60GHz Physical Layer Convergence Protocol (PLCP) Protocol Data Unit (PPDU) Format

Abstract

The present disclosure provides methods, devices, and systems for increasing carrier frequencies for wireless communication in wireless local area networks (WLANs). Some implementations relate more specifically to packet designs that support wireless communication at carrier frequencies above 7 GHz. In some aspects, a wireless communication device may map a physical layer convergence protocol (PLCP) protocol data unit (PPDU) to orthogonal subcarriers according to an existing tone plan associated with a carrier frequency below 7 GHz, and up - clock the PPDU for transmission at a carrier frequency above 7 GHz (such as by increasing the frequency of a clock signal used to convert the PPDU between the frequency domain and the time domain). In some implementations, the PPDU may conform to an existing PPDU format designed for sub - 7 GHz wireless communication. In some other implementations, the PPDU may conform to a “greenfield” PPDU format optimized for wireless communication at carrier frequencies above 7 GHz.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This patent application claims priority to U.S. Patent Application No. 17 / 828,085, filed May 31, 2022, by Yang et al., titled "60GHz PHYSICAL LAYER CONVERGENCE PROTOCOL (PLCP) PROTOCOL DATA UNIT (PPDU) FORMATS", which has been assigned to the assignee of this application and is hereby expressly incorporated by reference herein.

[0002] The present disclosure generally relates to wireless communication, and more specifically, to physical layer convergence protocol (PLCP) protocol data unit (PPDU) formats for wireless communication in the 60 GHz frequency band.

Background Art

[0003] A wireless local area network (WLAN) may be formed by one or more access points (APs) that provide a shared wireless communication medium for use by several client devices, also called stations (STAs). The basic building block of a WLAN that complies with 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) advertised by the AP. The AP periodically broadcasts beacon frames to enable any STA within the wireless range of the AP to establish or maintain a communication link with the WLAN.

[0004] Many existing WLAN communication protocols are designed for wireless communication on carrier frequencies below 7 GHz, such as the 2.4 GHz, 5 GHz, or 6 GHz frequency bands. However, new WLAN communication protocols are being developed to enable extended WLAN communication capabilities (such as higher throughput and wider bandwidth) that require even higher carrier frequencies, such as the 45 GHz or 60 GHz frequency bands. Wireless communication on higher carrier frequencies can suffer from greater phase noise and greater path loss compared to wireless communication on lower carrier frequencies. Therefore, new packet designs and numerologies are needed to support wireless communication on carrier frequencies above 7 GHz such that the new WLAN communication protocols enable extended capabilities. SUMMARY OF THE INVENTION

[0005] The systems, methods, and devices of the present disclosure each have several innovative aspects, and no single one of those aspects alone bears the desirable attributes disclosed herein.

[0006] One innovative aspect of the subject matter described in the present disclosure can be implemented as a method of wireless communication. The method can be performed by a wireless communication device and includes mapping a first portion of a physical layer (PHY) convergence protocol (PLCP) protocol data unit (PPDU) to several (N) subcarriers, where the first portion of the PPDU represents at least a portion of a PHY preamble that includes a short training field (STF), a long training field (LTF), and one or more signal (SIG) fields that follow immediately after the LTF and carry information for interpreting the PPDU. The method further includes converting the N subcarriers to a first time-varying signal at a sampling rate (f s ) associated with a first subcarrier spacing (SCS) greater than 1.2 MHz, where the first SCS represents the separation between adjacent subcarriers among the N subcarriers in the frequency domain, and transmitting the first time-varying signal over a wireless channel having a bandwidth (BW) associated with the sampling rate f s . In some aspects, the first time-varying signal can be transmitted at a carrier frequency above 7 GHz.

[0007] In some aspects, the PPDU may conform to a PPDU format associated with wireless communication on a carrier frequency below 7 GHz. In some implementations, one or more SIG fields may include a legacy SIG field (legacy SIG, L-SIG) and a non-legacy SIG field that follows immediately after the L-SIG. In some other implementations, one or more SIG fields may include an L-SIG, a repeat of the L-SIG (repeat of L-SIG, RL-SIG) that follows immediately after the L-SIG, and a non-legacy SIG field that follows immediately after the RL-SIG. In some implementations, the STF and the non-legacy SIG field may each consist of two orthogonal frequency-division multiplexing (OFDM) symbols. In some other implementations, the STF may consist of two OFDM symbols that are repeated in time, and the non-legacy SIG field may consist of four OFDM symbols.

[0008] In some aspects, the PPDU may consist of only a first portion. In some other aspects, the method further includes mapping a second portion of the PPDU, including at least a data field, a packet extension, or one or more training fields (TRNs), to M subcarriers, converting the M subcarriers to a second time-varying signal at a sampling rate f s and transmitting the second time-varying signal via a wireless channel that follows immediately after the first time-varying signal. In some implementations, one or more SIG fields may consist of a single SIG field followed immediately by a data field, a packet extension, or one or more TRNs. In some implementations, the second portion of the PPDU may further include one or more additional LTFs. In some implementations, one or more SIG fields may consist of a single SIG field followed immediately by one or more additional LTFs.

[0009] In some implementations, M may be equal to N, and BW may be equal to f s In some other implementations, M may be equal to N, and the PPDU may be replicated for transmission on several (m) sub-bands, each having a bandwidth equal to BW / m, and BW may be equal to m * f s In still other implementations, M may be greater than N. In some implementations, the first part of the PPDU may be replicated for transmission on several (n) sub-bands, each having a bandwidth equal to BW / n, and BW may be equal to f s In some implementations, the conversion of the M sub-carriers to a second time-varying signal may result in a second SCS equal to the first SCS, where the second SCS represents, in the frequency domain, the separation between adjacent sub-carriers among the M sub-carriers. In some other implementations, the conversion of the M sub-carriers to a second time-varying signal may result in a second SCS different from the first SCS, where the second SCS represents, in the frequency domain, the separation between adjacent sub-carriers among the M sub-carriers.

[0010] In some implementations, the LTF may be transmitted on the same sub-carriers as the second part of the PPDU as a result of replicating the first part of the PPDU for transmission on n sub-bands. In some implementations, the LTF may include a first OFDM symbol and a second OFDM symbol identical to the first OFDM symbol. In some other implementations, the LTF may include a first OFDM symbol and a second OFDM symbol, and the method may further include applying a P matrix to the LTF such that the first OFDM symbol is different from the second OFDM symbol. In some implementations, the STF may include a Golay sequence. In some implementations, the information carried in one or more SIG fields may include an indication of whether the PPDU is associated with a beamforming training operation.

[0011] 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 can include at least one memory and at least one processor communicatively coupled to the at least one memory, and the at least one processor is configured to cause the wireless communication device to map a first portion of a PPDU to several (N) subcarriers, where the first portion of the PPDU includes at least a portion of a PHY preamble that includes an STF, an LTF, and one or more SIG fields that follow immediately after the LTF and carry information for interpreting the PPDU, and to map the N subcarriers to a first time-varying signal at a sampling rate (f s ) associated with a first SCS greater than 1.2 MHz, where the first SCS represents the separation between adjacent subcarriers among the N subcarriers in the frequency domain, and to transmit the first time-varying signal via a wireless channel having a bandwidth (BW) associated with the sampling rate f s .

[0012] Another innovative aspect of the subject matter described in this disclosure can be implemented as a method of wireless communication. The method can be performed by a wireless communication device and can include mapping a first portion of a PPDU to several (N) subcarriers, where the first portion of the PPDU represents at least a portion of a PHY preamble that includes an STF and one or more SIG fields that carry information for interpreting the PPDU, mapping an LTF of the PHY preamble to several (M) subcarriers, where the LTF follows the STF and precedes one or more SIG fields within the PHY preamble and M is greater than N, converting the N subcarriers and the M subcarriers to a time-varying signal, and transmitting the time-varying signal via a wireless channel. In some aspects, the wireless channel can be associated with a carrier frequency above 7 GHz.

[0013] In some implementations, the method may further include mapping a second portion of the PPDU, including at least data fields, packet extensions, or one or more TRNs, to M subcarriers. In some implementations, the N subcarriers and the M subcarriers may be converted to time-varying signals at a sampling rate (f s ) associated with an SCS greater than 1.2 MHz, where the SCS represents the amount of separation between adjacent subcarriers among the N subcarriers in the frequency domain. In some implementations, the first portion of the PPDU may be replicated for transmission on several (n) subbands, each covering a respective bandwidth portion equal to BW / n.

[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 memory and at least one processor communicatively coupled to the at least one memory, and the at least one processor may cause the wireless communication device to map a first portion of the PPDU to several (N) subcarriers, where the first portion of the PPDU represents at least a portion of a PHY preamble including an STF and one or more SIG fields carrying information for interpreting the PPDU, map the LTF of the PHY preamble to several (M) subcarriers, where the LTF follows the STF and precedes one or more SIG fields within the PHY preamble and M > N, convert the N subcarriers and the M subcarriers to time-varying signals, and transmit the time-varying signals over a wireless channel.

[0015] Details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings, and the claims. Note that the relative dimensions of the figures below may not be drawn to scale.

Brief Description of the Drawings

[0016]

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[0017] Like reference numbers and designations in the various drawings indicate like elements.

DETAILED DESCRIPTION OF THE INVENTION

[0018] The following description is directed to several implementations for the purpose of describing innovative aspects of the present disclosure. However, those skilled in the art will readily recognize that the teachings herein can be applied in many different ways. The described implementations can be realized, inter alia, in any device, system, or network capable of transmitting and receiving radio frequency (RF) signals in accordance with one or more of the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards, IEEE 802.15 standards, Bluetooth® standards defined by the Bluetooth Special Interest Group (SIG), or Long Term Evolution (LTE), 3G, 4G, or 5G (New Radio (NR)) standards published by the 3rd Generation Partnership Project (3GPP®). The described implementations can be realized in any device, system, or network capable of transmitting and receiving RF signals in accordance with one or more of the following techniques or technologies, namely, 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 implementation forms can also be implemented using other wireless communication protocols or RF signals suitable for use in one or more of a wireless personal area network (WPAN), wireless local area network (WLAN), wireless wide area network (WWAN), or internet of things (IoT) network.

[0019] As described above, a new WLAN communication protocol is being developed to enable enhanced functionality for wireless communication at carrier frequencies above 7 GHz (such as within the 45 GHz or 60 GHz frequency bands). However, wireless communication at higher carrier frequencies can suffer from greater phase noise and path loss compared to wireless communication at lower frequency bands. For example, increasing the carrier frequency from 5.8 GHz to 60 GHz results in a ten-fold increase in phase noise. Aspects of the present disclosure recognize that phase noise can be mitigated by increasing the subcarrier spacing (SCS) between modulated subcarriers. Existing WLAN packet formats include a legacy short training field (L-STF) that is modulated every fourth subcarrier over a given bandwidth to support carrier frequency offset (CFO) estimation up to two subcarriers apart. Aspects of the present disclosure also recognize that local oscillators (LOs) implemented by existing WLAN transmitters and receivers are required to be accurate up to a maximum of ±20 ppm. Thus, existing WLAN architectures can support a CFO of up to ±40 ppm (between the transmitter and receiver), which corresponds to ±2.4 MHz in the 60 GHz frequency band and ±1.8 MHz in the 45 GHz frequency band. To support a maximum CFO of ±2.4 MHz, the SCS associated with the L-STF should be 1.2 MHz or greater.

[0020] Various aspects generally relate to increasing carrier frequencies for wireless communication in a WLAN, and more specifically, to packet designs that support wireless communication at carrier frequencies above 7 GHz. In some aspects, a wireless communication device may map a Physical Layer Convergence Protocol (PLCP) Protocol Data Unit (PPDU) to Orthogonal Frequency Division Multiplexing (OFDM) subcarriers according to an existing tone plan associated with carrier frequencies below 7 GHz (also referred to as a “sub-7 GHz” tone plan), and may upclock the PPDU for transmission at carrier frequencies above 7 GHz. As used herein, the term “upclocking” refers to increasing the frequency of a clock signal used to convert a PPDU between the frequency domain and the time domain (beyond a frequency (f o )) associated with the existing sub-7 GHz tone plan), and the ratio (K) of the upclocked frequency (f s ) to f o is referred to as the “upclocking ratio” (where

[0021]

Number

[0022] To realize one or more of the following potential advantages, certain implementations of the subject matter described in this disclosure may be implemented. By upclocking a PPDU mapped to OFDM subcarriers according to an existing sub-7 GHz tone plan, aspects of the present disclosure can utilize existing WLAN hardware to increase the carrier frequency at which such a PPDU is transmitted (such as to the 60 GHz or 45 GHz frequency bands). As described above, an existing WLAN architecture may support CFO estimation in the 60 GHz frequency band if the SCS associated with the L-STF is 1.2 MHz or greater. The SCS depends in part on the tone plan used to map the PPDU to the OFDM subcarriers, and more specifically, on the size of the inverse fast Fourier transform (IFFT) associated with the tone plan. Aspects of the present disclosure recognize that for any given IFFT size (N IFFT ) associated with an existing sub-7 GHz tone plan, an appropriate sampling rate f s can be selected such that

[0023]

Number

[0024] FIG. 1 shows a block diagram of an exemplary 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 (also referred to hereinafter as WLAN 100). For example, WLAN 100 may be a network that implements at least one of the IEEE 802.11 family of wireless communication protocol standards (such as those defined in the IEEE 802.11-2020 specification or a revised version thereof, 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 (STAs) 104. Although only one AP 102 is shown, WLAN network 100 may include multiple APs 102.

[0025] Each of the STAs 104 may be referred to, among other things, as a mobile station (MS), mobile device, mobile handset, wireless handset, access terminal (AT), user equipment (UE), subscriber station (SS), or subscriber unit. The STA 104 may represent various devices, among other things, such as a mobile phone, personal digital assistant (PDAs), other handheld devices, netbooks, notebook computers, tablet computers, laptops, display devices (e.g., in particular, TVs, computer monitors, navigation systems), music devices or other audio devices or stereo devices, remote control devices ("remotes"), printers, kitchen appliances or other household appliances, key fobs (e.g., for passive keyless entry and start (PKES) systems), etc.

[0026] A single associated set of AP102 and STA104 may be referred to as a basic service set (BSS) managed by each AP102. FIG. 1 additionally shows an exemplary coverage area 108 of an AP102 that may represent the basic service area (BSA) of the WLAN100. The BSS may be identified to a user by a service set identifier (SSID) and to other devices by a basic service set identifier (BSSID), which may be the medium access control (MAC) address of the AP102. The AP102 enables any STA104 within the wireless range of the AP102 to "associate" or re-associate with the AP102 in order to establish or maintain a respective communication link 106 (hereinafter also referred to as "Wi-Fi link") with the AP102 by periodically broadcasting a beacon frame ("beacon") containing the BSSID. For example, the beacon may include identification information of the primary channel used by each AP102 and a timing synchronization function for establishing or maintaining timing synchronization with the AP102. The AP102 may provide access to an external network to various STA104 in the WLAN via each communication link 106.

[0027] To establish a communication link 106 with an AP102, each of the STAs 104 is configured to perform a passive scan operation or an active scan operation ("scan") on a frequency channel within one or more frequency bands (e.g., a band of 2.4 GHz, 5 GHz, 6 GHz, or 60 GHz). To perform a passive scan, the STA 104 listens for beacons, which are transmitted by respective AP102s at periodic time intervals called target beacon transmission times (TBTTs), measured in time units (TUs), where 1 TU may be equal to 1024 microseconds (μs). To perform an active scan, the STA 104 generates probe requests, transmits them continuously on each channel to be scanned, and listens for probe responses from the AP102s. Each STA 104 may be configured to identify or select an AP102 to associate with based on scan information obtained through the passive or active scan, and to perform an authentication operation and an association operation to establish a communication link 106 with the selected AP102. The AP102 assigns an association identifier (AID) to the STA 104 upon completion of the association operation, and the AP102 uses it to track the STA 104.

[0028] As a result of the increasing pervasiveness of wireless networks, STA104 may have the opportunity to select one of many BSSs within the range of the STA, or to select from among multiple APs102 that together form an extended service set (ESS) that includes multiple connected BSSs. An extended network station associated with WLAN100 may be connected to a wired or wireless distribution system that may enable multiple APs102 to be connected within such an ESS. Thus, STA104 can be covered by two or more APs102 and can be associated with different APs102 at different times for different transmissions. Additionally, after association with an AP102, STA104 can also be configured to periodically scan its surroundings to find a more suitable AP102 to associate with. For example, STA104, which is moving relative to its associated AP102, may perform a "roaming" scan to find another AP102 with more desirable network characteristics such as a greater received signal strength indicator (RSSI) or a reduced traffic load.

[0029] In some cases, STA104 may form a network without involving AP102 or other devices other than itself. An example of such a network is an ad-hoc network (or a wireless ad-hoc network). An ad-hoc network may alternatively be referred to as a mesh network or a peer-to-peer (P2P) network. In some cases, an ad-hoc network may be implemented within a larger wireless network such as WLAN100. In such an implementation, STA104 may be able to communicate with each other via AP102 using communication link 106, but STA104 may also be able to communicate directly with each other via direct wireless link 110. Additionally, two STA104 may communicate via direct communication link 110 regardless of whether both STA104 are associated with and served by the same AP102. In such an ad-hoc system, one or more of STA104 may assume the role that AP102 plays in a BSS. Such STA104 may sometimes be called a group owner (GO) and may be able to coordinate transmissions within the ad-hoc network. Examples of direct wireless link 110 include Wi-Fi Direct connections, connections established by using Wi-Fi Tunneled Direct Link Setup (TDLS) links, and other P2P group connections.

[0030] AP102 and STA104 can function and communicate (via their respective communication links 106) in accordance with the IEEE 802.11 family of wireless communication protocol standards (including, but not limited to, 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be, as defined in the IEEE 802.11-2016 specification or a revision thereof). These standards define WLAN wireless and baseband protocols for the PHY layer and the Medium Access Control (MAC) layer. AP102 and STA104 transmit and receive wireless communication (hereinafter also referred to as "Wi-Fi communication") with each other in the form of Physical Layer Convergence Protocol (PLCP) Protocol Data Units (PPDUs). AP102 and STA104 in WLAN100 may transmit PPDUs via an unlicensed spectrum, and the unlicensed spectrum may be a portion of the spectrum that includes frequency bands conventionally used by Wi-Fi technologies such as the 2.4 GHz band, 5 GHz band, 60 GHz band, 3.6 GHz band, and 700 MHz band. Some implementations of AP102 and STA104 described herein may also communicate within other frequency bands, such as the 6 GHz band, that can support both licensed and unlicensed communication. AP102 and STA104 may also be configured to communicate via other frequency bands, such as shared license frequency bands, where multiple operators may have licenses to operate within the same or overlapping frequency bands.

[0031] Each frequency band may include a plurality of sub - bands or frequency channels. For example, PPDUs compliant with the IEEE802.11n, 802.11ac, 802.11ax, and 802.11be standard revisions can be transmitted via the 2.4GHz, 5GHz, or 6GHz bands, each of which is divided into a plurality of 20MHz channels. Thus, these PPDUs are transmitted via physical channels having a minimum bandwidth of 20MHz, but larger channels can be formed through channel bonding. For example, a PPDU can be transmitted via a physical channel having a bandwidth of 40MHz, 80MHz, 160MHz, or 320MHz by bonding a plurality of 20MHz channels together.

[0032] Each PPDU is a composite structure that includes a PHY preamble and a payload in the form of a PHY service data unit (PSDU). The information provided within the preamble may be used by the receiving device to decode the subsequent data within the PSDU. In cases where a PPDU is transmitted via a bonded channel, the preamble field may be replicated and transmitted in each of the plurality of component channels. The PHY preamble may include both a legacy portion (or "legacy preamble") and a non - legacy portion (or "non - legacy preamble"). The legacy preamble can be used, among other uses, for packet detection, automatic gain control, and channel estimation. The legacy preamble can also generally be used to maintain compatibility with legacy devices. The format, coding, and information provided in the non - legacy portion of the preamble are based on the specific IEEE802.11 protocol that will be used to transmit the payload.

[0033] FIG. 2A shows an exemplary protocol data unit (PDU) 200 that can be used for wireless communication between the AP 102 and one or more STAs 104. For example, the PDU 200 can be configured as a PPDU. As shown, the PDU 200 includes a PHY preamble 202 and a PHY payload 204. For example, the preamble 202 can 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 the preamble 202 can be configured in accordance with the IEEE 802.11a wireless communication protocol standard. The preamble 202 can also include a non-legacy portion that includes one or more non-legacy fields 212 that comply with an IEEE wireless communication protocol, such as, for example, the IEEE 802.11ac, 802.11ax, 802.11be, or later wireless communication protocol standards.

[0034] L-STF206 generally enables the receiving device to perform automatic gain control (AGC), coarse timing estimation, and frequency estimation. L-LTF208 generally enables the receiving device to perform fine timing estimation and frequency estimation and also enables the receiving device to perform an initial estimation of the wireless channel. L-SIG210 generally enables the receiving device to determine the duration of the PDU and use the determined duration to avoid overlapping transmissions with the PDU. For example, L-STF206, L-LTF208, and L-SIG210 may be modulated according to a binary phase shift keying (BPSK) modulation scheme. Payload 204 may be modulated according to a BPSK modulation scheme, a quadrature BPSK (Q-BPSK) modulation scheme, a quadrature amplitude modulation (QAM) modulation scheme, or another suitable modulation scheme. Payload 204 may include a PSDU that includes a data field (DATA) 214, and the data field (DATA) 214 may carry upper layer data, for example, in the form of media access control (MAC) protocol data units (MPDUs) or aggregated MPDUs (A-MPDUs).

[0035] FIG. 2B shows an exemplary L-SIG 210 within the PDU 200 of FIG. 2A. The L-SIG 210 includes a data rate field 222, a reserved bit 224, a length field 226, a parity bit 228, and a tail field 230. The data rate field 222 indicates the data rate (note that the data rate indicated within 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 length of the packet, for example, in units of symbols or bytes. The parity bit 228 may be used to detect bit errors. The tail field 230 includes tail bits that may be used by the receiving device to terminate the operation of a decoder (e.g., a Viterbi decoder). The receiving device may utilize the data rate and length indicated within the data rate field 222 and the length field 226 to determine the duration of the packet, for example, in units of microseconds (μs) or other time units.

[0036] FIG. 3 shows an exemplary PPDU 300 that can be used for communication between the AP 102 and one or more STAs 104. As described above, each PPDU 300 includes a PHY preamble 302 and a PSDU 304. Each PSDU 304 may represent (or “carry”) one or more MAC protocol data units (MPDUs) 316. For example, each PSDU 304 may carry an aggregated MPDU (A-MPDU) 306 that includes an aggregation of a plurality of A-MPDU subframes 308. Each A-MPDU subframe 306 may include an MPDU frame 310 that includes a MAC delimiter 312 and a MAC header 314 prior to the data portion (“payload” or “frame body”) of the MPDU frame 310 of the accompanying MPDU 316. Each MPDU frame 310 may include a frame check sequence (FCS) field 318 for error detection (e.g., the FCS field may include a cyclic redundancy check (CRC)) and padding bits 320. The MPDU 316 can carry one or more MAC service data units (MSDUs) 326. For example, the MPDU 316 may carry an aggregated MSDU (A-MSDU) 322 that includes a plurality of A-MSDU subframes 324. Each A-MSDU subframe 324 includes a corresponding MSDU 330 preceded by a subframe header 328 and optionally followed by padding bits 332.

[0037] Referring again to the MPDU frame 310, the MAC delimiter 312 serves as a marker for the start of the associated MPDU 316 and may indicate the length of the associated MPDU 316. The MAC header 314 may include a plurality of fields containing information that defines or indicates the characteristics or attributes of the data encapsulated within the frame body 316. The MAC header 314 includes a duration field that indicates a duration that at least continues from the end of the PPDU to the end of an acknowledgment (ACK) or Block ACK (BA) of the PPDU that is to be transmitted by the receiving wireless communication device. The use of the duration field helps to reserve the wireless medium for the indicated duration and enables the receiving device to establish its network allocation vector (NAV). The MAC header 314 also includes one or more fields indicating the address of the data encapsulated within the frame body 316. For example, the MAC header 314 may include a combination of a source address, a transmitter address, a receiver address, or a destination address. The MAC header 314 may further include a frame control field that contains control information. The frame control field can specify the frame type, for example, a data frame, a control frame, or a management frame.

[0038] FIG. 4 shows a block diagram of an exemplary wireless communication device 400. In some implementations, the wireless communication device 400 can be an example of a device used in a STA such as one of the STAs 104 described with reference to FIG. 1. In some implementations, the wireless communication device 400 can be an example of a device used in an AP such as the AP 102 described with reference to FIG. 1. The wireless communication device 400 is capable of transmitting (or outputting for transmission) and receiving wireless communication (e.g., in the form of wireless packets). For example, the wireless communication device can transmit and receive packets in the form of physical layer convergence protocol (PLCP) protocol data units (PPDUs) and medium access control (MAC) protocol data units (MPDUs) compliant with the IEEE 802.11 wireless communication protocol standards as defined in the IEEE 802.11-2016 specification or a revised version thereof, including but not limited to 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be.

[0039] The wireless communication device 400 can be a chip, a system on chip (SoC), a chipset, a package, or a device, or can include one or more modems 402, such as a Wi-Fi (IEEE 802.11 compliant) 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").

[0040] The modem 402 can include intelligent hardware blocks or devices, such as, for example, an application-specific integrated circuit (ASIC), among other possibilities. The modem 402 is generally configured to implement the PHY layer. For example, the modem 402 is configured to output a modulated packet to the radio 404 for transmission via a wireless medium by modulating the packet. The modem 402 is similarly configured to obtain a modulated packet received by the radio 404 and demodulate the packet to provide a demodulated packet. In addition to the modulator and demodulator, the modem 402 may further include a digital signal processing (DSP) circuit, an automatic gain control (AGC), a coder, a decoder, a multiplexer, and a demultiplexer. For example, during the transmit mode, data obtained from the processor 406 is provided to the coder, which encodes the data and provides the encoded bits. The encoded bits are then mapped to points within a modulation constellation (using the selected MCS) to provide modulated symbols. The modulated symbols can then be mapped to N SS number of spatial streams or N STS number of spatio-temporal streams. The modulated symbols in each spatial or spatio-temporal stream are then multiplexed, converted via an inverse fast Fourier transform (IFFT) block, and can subsequently be provided to the DSP circuit for Tx window processing 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 a frequency upconverter and ultimately to the radio 404. In an implementation with beamforming, the modulated symbols in each spatial stream are precoded via a steering matrix before being provided to the IFFT block.

[0041] While in the receive mode, the digital signal received from radio 404 is provided to the DSP circuit, which is configured to acquire the received signal, for example, by detecting the presence of the signal and estimating the initial timing and frequency offset. The DSP circuit configuration is further configured to digitally condition the digital signal using, for example, channel (narrowband) filtering, analog impairment conditioning (such as correcting I / Q imbalance), and applying digital gain to finally obtain a narrowband signal. The output of the DSP circuit may then be supplied to the AGC, which is configured to use information extracted from the digital signal within one or more received training fields, for example, to determine an appropriate gain. The output of the DSP circuit is also coupled to a demodulator, which is configured to extract the modulated symbols from the signal and calculate, for example, the logarithm likelihood ratios (LLRs) for each bit position of each subcarrier in each spatial stream. The demodulator is coupled to a decoder, which may be configured to process the LLRs to provide the decoded bits. The decoded bits from all of the spatial streams are then supplied to a demultiplexer for demultiplexing. The demultiplexed bits may then be descrambled and provided to the MAC layer (processor 406) for processing, evaluation, or interpretation.

[0042] The radio 404 generally includes at least one radio frequency (RF) transmitter (or "transmitter chain") and at least one RF receiver (or "receiver chain"), which can be combined into one or more transceivers. For example, the RF transmitter and the RF receiver may each include various DSP circuits including at least one power amplifier (PA) and at least one low-noise amplifier (LNA). Next, the RF transmitter and the RF receiver can be coupled to one or more antennas. For example, in some implementations, the wireless communication device 400 may include or be coupled to a plurality of transmit antennas (each with a corresponding transmit chain) and a plurality of receive antennas (each with a corresponding receive chain). The symbols output from the modem 402 are provided to the radio 404, and then the radio 404 transmits the symbols via the coupled antennas. Similarly, the symbols received via the antennas are acquired by the radio 404, and then the radio 404 provides the symbols to the modem 402.

[0043] Processor 406 can include intelligent hardware blocks or devices such as, for example, a processing core, a processing block, a central processing unit (CPU), a microprocessor, a microcontroller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gates or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. 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 a 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, among other operations or techniques, frame coding and decoding, spatial multiplexing, space-time block coding (STBC), beamforming, and OFDMA resource allocation. In some implementations, processor 406 may generally control modem 402 to cause the modem to perform the various operations described above.

[0044] Memory 408 can include a tangible storage medium such as a random-access memory (RAM), a read-only memory (ROM), or a combination thereof. Memory 408 can also store non-transitory processor or computer-executable software (SW) code that, when executed by processor 406, causes the processor to perform various operations described herein for wireless communication, including generating, transmitting, receiving, and interpreting 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, can be implemented as one or more modules of one or more computer programs.

[0045] FIG. 5A shows a block diagram of an exemplary AP502. For example, AP502 may be an exemplary implementation of AP102 described with reference to FIG. 1. AP502 includes a wireless communication device (WCD) 510 (although AP502 itself may also be generally referred to as a wireless communication device as used herein). For example, wireless communication device 510 may be an exemplary implementation of wireless communication device 400 described with reference to FIG. 4. AP502 also includes a plurality of antennas 520 coupled to wireless communication device 510 for transmitting and receiving wireless communications. In some implementations, AP502 additionally includes an application processor 530 coupled to wireless communication device 510 and a memory 540 coupled to application processor 530. AP502 further includes at least one external network interface 550 that enables AP502 to communicate with a core network or a backhaul network to access an external network including the Internet. For example, 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). Some of the above-described components can communicate directly or indirectly with some of the other components via at least one bus. AP502 further includes a housing that includes at least a portion of wireless communication device 510, application processor 530, memory 540, and antennas 520 and external network interface 550.

[0046] FIG. 5B shows a block diagram of an exemplary STA504. For example, STA504 can be an exemplary implementation of STA104 described with reference to FIG. 1. STA504 includes a wireless communication device 515 (although STA504 itself may also generally be referred to as a wireless communication device as used herein). For example, wireless communication device 515 can be an exemplary implementation of wireless communication device 400 described with reference to FIG. 4. STA504 also includes one or more antennas 525 coupled to wireless communication device 515 for transmitting and receiving wireless communication. Additionally, STA504 includes an application processor 535 coupled to wireless communication device 515 and a memory 545 coupled to application processor 535. In some implementations, STA504 further includes a user interface (UI) 555 (such as a touch screen or keypad) and a display 565, and display 565 can be integrated with UI555 to form a touch screen display. In some implementations, STA504 can further include one or more sensors 575, such as one or more inertial sensors, accelerometers, temperature sensors, pressure sensors, or altitude sensors. Some of the components described above can communicate directly or indirectly with some of the other components via at least one bus. STA504 further includes a housing that encompasses at least a portion of wireless communication device 515, application processor 535, memory 545, and antennas 525, UI555, and display 565.

[0047] As described above, a new WLAN communication protocol is being developed to enable enhanced functionality for wireless communication on carrier frequencies above 7 GHz (such as within the 45 GHz or 60 GHz frequency bands). However, wireless communication on higher carrier frequencies can suffer from greater phase noise and path loss compared to wireless communication on lower frequency bands. For example, increasing the carrier frequency from 5.8 GHz to 60 GHz results in a 10-fold increase in phase noise. Aspects of the present disclosure recognize that phase noise can be reduced by increasing the SCS between modulated subcarriers. Existing WLAN packet formats include an L-STF (such as the L-STF 206 in FIG. 2A) that is modulated every fourth subcarrier across a given bandwidth to support CFO estimation up to two subcarriers apart. Aspects of the present disclosure also recognize that the LO implemented by existing WLAN transmitters and receivers needs to be accurate up to a maximum of ±20 ppm. Thus, existing WLAN architectures can support a CFO of up to ±40 ppm (between the transmitter and the receiver), which corresponds to ±2.4 MHz in the 60 GHz frequency band and ±1.8 MHz in the 45 GHz frequency band. To support a CFO of up to ±2.4 MHz, the SCS associated with the L-STF should be 1.2 MHz or greater.

[0048] Various aspects generally relate to increasing the carrier frequency for wireless communication in a WLAN, and more specifically, to packet designs that support wireless communication on carrier frequencies above 7 GHz. In some aspects, a wireless communication device may map a PPDU to OFDM subcarriers according to an existing tone plan associated with a carrier frequency below 7 GHz (also referred to as a "sub-7 GHz" tone plan) and may upclock the PPDU for transmission on a carrier frequency above 7 GHz. As used herein, the term "upclocking" refers to (the frequency (f associated with an existing sub-7 GHz tone plan) o) refers to increasing the frequency of the clock signal used to convert a PPDU between the frequency domain and the time domain beyond), and the ratio (K) of the up - clocked frequency (f s ) to f o is called the "up - clocking ratio" (where

[0049]

Number

[0050] To achieve one or more of the following potential advantages, certain implementations of the subject matter described in this disclosure may be implemented. By upclocking a PPDU mapped to OFDM subcarriers according to an existing sub-7 GHz tone plan, aspects of the present disclosure can utilize existing WLAN hardware to increase the carrier frequency at which such a PPDU is transmitted (such as to the 60 GHz or 45 GHz frequency bands). As described above, an existing WLAN architecture may support CFO estimation in the 60 GHz frequency band if the SCS associated with the L-STF is 1.2 MHz or greater. The SCS depends in part on the tone plan used to map the PPDU to OFDM subcarriers, and more particularly, on the size of the IFFT associated with the tone plan. Aspects of the present disclosure recognize that for any given IFFT size (N IFFT ) associated with an existing sub-7 GHz tone plan, an appropriate sampling rate f s can be selected such that

[0051]

Number

[0052] FIG. 6 shows an exemplary communication environment 600 including an AP610 and a STA620 according to some implementations. In some implementations, the AP610 can be an example of either the AP102 or the AP502 of FIGS. 1 and 5A, respectively. In some implementations, the STA620 can be an example of either the STA104 or the STA504 of FIGS. 1 and 5B, respectively. In the example of FIG. 6, the AP610 is associated with a BSS that supports wireless communication at carrier frequencies above 7 GHz (such as the 60 GHz frequency band).

[0053] As described above, wireless communication in the 60 GHz frequency band can suffer from greater path loss compared to wireless communication in the sub-7 GHz frequency band. Aspects of the present disclosure recognize that analog beamforming (using multiple antenna elements) can mitigate the effects of path loss and achieve a greater wireless communication range at carrier frequencies above 7 GHz. Analog beamforming is a wireless communication technique in which a transmitting device and a receiving device can adjust the gains and phases of their transmit (TX) and receive (RX) antenna elements to achieve directivity in wireless communication. The process by which the transmitting device and the receiving device adjust their antennas for beamforming is called "beamforming training."

[0054] In some implementations, AP610 may use analog beamforming techniques to communicate with STA620. In the example of FIG. 6, AP610 is shown as a transmitting device. Thus, AP610 may adjust a set of TX antennas to focus the energy of the transmitted signal in a specific direction (referred to as "TX beamforming"). For example, AP610 may transmit a packet or PPDU via several antenna sectors T1 - T7 configured or adjusted for TX beamforming (also referred to as "TX sectors"). The antenna elements associated with each TX sector are weighted such that the energy radiated by each antenna element combines along a specific beam direction. Thus, each of TX sectors T1 - T7 can be adjusted to its respective TX beam direction. For simplicity, AP610 is shown as including seven TX sectors T1 - T7. However, in an actual implementation, AP610 may include fewer or more TX sectors than shown in FIG. 6.

[0055] In some implementations, STA620 may also use analog beamforming techniques to communicate with AP610. In the example of FIG. 6, STA620 is shown as a receiving device. Thus, STA620 may adjust a set of RX antennas to focus the energy of the received signal in a specific direction (referred to as "RX beamforming"). For example, STA620 may receive a packet or PPDU via several antenna sectors R1 - R7 configured or adjusted for RX beamforming (also referred to as "RX sectors"). The antenna elements associated with each RX sector are weighted such that the energy received by each antenna element combines along a specific beam direction. Thus, each of RX sectors R1 - R7 can be adjusted to its respective RX beam direction. For simplicity, STA620 is shown as including seven RX sectors R1 - R7. However, in an actual implementation, STA620 may include fewer or more RX sectors than shown in FIG. 6.

[0056] In some embodiments, the AP610 may perform a beamforming training operation with the STA620 to determine TX and RX beam directions that optimize the beamforming gain for wireless communication between the AP610 and the STA620. For example, the AP610 may transmit respective beamforming training (BFT) packets via each of the TX sectors T1 - T7, and train its TX antenna for TX beamforming by receiving feedback from the STA620 indicating the TX beam direction associated with the highest TX beamforming gain. Further, the STA620 may listen for respective BFT packets from the AP610 via each of the RX sectors R1 - R7, and train its RX antenna for RX beamforming by determining the RX beam direction associated with the highest RX beamforming gain based on the received BFT packets. In some implementations, the AP610 may further train its RX antenna (not shown for simplicity) for RX beamforming, and the STA620 may further train its TX antenna (not shown for simplicity) for TX beamforming.

[0057] In the example of FIG. 6, the AP610 and the STA620 may achieve an optimal beamforming gain with a beam transmitted via the TX sector T1 (of the AP610) and received via the RX sector R7 (of the STA620). In contrast, beams transmitted by the AP610 in other TX beam directions (such as via any of the TX sectors T2 - T7) may not be able to reach the STA620. The direction of the STA620 is generally not known to the AP610 before performing the beamforming training operation. In some embodiments, the AP610 may transmit a beam in each of its TX beam directions while the STA620 is listening in an omni - directional mode to increase the likelihood that at least one of the beams transmitted by the AP610 is received by the STA620 before performing the beamforming training operation.

[0058] Aspects of the present disclosure recognize that the beamforming gain is significantly greater when TX beamforming is used in a transmitting device in combination with RX beamforming in a receiving device (also referred to as "full beamforming gain") than when TX beamforming is used in a transmitting device while the receiving device is operating in an omnidirectional mode (also referred to as "one-sided beamforming gain"). In some aspects, different PPDU formats may be used for wireless communication between an AP610 and an STA620 depending on the level of beamforming gain that can be achieved. More specifically, the "data PHY" (DPHY) PPDU format may be used when full beamforming gain is achievable, and the "control PHY" (CPHY) PPDU format may be used when only one-sided beamforming gain is achievable.

[0059] FIG. 7 shows a block diagram of an exemplary TX processing chain 700 of a wireless communication device according to some implementations. The TX processing chain 700 is configured to process a PPDU 701 for transmission as a radio frequency (RF) signal 705. In some aspects, the PPDU 701 may be an example of the PPDU 300 of FIG. 3. In some implementations, the wireless communication device may be an example of the AP610 of FIG. 6. In some other implementations, the wireless communication device may be an example of the STA620 of FIG. 6. For simplicity, only a single spatial stream of the TX processing chain 700 is shown in FIG. 7. In an actual implementation, the TX processing chain 700 may include any number of spatial streams.

[0060] The TX processing chain 700 includes a constellation mapper 710, an OFDM modulator 720, an RF mixer 730, and a power amplifier (PA) 740. The constellation mapper 710 maps the PPDU 701 to one or more frequency-domain (FD) symbols 702 associated with a modulation scheme. Exemplary suitable modulation schemes include binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), and quadrature amplitude modulation (QAM). The OFDM modulator 720 modulates the FD symbols 702 onto a set of orthogonal subcarriers and converts the modulated subcarriers into a time-varying TX signal 703. The RF mixer 730 up-converts the TX signal 703 to a carrier frequency, and the power amplifier 740 amplifies the resulting RF signal 705 for transmission via one or more antennas 750. For example, the RF mixer 730 may modulate the TX signal 703 onto an LO signal 704 oscillating at the carrier frequency. In some aspects, the carrier frequency associated with the LO signal 704 may be higher than 7 GHz. In some implementations, the carrier frequency may be within the 60 GHz frequency band. In some other implementations, the carrier frequency may be within the 45 GHz frequency band.

[0061] As described above, many existing WLAN architectures are designed for wireless communication at carrier frequencies below 7 GHz (such as the 2.4 GHz, 5 GHz, or 6 GHz frequency bands). In some aspects, existing WLAN hardware can be repurposed to support wireless communication at carrier frequencies above 7 GHz. For example, TX processing chain 700 can receive LO signal 704 from a local oscillator that is accurate up to a maximum of ±20 ppm. As described above, increasing the carrier frequency of LO signal 704 also increases the phase noise associated with RF signal 705. For example, operating the local oscillator at 60 GHz can result in a CFO of ±2.4 MHz between the transmitter and the receiver. According to existing versions of the IEEE 802.11 standard, the PHY preamble of PPDU 701 includes an L-STF with a symbol duration of 1x associated with an SCS equal to 312.5 kHz that can support CFO estimation up to 2 subcarriers apart. As used herein, the term "1xSCS" refers to the subcarrier spacing between the subcarriers to which the L-STF is mapped. Therefore, to support a maximum CFO of ±2.4 MHz, the 1xSCS associated with PPDU 701 should be 1.2 MHz or greater.

[0062] Aspects of the present disclosure recognize that any SCS greater than or equal to 1.2 MHz may not be suitable for wireless communication on sub-7 GHz carrier frequencies. Thus, existing WLAN communication protocols for sub-7 GHz wireless communication (such as IEEE 802.11be, 11ax, 11ac, and initial revisions of the IEEE 802.11 standard) do not define PPDU formats or tone plans associated with SCSs of 1.2 MHz or greater. In some aspects, the TX processing chain 700 may receive a PPDU 701 formatted for transmission on a sub-7 GHz carrier frequency and may up-convert the PPDU 701 to a wider bandwidth suitable for transmission on a carrier frequency above 7 GHz (such as within the 60 GHz or 45 GHz frequency bands). For example, the wider bandwidth is achieved by spreading the subcarriers to which the PPDU 701 is mapped. In some implementations, the TX processing chain 700 may up-convert the PPDU 701 such that the 1xSCS associated with the PPDU 701 is 1.2 MHz or greater.

[0063] In some implementations, PPDU 701 may conform to the PPDU format defined by the IEEE 802.11ac amendment of the IEEE 802.11 standard (also referred to as the "11ac PPDU format"). For example, PPDU 701 may conform to the 11ac PPDU format associated with a 20 MHz, 40 MHz, 80 MHz, 80 + 80 MHz, or 160 MHz channel bandwidth and may be upclocked for transmission on an 80 MHz, 160 MHz, 320 MHz, 480 MHz, 640 MHz, 960 MHz, 1.28 GHz, 1.92 GHz, or 2.56 GHz bandwidth wireless channel within the 60 GHz or 45 GHz frequency band. In some other implementations, PPDU 701 may conform to the PPDU format defined by the IEEE 802.11be (or 11ax) amendment of the IEEE 802.11 standard (also referred to as the "11be PPDU format"). For example, PPDU 701 may conform to the 11be PPDU format associated with a 20 MHz, 40 MHz, or 80 MHz channel bandwidth and may be upclocked for transmission on an 80 MHz, 160 MHz, 320 MHz, 480 MHz, 640 MHz, 960 MHz, 1.28 GHz, 1.92 GHz, or 2.56 GHz bandwidth wireless channel within the 60 GHz or 45 GHz frequency band. Additionally, in some implementations, PPDU 701 may conform to a new greenfield PPDU format optimized for communication in the 60 GHz or 45 GHz frequency band.

[0064] FIG. 8 shows a block diagram of an exemplary OFDM upconverting system 800 according to some implementations. In some aspects, the OFDM upconverting system 800 may be configured to upconvert a PPDU 801 to a TX signal 806 suitable for transmission at a carrier frequency above 7 GHz (such as within the 60 GHz or 45 GHz frequency bands). More specifically, the OFDM upconverting system 800 may map the PPDU 801 onto a set of orthogonal subcarriers associated with 1xSCS of 1.2 MHz or more. In some implementations, the OFDM upconverting system 800 may be an example of the OFDM modulator 720 of FIG. 7. In such an implementation, the PPDU 801 and the TX signal 806 may be examples of the FD symbol 702 and the TX signal 703 of FIG. 7, respectively.

[0065] The OFDM upconverting system 800 includes a tone mapper 810, an N-point IFFT 820, a CP adder 830, and a DAC 840. The tone mapper 810 is configured to map the PPDU 801 onto some (N) subcarriers associated with a sub-7 GHz tone plan to generate N modulated subcarriers 802. In some implementations, the sub-7 GHz tone plan may include 64 subcarriers associated with a 20 MHz channel bandwidth (such as according to the 11ac PPDU format). For example, the 64 subcarriers may include 52 data subcarriers, 4 pilot subcarriers, 7 guard subcarriers, and 1 direct current (DC) subcarrier. In some other implementations, the sub-7 GHz tone plan may include 128 subcarriers associated with a 40 MHz channel bandwidth (such as according to the 11ac PPDU format). For example, the 128 subcarriers may include 108 data subcarriers, 6 pilot subcarriers, 11 guard subcarriers, and 3 DC subcarriers.

[0066] In some implementations, the sub-7 GHz tone plan may include 256 subcarriers associated with an 80 MHz channel bandwidth (such as in accordance with the 11ac PPDU format) or a 20 MHz channel bandwidth (such as in accordance with the 11be PPDU format). For example, the 256 subcarriers may include 234 data subcarriers, 8 pilot subcarriers, 11 guard subcarriers, and 3 DC subcarriers. In some other implementations, the sub-7 GHz tone plan may include 512 subcarriers associated with a 160 MHz channel bandwidth (such as in accordance with the 11ac PPDU format). In such implementations, the 512 subcarriers may include 468 data subcarriers, 16 pilot subcarriers, 11 guard subcarriers, and 11 DC subcarriers. Additionally, in some implementations, the sub-7 GHz tone plan may include 512 subcarriers associated with a 40 MHz channel bandwidth (such as in accordance with the 11be PPDU format). In such implementations, the 512 subcarriers may include 468 data subcarriers, 16 pilot subcarriers, 23 guard subcarriers, and 5 DC subcarriers.

[0067] In some implementations, the sub-7 GHz tone plan may include 1024 subcarriers associated with an 80 MHz channel bandwidth (such as in accordance with the 11be PPDU format). In such implementations, the 1024 subcarriers may include 980 data subcarriers, 16 pilot subcarriers, 23 guard subcarriers, and 5 DC subcarriers. In some other implementations, the sub-7 GHz tone plan may include 2048 subcarriers associated with a 160 MHz channel bandwidth (such as in accordance with the 11be PPDU format). In such implementations, the 2048 subcarriers may include 1960 data subcarriers, 32 pilot subcarriers, 23 guard subcarriers, and 23 DC subcarriers. Additionally, in some implementations, the sub-7 GHz tone plan may include 4096 subcarriers associated with a 320 MHz channel bandwidth (such as in accordance with the 11be PPDU format). In such implementations, the 4096 subcarriers may include 3920 data subcarriers, 64 pilot subcarriers, 23 guard subcarriers, and 23 DC subcarriers.

[0068] The N-point IFFT 820 converts N modulated subcarriers 802 into N time-domain samples 803 from the frequency domain to the time domain. The CP adder 830 adds a cyclic prefix to the N time-domain samples 803 to generate some prefixed samples 804. The DAC 840 converts the prefixed samples 804 into a TX signal 806 based on a clock signal 805. More specifically, the frequency of the clock signal 805 controls the sampling rate (f s ) of the DAC 840. Further, the SCS associated with the TX signal 806 depends on the sampling rate f s of the DAC 840 (controlled by the frequency of the clock signal 805) and the size (N IFFT ) of the IFFT 820, where

[0069]

Number

[0070] Aspects of the present disclosure recognize that some existing versions of the IEEE802.11 standard support channel bonding, whereby a PPDU can be transmitted simultaneously over multiple channels to achieve a gain similar to that of a wider - bandwidth channel. For example, the IEEE802.11ac revision of the IEEE802.11 standard defines a PPDU format that can be transmitted simultaneously on two 80 MHz channels (also called 80 + 80 channel bandwidth) to achieve a gain similar to that of a 160 MHz channel. In some embodiments, the OFDM up - clocking system 800 may utilize existing channel - bonding hardware to transmit a PPDU having a wider bandwidth (without additional up - clocking). In such an embodiment, the PPDU801 may represent a first PPDU segment configured to be transmitted via a first wireless channel. The OFDM up - clocking system 800 may further receive a second PPDU segment 801' configured to be transmitted via a second wireless channel, and the PPDU segment 801 and the PPDU segment 801' collectively form a single PPDU.

[0071] In some implementations, the OFDM upconverting system 800 may include an additional tone mapper 850, an additional N-point IFFT 860, an additional CP adder 870, and an additional DAC 880. The tone mapper 850 is configured to map the second PPDU segment 801’ to N subcarriers associated with the sub-7 GHz tone plan to generate N modulated subcarriers 802’. More specifically, the tone mapper 810 and the tone mapper 850 may implement the same sub-7 GHz tone plan. The N-point IFFT 860 converts the N modulated subcarriers 802’ from the frequency domain to the time domain as N time domain samples 803’. The CP adder 870 adds a cyclic prefix to the time domain samples 803 to generate some prefixed samples 804. The DAC 880 converts the prefixed samples 804’ to the TX signal 806’ based on the clock signal 805. In some implementations, the TX signals 806 and 806’ can be transmitted simultaneously on respective bandwidth portions of the wireless channel.

[0072] FIG. 9A shows an exemplary PPDU 900 formatted according to the legacy PPDU format. In the example of FIG. 9A, the legacy PPDU format is the 11ac PPDU format associated with a 160 MHz channel bandwidth. More specifically, the PPDU 900 conforms to the non-High Throughput (non-HT) duplicate transmission (DUP) PPDU format. The PPDU 900 includes a PHY preamble 901 followed by a data portion 902. The PHY preamble includes an L-STF, an L-LTF, and an L-SIG. As shown in FIG. 9A, the PHY preamble 901 and the data portion 902 are replicated on eight 20 MHz subbands spanning a 160 MHz bandwidth. Thus, the bandwidth (BW) of the PPDU 900 is a multiple of the sampling rate (f s ) of the clock signal used to convert the PPDU 900 from the frequency domain to the time domain (BW = 8* f s )。According to the PPDU format of 11ac, PPDU900 is mapped to the data subcarriers associated with the 64 subcarrier tone plan (within each 20 MHz subband). In other words, PHY preamble 901 is mapped to the same number of subcarriers as data portion 902.

[0073] In some aspects, PPDU900 can be up - clocked as a CPHY PPDU for wireless communication at carrier frequencies above 7 GHz. More specifically, PPDU900 can be used for wireless communication when only unilateral beamforming gain can be achieved between the transmitting device and the receiving device. In some implementations, the transmitting device can transmit PPDU900 before performing a beamforming training operation with the receiving device. In some other implementations, the transmitting device can transmit PPDU900 as part of a beamforming training operation with the receiving device. Thus, PPDU900 can carry beam management information 905 indicating whether PPDU900 is associated with a beamforming training operation or with various parameters associated with a beamforming training operation. Exemplary beam management information 905 can include, among other examples, PPDU type, training direction, beam tracking requirements, training length, countdown, sector ID, antenna ID, best antenna ID, best sector ID, the number of RX sectors or RX antennas of the transmitting device, or SNR reports. In some implementations, beam management information 905 can be carried in data portion 902 (such as in the MAC payload).

[0074] Figure 9B shows an exemplary up - clocked PPDU 910 based on the PPDU format shown in Figure 9A according to some implementations. The PPDU 910 includes a PHY preamble 911 and a subsequent data portion 912. In some aspects, the PPDU 910 may represent an M - fold up - clocking of the PPDU 900. In such aspects, the PHY preamble 911 and the data portion 912 may be examples of the PHY preamble 901 and the data portion 902 of Figure 9A, respectively. In some implementations, a packet extension (PE) or one or more training fields (TRNs) 913 may be added to the PPDU 910 to support extended functions (such as beamforming training operations) for wireless communication at carrier frequencies above 7 GHz. In some aspects, the up - clocking may be performed by the OFDM up - clocking system 800 of Figure 8.

[0075] As a result of the up - clocking, the PHY preamble 911, the data portion 912, and the PE or TRN 913 are * replicated over eight 20 * M MHz sub - bands spanning a 160

[0076] M MHz bandwidth. For example, given a 2 - fold up - clocking ratio (M = 2), the PHY preamble 911, the data portion 912, and the PE or TRN 913 are replicated over eight 40 MHz sub - bands spanning a 320 MHz bandwidth. In some aspects, the PPDU 910 may be a CPHY PPDU that can be used for wireless communication at carrier frequencies above 7 GHz when only a unilateral beamforming gain is achievable between the transmitting device and the receiving device. In some implementations, the data portion 912 may carry beam management information (such as the beam management information 905 of Figure 9A) indicating whether the PPDU 910 is associated with a beamforming training operation or associated with various parameters related to a beamforming training operation.Aspects of the present disclosure recognize that the data portion 912 may not carry any user data because the CPHY PPDU format is used for wireless communication before (or during) the execution of the beamforming training operation between the transmitting device and the receiving device. In some aspects, the overhead associated with the PPDU 910 (or the delay in processing the PPDU 910) can be reduced by moving beam management information 905 from the MAC layer to the PHY layer. For example, the L-SIG can be repurposed to carry at least a portion of the beam management information 905. However, aspects of the present disclosure recognize that the length of the L-SIG may not be sufficient to accommodate all of the beam management information 905. In other words, the PHY preamble 911 may require one or more additional SIG fields (or symbols) to carry the beam management information 905 (instead of the data portion 912).

[0077] FIG. 9C shows another exemplary up-clocked PPDU 920 based on the PPDU format shown in FIG. 9A, according to some implementations. The PPDU 920 includes a PHY preamble having a first portion 921 and a second portion 922. In contrast to the PPDU 910 of FIG. 9B, the PPDU 920 does not include a data portion, but adds two SIG symbols (SIG-A1 and SIG-A2) via the second preamble portion 922 (similar to the very high throughput (VHT) 11ac PPDU format). In some aspects, the PPDU 920 may represent an M-fold up-clocking of the PPDU 900. In such aspects, the first preamble portion 921 may be an example of the PHY preamble 901 of FIG. 9A. In some implementations, a PE or one or more TRNs 923 may be added to the PPDU 920 to support enhanced functionality (such as beamforming training operations) for wireless communication at carrier frequencies above 7 GHz. In some aspects, the up-clocking may be performed by the OFDM up-clocking system 800 of FIG. 8.

[0078] As a result of upconversion, the first preamble portion 921, the second preamble portion 922, and the PE or TRN 923 span 160 * M MHz bandwidth and are replicated over eight 20 * M MHz sub-bands. For example, with a 2x upconversion ratio (M = 2), the first preamble portion 921, the second preamble portion 922, and the PE or TRN 923 are replicated over eight 40 MHz sub-bands spanning 320 MHz bandwidth. In some aspects, the PPDU 920 can be a CPHY PPDU that can be used for wireless communication at carrier frequencies above 7 GHz when only a unilateral beamforming gain can be achieved between the transmitting device and the receiving device. In some implementations, the L-SIG, SIG-A1, and SIG-A2 can be repurposed to carry beam management information (such as the beam management information 905 in FIG. 9A) indicating whether the PPDU 920 is associated with a beamforming training operation or with various parameters associated with a beamforming training operation.

[0079] Figure 9D shows another exemplary up - clocked PPDU 930 based on the PPDU format shown in Figure 9A according to some implementations. The PPDU 930 includes a PHY preamble having a first part 931 and a second part 932. In contrast to the PPDU 910 of Figure 9B, the PPDU 930 does not include a data part, but (similar to the 11be PPDU format) adds repetitions of L - SIG (RL - SIG) and two further SIG symbols (SIG1 and SIG2) via the second preamble part 932. In some aspects, the PPDU 930 may represent an M - fold up - clocking of the PPDU 900. In such aspects, the first preamble part 931 may be an example of the PHY preamble 901 of Figure 9A. In some implementations, a PE or one or more TRNs 933 may be added to the PPDU 930 to support enhanced functionality (such as beamforming training operations) for wireless communication at carrier frequencies above 7 GHz. In some aspects, the up - clocking may be performed by the OFDM up - clocking system 800 of Figure 8.

[0080] As a result of the up - clocking, the first preamble part 931, the second preamble part 932, and the PE or TRN 933 span 160 * eight 20 that span an M MHz bandwidth *It is replicated on the M MHz sub-band. For example, when a 2x up-clocking ratio (M = 2) is given, the first preamble portion 931, the second preamble portion 932, and the PE or TRN 933 are replicated on eight 40 MHz sub-bands spanning a 320 MHz bandwidth. In some aspects, the PPDU 930 can be a CPHY PPDU that can be used for wireless communication on a carrier frequency above 7 GHz when only a unilateral beamforming gain can be achieved between the transmitting device and the receiving device. In some implementations, L-SIG, RL-SIG, SIG1, and SIG2 can be diverted to carry beam management information (such as the beam management information 905 in FIG. 9A) indicating whether the PPDU 930 is associated with a beamforming training operation or is associated with various parameters associated with the beamforming training operation.

[0081] FIG. 10A shows an exemplary PPDU 1000 formatted according to the legacy PPDU format. In the example of FIG. 10A, the legacy PPDU format is the 11be PPDU format associated with a 20 MHz channel bandwidth. More specifically, the PPDU 1000 conforms to the extended range (ER) single user (SU) PPDU format. The PPDU 1000 includes a PHY preamble having a first portion 1001 and a second portion 1002, followed by a data portion 1003 and a PE 1004. The first preamble portion 1001 includes an L-STF, an L-LTF, an L-SIG, an RL-SIG, and four non-legacy signal fields (SIG1 to SIG4). The second preamble portion 1002 includes a non-legacy short training field (STF) and one or more non-legacy long training fields (LTFs).

[0082] The IEEE 802.11be amendment to the IEEE 802.11 standard defines each of the non-legacy signal fields SIG1 to SIG4 as symbols of a universal signal field (U-SIG), and defines the remaining non-legacy fields STF and LTF as the Extremely High Throughput (EHT) fields EHT-STF and EHT-LTF, respectively. Further, the STF sequence associated with L-STF is repeated (2x) in the time domain to generate an "extended L-STF". According to the 11be PPDU format, the data part 1003 (and PE1004) is mapped to each consecutive data subcarrier associated with a 256 subcarrier tone plan. In contrast, L-STF is mapped to every fourth data subcarrier associated with a 64 subcarrier tone plan, while the remainder of the first preamble part 1001 is mapped to each consecutive data subcarrier associated with a 64 subcarrier tone plan. Thus, the bandwidth (BW) of PPDU1000 is equal to the sampling rate (f s ) of the clock signal used to convert PPDU1000 from the frequency domain to the time domain (BW = f s ), while the SCS associated with L-STF is four times larger than the SCS associated with the data part 1003.

[0083] In some aspects, the PPDU1000 can be up - clocked as a CPHY PPDU for wireless communication at carrier frequencies above 7 GHz. More specifically, the PPDU1000 can be used for wireless communication when only a unilateral beamforming gain can be achieved between the transmitting device and the receiving device. In some implementations, the transmitting device can transmit the PPDU1000 before performing a beamforming training operation with the receiving device. In some other implementations, the transmitting device can transmit the PPDU1000 as part of a beamforming training operation with the receiving device. Thus, the PPDU1000 can carry beam management information 1005 indicating whether the PPDU1000 is associated with a beamforming training operation or associated with various parameters associated with a beamforming training operation (as described with reference to FIG. 9A). In some implementations, the beam management information 1005 can be carried in one or more of the L - SIG, RL - SIG, or SIG1 - SIG4 which are SIG fields. In such implementations, the data part 1003 and its associated PHY preamble field (such as the second preamble part 1002) can be omitted from the PPDU1000 to reduce overhead.

[0084] Figure 10B shows an exemplary up - clocked PPDU 1010 based on the PPDU format shown in Figure 10A according to some implementations. In some aspects, PPDU 1010 can be a CPHY PPDU that can be used for wireless communication at carrier frequencies above 7 GHz when only a single - sided beamforming gain can be achieved between the transmitting device and the receiving device. PPDU 1010 includes a PHY preamble 1011 followed by a PE or one or more TRNs 1014. In some aspects, PPDU 1010 can represent an up - clocking of the M - fold PPDU 1000. In such aspects, the PHY preamble 1011 and the PE or TRN 1014 can be examples of the first preamble portion 1001 and the PE 1004 in Figure 10A, respectively. However, in contrast to the PPDU format shown in Figure 10A, the second preamble portion 1002 and the data portion 1003 in Figure 10A are omitted from PPDU 1010. In some aspects, the up - clocking can be performed by the OFDM up - clocking system 800 of Figure 8.

[0085] As described with reference to Figure 10A, the SCS associated with the L - STF is four times larger than the SCS associated with the data portion 1003. Thus, the first preamble portion 1001 can be up - clocked by a factor of M / 4 and replicated four times in the frequency domain to achieve an SCS in the L - STF of 1.2 MHz or more. In some implementations, the OFDM up - clocking system 800 can up - clock the first preamble portion 1001 by a factor of M / 4 to achieve a PPDU bandwidth equal to 20 * M MHz. As a result, the PHY preamble 1011 spans a 20 * M MHz bandwidth with four 5 *It is replicated over the M MHz sub-band. For example, when a 16-fold up-clocking ratio (M = 16) is given, the PHY preamble 1011 is replicated over four 80 MHz sub-bands spanning a 320 MHz bandwidth. Replicating the PHY preamble 1011 four times in the frequency domain results in a 6 dB frequency synthesis gain at the receiving device. Further, repeating the various fields (such as each of the L-STF, L-LTF, and SIG fields or symbols) of the PHY preamble 1011 in the time domain results in an additional 3 dB gain at the receiving device. Such replication in the frequency domain and repetition in the time domain of the various fields of the PPDU 1010 can result in a 9 dB combined gain at the receiving device, which can help compensate for the single-sided beamforming gain.

[0086] Figure 11A shows an exemplary PPDU 1100 formatted according to the legacy PPDU format. In the example of Figure 11A, the legacy PPDU format is the 11be PPDU format associated with a 20 MHz channel bandwidth. The PPDU 1100 includes a PHY preamble having a first part 1101 and a second part 1102, followed by a data part 1103 and a PE 1104. The first preamble part 1101 includes an L-STF, an L-LTF, an L-SIG, an RL-SIG, a first non-legacy signal field (SIG1), and a second non-legacy signal field (SIG2). The second preamble part 1102 includes a non-legacy short training field (STF) and one or more non-legacy long training fields (LTFs).

[0087] The IEEE 802.11 amendment to the IEEE 802.11 standard defines the first non-legacy signal field SIG1 as the Universal Signal Field (U-SIG), and the remaining non-legacy fields SIG2, STF, and LTF as the EHT-SIG, EHT-STF, and EHT-LTF, which are EHT fields respectively. According to the PPDU format of 11be, the data part 1103 (and PE1104) is mapped to each consecutive data subcarrier associated with the 256-subcarrier tone plan. In contrast, the L-STF is mapped to every fourth data subcarrier associated with the 64-subcarrier tone plan, while the rest of the first preamble part 1101 is mapped to each consecutive data subcarrier associated with the 64-subcarrier tone plan. Therefore, the bandwidth (BW) of the PPDU1100 is equal to the sampling rate (f s ) used to convert the PPDU1100 from the frequency domain to the time domain (BW = f s ), while the SCS associated with the L-STF is four times larger than the SCS associated with the data part 1103.

[0088] In some aspects, PPDU 1100 can be up - clocked as a DPHY PPDU for wireless communication at carrier frequencies above 7 GHz. More specifically, PPDU 1100 can be used for wireless communication when a full - beamforming gain is achievable between a transmitting device and a receiving device. In other words, the transmitting device can transmit PPDU 1100 after performing a beamforming training operation with the receiving device. In some other implementations, the transmitting device can transmit PPDU 1100 as part of a beamforming training operation with the receiving device (such as when the transmitting device trains its TX antenna for TX beamforming while the receiving device simultaneously trains its RX antenna for RX beamforming), or as part of a beam improvement procedure associated with a beam - tracking request. In some implementations, PPDU 1100 can carry beam management information 1105 indicating whether PPDU 1100 is associated with a beamforming training operation or with various parameters associated with a beamforming training operation (as described with reference to FIG. 9A). In some implementations, the beam management information 1105 can be carried in one or more of the SIG fields L - SIG, RL - SIG, SIG1, or SIG2.

[0089] In some implementations, the training sequence associated with the L-STF can be replaced with a Golay sequence to simplify packet detection. For example, Golay sequences are sequences of bipolar symbols (+1 or -1) that are often used for channel estimation due to their autocorrelation properties. According to the 11be PPDU format, the non-legacy STF (within the second preamble part 1102) provides AGC and CFO estimation for the data part 1103. However, aspects of the present disclosure recognize that since the channel (or beam) does not change between the transmission of the first preamble part 1101 and the transmission of the data part 1103, the receiving device can perform AGC and CFO estimation for the data part 1103 based on the L-STF (within the first preamble part 1101). In some aspects, the non-legacy STF can be "turned off" in the PPDU 1100 or otherwise ignored. In some implementations, the turned-off field can carry padding bits or non-essential information. In some other implementations, the turned-off field can be completely omitted from the PPDU 1100.

[0090] FIG. 11B shows an exemplary up - clocked PPDU 1110 based on the PPDU format shown in FIG. 11A according to some implementations. In some aspects, PPDU 1110 can be a DPHY PPDU that can be used for wireless communication at carrier frequencies above 7 GHz when a full - beamforming gain can be achieved between a transmitting device and a receiving device. PPDU 1110 includes a PHY preamble having a first portion 1111 and a second portion 1112, followed by a data portion 1113 and a PE or one or more TRNs 1114. In some aspects, PPDU 1110 can represent an M - fold up - clocking of PPDU 1100. In such aspects, the first preamble portion 1111, the second preamble portion 1112, the data portion 1113, and the PE or TRN 1114 can be examples of the first preamble portion 1101, the second preamble portion 1102, the data portion 1103, and the PE 1104 of FIG. 11A, respectively. In some aspects, the up - clocking can be performed by the OFDM up - clocking system 800 of FIG. 8.

[0091] As described with reference to FIG. 11A, the SCS associated with the L - STF is four times larger than the SCS associated with the data portion 1113. Thus, the first preamble portion 1101 can be up - clocked by a factor of M / 4 and replicated four times in the frequency domain to achieve the same SCS as the data portion 1103 in the L - STF. In some implementations, the OFDM up - clocking system 800 can up - clock the first preamble portion 1101 by a factor of M / 4 and up - clock the remainder of PPDU 1100 by a factor of M to generate PPDU 1110. As a result, the second preamble portion 1112 and the data portion 1113 are spread over a 20 * M MHz bandwidth, and the first preamble portion 1111 spans a 20 * M MHz bandwidth with four 5 *It is replicated over the M MHz sub-band. For example, when a 16-fold upconversion ratio (M = 16) is given, the second preamble portion 1112 and the data portion 1113 are spread over a 320 MHz bandwidth, while the first preamble portion 1111 is replicated over four 80 MHz sub-bands spanning a 320 MHz bandwidth.

[0092] As described with reference to FIG. 11A, the non-legacy STF (within the second preamble portion 1112) can be turned off to reduce the overhead associated with the PPDU 1110. In the example of FIG. 11B, the non-legacy LTF is retained within the second preamble portion 1112. The non-legacy LTF provides channel estimation for the data portion 1113. Aspects of the present disclosure recognize that since the channel (or beam) does not change between the transmission of the first preamble portion 1111 and the transmission of the data portion 1113, the receiving device can estimate the channel associated with the data portion 1113 based on the L-LTF (within the first preamble portion 1111). In some aspects, the non-legacy LTF can be turned off or otherwise ignored to further reduce the overhead associated with the PPDU 1110 when the PPDU 1110 is transmitted on a single spatial stream (N SS = 1). In some implementations, the non-legacy LTF can carry padding bits or non-essential information. In some other implementations, the non-legacy LTF can be completely omitted from the PPDU 1110.

[0093] Aspects of the present disclosure further recognize that L-LTF and non-legacy LTF are mapped to different subcarriers according to different tone plans. As described with reference to FIG. 11A, L-LTF is mapped to (and replicated 4 times in the frequency domain) the (52) data subcarriers associated with a 64-point IFFT, while non-legacy LTF is mapped to the (234) data subcarriers associated with a 256-point IFFT. Thus, L-LTF is mapped to fewer data subcarriers (across the bandwidth of PPDU 1110) than non-legacy LTF. In some implementations, the receiving device may need to interpolate missing data subcarriers (such as data subcarriers to which the data portion 1113 is mapped but L-LTF is not mapped) when using the existing L-LTF to estimate the channel associated with the data portion 1113. However, such channel interpolation can result in a loss of performance. In some other implementations, L-LTF may be modified or redesigned to provide a more accurate channel estimate for the data portion 1113.

[0094] FIG. 11C shows another exemplary up - clocked PPDU 1120 based on the PPDU format shown in FIG. 11A according to some implementations. In some aspects, PPDU 1120 can be a DPHY PPDU that can be used for wireless communication at carrier frequencies above 7 GHz when a full - beamforming gain can be achieved between the transmitting device and the receiving device. PPDU 1120 includes a PHY preamble having a first portion 1121 and a second portion 1122, followed by a data portion 1123 and a PE or one or more TRNs 1124. In some aspects, PPDU 1120 can represent an M - fold up - clocking of PPDU 1100. In such aspects, the first preamble portion 1121, the second preamble portion 1122, the data portion 1123, and the PE or TRN 1124 can be examples of the first preamble portion 1101, the second preamble portion 1102, the data portion 1103, and the PE 1104 of FIG. 11A, respectively. In some aspects, the up - clocking can be performed by the OFDM up - clocking system 800 of FIG. 8.

[0095] As described with reference to FIG. 11A, the SCS associated with the L - STF is four times larger than the SCS associated with the data portion 1123. Thus, the first preamble portion 1101 can be up - clocked by a factor of M / 4 and replicated four times in the frequency domain to achieve the same SCS as the data portion 1103 in the L - STF. In some implementations, the OFDM up - clocking system 800 can up - clock the first preamble portion 1101 by a factor of M / 4 and up - clock the rest of the PPDU 1100 by a factor of M to generate the PPDU 1120. As a result, the second preamble portion 1122 and the data portion 1123 are spread over a 20 * M MHz bandwidth, and the PHY preamble 1121 spans a 20 * M MHz bandwidth in four 5 *It is replicated over an M MHz sub-band. For example, given a 16x up-clocking ratio (M = 16), the second preamble portion 1122 and the data portion 1123 are spread over a 320 MHz bandwidth, and the first preamble portion 1121 is replicated over four 80 MHz sub-bands spanning a 320 MHz bandwidth.

[0096] As described with reference to FIG. 11A, the non-legacy STF (within the second preamble portion 1122) can be turned off to reduce the overhead associated with the PPDU 1120. In some implementations, the non-legacy LTF (within the second preamble portion 1122) can also be turned off to further reduce the overhead associated with the PPDU 1120. In the example of FIG. 11C, the L-LTF can be populated on the same subcarriers as the data portion 1123 to compensate for the lack of the non-legacy LTF. As described with reference to FIG. 11B, the existing L-LTF is mapped to fewer data subcarriers than the data portion 1123 due to the difference in the tone plan associated therewith. More specifically, the tone plan associated with the first preamble portion 1121 includes guard subcarriers at the boundaries of each 5 * M MHz sub-band. In some aspects, non-zero values can be modulated on at least a portion of the guard subcarriers associated with the data subcarriers to which the L-LTF is mapped. In other words, the L-LTF can include non-zero values that are mapped to each data subcarrier of its associated tone plan and to some of the guard subcarriers at each sub-band boundary (that match the data subcarriers to which the data portion 1123 is mapped).

[0097] Aspects of the present disclosure recognize that mapping of non-zero values to guard subcarriers can be implemented by existing WLAN hardware (operating on a 20 MHz bandwidth portion). However, the resulting LTF values can increase the peak-to-average power ratio (PAPR) of the PPDU 1120. Aspects of the present disclosure further recognize that additional LTFs may be required to support multiple spatial streams. More specifically, application of the P matrix requires that the LTF values be the same for each spatial stream. Thus, in some implementations, non-legacy LTF may be included within the second preamble portion 1122 only when the PPDU 1120 is to be transmitted via two or more spatial streams (N SS > 1). In some other implementations, the P matrix is applied directly to the L-LTF (within the first preamble portion 1121) to generate two non-identical OFDM symbols that can support up to two spatial streams. In such implementations, non-legacy LTF may be included within the second preamble portion 1122 only when the PPDU 1120 is to be transmitted via three or more spatial streams (N SS > 2).

[0098] FIG. 11D shows another exemplary up - clocked PPDU 1130 based on the PPDU format shown in FIG. 11A according to some implementations. In some aspects, PPDU 1130 can be a DPHY PPDU that can be used for wireless communication at carrier frequencies above 7 GHz when a full - beamforming gain can be achieved between a transmitting device and a receiving device. PPDU 1130 includes a PHY preamble having a first part 1131 and a second part 1132, followed by a data part 1133 and a PE or one or more TRNs 1134. In some aspects, PPDU 1130 can represent an M - fold up - clocking of PPDU 1100. However, in contrast to PPDU 1100 of FIG. 11A, the first preamble part 1131 replaces the L - LTF and includes a non - legacy long training field (LTF) that is mapped to the same data sub - carriers as the data part 1133 (according to the same tone plan). In some aspects, the up - clocking can be performed by the OFDM up - clocking system 800 of FIG. 8.

[0099] As described with reference to FIG. 11A, the SCS associated with the L - STF is four times larger than the SCS associated with the data part 1133. Thus, the first preamble part 1101 (excluding the LTF) can be up - clocked by a factor of M / 4 and replicated four times in the frequency domain to achieve the same SCS as the data part 1103 in the L - STF. In some implementations, the OFDM up - clocking system 800 can up - clock the first preamble part 1101 (excluding the LTF) by a factor of M / 4 and up - clock the rest of PPDU 1100 (including the LTF within the first preamble part 1101) by a factor of M to generate PPDU 1130. As a result, the non - legacy LTF within the first preamble part 1131, the second preamble part 1132, and the data part 1133 are spread over a 20 * M MHz bandwidth, and the rest of the first preamble part 1131 is 20 * M MHz wide and consists of four 5 *It is replicated over the M MHz sub-band. For example, when a 16-fold up-clocking ratio (M = 16) is given, the non-legacy LTF in the first preamble portion 1131, the second preamble portion 1132, and the data portion 1133 are spread over a 320 MHz bandwidth, while the remainder of the first preamble portion 1131 is replicated over four 80 MHz sub-bands spanning a 320 MHz bandwidth.

[0100] As described with reference to FIG. 11A, the non-legacy STF (in the second preamble portion 1132) can be turned off to reduce the overhead associated with the PPDU 1130. In some implementations, the non-legacy LTF (in the second preamble portion 1132) can also be turned off to further reduce the overhead associated with the PPDU 1130. In the example of FIG. 11D, the non-legacy LTF in the first preamble portion 1131 is populated on the same sub-carriers as the data portion 1133 to compensate for the absence of the non-legacy LTF in the second preamble portion 1132. In some implementations, the non-legacy LTF can be optimized for the bandwidth associated with the PPDU 1130. For example, referring to FIG. 11C, the non-legacy LTF in the first preamble portion 1131 can result in a lower PAPR than the L-LTF mapping in the first preamble portion 1121 of the PPDU 1120.

[0101] Aspects of the present disclosure further recognize that additional LTFs may be required to support multiple spatial streams (as described with reference to FIG. 11C). Thus, in some implementations, when the PPDU 1130 has multiple spatial streams (N SSAdditional non-legacy LTFs may be included within the second preamble portion 1132 only when they are to be transmitted via >1). In some other implementations, the P matrix may be applied directly to the non-legacy LTFs within the first preamble portion 1131 to generate two non-identical OFDM symbols that support up to two spatial streams. In such implementations, additional non-legacy LTFs may be included within the second preamble portion 1132 only when the PPDU 1130 is to be transmitted via three or more spatial streams (NSS > 2).

[0102] FIG. 12A shows an exemplary PPDU 1200 formatted according to the legacy PPDU format. In the example of FIG. 12A, the legacy PPDU format is the 11ac PPDU format associated with an 80 MHz channel bandwidth. The PPDU 1200 includes a PHY preamble having a first portion 1201 and a second portion 1202, followed by a data portion 1203. The first preamble portion 1201 includes an L-STF, an L-LTF, an L-SIG, and a first non-legacy signal field (SIG-A) spanning the first OFDM symbol (SIG-A1) and the second OFDM symbol (SIG-A2). The second preamble portion 1202 includes a non-legacy short training field (STF), one or more non-legacy long training fields (LTFs), and a second non-legacy signal field (SIG-B).

[0103] The IEEE 802.11ac amendment to the IEEE 802.11 standard defines the non-legacy fields SIG-A1, SIG-A2, STF, LTF, and SIG-B as VHT fields VHT-SIG-A1, VHT-SIG-A2, VHT-STF, VHT-LTF, and VHT-SIG-B, respectively. According to the 11ac PPDU format, the data part 1203 is mapped to each consecutive data subcarrier associated with a 256-subcarrier tone plan spanning an 80 MHz bandwidth. In contrast, the first preamble part 1201 is replicated over four 20 MHz sub-bands spanning an 80 MHz bandwidth. More specifically, L-STF is mapped to every fourth data subcarrier associated with a 64-subcarrier tone plan, while the remainder of the first preamble part 1201 is mapped to each consecutive data subcarrier associated with a 64-subcarrier tone plan. Thus, the bandwidth (BW) of the PPDU 1200 is equal to the sampling rate (f s ) of the clock signal used to convert the PPDU 1200 from the frequency domain to the time domain (BW = f s ), and the SCS associated with L-STF is equal to the SCS associated with the data part 1203.

[0104] In some aspects, PPDU 1200 can be up - clocked as a DPHY PPDU for wireless communication at carrier frequencies above 7 GHz. More specifically, PPDU 1200 can be used for wireless communication when a full - beamforming gain can be achieved between a transmitting device and a receiving device. In other words, after performing a beamforming training operation with the receiving device, the transmitting device can transmit PPDU 1200. In some implementations, PPDU 1200 can carry beam management information 1205 indicating whether PPDU 1200 is associated with a beamforming training operation or with various parameters associated with a beamforming training operation (such as those described with reference to FIG. 9A). In some implementations, beam management information 1205 can be carried in one or more of the SIG fields (such as L - SIG, SIG - A1, or SIG - A2) within the first preamble portion 1201.

[0105] In some implementations, the training sequence associated with the L-STF can be replaced with a Golay sequence to simplify packet detection (as described with reference to FIG. 11A). In some aspects, the non-legacy STF can be turned off to reduce the overhead associated with the PPDU 1200 (as described with reference to FIG. 11A). According to the 11ac PPDU format, the SIG-B (within the second preamble portion 1202) provides signaling for multi-user (MU) communication. However, aspects of the present disclosure recognize that the PPDU 1200 may not support MU communication due to the narrow beams required to overcome path loss at carrier frequencies above 7 GHz (as described with reference to FIG. 6). In some aspects, the SIG-B can also be turned off to further reduce the overhead associated with the PPDU 1200. In some implementations, the turned-off field can carry padding bits or non-essential information. In some other implementations, the turned-off field can be completely omitted from the PPDU 1200.

[0106] Figure 12B shows an exemplary up - clocked PPDU 1210 based on the PPDU format shown in Figure 12A according to some implementations. In some aspects, PPDU 1210 can be a DPHY PPDU that can be used for wireless communication at carrier frequencies above 7 GHz when a full - beamforming gain can be achieved between the transmitting device and the receiving device. PPDU 1210 includes a PHY preamble having a first part 1211 and a second part 1212, followed by a data part 1213. In some aspects, PPDU 1210 can represent an up - clocking of the M - fold PPDU 1200. In such aspects, the first preamble part 1211, the second preamble part 1212, and the data part 1213 can be examples of the first preamble part 1201, the second preamble part 1202, and the data part 1203 of Figure 12A, respectively. In some aspects, the up - clocking can be performed by the OFDM up - clocking system 800 of Figure 8.

[0107] In some implementations, to support extended functions (such as beamforming training operations) for wireless communication at carrier frequencies above 7 GHz, a PE or one or more TRN 1214 can be added to PPDU 1210. As a result of the up - clocking, the second preamble part 1212 and the data part 1213 are spread over an 80 * M MHz bandwidth, and the first preamble part 1211 is * replicated over four 20 * M MHz sub - bands spanning an 80

[0108] As described with reference to FIG. 12A, the non-legacy STF and SIG-B (within the second preamble portion 1212) can be turned off to reduce the overhead associated with the PPDU 1210. In the example of FIG. 12B, the non-legacy LTF is retained within the second preamble portion 1212. In some other aspects, the non-legacy LTF can be turned off or otherwise ignored to further reduce the overhead associated with the PPDU 1210 (as described with reference to FIG. 11B). In some implementations, the receiving device can estimate the channel associated with the data portion 1213 based on the existing L-LTF within the first preamble portion 1211 (such as through interpolation of missing data subcarriers). In some other implementations, the L-LTF can be modified or redesigned to provide a more accurate channel estimate for the data portion 1213.

[0109] FIG. 12C shows another exemplary upclocked PPDU 1220 based on the PPDU format shown in FIG. 12A according to some implementations. In some aspects, the PPDU 1220 can be a DPHY PPDU that can be used for wireless communication at carrier frequencies above 7 GHz when a full beamforming gain is achievable between the transmitting device and the receiving device. The PPDU 1220 includes a PHY preamble having a first portion 1221 and a second portion 1222, followed by a data portion 1223. In some aspects, the PPDU 1220 can represent an M-fold upclocking of the PPDU 1200. In such an aspect, the first preamble portion 1221, the second preamble portion 1222, and the data portion 1223 can be examples of the first preamble portion 1201, the second preamble portion 1202, and the data portion 1203 of FIG. 12A, respectively. In some aspects, the upclocking can be performed by the OFDM upclocking system 800 of FIG. 8.

[0110] In some implementations, to support extended functionality (such as beamforming training operations) for wireless communication at carrier frequencies above 7 GHz, a PE or one or more TRNs 1224 may be added to the PPDU 1220. As a result of upclocking, the second preamble portion 1222 and the data portion 1223 are spread over an 80 * M MHz bandwidth, and the first preamble portion 1221 is replicated over four 20 * M MHz sub-bands spanning an 80 * M MHz bandwidth. For example, given a 4x upclocking ratio (M = 4), the second preamble portion 1222 and the data portion 1223 are spread over a 320 MHz bandwidth, while the first preamble portion 1221 is replicated over four 80 MHz sub-bands spanning a 320 MHz bandwidth.

[0111] As described with reference to FIG. 12A, the non-legacy STF and SIG-B (within the second preamble portion 1222) may be turned off to reduce the overhead associated with the PPDU 1220. In some implementations, the non-legacy LTF (within the second preamble portion 1222) may also be turned off to further reduce the overhead associated with the PPDU 1220. In the example of FIG. 12C, the L-LTF may be populated on the same subcarriers as the data portion 1223 to compensate for the absence of the non-legacy LTF. In some aspects, non-zero values may be modulated on at least a portion of the guard subcarriers associated with the data subcarriers on which the L-LTF is mapped (as described with reference to FIG. 11C). In some implementations, the non-legacy LTF may be included in the second preamble portion 1222 only when the PPDU 1220 is to be transmitted via multiple spatial streams (N SS > 1). In some other implementations, the P matrix may be applied directly to the L-LTF (within the first preamble portion 1221) to generate two non-identical OFDM symbols. In such implementations, when the PPDU 1220 has three or more spatial streams (NSS The non-legacy LTF may be included within the second preamble part 1222 only when it is to be transmitted via >2).

[0112] FIG. 12D shows another exemplary up-clocked PPDU 1230 based on the PPDU format shown in FIG. 12A according to some implementations. In some aspects, the PPDU 1230 can be a DPHY PPDU that can be used for wireless communication at carrier frequencies above 7 GHz when a full-beamforming gain can be achieved between the transmitting device and the receiving device. The PPDU 1230 includes a PHY preamble having a first part 1231 and a second part 1232, followed by a data part 1233. In some aspects, the PPDU 1230 can represent an up-clocking of the M-fold PPDU 1200. However, in contrast to the PPDU 1200 of FIG. 12A, the first preamble part 1231 replaces the L-LTF and includes a non-legacy long training field (LTF) that is mapped to the same data subcarriers as the data part 1233 (according to the same tone plan). In some aspects, the up-clocking can be performed by the OFDM up-clocking system 800 of FIG. 8.

[0113] In some implementations, a PE or one or more TRNs 1234 can be added to the PPDU 1230 to support enhanced functionality (such as beamforming training operations) for wireless communication at carrier frequencies above 7 GHz. As a result of the up-clocking, the non-legacy LTF within the first preamble part 1231, the second preamble part 1232, and the data part 1233 are spread over an 80 * M MHz bandwidth, and the first preamble part 1231 (excluding the LTF) spans 80 * M MHz bandwidth in four 20 *It is replicated over the M MHz sub-band. For example, when a 4x up-clocking ratio (M = 4) is given, the non-legacy LTF in the first preamble part 1231, the second preamble part 1232, and the data part 1233 are spread over a 320 MHz bandwidth, while the first preamble part 1231 (excluding the LTF) is replicated over four 80 MHz sub-bands spanning a 320 MHz bandwidth.

[0114] As described with reference to FIG. 12A, the non-legacy STF and SIG-B (within the second preamble part 1232) can be turned off to reduce the overhead associated with the PPDU 1230. In some implementations, the non-legacy LTF (within the second preamble part 1232) can also be turned off to further reduce the overhead associated with the PPDU 1230. In the example of FIG. 12D, the non-legacy LTF in the first preamble part 1231 is populated on the same sub-carriers as the data part 1233 to compensate for the lack of the non-legacy LTF in the second preamble part 1232. In some implementations, the non-legacy LTF can be optimized for the bandwidth associated with the PPDU 1230 (as described with reference to FIG. 11D). In some implementations, additional non-legacy LTF can be added to the second preamble part 1232 only when the PPDU 1230 is to be transmitted via multiple spatial streams (N SS > 1). In some other implementations, the P matrix can be applied directly to the non-legacy LTF in the first preamble part 1231 to generate two non-identical OFDM symbols. In such implementations, additional non-legacy LTF can be included within the second preamble part 1232 only when the PPDU 1230 is to be transmitted via three or more spatial streams (NSS > 2).

[0115] FIG. 13A shows an exemplary PPDU 1300 formatted according to the legacy PPDU format. In the example of FIG. 13A, the legacy PPDU format is the 11ac PPDU format associated with an 80 + 80 MHz channel bandwidth. The PPDU 1300 includes a PHY preamble having a first portion 1301 and a second portion 1302, followed by a data portion 1303. The first preamble portion 1301 includes an L-STF, an L-LTF, an L-SIG, and a first non-legacy signal field (SIG-A) spanning a first OFDM symbol (SIG-A1) and a second OFDM symbol (SIG-A2). The second preamble portion 1302 includes a non-legacy short training field (STF), one or more non-legacy long training fields (LTFs), and a second non-legacy signal field (SIG-B).

[0116] The IEEE 802.11ac amendment to the IEEE 802.11 standard defines the non-legacy fields SIG-A1, SIG-A2, STF, LTF, and SIG-B as VHT fields VHT-SIG-A1, VHT-SIG-A2, VHT-STF, VHT-LTF, and VHT-SIG-B, respectively. According to the 11ac PPDU format, the data portion 1303 is mapped to each consecutive data subcarrier associated with a 256 subcarrier tone plan spanning a first 80 MHz bandwidth and each consecutive data subcarrier associated with a 256 subcarrier tone plan spanning a second 80 MHz bandwidth. In contrast, the first preamble portion 1301 is replicated over four 20 MHz subbands spanning a first 80 MHz bandwidth and another four 20 MHz subbands spanning a second 80 MHz bandwidth. More specifically, the L-STF is mapped to every fourth data subcarrier associated with a 64 subcarrier tone plan, while the remainder of the first preamble portion 1301 is mapped to each consecutive data subcarrier associated with a 64 subcarrier tone plan. Referring to FIG. 12A for example, each 80 MHz bandwidth portion of the PPDU 1300 reflects the format of the PPDU 1200.

[0117] In some embodiments, PPDU 1300 can be upclocked as a DPHY PPDU for wireless communication on a carrier frequency above 7 GHz. More specifically, PPDU 1300 can be used for wireless communication when a full beamforming gain can be achieved between a transmitting device and a receiving device. In other words, after performing a beamforming training operation with the receiving device, the transmitting device can transmit PPDU 1300. In some implementations, PPDU 1300 can carry beam management information 1305 indicating whether PPDU 1300 is associated with a beamforming training operation or with various parameters associated with a beamforming training operation (as described with reference to FIG. 9A). In some implementations, the beam management information 1305 can be carried in one or more (such as L-SIG, SIG-A1, or SIG-A2) of the SIG fields within the first preamble portion 1301.

[0118] In some implementations, the training sequence associated with the L-STF can be replaced with a Golay sequence to simplify packet detection (as described with reference to FIG. 11A). In some embodiments, the non-legacy STF can be turned off to reduce the overhead associated with PPDU 1300 (as described with reference to FIG. 11A). In some embodiments, SIG-B can also be turned off to further reduce the overhead associated with PPDU 1300 (as described with reference to FIG. 12A). In some implementations, the turned-off fields can carry padding bits or non-essential information. In some other implementations, the turned-off fields can be completely omitted from PPDU 1300.

[0119] Figure 13B shows an exemplary up - clocked PPDU 1310 based on the PPDU format shown in Figure 13A according to some implementations. In some aspects, PPDU 1310 can be a DPHY PPDU that can be used for wireless communication at carrier frequencies above 7 GHz when a full - beamforming gain can be achieved between a transmitting device and a receiving device. PPDU 1310 includes a PHY preamble having a first part 1311 and a second part 1312, followed by a data part 1313. In some aspects, PPDU 1310 can represent an M - fold up - clocking of PPDU 1300. In such aspects, the first preamble part 1311, the second preamble part 1312, and the data part 1313 can be examples of the first preamble part 1301, the second preamble part 1302, and the data part 1303 of Figure 13A, respectively. In some aspects, the up - clocking can be performed by the OFDM up - clocking system 800 of Figure 8.

[0120] In some implementations, to support extended functions (such as beamforming training operations) for wireless communication at carrier frequencies above 7 GHz, a PE or one or more TRNs 1314 can be added to PPDU 1310. As a result of the up - clocking, the second preamble part 1312 and the data part 1313 are spread over two 80 * M MHz bandwidth portions, and the first preamble part 1311 is in the first 80 * M MHz bandwidth covering four 20 * M MHz sub - bands, and another four 20 * M MHz sub - bands covering the second 80 *It is replicated over the M MHz sub-band. For example, when a 4x up-clocking ratio (M = 4) is given, the second preamble part 1312 and the data part 1313 are spread over a 640 MHz bandwidth, while the first preamble part 1311 is replicated over eight 80 MHz sub-bands spanning a 640 MHz bandwidth. Referring to, for example, FIG. 12B, each 80 MHz bandwidth part of the PPDU 1310 reflects the format of the PPDU 1210.

[0121] As described with reference to FIG. 13A, the non-legacy STF and SIG-B (within the second preamble part 1312) can be turned off to reduce the overhead associated with the PPDU 1310. In the example of FIG. 13B, the non-legacy LTF is retained within the second preamble part 1312. In some other aspects, the non-legacy LTF can be turned off or otherwise ignored to further reduce the overhead associated with the PPDU 1310 (as described with reference to FIG. 11B). In some implementations, the receiving device can estimate the channel associated with the data part 1313 based on the existing L-LTF within the first preamble part 1311 (such as through interpolation of missing data sub-carriers). In some other implementations, the L-LTF can be modified or redesigned to provide a more accurate channel estimate for the data part 1313.

[0122] FIG. 13C shows another exemplary up - clocked PPDU 1320 based on the PPDU format shown in FIG. 13A according to some implementations. In some aspects, PPDU 1320 can be a DPHY PPDU that can be used for wireless communication at carrier frequencies above 7 GHz when a full - beam forming gain can be achieved between the transmitting device and the receiving device. PPDU 1320 includes a PHY preamble having a first part 1321 and a second part 1322, followed by a data part 1323. In some aspects, PPDU 1320 can represent an M - fold up - clocking of PPDU 1300. In such aspects, the first preamble part 1321, the second preamble part 1322, and the data part 1323 can be examples of the first preamble part 1301, the second preamble part 1302, and the data part 1303 of FIG. 13A, respectively. In some aspects, the up - clocking can be performed by the OFDM up - clocking system 800 of FIG. 8.

[0123] In some implementations, to support extended functions (such as beamforming training operations) for wireless communication at carrier frequencies above 7 GHz, a PE or one or more TRNs 1324 can be added to PPDU 1320. As a result of the up - clocking, the second preamble part 1322 and the data part 1323 are spread over two 80 * M MHz bandwidth parts, and the first preamble part 1321 is four 20 * M MHz sub - bands covering the first 80 * M MHz bandwidth part, and another four 20 * M MHz sub - bands covering the second 80 *It is replicated over the M MHz sub-band. For example, when a 4x up-clocking ratio (M = 4) is given, the second preamble part 1322 and the data part 1323 are spread over a 640 MHz bandwidth, while the first preamble part 1321 is replicated over eight 80 MHz sub-bands spanning a 640 MHz bandwidth. Referring to FIG. 12C for example, each 80 MHz bandwidth portion of the PPDU1320 reflects the format of the PPDU1220.

[0124] As described with reference to FIG. 13A, the non-legacy STF and SIG-B (within the second preamble part 1322) can be turned off to reduce the overhead associated with the PPDU1320. In some implementations, the non-legacy LTF (within the second preamble part 1322) can also be turned off to further reduce the overhead associated with the PPDU1320. In the example of FIG. 13C, the L-LTF can be populated on the same sub-carriers as the data part 1323 to compensate for the lack of the non-legacy LTF. In some aspects, non-zero values can be modulated on at least a portion of the guard sub-carriers associated with the data sub-carriers on which the L-LTF is mapped (as described with reference to FIG. 11C). In some implementations, the non-legacy LTF can be included within the second preamble part 1322 only when the PPDU1320 is to be transmitted via multiple spatial streams (N SS > 1). In some other implementations, the P matrix can be applied directly to the L-LTF (within the first preamble part 1321) to generate two non-identical OFDM symbols. In such implementations, the non-legacy LTF can be included within the second preamble part 1322 only when the PPDU1320 is to be transmitted via three or more spatial streams (N SS > 2).

[0125] Figure 13D shows another exemplary up - clocked PPDU 1330 based on the PPDU format shown in Figure 13A according to some implementations. In some aspects, PPDU 1330 can be a DPHY PPDU that can be used for wireless communication at carrier frequencies above 7 GHz when a full - beamforming gain can be achieved between the transmitting device and the receiving device. PPDU 1330 includes a PHY preamble having a first part 1331 and a second part 1332, followed by a data part 1333. In some aspects, PPDU 1330 can represent an M - fold up - clocking of PPDU 1300. However, in contrast to PPDU 1300 of Figure 13A, the first preamble part 1331 replaces the L - LTF and includes a non - legacy long training field (LTF) that is mapped to the same data sub - carriers as the data part 1333 (according to the same tone plan). In some aspects, the up - clocking can be performed by the OFDM up - clocking system 800 of Figure 8.

[0126] In some implementations, a PE or one or more TRNs 1334 can be added to PPDU 1330 to support enhanced functionality (such as beamforming training operations) for wireless communication at carrier frequencies above 7 GHz. As a result of the up - clocking, the non - legacy LTF within the first preamble part 1331, the second preamble part 1332, and the data part 1333 are spread over two 80 * M MHz bandwidth parts, and the first preamble part 1331 (excluding the LTF) spans four 20 * M MHz sub - bands in the first 80 * M MHz bandwidth part, and another four 20 * M MHz sub - bands in the second 80 *It is replicated over the M MHz sub-band. For example, when a 4x up-clocking ratio (M = 4) is given, the non-legacy LTFs in the first preamble part 1331, the second preamble part 1332, and the data part 1333 are spread over a 640 MHz bandwidth, while the first preamble part 1331 (excluding the LTF) is replicated over eight 80 MHz sub-bands spanning a 640 MHz bandwidth. Referring to FIG. 12D for example, each 80 MHz bandwidth part of the PPDU1330 reflects the format of the PPDU1230.

[0127] As described with reference to FIG. 13A, the non-legacy STF and SIG-B (in the second preamble part 1332) can be turned off to reduce the overhead associated with the PPDU1330. In some implementations, the non-legacy LTF (in the second preamble part 1332) can also be turned off to further reduce the overhead associated with the PPDU1330. In the example of FIG. 13D, the non-legacy LTF in the first preamble part 1331 is populated on the same sub-carriers as the data part 1333 to compensate for the absence of the non-legacy LTF in the second preamble part 1332. In some implementations, the non-legacy LTF can be optimized for the bandwidth associated with the PPDU1330 (as described with reference to FIG. 11D). In some implementations, additional non-legacy LTFs can be included in the second preamble part 1332 only when the PPDU1130 is to be transmitted via multiple spatial streams (N SS > 1). In some other implementations, the P matrix can be directly applied to the L-LTF (in the first preamble part 1331) to generate two non-identical OFDM symbols. In such implementations, additional non-legacy LTFs can be included in the second preamble part 1332 only when the PPDU1330 is to be transmitted via three or more spatial streams (NSS > 2).

[0128] Aspects of the present disclosure recognize that the CPHY PPDU format of FIG. 10B and the DPHY PPDU format of FIG. 11B can be implemented using the same processing and up - clocking resources. For example, the PHY preamble 1011 and the first preamble portion 1111 each include an RL - SIG and have the same SCS and frequency repetition. Thus, the CPHY PPDU format of FIG. 10B and the DPHY PPDU format of FIG. 11B can collectively represent a "harmonized" PPDU format. In some aspects, the harmonized PPDU format can include signaling to indicate whether the PPDU conforms to the CPHY PPDU format (including four L - STF symbols and four non - legacy SIG symbols SIG1 to SIG4) or the DPHY PPDU format (including two L - STF symbols and two non - legacy SIG symbols SIG1 and SIG2).

[0129] In some implementations, the PPDU format (CPHY or DPHY) can be signaled by the value of the length field (L_LEN) within the L - SIG. For example, the PPDU can conform to either the DPHY PPDU format or the CPHY PPDU format depending on whether L_LEN % 3 = 0. In some other implementations, the PPDU format (CPHY or DPHY) can be signaled by the modulation scheme associated with one of the non - legacy SIG fields (or SIG symbols). For example, the second SIG symbol SIG2 can be modulated according to either the BPSK modulation scheme or the quadrature BPSK (QBPSK) modulation scheme to indicate whether the PPDU conforms to the DPHY PPDU format or the CPHY PPDU format.

[0130] As described with reference to FIGS. 9A - 13D, many existing PPDU formats (including the 11ac PPDU format and the 11be PPDU format) include redundant fields or signaling. Such redundancy can provide backward compatibility with legacy WLAN devices operating in the sub - 7 GHz frequency band. However, aspects of the present disclosure recognize that there are currently no legacy WLAN devices operating at carrier frequencies above 7 GHz. Thus, in some aspects, a new “greenfield” PPDU format can be designed for carrier frequencies above 7 GHz. More specifically, the greenfield PPDU format can be optimized for communication at carrier frequencies above 7 GHz, for example, by reducing or removing redundant fields or signaling that would otherwise be included for backward compatibility with legacy WLAN devices. In some implementations, the PHY preamble of the greenfield PPDU format can have the same symbol duration as the data portion. In some other implementations, the PHY preamble of the greenfield PPDU format can have a shorter symbol duration than the data portion (to further reduce the overhead of the PPDU).

[0131] FIG. 14A shows an exemplary PPDU 1400 compliant with the greenfield PPDU format according to some implementations. In some implementations, the PPDU 1400 can be a DPHY PPDU that can be used for wireless communication at carrier frequencies above 7 GHz when a full - beamforming gain is achievable between the transmitting device and the receiving device. The PPDU 1400 includes a PHY preamble 1401, a data portion 1402 following it, and a PE or one or more TRNs 1403. The PHY preamble 1401 includes a Short Training Field (STF), a Long Training Field (LTF), and a Signal (SIG) field.

[0132] In some implementations, the PHY preamble 1401 may have the same symbol duration as the data portion 1402. In the example of FIG. 14A, the data portion 1402 is mapped to 256 subcarriers associated with the sub-7 GHz tone plan, and the PHY preamble 1401 is also mapped to the same 256 subcarriers. Thus, the SCS associated with the PHY preamble 1401 is equal to the SCS associated with the data portion 1402. As described with reference to FIG. 8, the sub-7 GHz tone plan maps subcarriers to a channel bandwidth suitable for wireless communication in the sub-7 GHz frequency band. For example, the tone plan associated with the 11ac PPDU format spreads 256 subcarriers over an 80 MHz bandwidth. Thus, the PPDU 1400 can be further upclocked to a wider bandwidth to achieve an SCS suitable for wireless communication at carrier frequencies above 7 GHz (as described with reference to FIGS. 9A-13D). In some aspects, the upclocking can be performed by the OFDM upclocking system 800 of FIG. 8.

[0133] In some aspects, the STF can extend over two OFDM symbols (similar to the L-STF in existing PPDU formats). In some implementations, the STF can reuse an existing training sequence associated with wireless communication on a carrier frequency below 7 GHz (such as the STF sequence associated with the 11ac PPDU format or the 11be PPDU format). For example, the training sequence can be mapped to every fourth, eighth, or sixteenth data subcarrier associated with a 256 subcarrier tone plan (similar to the periodicity of the L-STF in existing PPDU formats). In some implementations, the existing training sequence can be a trigger-based (TB) STF sequence associated with an upclocked PPDU bandwidth. For example, when PPDU1400 is upclocked four times from an 80 MHz sub-7 GHz channel bandwidth, the STF can carry a TB STF sequence associated with a 320 MHz bandwidth. In some other implementations, the STF can include a Golay sequence to simplify packet detection (as described with reference to FIG. 11A).

[0134] In some aspects, the LTF can extend over two OFDM symbols (similar to the L-LTF in existing PPDU formats). In some implementations, the LTF can reuse an existing training sequence associated with wireless communication on a carrier frequency below 7 GHz (such as the LTF sequence associated with the 11ac PPDU format or the 11be PPDU format). For example, the training sequence can be mapped to each of the (234) data + (8) pilot subcarriers associated with a 256 subcarrier tone plan. In some implementations, when PPDU1400 has multiple spatial streams (N SSWhen transmitted via >1), PHY preamble 1401 may include one or more additional LTFs (following the SIG field). In some other implementations, the P matrix may be applied directly to the first LTF (preceding the SIG field) to generate two non-identical OFDM symbols. In such implementations, when PPDU1400 has three or more spatial streams (N SS PHY preamble 1401 may include one or more additional LTFs (following the SIG field) only when transmitted via >2).

[0135] The SIG field may carry any information required to demodulate PPDU1400. Exemplary demodulation information may include, among other examples, bandwidth, length, MCS, N SS , BSS color, padding, PE ambiguity, or an indication of LDPC extra symbols. In some implementations, the SIG field may also carry beam management information indicating whether PPDU1400 is associated with a beamforming training operation or with various parameters associated with a beamforming training operation. Exemplary beam management information may include, among other examples, PPDU type, training direction, beam tracking requirements, training length, countdown, sector ID, antenna ID, best antenna ID, best sector ID, the number of RX sectors or RX antennas of the transmitting device, or SNR reporting. The information carried in the SIG field may be modulated on each of the (234) data subcarriers associated with the 256 subcarrier tone plan. Aspects of the present disclosure recognize that 234 data subcarriers can carry 117 bits of information, which may be sufficient to capture demodulation information and beam management information. Thus, in some aspects, the SIG field may extend over one OFDM symbol.

[0136] FIG. 14B shows another exemplary PPDU 1410 compliant with the Greenfield PPDU format according to some implementations. In some implementations, PPDU 1410 can be a DPHY PPDU used for wireless communication on a carrier frequency above 7 GHz when a full beamforming gain can be achieved between the transmitting device and the receiving device. PPDU 1410 includes a PHY preamble 1411, a data portion 1412 following it, and a PE or one or more TRNs 1413. The PHY preamble 1411 includes a Short Training Field (STF), a Long Training Field (LTF), and a Signal (SIG) field.

[0137] In some implementations, the PHY preamble 1411 can have the same symbol duration as the data portion 1412. In the example of FIG. 14B, while the data portion 1412 is mapped to 256 subcarriers associated with the sub-7 GHz tone plan, the PHY preamble 1411 is mapped to 128 subcarriers (2x) replicated across the bandwidth associated with the data portion 1412 in the frequency domain. Thus, the SCS associated with the PHY preamble 1411 is equal to the SCS associated with the data portion 1412. In contrast to the PPDU 1400 of FIG. 14A, the PHY preamble 1411 supports frequency synthesis at the receiving device, which improves the reliability of the SIG field but requires more SIG symbols to carry the same amount of information (due to fewer data subcarriers). In some aspects, PPDU 1410 can be upclocked to a wider bandwidth to achieve an SCS suitable for wireless communication on a carrier frequency above 7 GHz (as described with reference to FIGS. 9A - 13D). In some implementations, the upclocking can be performed by the OFDM upclocking system 800 of FIG. 8.

[0138] In some aspects, the STF can extend over two OFDM symbols (similar to the L-STF in existing PPDU formats). In some implementations, the STF can reuse an existing training sequence associated with wireless communication at carrier frequencies below 7 GHz (such as the STF sequence associated with the 11ac PPDU format or the 11be PPDU format). For example, the training sequence can be mapped to every fourth, eighth, or sixteenth data subcarrier associated with a 128 subcarrier tone plan (similar to the periodicity of the L-STF in existing PPDU formats). In some implementations, the existing training sequence can be a legacy STF sequence associated with a sub-7 GHz channel bandwidth. For example, when PPDU 1410 is upclocked from an 80 MHz sub-7 GHz channel bandwidth, the STF can carry a legacy STF sequence associated with a 40 MHz bandwidth. In some other implementations, the STF can include a Golay sequence to simplify packet detection (as described with reference to FIG. 11A).

[0139] In some aspects, the LTF can extend over two OFDM symbols (similar to the L-LTF in existing PPDU formats). In some implementations, the PHY preamble 1411 can include one or more additional LTFs (following the SIG field) to support channel estimation for the data portion 1412. For example, the additional LTF can be mapped according to the same 256 subcarrier tone plan as the data portion 1412. In some other implementations, when PPDU 1410 has multiple spatial streams (N SSAdditional LTF may be included within PHY preamble 1411 only when transmitted via >1). In some such implementations, non-zero values are associated with at least some of the guard subcarriers among the 128 subcarriers to which the first LTF (preceding the SIG field) is mapped such that the LTF is populated on the same subcarriers as the data portion 1412 (as described with reference to FIGS. 11C, 12C, and 13C). In some other such implementations, the first LTF may be directly mapped to the same data subcarriers as the data portion 1412 (as described with reference to FIGS. 11D, 12D, and 13D). Still further, in some other implementations, the P matrix may be directly applied to the first LTF to generate two non-identical OFDM symbols. In such implementations, PPDU 1410 is >3 spatial streams (N SS Additional LTF may be included within PHY preamble 1411 only when transmitted via >2).

[0140] The SIG field may carry any information required to demodulate PPDU 1410. Exemplary demodulation information includes, among other examples, bandwidth, length, MCS, N SS, may include an indication of BSS color, padding, PE ambiguity, or LDPC extra symbols. In some implementations, the SIG field may also carry beam management information indicating whether PPDU 1410 is associated with a beamforming training operation or associated with various parameters associated with the beamforming training operation. Exemplary beam management information may include, among other examples, PPDU type, training direction, beam tracking requirements, training length, countdown, sector ID, antenna ID, best antenna ID, best sector ID, number of RX sectors or RX antennas of the transmitting device, or SNR report. The information carried in the SIG field may be modulated on each of the (108) data subcarriers associated with the 128 subcarrier tone plan. Aspects of the present disclosure recognize that 108 data subcarriers may not be sufficient to carry 54 bits of information, which may be insufficient to capture demodulation information and beam management information. Thus, in some aspects, the SIG field may span two OFDM symbols.

[0141] Figure 14C shows another exemplary PPDU 1420 compliant with the greenfield PPDU format according to some implementations. In some implementations, PPDU 1420 may be a DPHY PPDU that can be used for wireless communication at carrier frequencies above 7 GHz when a full beamforming gain is achievable between the transmitting device and the receiving device. PPDU 1420 includes a PHY preamble 1421, a data portion 1422 following it, and a PE or one or more TRNs 1423. The PHY preamble 1421 includes a short training field (STF), a long training field (LTF), and a signal (SIG) field.

[0142] In some implementations, the PHY preamble 1421 may have the same symbol duration as the data portion 1422. In the example of FIG. 14C, while the data portion 1422 is mapped to 256 subcarriers associated with the sub-7 GHz tone plan, the PHY preamble 1421 is mapped to 64 subcarriers that are replicated (4x) across the bandwidth associated with the data portion 1422 in the frequency domain. Thus, the SCS associated with the PHY preamble 1421 is equal to the SCS associated with the data portion 1422. In contrast to the PPDU 1410 of FIG. 14B, the PHY preamble 1421 supports a larger frequency synthesis in the receiving device, which further improves the reliability of the SIG field but requires more SIG symbols to carry the same amount of information (due to fewer data subcarriers). In some aspects, the PPDU 1420 may be upclocked to a wider bandwidth to achieve an SCS suitable for wireless communication at carrier frequencies above 7 GHz (as described with reference to FIGS. 9A-13D). In some implementations, the upclocking may be performed by the OFDM upclocking system 800 of FIG. 8.

[0143] In some aspects, the STF can extend over two OFDM symbols (similar to the L-STF in existing PPDU formats). In some implementations, the STF can reuse an existing training sequence associated with wireless communication at carrier frequencies below 7 GHz (such as the STF sequence associated with the 11ac PPDU format or the 11be PPDU format). For example, the training sequence can be mapped to every fourth, eighth, or sixteenth data subcarrier associated with a 64-subcarrier tone plan (similar to the periodicity of the L-STF in existing PPDU formats). In some implementations, the existing training sequence can be a legacy STF sequence associated with a sub-7 GHz channel bandwidth. For example, when PPDU 1420 is upclocked from an 80 MHz sub-7 GHz channel bandwidth, the STF can carry a legacy STF sequence associated with a 20 MHz bandwidth. In some other implementations, the STF can include a Golay sequence to simplify packet detection (as described with reference to FIG. 11A).

[0144] In some aspects, the LTF can extend over two OFDM symbols (similar to the L-LTF in existing PPDU formats). In some implementations, the PHY preamble 1421 can include one or more additional LTFs (following the SIG field) to support channel estimation for the data portion 1422. For example, the additional LTF can be mapped according to the same 256-subcarrier tone plan as the data portion 1422. In some other implementations, when PPDU 1420 has multiple spatial streams (N SSAdditional LTFs may be included within the PHY preamble 1421 only when transmitted via >1). In some such implementations, non-zero values are associated with guard subcarriers, at least some of which are modulated on the 64 subcarriers to which the first LTF (preceding the SIG field) is mapped such that the LTFs are populated on the same subcarriers as the data portion 1422 (as described with reference to FIGS. 11C, 12C, and 13C). In some other such implementations, the first LTF may be directly mapped to the same data subcarriers as the data portion 1422 (as described with reference to FIGS. 11D, 12D, and 13D). Still further, in some other implementations, the P matrix may be applied directly to the first LTF to generate two non-identical OFDM symbols. In such implementations, the PPDU 1420 has three or more spatial streams (N SS Additional LTFs may be included within the PHY preamble 1421 only when transmitted via >2).

[0145] The SIG field may carry any information required to demodulate the PPDU 1420. Exemplary demodulation information includes, among other examples, bandwidth, length, MCS, N SSmay include an indication of BSS color, padding, PE ambiguity, or LDPC extra symbols. In some implementations, the SIG field may also carry beam management information indicating whether the PPDU 1420 is associated with a beamforming training operation or with various parameters associated with a beamforming training operation. Exemplary beam management information may include, among other examples, PPDU type, training direction, beam tracking requirements, training length, countdown, sector ID, antenna ID, best antenna ID, best sector ID, number of RX sectors or RX antennas of the transmitting device, or SNR reports. The information carried in the SIG field may be modulated on each of the (48) data subcarriers associated with the 64 subcarrier tone plan. Aspects of the present disclosure recognize that 48 data subcarriers may not be sufficient to carry 24 bits of information, which may be insufficient to capture demodulation information and beam management information. Thus, in some aspects, the SIG field may extend over three or four OFDM symbols.

[0146] FIG. 15A shows an exemplary PPDU 1500 compliant with the greenfield PPDU format according to some implementations. In some implementations, the PPDU 1500 may be a DPHY PPDU that can be used for wireless communication at carrier frequencies above 7 GHz when a full beamforming gain is achievable between the transmitting device and the receiving device. The PPDU 1500 includes a PHY preamble 1501, followed by a data portion 1502, and a PE or one or more TRNs 1503. The PHY preamble 1501 includes a short training field (STF), a long training field (LTF), and a signal (SIG) field.

[0147] In some implementations, the PHY preamble 1501 may have a shorter symbol duration than the data portion 1502. In the example of FIG. 15A, the data portion 1502 is mapped to 256 subcarriers associated with the sub-7 GHz tone plan, while the PHY preamble 1501 is mapped to 64 subcarriers spanning the bandwidth associated with the data portion 1502. Thus, the SCS associated with the PHY preamble 1501 is four times larger than the SCS associated with the data portion 1502 (resulting in a symbol duration that is four times shorter). Compared to the PPDU 1400 of FIG. 14A, the PHY preamble 1501 may be shorter than the PHY preamble 1401, but may require more SIG symbols to carry the same amount of information (due to fewer data subcarriers). In some aspects, the PPDU 1500 may be upclocked to a wider bandwidth to achieve an SCS suitable for wireless communication at carrier frequencies above 7 GHz (as described with reference to FIGS. 9A-13D). In some implementations, the upclocking may be performed by the OFDM upclocking system 800 of FIG. 8.

[0148] In some aspects, the STF may span two OFDM symbols (similar to the L-STF in existing PPDU formats) or may be longer for AGC gain calibration. In some implementations, the STF may reuse an existing training sequence associated with wireless communication at carrier frequencies below 7 GHz (such as the STF sequence associated with the 11ac PPDU format or the 11be PPDU format). For example, the training sequence may be mapped to every fourth, eighth, or sixteenth data subcarrier associated with a 64 subcarrier tone plan (similar to the periodicity of the L-STF in existing PPDU formats). In some implementations, the existing training sequence may be the TB STF sequence associated with the upclocked PPDU bandwidth. For example, when PPDU1500 is upclocked 16 times from a 20 MHz sub-7 GHz channel bandwidth, the STF may carry the TB STF sequence associated with a 320 MHz bandwidth. In some other implementations, the STF may include a Golay sequence to simplify packet detection (as described with reference to FIG. 11A).

[0149] In some aspects, the LTF may span two OFDM symbols (similar to the L-LTF in existing PPDU formats). In some implementations, the PHY preamble 1501 may include one or more additional LTFs (following the SIG field) to support channel estimation for the data portion 1502. For example, the additional LTF may be mapped according to the same 256 subcarrier tone plan as the data portion 1502. In some other implementations, when PPDU1500 has multiple spatial streams (N SSAdditional LTF may be included within PHY preamble 1501 only when transmitted via >1). In such an implementation, the first LTF (preceding the SIG field) may be mapped to the same data subcarriers as the data part 1502 (as described with reference to FIGS. 11D, 12D, and 13D) and according to the same 256 subcarrier tone plan. Still further, in some implementations, the P matrix may be applied directly to the first LTF to generate two non-identical OFDM symbols. In such an implementation, when PPDU 1500 has three or more spatial streams (N SS Additional LTF may be included within PHY preamble 1501 only when transmitted via >2).

[0150] The SIG field may carry any information required to demodulate PPDU 1500. Exemplary demodulation information may include, among other examples, bandwidth, length, MCS, N SS , BSS color, padding, PE ambiguity, or indication of LDPC extra symbols. In some implementations, the SIG field may also carry beam management information indicating whether PPDU 1500 is associated with a beamforming training operation or with various parameters associated with a beamforming training operation. Exemplary beam management information may include, among other examples, PPDU type, training direction, beam tracking requirements, training length, countdown, sector ID, antenna ID, best antenna ID, best sector ID, number of RX sectors or RX antennas of the transmitting device, or SNR report. The information carried in the SIG field may be modulated on each of the (48) data subcarriers associated with the 64 subcarrier tone plan. Aspects of the present disclosure recognize that 48 data subcarriers may not be sufficient to carry 24 bits of information, which may be insufficient to capture demodulation information and beam management information. Thus, in some aspects, the SIG field may extend over three or four OFDM symbols.

[0151] FIG. 15B shows another exemplary PPDU 1510 compliant with the Greenfield PPDU format according to some implementations. In some implementations, PPDU 1510 can be a DPHY PPDU that can be used for wireless communication at carrier frequencies above 7 GHz when a full beamforming gain can be achieved between the transmitting device and the receiving device. PPDU 1510 includes a PHY preamble 1511, a data portion 1512 following it, and a PE or one or more TRNs 1513. The PHY preamble 1511 includes a Short Training Field (STF), a Long Training Field (LTF), and a Signal (SIG) field.

[0152] In some implementations, the PHY preamble 1511 can have a shorter symbol duration than the data portion 1512. In the example of FIG. 15B, the data portion 1512 is mapped to 256 subcarriers associated with the sub-7 GHz tone plan, while the PHY preamble 1511 is mapped to 128 subcarriers spanning the bandwidth associated with the data portion 1512. Thus, the SCS associated with the PHY preamble 1511 is twice as large as (resulting in a symbol duration twice as short as) the SCS associated with the data portion 1512. Compared to the PPDU 1500 of FIG. 15A, the PHY preamble 1511 may be longer than the PHY preamble 1501, but may also be shorter than the data portion, and may require fewer SIG symbols than the PHY preamble 1501 to carry the same amount of information (due to more data subcarriers). In some aspects, PPDU 1510 can be upclocked to a wider bandwidth to achieve an SCS suitable for wireless communication at carrier frequencies above 7 GHz (as described with reference to FIGS. 9A - 13D). In some implementations, the upclocking can be performed by the OFDM upclocking system 800 of FIG. 8.

[0153] In some aspects, the STF may span two OFDM symbols (similar to the L-STF in existing PPDU formats) or may be longer for AGC gain calibration. In some implementations, the STF may reuse existing training sequences associated with wireless communication at carrier frequencies below 7 GHz (such as the STF sequence associated with the 11ac PPDU format or the 11be PPDU format). For example, the training sequence may be mapped to every fourth, eighth, or sixteenth data subcarrier associated with a 128-subcarrier tone plan (similar to the periodicity of the L-STF in existing PPDU formats). In some implementations, the existing training sequence may be a TB STF sequence associated with an upclocked PPDU bandwidth. For example, when PPDU1510 is upclocked 16 times from a 20 MHz sub-7 GHz channel bandwidth, the STF may carry a TB STF sequence associated with a 320 MHz bandwidth. In some other implementations, the STF may include a Golay sequence to simplify packet detection (as described with reference to FIG. 11A).

[0154] In some aspects, the LTF may span two OFDM symbols (similar to the L-LTF in existing PPDU formats). In some implementations, the PHY preamble 1511 may include one or more additional LTFs (following the SIG field) to support channel estimation for the data portion 1512. For example, the additional LTF may be mapped according to the same 256-subcarrier tone plan as the data portion 1512. In some other implementations, when PPDU1510 has multiple spatial streams (N SS>Additional LTF may be included within PHY preamble 1511 only when transmitted via >1). In such an implementation, the first LTF (preceding the SIG field) may be mapped to the same data subcarriers as the data part 1512 (as described with reference to FIGS. 11D, 12D, and 13D) and according to the same 256 subcarrier tone plan. Furthermore, in some implementations, the P matrix may be applied directly to the first LTF to generate two non-identical OFDM symbols. In such an implementation, when PPDU 1510 has three or more spatial streams (N SS >Additional LTF may be included within PHY preamble 1511 only when transmitted via >2).

[0155] The SIG field may carry any information required to demodulate PPDU 1510. Exemplary demodulation information may include, among other examples, bandwidth, length, MCS, N SS , BSS color, padding, PE ambiguity, or an indication of LDPC extra symbols. In some implementations, the SIG field may also carry beam management information indicating whether PPDU 1510 is associated with a beamforming training operation or with various parameters associated with a beamforming training operation. Exemplary beam management information may include, among other examples, PPDU type, training direction, beam tracking requirements, training length, countdown, sector ID, antenna ID, best antenna ID, best sector ID, number of RX sectors or RX antennas of the transmitting device, or SNR report. The information carried in the SIG field may be modulated on each of the (108) data subcarriers associated with the 128 subcarrier tone plan. Aspects of the present disclosure recognize that 108 data subcarriers may not be sufficient to capture demodulation information and beam management information, which may be 54 bits of information. Thus, in some aspects, the SIG field may extend over two OFDM symbols.

[0156] FIG. 15C shows another exemplary PPDU 1520 compliant with the Greenfield PPDU format according to some implementations. In some implementations, PPDU 1520 can be a DPHY PPDU that can be used for wireless communication at carrier frequencies above 7 GHz when a full beamforming gain can be achieved between the transmitting device and the receiving device. PPDU 1520 includes a PHY preamble 1521, a data portion 1522 following it, and a PE or one or more TRNs 1523. The PHY preamble 1521 includes a Short Training Field (STF), a Long Training Field (LTF), and a Signal (SIG) field.

[0157] In some implementations, the PHY preamble 1521 can have a shorter symbol duration than the data portion 1522. In the example of FIG. 15B, while the data portion 1522 is mapped to 256 subcarriers associated with the sub-7 GHz tone plan, the PHY preamble 1521 is mapped to 64 subcarriers replicated (2x) across the bandwidth associated with the data portion 1522 in the frequency domain. Thus, the SCS associated with the PHY preamble 1521 is twice as large (and has a symbol duration twice as short) as the SCS associated with the data portion 1522. In contrast to the PPDU 1510 of FIG. 15B, the PHY preamble 1521 supports a larger frequency synthesis at the receiving device, which further improves the reliability of the SIG field but requires more SIG symbols to carry the same amount of information (due to fewer data subcarriers). In some aspects, PPDU 1520 can be upclocked to a wider bandwidth to achieve an SCS suitable for wireless communication at carrier frequencies above 7 GHz (as described with reference to FIGS. 9A-13D). In some implementations, the upclocking can be performed by the OFDM upclocking system 800 of FIG. 8.

[0158] In some aspects, the STF may span two OFDM symbols (similar to the L-STF in existing PPDU formats) or may be longer for AGC gain calibration. In some implementations, the STF may reuse existing training sequences associated with wireless communication at carrier frequencies below 7 GHz (such as the STF sequence associated with the 11ac PPDU format or the 11be PPDU format). For example, the training sequence may be mapped to every fourth, eighth, or sixteenth data subcarrier associated with a 64-subcarrier tone plan (similar to the periodicity of the L-STF in existing PPDU formats). In some implementations, the existing training sequence may be a legacy STF sequence associated with a sub-7 GHz channel bandwidth. For example, when PPDU1420 is upclocked from a 20 MHz sub-7 GHz channel bandwidth, the STF may carry a legacy STF sequence associated with a 20 MHz bandwidth. In some other implementations, the STF may include a Golay sequence to simplify packet detection (as described with reference to FIG. 11A).

[0159] In some aspects, the LTF may span two OFDM symbols (similar to the L-LTF in existing PPDU formats). In some implementations, the PHY preamble 1521 may include one or more additional LTFs (following the SIG field) to support channel estimation for the data portion 1522. For example, the additional LTF may be mapped according to the same 256-subcarrier tone plan as the data portion 1522. In some other implementations, when PPDU1520 has multiple spatial streams (N SSAdditional LTFs may be included within the PHY preamble 1521 only when transmitted via >1). In such an implementation, the first LTF (preceding the SIG field) may be mapped to the same data subcarriers as the data portion 1522 (as described with reference to FIGS. 11D, 12D, and 13D) and according to the same 256 subcarrier tone plan. Still further, in some implementations, the P matrix may be applied directly to the first LTF to generate two non-identical OFDM symbols. In such an implementation, when the PPDU 1520 has three or more spatial streams (N SS Additional LTFs may be included within the PHY preamble 1521 only when transmitted via >2).

[0160] The SIG field may carry any information required to demodulate the PPDU 1520. Exemplary demodulation information may include, among other examples, bandwidth, length, MCS, N SS , BSS color, padding, PE ambiguity, or an indication of LDPC extra symbols. In some implementations, the SIG field may also carry beam management information indicating whether the PPDU 1520 is associated with a beamforming training operation or associated with various parameters associated with a beamforming training operation. Exemplary beam management information may include, among other examples, PPDU type, training direction, beam tracking requirements, training length, countdown, sector ID, antenna ID, best antenna ID, best sector ID, number of RX sectors or RX antennas of the transmitting device, or SNR report. The information carried in the SIG field may be modulated on each of the (48) data subcarriers associated with the 64 subcarrier tone plan. Aspects of the present disclosure recognize that 48 data subcarriers may not be sufficient to carry 24 bits of information, which may be insufficient to capture demodulation information and beam management information. Thus, in some aspects, the SIG field may extend over three or four OFDM symbols.

[0161] Aspects of the present disclosure recognize that the CPHY PPDU format of FIG. 9B and the DPHY PPDU format of FIG. 14C can be implemented using the same processing and up - clocking resources. For example, PHY preamble 911 and PHY preamble 1421 each contain a single SIG field and have the same SCS and frequency repetitions. Thus, the CPHY PPDU format of FIG. 9B and the DPHY PPDU format of FIG. 14C can collectively represent a harmonized green - field PPDU format. In some implementations, the SIG field of PHY preamble 1421 can be repeated in the time domain or can include additional OFDM symbols (as described with reference to FIGS. 9C and 9D). In some aspects, the harmonized PPDU format can include signaling to indicate whether the PPDU conforms to the CPHY PPDU format or the DPHY PPDU format.

[0162] In some implementations, the PPDU format (CPHY or DPHY) can be signaled by the value of a length field (L_LEN) within the SIG field (or L - SIG). For example, the PPDU can conform to either the DPHY PPDU format or the CPHY PPDU format depending on whether L_LEN % 3 = 0. In some other implementations, the PPDU format (CPHY or DPHY) can be signaled by the modulation scheme associated with one of the SIG fields (or SIG symbols). For example, the second OFDM symbol of the SIG field can be modulated according to either the BPSK modulation scheme or the QBPSK modulation scheme to indicate whether the PPDU conforms to the DPHY PPDU format or the CPHY PPDU format.

[0163] FIG. 16 shows a flowchart of an exemplary process 1600 for wireless communication that supports a 60 GHz PPDU format. In some implementations, process 1600 may be performed by an AP, such as any one of AP102 or AP502 described above with reference to FIGS. 1 and 5A respectively, or by a wireless communication device operating within the AP. In some other implementations, process 1600 may be performed by a STA, such as any one of STA104 or STA504 described above with reference to FIGS. 1 and 5B respectively, or by a wireless communication device within the STA.

[0164] In some implementations, process 1600 begins, at block 1602, by mapping a first portion of the PPDU to a number (N) of subcarriers, where the first portion of the PPDU represents at least a portion of a PHY preamble that includes an STF, an LTF, and one or more SIG fields that follow immediately after the LTF and carry information for interpreting the PPDU. At block 1604, process 1600 proceeds to convert the N subcarriers to a first time-varying signal at a sampling rate (f S ) associated with a first SCS greater than 1.2 MHz, where the first SCS represents the separation between adjacent subcarriers among the N subcarriers in the frequency domain. At block 1606, process 1600 proceeds to transmit the first time-varying signal over a wireless channel having a bandwidth (BW) associated with the sampling rate f S .

[0165] In some aspects, the PPDU may conform to a PPDU format associated with wireless communication on a carrier frequency below 7 GHz. In some implementations, one or more SIG fields may include an L-SIG and a non-legacy SIG field that immediately follows the L-SIG. In some other implementations, one or more SIG fields may include an L-SIG, an RL-SIG that immediately follows the L-SIG, and a non-legacy SIG field that immediately follows the RL-SIG. In some implementations, the STF and the non-legacy SIG field may each consist of two OFDM symbols. In some other implementations, the STF may consist of two OFDM symbols that are repeated in time, and the non-legacy SIG field may consist of four OFDM symbols.

[0166] In some aspects, the PPDU may consist of only a first portion. In some other aspects, process 1600 further includes mapping at least a data field, a packet extension, or a second portion of the PPDU including one or more TRNs to several (M) subcarriers, converting the M subcarriers to a second time-varying signal at a sampling rate f s and transmitting the second time-varying signal via a wireless channel that immediately follows the first time-varying signal. In some implementations, one or more SIG fields may consist of a single SIG field that immediately follows a data field, a packet extension, or one or more TRNs. In some implementations, the second portion of the PPDU may further include one or more additional LTFs. In some implementations, one or more SIG fields may consist of a single SIG field that immediately follows one or more additional LTFs.

[0167] In some implementations, M may be equal to N, and BW may be equal to f s In some other implementations, M may be equal to N, the PPDU may be replicated for transmission on several (m) subbands each covering a respective bandwidth portion equal to BW / m, and BW may be m* f s is equal to. Further, in some implementations, M may be greater than N. In some implementations, the first part of the PPDU can be replicated for transmission on several (n) subbands, each having a bandwidth equal to BW / n, where BW is equal to f s is equal to. In some implementations, the conversion of the M subcarriers to a second time-varying signal can result in a second SCS equal to the first SCS, where the second SCS represents the separation between adjacent subcarriers among the M subcarriers in the frequency domain. In some other implementations, the conversion of the M subcarriers to a second time-varying signal can result in a second SCS different from the first SCS, where the second SCS represents the separation between adjacent subcarriers among the M subcarriers in the frequency domain.

[0168] In some implementations, the LTF can be transmitted on the same subcarriers as the second part of the PPDU as a result of replicating the first part of the PPDU for transmission on n subbands. In some implementations, the LTF can include a first OFDM symbol and a second OFDM symbol identical to the first OFDM symbol. In some other implementations, the LTF can include a first OFDM symbol and a second OFDM symbol, and process 1600 further includes applying the P matrix to the LTF such that the first OFDM symbol is different from the second OFDM symbol. In some implementations, the STF can include a Golay sequence. In some implementations, the information carried in one or more SIG fields can include an indication of whether the PPDU is associated with a beamforming training operation.

[0169] FIG. 17 shows a flowchart illustrating an exemplary process for wireless communication that supports a 60 GHz PPDU format. In some implementations, process 1700 can be performed by an AP, such as any one of AP102 or AP502, described above with reference to FIGS. 1 and 5A respectively, or by a wireless communication device operating within the AP. In some other implementations, process 1700 can be performed by a STA, such as any one of STA104 or STA504, described above with reference to FIGS. 1 and 5B respectively, or by a wireless communication device within the STA.

[0170] In some implementations, process 1700 begins, at block 1702, by mapping a first portion of the PPDU to a number (N) of subcarriers, where the first portion of the PPDU represents at least a portion of a PHY preamble that includes an STF and one or more SIG fields that carry information for interpreting the PPDU. At block 1704, process 1700 proceeds to map a LTF of the PHY preamble to a number (M) of subcarriers, where the LTF follows the STF and precedes one or more SIG fields within the PHY preamble, and where M > N. At block 1706, process 1700 proceeds to convert the N subcarriers and the M subcarriers to a time-varying signal. At block 1708, process 1700 proceeds to transmit the time-varying signal over a wireless channel.

[0171] In some implementations, process 1700 can further include mapping a second portion of the PPDU, including at least a data field, packet extension, or one or more TRNs, to the M subcarriers. In some implementations, the N subcarriers and the M subcarriers are associated with a sampling rate (f) related to a SCS greater than 1.2 MHz s) can be converted into a time-varying signal, and SCS represents the separation amount between adjacent subcarriers among N subcarriers in the frequency domain. In some implementations, the first part of the PPDU can be replicated for transmission on several (n) sub-bands, each covering a respective bandwidth portion equal to BW / n.

[0172] FIG. 18 shows a block diagram of an exemplary wireless communication device 1800 according to some implementations. In some implementations, the wireless communication device 1800 is configured to execute the process 1600 described with reference to FIG. 16. The wireless communication device 1800 can be an exemplary implementation of the wireless communication device 400 described above with reference to FIG. 4. For example, the wireless communication device 1800 can 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).

[0173] The wireless communication device 1800 includes a receiving component 1810, a communication manager 1820, and a transmitting component 1830. The communication manager 1820 further includes a PPDU mapping component 1822 and a time-domain conversion component 1824. One or more parts of component 1822 and component 1824 can be implemented at least partially in hardware or firmware. In some implementations, at least a part of component 1822 or component 1824 is implemented as software stored at least partially in a memory (such as memory 408). For example, one or more parts of component 1822 and component 1824 can be implemented as non-transitory instructions (or "code") executable by a processor (such as processor 406) to perform the functions or operations of the respective components.

[0174] The receiving component 1810 is configured to receive an RX signal from one or more other wireless communication devices via a wireless channel. The communication manager 1820 is configured to control or manage communication with one or more other wireless communication devices. In some implementations, the PPDU mapping component 1822 may map a first portion of the PPDU to several (N) subcarriers, and the first portion of the PPDU represents at least a part of the PHY preamble including a Short Training Field (STF), a Long Training Field (LTF), and one or more Signal (SIG) fields that follow immediately after the LTF and carry information for interpreting the PPDU. The time-domain conversion component 1824 may convert the N subcarriers into a time-varying signal at a sampling rate (f s ) associated with a subcarrier spacing (SCS) greater than 1.2 MHz, where the SCS represents the separation between adjacent subcarriers among the N subcarriers in the frequency domain. The transmitting component 1830 is configured to transmit a TX signal to one or more other wireless communication devices via a wireless channel. In some implementations, the transmitting component 1930 may transmit a first time-varying signal via a wireless channel having a bandwidth (BW) associated with the sampling rate f s .

[0175] FIG. 19 shows a block diagram of an exemplary wireless communication device 1900 according to some implementations. In some implementations, the wireless communication device 1900 is configured to execute the process 1700 described with reference to FIG. 17. The wireless communication device 1900 may be an exemplary implementation of the wireless communication device 400 described above with reference to FIG. 4. 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 (IEEE802.11) modem or a cellular modem).

[0176] Wireless communication device 1900 includes a receiving component 1910, a communication manager 1920, and a transmitting component 1930. The communication manager 1920 further includes a PPDU mapping component 1922, an LTF mapping component 1924, and a time domain conversion component 1926. One or more portions of component 1922, component 1924, and component 1926 may be implemented at least partially in hardware or firmware. In some implementations, at least a portion of component 1922, component 1924, or component 1926 is implemented as software stored at least partially in a memory (such as memory 408). For example, one or more portions of component 1922, component 1924, and component 1926 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 respective components.

[0177] The receiving component 1910 is configured to receive an RX signal from one or more other wireless communication devices via a wireless channel. The communication manager 1920 is configured to control or manage communication with one or more other wireless communication devices. In some implementations, the PPDU mapping component 1922 may map a first portion of the PPDU to a number (N) of subcarriers, where the first portion of the PPDU represents at least a portion of a PHY preamble including a Short Training Field (STF) and one or more Signal (SIG) fields that carry information for interpreting the PPDU. The LTF mapping component 1924 may map the Long Training Field (LTF) of the PHY preamble to a number (M) of subcarriers, where the LTF follows the STF and precedes one or more SIG fields within the PHY preamble, where M > N, and the time domain conversion component 1924 may convert the N subcarriers and the M subcarriers into time-varying signals. The transmitting component 1930 is configured to transmit a TX signal to one or more other wireless communication devices via a wireless channel. In some implementations, the transmitting component 1930 may transmit a time-varying signal via the wireless channel.

[0178] In the following numbered clauses, implementation examples are described. 1. A method for wireless communication by a wireless communication device, comprising: mapping a first portion of a Physical Layer (PHY) Convergence Protocol (PLCP) Protocol Data Unit (PPDU) to a number (N) of subcarriers, where the first portion of the PPDU represents at least a portion of a PHY preamble including a Short Training Field (STF), a Long Training Field (LTF), and one or more Signal (SIG) fields that follow immediately after the LTF and carry information for interpreting the PPDU; Convert N subcarriers into a first time-varying signal at a sampling rate (f s ) associated with a first subcarrier spacing (SCS) greater than 1.2 MHz, wherein the first SCS represents, in the frequency domain, the separation between adjacent subcarriers among the N subcarriers, and the converting; Transmit the first time-varying signal via a wireless channel having a bandwidth (BW) associated with the sampling rate f s ). A method comprising: 2. The method according to clause 1, wherein the first time-varying signal is transmitted at a carrier frequency above 7 GHz. 3. The method according to clause 1 or 2, wherein the PPDU complies with a PPDU format associated with wireless communication at a carrier frequency below 7 GHz. 4. The method according to any one of clauses 1 to 3, wherein one or more SIG fields include a legacy SIG field (L-SIG) and a non-legacy SIG field following immediately after the L-SIG. 5. The method according to any one of clauses 1 to 3, wherein one or more SIG fields include an L-SIG, a repetition of the L-SIG (RL-SIG) following immediately after the L-SIG, and a non-legacy SIG field following immediately after the RL-SIG. 6. The method according to any one of clauses 1 to 3, or 5, wherein the STF and the non-legacy SIG field each consist of two orthogonal frequency division multiplexing (OFDM) symbols. 7. The method according to any one of clauses 1 to 3, or 5, wherein the STF consists of two OFDM symbols that are repeated in time, and the non-legacy SIG field consists of four OFDM symbols. 8. The method according to any one of clauses 1 to 7, wherein the PPDU consists of only a first part. 9. Map a second part of the PPDU including at least a data field, a packet extension, or one or more training fields (TRNs) to several (M) subcarriers; Map the M subcarriers to a sampling rate f sand converting it into a second time-varying signal; transmitting the second time-varying signal via a wireless channel following immediately after the first time-varying signal, the method according to any one of clauses 1 to 7. 10. A method according to any one of clauses 1 to 7, or 9, wherein one or more SIG fields consist of a single SIG field followed immediately by a data field, a packet extension, or one or more TRNs. 11. A method according to any one of clauses 1 to 7, or 9, wherein the second portion of the PPDU further includes one or more additional LTFs. 12. A method according to any one of clauses 1 to 7, 9, or 10, wherein one or more SIG fields consist of a single SIG field followed immediately by one or more additional LTFs. 13. M = N and BW = f s the method according to any one of clauses 1 to 7, or 9 to 12. 14. M = N, and the PPDU is replicated for transmission on several (m) subbands each covering a respective bandwidth portion equal to BW / m, and BW = m * f s the method according to any one of clauses 1 to 7, 9, or 10. 15. M > N, the method according to any one of clauses 1 to 7, or 9 to 12. 16. The first portion of the PPDU is replicated for transmission on several (n) subbands each covering a respective bandwidth portion equal to BW / n, and BW = f s the method according to any one of clauses 1 to 7, 9 to 12, or 15. 17. The conversion of the M subcarriers into a second time-varying signal results in a second SCS equal to the first SCS, and the second SCS represents, in the frequency domain, the separation between adjacent subcarriers among the M subcarriers, the method according to any one of clauses 1 to 7, 9 to 12, 15, or 16. 18. The conversion of the M subcarriers to a second time-varying signal results in a second SCS different from the first SCS, and the second SCS represents, in the frequency domain, the separation amount between adjacent subcarriers among the M subcarriers, according to any one of clauses 1 to 7, 9 to 12, 15, or 16. 19. The LTF is transmitted via the same subcarriers as the second part of the PPDU as a result of replicating the first part of the PPDU for transmission on n subbands, according to any one of clauses 1 to 7, 9 to 12, or 15 to 18. 20. The LTF includes a first OFDM symbol and a second OFDM symbol identical to the first OFDM symbol, according to any one of clauses 1 to 19. 21. The LTF includes a first OFDM symbol and a second OFDM symbol, and the method further includes applying a P matrix to the LTF such that the first OFDM symbol is different from the second OFDM symbol, according to any one of clauses 1 to 19. 22. The STF includes a Golay sequence, according to any one of clauses 1 to 21. 23. The information carried in one or more SIG fields includes an indication of whether the PPDU is associated with a beamforming training operation, according to any one of clauses 1 to 22. 24. A wireless communication device, including at least one memory, and at least one processor communicatively coupled to the at least one memory and configured to cause the wireless communication device to execute the method according to any one of clauses 1 to 23. 25. A method for wireless communication by a wireless communication device, Mapping a first portion of a Physical (PHY) Layer Convergence Protocol (PLCP) Protocol Data Unit (PPDU) to a number (N) of sub-carriers, wherein the first portion of the PPDU represents at least a portion of a PHY preamble that includes a Short Training Field (STF) and one or more Signal (SIG) fields that carry information for interpreting the PPDU. Mapping a Long Training Field (LTF) of the PHY preamble to a number (M) of sub-carriers, wherein the LTF follows the STF and precedes one or more SIG fields within the PHY preamble, and M > N. Converting the N sub-carriers and the M sub-carriers into time-varying signals. Transmitting the time-varying signals via a wireless channel. A method comprising the above steps. 26. The method according to clause 25, wherein the wireless channel is associated with a carrier frequency greater than 7 GHz. 27. Further comprising mapping a second portion of the PPDU, including at least a data field, a packet extension, or one or more Training fields (TRNs), to the M sub-carriers. The method according to clause 25 or 26. 28. The N sub-carriers and the M sub-carriers are converted into time-varying signals at a sampling rate (f s ) associated with a sub-carrier spacing (SCS) greater than 1.2 MHz, and the SCS represents the separation between adjacent sub-carriers among the N sub-carriers in the frequency domain. The method according to any one of clauses 25 to 27. 29. The method according to any one of clauses 25 to 28, wherein the first portion of the PPDU is replicated for transmission on a number (N) of sub-bands, each having a bandwidth portion equal to BW / n. 30. A wireless communication device, including at least one memory, At least one processor communicatively coupled to at least one memory and configured to cause the wireless communication device to execute the method according to any one or more of clauses 25 to 29, a wireless communication device comprising.

[0179] As used herein, the phrase referring to a list of items "at least one of" or "one or more of" refers to any combination of those items, including a single member. For example, "at least one of a, b, or c" is intended to encompass the possibilities of a only, b only, c only, 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. As used herein, "based on" is intended to be construed in an inclusive sense unless explicitly stated otherwise. For example, "based on" can be used interchangeably with "at least partially based on" unless explicitly stated otherwise. Specifically, unless the phrase refers to "only based on 'a'" or an equivalent in the context, anything that is "based on 'a'" or "at least partially based on 'a'" can be based on only "a" or a combination of "a" and one or more other factors, conditions, or information.

[0180] The various exemplary components, logics, logical blocks, modules, circuits, operations, and algorithmic processes described with respect to the implementations disclosed herein can be implemented as electronic hardware, firmware, software, or a combination of hardware, firmware, or software, including the structures disclosed herein and their structural equivalents. The interchangeability of hardware, firmware, and software is schematically described from a functional perspective and is shown in the various exemplary components, blocks, modules, circuits, and processes described above. Whether such functionality is implemented in hardware, firmware, or software depends on the specific application and design constraints imposed on the overall system.

[0181] Various modifications to the implementations described in this disclosure may become readily apparent to those skilled in the art, and the general principles defined herein may be applied to other implementations without departing from the spirit or scope of the disclosure. Accordingly, 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 presented.

[0182] Additionally, the various features described herein in the context of separate implementations may also be implemented in combination within a single implementation. Conversely, the various features described herein in the context of a single implementation may also be implemented separately, or in any suitable sub-combination, in multiple implementations. Thus, although features may be described above as acting in certain combinations and even claimed as such initially, in some cases, one or more features from a claimed combination may be deleted from that combination, and the claimed combination may be directed to a sub-combination or a variation of a sub-combination.

[0183] Similarly, the operations are illustrated in the drawings in a particular order, but this should not be understood as requiring that such operations be performed in the particular order shown or in a sequential order, or that all of the operations shown be performed. Further, the drawings may schematically illustrate another exemplary process in the form of a flowchart or a flow diagram. However, other operations not shown may be incorporated into the exemplary process that is schematically shown. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the operations shown. In some situations, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementation forms described above should not be understood as requiring such separation in all implementation forms, and it should be understood that the described program components and systems may generally be integrated together in a single software product or packaged into multiple software products.

Claims

1. A method of wireless communication performed by a wireless communication device, Mapping a first portion of a Physical Layer (PHY) Convergence Protocol (PLCP) protocol data unit (PPDU) to several (N) subcarriers, wherein the first portion of the PPDU represents at least a portion of a PHY preamble that includes a short training field (STF) and one or more signal (SIG) fields that carry information for interpreting the PPDU. The mapping of the long training field (LTF) of the PHY preamble to several (M) subcarriers, wherein the LTF follows the STF and precedes one or more SIG fields in the PHY preamble, and the mapping is M > N. Converting the N subcarriers and the M subcarriers into time-varying signals, Transmitting the time-varying signal via a wireless channel, Methods that include...

2. The method according to claim 1, wherein the wireless channel is associated with a carrier frequency above 7 GHz.

3. Mapping a second portion of the PPDU, which includes at least a data field, a packet extension, or one or more training fields (TRNs), to the M subcarriers. The method according to claim 1, further comprising:

4. The method according to claim 1, wherein the N subcarriers and the M subcarriers are converted into a time-varying signal at a sampling rate associated with a subcarrier spacing (SCS) greater than 1.2 MHz, and the SCS represents the degree of separation between adjacent subcarriers among the N subcarriers in the frequency domain.

5. The method according to claim 4, wherein the first portion of the PPDU is duplicated for transmission over several (N) subbands, each extending over a bandwidth (BW) portion equal to BW / n.

6. The method according to claim 1, wherein the PPDU conforms to the IEEE 802.11ac standard.

7. A wireless communication device, Means for mapping a first portion of a Physical Layer (PHY) Convergence Protocol (PLCP) protocol data unit (PPDU) to several (N) subcarriers, wherein the first portion of the PPDU represents at least a portion of a PHY preamble that includes a short training field (STF) and one or more signal (SIG) fields that carry information for interpreting the PPDU; A means for mapping the long training field (LTF) of the PHY preamble to several (M) subcarriers, wherein the LTF follows the STF and precedes one or more SIG fields, and M > N. Means for converting the N subcarriers and the M subcarriers into time-varying signals, means for transmitting the time-varying signal via a wireless channel, A wireless communication device equipped with the following features.

8. The wireless communication device according to claim 7, wherein the wireless channel is associated with a carrier frequency above 7 GHz.

9. The wireless communication device according to claim 7, further comprising means for mapping a second portion of the PPDU, which includes at least a data field, a packet extension, or one or more training fields (TRNs), to the M subcarriers.

10. The wireless communication device according to claim 7, wherein the N subcarriers and the M subcarriers are converted into a time-varying signal at a sampling rate associated with a subcarrier spacing (SCS) greater than 1.2 MHz, and the SCS represents the degree of separation between adjacent subcarriers among the N subcarriers in the frequency domain.

11. The wireless communication device according to claim 10, wherein the first portion of the PPDU is duplicated for transmission over several (n) subbands, each extending over a bandwidth portion equal to BW / n.

12. The wireless communication device according to claim 7, wherein the PPDU conforms to the IEEE 802.11ac standard.

13. A computer program that, when executed by at least one processor of a wireless communication device, includes instructions causing the wireless communication device to perform the method according to any one of claims 1 to 6.

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