identifier subfield, an uplink or downlink subfield, a transmission opportunity duration subfield, a basic service set color subfield, a physical protocol data unit bandwidth subfield, or any combination thereof.

18. The method according to claim 16, wherein the one or more version-dependent fields include a spatial reuse subfield, a physical protocol data unit type and compression mode subfield, a modulation and coding scheme subfield, or any combination thereof.

19. The method according to claim 17, wherein the packet further includes a user field, and wherein the user field includes a beamforming subfield, a decoding subfield, a modulation and coding scheme subfield, or any combination thereof.

20. A method for wireless communication by a wireless communication device, comprising: Receiving a packet including a physical layer preamble, the physical layer preamble including a legacy short training field L-STF, a legacy long training field L-LTF, a legacy signal field L-SIG, a repetition RL-SIG of L-SIG following L-SIG, and a universal signal field U-SIG following RL-SIG and including information of one or more subsequent fields for interpreting the packet, L-SIG including a length field having a value L_LEN satisfying L_LEN % 3 = 0; Detecting one or more modulation schemes associated with U-SIG; And Determining a format of the packet based on the one or more modulation schemes associated with U-SIG.

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