WO2018031134A1

WO2018031134A1 - Preamble for extended range mode packet detection

Info

Publication number: WO2018031134A1
Application number: PCT/US2017/039698
Authority: WO
Inventors: Xiaogang Chen; Qinghua Li; Feng Jiang; Yuan Zhu; Yushu Zhang
Original assignee: Intel IP Corporation
Priority date: 2016-08-09
Filing date: 2017-06-28
Publication date: 2018-02-15

Abstract

An apparatus of a wireless device and related method decode a physical layer convergence protocol (PLCP) protocol data unit (PPDU) preamble comprising a short training field (STF) and a legacy long training field (L-LTF). The STF comprises an orthogonal frequency-division multiplexing (OFDM) quantity of symbols that is dependent upon whether the PPDU comprises a legacy short training field (L-STF) or an extended range short training field (ER-STF). When the STF is an L-STF, the STF comprises 10 OFDM symbols. When the STF is an ER-STF, the STF comprises 10+N OFDM symbols with N > 0. The apparatus decodes an automatic gain control (AGC) setting signal to produce an AGC setting, and utilizes a plurality of the STF OFDM symbols that includes a 10th OFDM symbol when the STF is an L-STF, and a 10+Nth OFDM symbol when the STF is an ER-STF to provide energy for packet detection.

Description

PREAMBLE FOR EXTENDED RANGE MODE PACKET DETECTION

PRIORITY CLAIM

[0001] The present application claims the benefit of U. S. Provisional Application No. 62/372,378, filed August 9, 2016, entitled, "PREAMBLE STRUCTURE FORPACKET DETECTION IN EXTENDED RANGE MODE," which is incorporated herein by reference,

TECHNICAL FIELD

[0002] Aspects pertain to wireless networks and wireless communications and wireless communication devices. Some aspects relate to wireless local area networks (WLANs) and Wi-Fi networks including networks operating in accordance with the IEEE 802, 11 family of standards. Some aspects relate to IEEE 802.1 lax. Some aspects relate to methods, computer readable media, and apparatus including packet preamble structure for packet detection in extended range mode.

BACKGROUND

[0003] Efficient use of the resources of a wireless local-area network (WLAN) is important to provide bandwidth and acceptable response times to the users of the WLAN. However, often there are many devices trying to share the same resources and some devices may be limited by the communication protocol they use or by their hardware bandwidth. Moreover, wireless devices may need to operate with both newer protocols and with legacy device protocols. When using extended ranges a low signal-to-noise ratio (SNR) may make it more challenging to properly detect packets.

Acronyms The following acronyms are used herein:

Table I Acronyms BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The present disclosure is illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements.

[0006] FIG. 1 is a block diagram that illustrates a WLAN and BSS in accordance with some aspects.

[0007] FIG. 2 is a block diagram that illustrates AGC, ADC, and packet detection in a receiver chain, in accordance with some aspects.

[0008] FIG. 3 is a block diagram that illustrates an IEEE 802.11 ax extend range PPDU preamble structure in accordance with some aspects.

[0009] FIG. 4 is a graph that illustrates performance of a packet detection in accordance with some aspects.

[0010] FIG. 5 A is a block diagram that illustrates an IEEE 802.1 lax extend range PPDU preamble structure with an L-STF in accordance with some aspects.

[0011] FIG. 5B is a block diagram that illustrates an IEEE 802.11 ax extend range PPDU preamble structure with an ER-STF in accordance with some aspects.

[0012] FIG. 6 is a block diagram that illustrates an ER-STF for packet detection in accordance with some aspects.

[0013] FIGS. 7 A. and 7B are block diagrams that illustrate IEEE 802.1 lax extend range PPDU preamble structures that make use of repetitions in an L-LTF, L-SIG / RL-SIG for packet detection in accordance with some aspects.

[0014] FIGS. 8A and 8B are block diagrams that illustrate IEEE 802.1 lax extend range PPDU preamble structures that make use of aggregation in an L- LTF, L-SIG / RL-SIG for packet detection in accordance with some aspects.

[0015] FIG. 9 A. is a flowchart 900 of a transmitter- side process for packet detection in accordance with some aspects.

[0016] FIG 9B is a flowchart 950 of a receiver-side process for packet- detection in accordance with some aspects.

[0017] FIG. 10 is a block diagram of an example machine upon which any one or more of the techniques (e.g., methodologies) discussed herein may perform. DESCRIPTION

[0018] The following description and the drawings sufficiently illustrate specific aspects to enable those skilled in the art to practice them. Other aspects may incorporate structural, logical, electrical, process, and other changes. Portions and features of some aspects may be included in, or substituted for, those of other aspects. Aspects set forth in the claims encompass all available equivalents of those claims.

[0019] FIG. 1 illustrates a WLAN in accordance with some aspects. The WLAIN may comprise a BSS 100 that may include a master station 102, which may be an AP, a plurality of HE (e.g., IEEE 802. lax) stations 104, and a plurality of legacy (e.g., IEEE 802.1 ln/ac) devices 106. A legacy IEEE 802.11 station and access point are defined herein to be devices using an IEEE 802.1 1 protocol that predates the IEEE 802.1 lax protocol.

[0020] The master station 102 may be an AP using one of the IEEE 802, 1 protocols to transmit and receive. The master station 102 may be a base station. The master station 102 may use other communications protocols as well as the IEEE 802.11 protocol. The IEEE 802.11 protocol may be IEEE 802.1 lax. The IEEE 802.11 protocol may include using OFDMA, TDMA, and/or CDMA. The IEEE 802.11 protocol may include a multiple access technique. For example, the IEEE 802.11 protocol may include SDMA and/or MU-MIMO. The master station 102 and/or HE station 104 may use one or both of MU-MIMO and OFDMA. There may be more than one master station 102 that is part of an ESS. A controller (not illustrated) may store information that is common to the more than one master station 102. The controller may have access to an external network such as the Internet.

[0021] The legacy devices 106 may operate in accordance with one or more of IEEE 802.11 a/b/g/n/ac/ad/af/ah/aj, or another legacy wireless communication standard. The legacy devices 106 may be ST As or IEEE 802.11 ST As. The HE stations 104 may be wireless transmit and receive devices such as cellular telephone, smart telephone, handheld wireless device, wireless glasses, wireless watch, wireless personal device, tablet, or another device that may be transmitting and receiving using the IEEE 802, 1 1 protocol such as IEEE 802. 1 l ax or another wireless protocol such as IEEE 802.11az. In some aspects, the HE stations 104, master station 102, and/or legacy devices 106 may be termed wireless devices. In some aspects, the HE station 104 may be a GO for P2P modes of operation where the HE station 104 may perform some operations of a master station 102.

[0022] The master station 102 may communicate with legacy devices 106 in accordance with legacy IEEE 802.11 communication techniques. In example aspects, the master station 102 may also be configured to communicate with HE stations 104 in accordance with legacy IEEE 802.11 communication techniques.

[0023] in some aspects, a HE frame may be configurable to have the same bandwidth as a channel. The bandwidth of a channel may be 2QMHz, 4()MHz, or 8QMHz, 160MHz, 320MHz contiguous bandwidths or an 80 · 80X11 !z (160MHz) non-contiguous bandwidth. In some aspects, the bandwidth of a channel may be 1 MHz, 1.25MHz, 2.03MHz, 2.5MHz, 5 MHz and 10MHz, or a combination thereof or another bandwidth that is less or equal to the available bandwidth may also be used. In some aspects, the bandwidth of the channels may be based on a number of active subcarriers. In some aspects, the bandwidth of the channels are multiples of 26 (e.g., 26, 52, 104, etc.) active subcarriers or tones that are spaced by 20 MHz. In some aspects, the bandwidth of the channels are 26, 52, 104, 242, etc. active data subcarriers or tones that are space 20 MHz apart. In some aspects, the bandwidth of the channels is 256 tones spaced by 20 MHz. In some aspects, a 20 MHz channel may comprise 256 tones for a 256 point FFT. In some aspects, a different number of tones is used. In some aspects, the OFDMA structure comprises a 26-subcarrier RU, 52-subcarrier RU, 106-subcarrier RU, 242- subcarrier RU, 484-subcarrier RU and 996-subcarrier RU. Resource allocations for SU comprises a 242 subcarrier RU, 484-subcarrier RU, 996-subcarrier RU and 2x996-subcarrier RU.

[0024] A HE frame may be configured for transmitting a number of spatial streams, which may be in accordance with MU-MIMO. In some aspects, a HE frame may be configured for transmitting in accordance with one or both of OFDMA and MU-MIMO. In other aspects, the master station 102, HE station 104, and/or legacy device 106 may also implement different technologies such as CDMA 2000, CDMA 2000 I X, CDMA 2000 EV-DO, Interim Standard 2000 (IS- 2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), LTE, GSM, EDGE, GSM EDGE (GERAN), IEEE 802.16 (i.e., WiMAX), BlueTooth®, WiGig, or other technologies.

[0025] Some aspects relate to HE communications. In accordance with some IEEE 802.1 lax aspects, a master station 102 may operate as a master station which may be arranged to contend for a wireless medium (e.g., during a contention period) to receive exclusive control of the medium for an HE control period. In some aspects, the HE control period may be termed a TXOP. The master station 102 may transmit a HE master-sync transmission, which may be a trigger frame or HE control and schedule transmission, at the beginning of the HE control period. The master station 102 may transmit a time duration of the TXOP and channel information. During the HE control period, HE stations 104 may communicate with the master station 102 in accordance with a non-contention based multiple access technique such as OFDMA and/or MU-MTMO. This is unlike WLAN communications in which devices communicate in accordance with a contention-based communication technique, rather than a multiple access technique. During the HE control period, the master station 102 may communicate with HE stations 104 using one or more HE frames. During the HE control period, the HE ST As 104 may operate on a channel smaller than the operating range of the master station 102. During the HE control period, legacy stations refrain from communicating.

[00261 In accordance with some aspects, during the master-sync transmission the HE ST As 104 may contend for the wireless medium with the legacy devices 106 being excluded from contending for the wireless medium during the master- sync transmission or TXOP. In some aspects, the trigger frame may indicate an uplink (UL) UL-MU-ΜΓΜΟ and/or UL OFDMA control period. In some aspects, the trigger frame may indicate portions of the TXOP that are contention based for some HE station 104 and portions that are not contention based.

[0027] In some aspects, the multiple-access technique used during the HE control period may be a scheduled OFDM A technique, although this is not a requirement. In some aspects, the multiple access technique may be a TDMA technique or a FDMA technique. In some aspects, the multiple access technique may be a SDMA technique. [0028] In example aspects, the HE device 104 and/or the master station 102 are configured to perform the methods and operations herein described in conjunction with FIGS. 1-9.

[0029] The operation of aspects for IEEE 802.1 lax involving an extended range mode may involve an SNR that is 9 dB lower than for operations under IEEE 802.1 lac, and such a low SNR can, in some aspects, be supported in Wave 2 of IEEE 802.1 l ax. In some aspects, a bottleneck of a long range mode results from packet detection. Aspects described herein may enhance packet detection to reduce this bottleneck,

[0030] Aspects described herein for enhancing packet detection may make one or more existing L-STF to be more reliable. An ER-STF may provide more signal energy for packet detection.

[0031] Aspects described herein may repurpose the existing L-LTF and L-SIG - RL-SIG, which have more signal energy than the L-STF, for packet detection.

[0032] FIG. 2 is a block diagram that illustrates an example of a receiver chain 200 with AGC, ADC, and packet detection. The AGC 220 adjusts an amplifier's gain such that an input signal 215 received from an antenna 210 to the ADC 230 falls into a proper range in accordance with various aspects. Within a proper range, the digital sample output 235 of ADC 230, in some aspects, does not have significant overflows and underflows in the digitized samples 235. The packet detection 240 may use the digital samples output 235, in some aspects, by the ADC 230 for detecting an arrival of an IEEE 802.1 1 packet. There are multiple ways to do the packet detection. The example illustrated in FIG. 2 uses autocorrelation of the input signal 215, in accordance with some aspects in which the output signal 235 and a path with a delay 242 is combined 244 and integrated 246 to produce a detector output 250, Another aspect may use cross-correlation, which correlates the received signal with a known reference signal at the receiver. Detection schemes may utilize integration of signals. In some aspects of an autocorrelation scheme, if the input signal has a periodic structure and the period matches a delay duration in the auto-correlator, peaks 252 may be observed at the output 250 of the correlator as illustrated in FIG. 2. If, in some aspects, the peak 252 passes a certain threshold 254, the receiver may declare that a packet is detected. [0033] FIG. 3 is a block diagram that illustrates a PPDU preamble structure 300 of an IEEE 802.1 lax extended range single user PPDU. It comprises an L- STF 305 followed by an L-LTF 3 10, an L-SIG 3 15, an RL-SIG 320, a first HE- SIG 325, a second HE-SIG 330, a first R-HE-SIG 335, a second R-HE-SIG 340, an HE-STF 345, and an HE-LTF 350. In some aspects, operation in a mode using this structure may not provide a benchmark 9 dB gain over use in an IEEE 802.1 lac mode, and enhancement may, in aspects, be needed during operation using the IEEE 802. 1 lax Wave 2 protocol.

[0034] The L-STF 305 may, in some aspects, be used for packet detection. For example, the L-STF 305 may, in some aspects, repeat ten cycles in a time domain with 0.8 [is per cycle (see FIG 5A discussion below). Ten cycles in such an example sum up to 8 [i with the duration of two Ix OFDM symbols. For packet- detection, in some aspects, products use autocorrelation, which may utilize the cyclical structure of the L-STF 305. However, a packet detection structure that meets a working SNR that is 9 dB lower than an IEEE 802, 1 lac standard may- have a bottleneck, for example, as illustrated in FIG. 4, which is a graph 400 illustrating performance of a packet detection in which the various curves show the ratios of packets that have failed to be detected (Y-axis) versus the SNR(X- axis). The graph line without symbols (410— PPDU detection) illustrates packet detection performance with limited overall performance,

[0035] Aspects described herein may improve detections of the PPDU preamble and data, and at least two general solutions are described below that may enhance the packet detection. One possible reason for packet detection failure may be a lack of signal energy. To meet a design goal of improving the SNR to, for example, 9 dB beyond IEEE 802.1 lac standards, in some aspects, a receiver may- operate at about a predefined SNR dB level SNR. In other words, a desired signal may be a predefined SNR dB level less than the noise. Various parameters may be adjusted to accommodate a different level of SNR based on a predefined specification.

[0036] The integration duration in the packet detection may, in some aspects, need to be longer for suppressing noise, or for boosting signal peaks (252, FIG. 2). For backward compatibility, additional L-Symbols of the STF (beyond ten) may be appended to an existing L-STF. [0037] FIG. 5 A is a block diagram illustrating a legacy L-STF for an example IEEE 802. 1 1 ax extended range SU PPDU preamble structure 500, which comprises ten L-Symbols of the STF 305A-305D having a total duration of, e.g., 8μ8 (with each symbol having a duration of 0.8 ps). The AGC Setting 520 is performed for the first five L-Symbols of the STF 305A-305B, and the remaining five L-Symbols of the STF 305C-305D are used for packet detection and rough symbol timing 530. In legacy IEEE 802.1 la/n/ac devices, the AGC 220 may need about five or six L-Symbols of the STF 305A-305C to properly set the amplification gain.

[0038] FIG. 5B is a block diagram illustrating a novel extended range L-STF (also called ER-STF) for an example IEEE 802.1 lax extend range SU PPDU preamble structure 500', which comprises 10+N (wherein N > 0) L-Symbols of the STF (adding N additional L-Symbols of the STF beyond the legacy ten) 305 A- 305G as an ER-STF. In this example, the first six L-Symbols of the STF 305A- 305C are used by the receiver for the AGC setting 520, and the last 10+N-6 LTF symbols 305E-305F are used for the packet detection and rough symbol timing 530. Besides the extended integration duration, in some aspects, the AGC 220 may also need additional signals to properly set the amplification gain at such a low SNR and a large delay spread for long range links. The additional added signals for the AGC 220, in some aspects, may be these additional N L-Symbols of the STF 305F-305G. In some aspects, the added signals for the AGC 220 may be other periodic signals, for example, signals with a period of 0,4 - 4 ps. Two examples which have more energy for packet detection are described in more detail below, Solution I: Extended L-STF (ER-STF)

[00391 A first option may be to add more cycles (N symbols) in the L-STF field, as discussed above and in accordance with various aspects. As illustrated in FIGs. 5A and 5B, an L-STF 305 in a legacy L-STF (FIG. 5A) may be replaced by an extended range STF (ER-STF 370, FIG. 5B). In some aspects, such an ER-STF 370 may be longer than the legacy L-STF 305 with two OFDM symbols, whose OFDM symbol may have five cycles in the time domain, with 0.8 ps per each cycle. For example, in some aspects, two to four cycles (N = 2, 4) may be added to a legacy of ten symbols to provide more energy for better detection performance. Such aspects may be fully backward compatible.

[0040J In some aspects, legacy devices may detect the packet with the same processing circuits. In the packet detection processing, in some aspects, new receivers may use longer integration durations such as 1.6 μ.3 or 3,2 μ5 instead of the legacy 0.8 \is. The added L-Symbols of the STF 305F-305G may enable the longer integration duration for suppressing noise and boosting the desired signal in accordance with various aspects.

[00411 I¹¹ some cases, chips may have a limit to the number of L-STF 305 symbols detected at their receivers. For example, if the receiver detects more than eight L-STF 305 symbols after the AGC 220 is set, in some aspects, the receiver may exit and stop searching for the subsequent L-LTF symbols 305. To address this potential problem, the first few L-Symbols of the STF 305 may, in some aspects, be replaced in the ER-STF 370 with an AGC 220 setting signal that does not have a period of 0.8 μβ. The AGC setting signal in some aspects, may set the AGC 220 properly so that subsequent L-Symbols of the STF 305 such as eight L- Symbols of the STF 305 may be used for packet detection.

[0042] In a second option, the L-STF 305 may, in some aspects, be boosted to provide an ER-STF 370, for example, as illustrated in FIG. 6, which is a block diagram of an extended range SU PPDU preamble 600 that illustrates an ER-STF 370 for packet detection in accordance with some aspects. Under IEEE 802. 1 l ax standards, the L-STF 305 has, in some aspects, been boosted by three dB for range extension. In some aspects, further boosting beyond three dB may be applied for greater range. Such an option may also be backward compatible with legacy devices,

[0043] This second option may be combined together with the first option described above. For example, the ER-STF 370 described for the first option may be boosted by three dB or more to obtain greater range.

Solution II: Repurpose L-LTF and L-SIG - RL-SIG for packet detection.

[0044] In some aspects, instead of using the short periodicity of the L~ Symbols of the STF 305 such as 0.8 us, the long periodicity of the L-LTF 310 and L-SIG 315/RL-SIG 320 may be used. For example, 4 μ8 may be used for packet detection. The longer period of 4 μ$ may, in some aspects, provide about 7 dB gain over the 0.8 lis period.

[0045] FIGS. 7A and 7B are block diagrams of PPDU preambles 700, 700' that illustrate use of repetitions in an L-LTF 310 (310 A, 310B) and L-SIG 315/RL- SIG 320 for packet detection in accordance with some aspects. As illustrated in FIG. 7A, both the L-LTF 31 OA, 310B and L-SIG 315/RL-SIG 320 may comprise of a pair of identical OFDM symbols each. If the receiver adjusts the autocorrelation window, in some aspects, to accommodate the L-STF 305 and L~ LTF 310 staictures, the receiver may use four symbols (310A-320) for packet detection, in accordance with various aspects. In other words, the receiver, in some aspects, may first make use of the L-STF 305 to set the AGC 220. After the AGC 220 setting converges, in some aspects, the receiver may use the periodicity of 4 μ.3 to detect the packet arrival.

Θ046] Because the L-LTF 310 may be used for channel training in a legacy system, if, in some aspects, it is used for packet detection 530 and the receiver doesn't buffer the L-LTF 310 samples, another field may be added for channel training or a channel training operation, for example, an extended range LTF (ER- LTF 770) as illustrated in FIGS. 7A and 7B. The ER-LTF 770 may, in some aspects, have a longer duration than an existing HE-LTF 350 for boosting the channel training energy. For example, a 4x symbol duration may be used, in some aspects, for the ER-LTF 770, In addition, the two or more 4x training symbols may, in some aspects, be used in the ER-LTF 770 for a single spatial stream. If the receiver buffers the L-LTF symbols 3 0A, 310B, in some aspects, the buffered L-LTF symbols 3 10A, 3 10B may still be used for channel training 730. If so, in some aspects, an ER-LTF 770 may be short or may not even be needed for channel training 730.

Θ047] FIGS. 8A and 8B are block diagrams of PPDU preambles 800, 800' that illustrate use of aggregation for packet detection in accordance with some aspects. In some aspects, if a 4 μ8 long L-LTF symbol 310 cannot meet the performance requirement, the L-LTF 310, L-SIG 3 15, and RL-SIG 320 may be aggregated (L-LTF 310, L-SIG 315) to form a 16 μ.3 long signal for packet detection 530. In FIG. 8 A, the L-LTF symbol 310 and the L-SIG 315 may be aggregated. In FIG. 8B, the L-LTF 310, L-SIG 3 15, and the RL-SIG 320 may be aggregated. Adjusting the auto-correlation window to be three or four symbols, for example 12 or 16 us, the receiver may, in some aspects, use up to six or up to eight symbols for packet detection 530. Similar to FIGS. 7 A & 7B, signals may be appended for channel training, for the ER-LTF 770.

[0048] FIG. 9A is a flowchart for an example transmitter process 900. In operation S905, an apparatus of the transmitter may encode a PPDU preamble comprising an L-STF and an L-LTF where the L-STF comprises 10+N (where N>0) OFDM symbols. In operation S910, the apparatus may encode an AGC setting signal from L-Symbols of the STF, and in operation S915, the apparatus may configure the transmitter to transmit the PPDU with preamble to a receiver.

[0049] FIG. 9B is a flowchart for an example receiver process 950 corresponding to the transmit process 900. In operation S955, an apparatus of the receiver may decode a PPDU preamble comprising an L-STF and an L-LTF where the L-STF comprises 10+N (where N>0) OFDM symbols. In operation S960, the apparatus may decode an AGC setting signal from L-Symbols of the STF, and in operation S965, the apparatus may utilize a plurality of the L-Symbols of the STF that includes a 10+Nth symbol to provide energy for packet detection when a signal-to-noise ratio (SNR) is at or above a predefined S R dB level.

[0050] FIG. 10 is a block diagram of an example machine 1000 upon which one or more of the techniques (e.g., methodologies) discussed herein may perform. In alternative aspects, the machine 1000 may operate as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, the machine 1000 may operate in the capacity of a server machine, a client machine, or both in server-client network environments. In an example, the machine 1000 may act as a peer machine in peer-to-peer (P2P) (or other distributed) network environment. The machine 1000 may be a master station 102, HE station 104, personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a mobile telephone, a smart phone, a web appliance, a network router, switch or bridge, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term "machine" shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein, such as cloud computing, software as a service (SaaS), other computer cluster configurations.

[00S1J Examples, as described herein, may include, or may operate on, logic or a number of components, modules, or mechanisms. Modules are tangible entities (e.g., hardware) capable of performing specified operations and may be configured or arranged in a certain manner. In an example, circuits may be arranged (e.g., internally or with respect to external entities such as other circuits) in a specified manner as a module. In an example, the whole or part of one or more computer systems (e.g., a standalone, client or server computer system) or one or more hardware processors may be configured by firmware or software (e.g., instructions, an application portion, or an application) as a module that operates to perform specified operations. In an example, the software may reside on a machine readable medium. In an example, the software, when executed by the underlying hardware of the module, causes the hardware to perform the specified operations.

Θ052] Accordingly, the term "module" is understood to encompass a tangible entity, be that an entity that is physically constructed, specifically configured (e.g., hardwired), or temporarily (e.g., transitorily) configured (e.g., programmed) to operate in a specified manner or to perform part or all of any operation described herein. Considering examples in which modules are temporarily configured, each of the modules need not be instantiated at any one moment in time. For example, where the modules comprise a general-purpose hardware processor configured using software, the general-purpose hardware processor may be configured as respective different modules at different times. Software may accordingly configure a hardware processor, for example, to constitute a particular module at one instance of time and to constitute a different module at a different instance of time.

[0053] Machine (e.g., computer system) 1000 may include a hardware processor 1002 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory 1004 and a static memory 1006, some or all of which may communicate with each other via an interlink (e.g., bus) 1008. The machine 1000 may further include a display device 1010, an input device 1012 (e.g., a keyboard), and a user interface (UI) navigation device 1014 (e.g., a mouse). In an example, the display device 1010, input device 1012 and UI navigation device 1014 may he a touch screen display. The machine 1000 may additionally include a mass storage (e.g., drive unit) 1016, a signal generation device 1018 (e.g., a speaker), a network interface device 1020, which may be a wireless communication device, and one or more sensors 1021, such as a global positioning system (GPS) sensor, compass, accelerometer, or other sensor. The machine 1000 may include an output controller 1028, such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate or control one or more peripheral devices (e.g., a printer, card reader, etc). In some aspects, the processor 1002 and/or instructions 1024 may comprise processing circuitry and/or transceiver circuitry.

[0054] The storage device 1016 may include a machine readable medium 022 on which is stored one or more sets of data structures or instaictions 1024 (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The instructions 1024 may also reside, completely or at least partially, within the main memory 1004, within static memory 1006, or within the hardware processor 1002 during execution thereof by the machine 1000. In an example, one or any combination of the hardware processor 1002, the main memory 1004, the static memory 1006, or the storage device 1016 may constitute machine readable media.

[0055] While the machine readable medium 1022 is illustrated as a single medium, the term "machine readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions 024.

[0056] An apparatus of the machine 1000 may be one or more of a hardware processor 1002 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory 1004 and a static memory 1006, some or all of which may communicate with each other via an interlink (e.g., bus) 1008.

[0057] The term "machine readable medium" may include any medium that is capable of storing, encoding, or carrying instructions for execution by the machine 1000 and that cause the machine 000 to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. on-limiting machine readable medium examples may include solid-state memories, and optical and magnetic media. Specific examples of machine readable media may include: non-volatile memory, such as semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; Random Access Memory (RAM); and CD-ROM and DVD-ROM disks. In some examples, machine readable media may include non-transitory machine readable media. In some examples, machine readable media may include machine readable media that is not a transitory propagating signal.

[0058] The instructions 1024 may further be transmitted or received over a communications network 1026 using a transmission medium via the network interface device 1020 utilizing any one of a number of transfer protocols (e.g., frame relay, internet protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HTTP), etc.). Example communication networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), mobile telephone networks (e.g., cellular networks), Plain Old Telephone (POTS) networks, and wireless data networks (e.g., Institute of Electrical and Electronics Engineers (IEEE) 802, 11 family of standards known as Wi-Fi®, IEEE 802.16 family of standards known as WiMax®), IEEE 802.15.4 family of standards, a Long Term Evolution (LTE) family of standards, a Universal Mobile Telecommunications System (UMTS ) family of standards, peer-to-peer (P2P) networks, among others.

[0059] In an example, the network interface device 1020 may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to the communications network 1026. In an example, the network interface device 1020 may include one or more antennas 1060 to wirelessiy communicate using at least one of single-input multiple-output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MISO) techniques. In some examples, the network interface device 1020 may wirelessiy communicate using Multiple User MIMO techniques. The term "transmission medium" shall be taken to include any intangible medium that is capable of storing, encoding or carrying instructions for execution by the machine 1000, and includes digital or analog communications signals or other intangible medium to facilitate communication of such software. The master station 102, HE station 104, and legacy device 06 may be a machine 1000.

[0060] Various aspects may be implemented fully or partially in software and/or firmware. This software and/or firmware may take the form of instructions contained in or on a non-transitory computer-readable storage medium. Those instructions may then be read and executed by one or more processors to enable performance of the operations described herein. The instructions may be in any suitable form, such as but not limited to source code, compiled code, interpreted code, executable code, static code, dynamic code, and the like. Such a computer- readable medium may include any tangible non-transitory medium for storing information in a form readable by one or more computers, such as but not limited to read only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media, flash memory, etc.

Examples

[0061] Example 1 is an apparatus of a wireless device comprising memory; and processor circuitry coupled to the memory, the processor circuity configured to: decode a physical layer convergence protocol (PLCP) protocol data unit (PPDU) preamble comprising a short training field (STF) and a legacy long training field (L-LTF), wherein: the STF comprises an orthogonal frequency- division multiplexing (OFDM) quantity of symbols that is dependent upon whether the PPDU comprises a legacy short training field (L-STF) or an extended range short training field (ER-STF); when the STF is an L-STF, the STF comprises 10 OFDM symbols; and when the STF is an ER-STF, the STF comprises 10+N OFDM symbols with N > 0; decode an automatic gain control (AGC) setting to produce an AGC setting to an AGC; and utilize a plurality of the STF OFDM symbols that includes a 10th OFDM symbol when the STF is an L- STF, and a 10+Nth OFD : symbol when the STF is an ER-STF to provide energy for packet detection.

[0062] In Example 2, the subject matter of Example 1 optionally includes \is. [0063] In Example 3, the subject matter of any one or more of Examples 1-2 optionally include wherein N is two or four.

[0064J In Example 4, the subject matter of any one or more of Examples 1-3 optionally include wherein the AGC setting signal utilizes a first plurality of the L-STF or Symbols of the ER-STF to produce the automatic gain control (AGC ) setting to the AGC.

[00651 I¹¹ Example 5, the subject matter of any one or more of Examples 1-4 optionally includes wherein the AGC setting signal has a period that differs from 0.8 p.s.

[0066] In Example 6, the subject matter of any one or more of Examples 1-5 optionally includes wherein the processor circuitry is further configured to configure a receiver to utilize an integration duration longer than 0.8 μ,3.

[0067] In Example 7, the subject matter of Examples 1-6 optionally includes wherein the integration duration is 1.6 με or 3.2 μ8.

[0068] In Example 8, the subject matter of any one or more of Examples 1-7 optionally includes wherein the utilization of the plurality of the L-Symbols of the STF to provide energy for packet detection occurs when a signal-to-noise ratio (SNR) is at or above a predefined SNR dB level.

[0069] In Example 9, the subject matter of any one or more of Examples 1-8 optionally include wherein the ER-STF is provided after a repeated legacy signal field (RL-SIG) in the PPDU and is configured to be processed after packet detection has been performed,

[0070] Example 10 is an apparatus of a wireless device comprising memory; and processor circuitry coupled to the memory, the processor circuity configured to: encode a physical layer convergence protocol (PLCP) protocol data unit (PPDU) preamble comprising: a legacy short training field (L-STF); for packet detection, a legacy long training field (L-LTF), a legacy signal field (L-SIG), and a repeated legacy signal field (RL-SIG); and for a channel training operation, an extended range long training field (ER-LTF) that follows the RL-SIG.

[0071] In Example 11, the subject matter of Example 10 optionally includes wherein the processor circuitry is further configured to encode the PPDU to additionally include an extended range short training field (ER-STF) between the RL-SIG and the ER-LTF. [0072] In Example 12, the subject matter of any one or more of Examples 10- 1 optionally includes wherein the ER-LTF has a 4x symbol duration.

[0073] In Example 13, the subject matter of any one or more of Examples 10-

12 optionally include wherein the processor circuitry is further configured to: decode a received PPDU preamble comprising a legacy short training field (L-

STF), a legacy long training field (L-LTF), a legacy signal field (L-SIG), and an extended range long training field (ER-LTF); perform the packet detection using the L-LTF, the L-SIG, and the RL-SIG fields: and perform the channel training operation using the ER-LTF,

[0074] In Example 14, the subject matter of Example 13 optionally includes wherein the processor circuitry is further configured to decode a repeated legacy signal field (R-LSIG) located between the L-SIG and the ER-LTF.

[0075] In Example 15, the subject matter of any one or more of Examples 10-

14 optionally include wherein the processor circuitry is further configured to encode a repeated L-LTF and a repeated L-SIG that follows the L-LTF and the L-

SIG in the PPDU, wherein the L-LTF, the L-SIG, the repeated L-LTF, and the repeated L-SIG are used for the packet detection.

[0076] In Example 16, the subject matter of any one or more of Examples 11-

15 optionally include wherein the processor circuitry is further configured to encode a repeated L-LTF, a repeated L-SIG, and a repeated RL-SIG that follows the L-LTF, the L-SIG, and the RL-SIG in the PPDU, wherein the L-LTF, the L- SIG, the RL-SIG, the repeated L-LTF, the repeated L-SIG, and the repeated RL- SIG are used for the packet detection.

[0077] In Example 17, the subject matter of any one or more of Examples 1 1- 16 optionally includes wherein the L-LTF, L-SIG, and RL-SIG form a 16 μ,3 long signal for the packet detection.

[0078] In Example 18, the subject matter of any one or more of Examples 13-

17 optionally include a buffer configured to store buffered L-LTF symbols usable for channel training.

[0079] In Example 19, the subject matter of any one or more of Examples 10-

18 optionally includes wherein the processor circuitry is further configured to configure the receiver to utilize an integration duration longer than 0.8 μβ. [0080] In Example 20, the subject matter of Example 19 optionally includes wherein the integration duration is 1 .6 p.s or 3.2 fis,

[0081] Example 21 is an apparatus of a wireless device comprising memory; and processor circuitry coupled to the memory, the processor circuity configured to: decode a physical layer convergence protocol (PLCP) protocol data unit (PPDU) preamble comprising: a legacy short training field (L-STF); a legacy long training field (L-LTF), a legacy signal field (L-SIG), and a repeated legacy signal field (RL-SIG); and an extended range long training field (ER-LTF) that follows the RL-SIG; the processor circuitry further configured to: utilize the legacy long training field (L-LTF), the legacy signal field (L-SIG), and the repeated legacy signal field (RL-SIG) for packet detection; and utilize the extended range long training field (ER-LTF) that follows the RL-SIG for a channel training operation.

[0082] Example 22 is a method performed by a wireless communication device, the device comprising memory; and processing circuitry coupled to the memory, the method comprising: decoding a physical layer convergence protocol (PLCP) protocol data unit (PPI3L1) preamble comprising a short training field (STF) and a legacy long training field (L-LTF); wherein: the STF comprises an orthogonal frequency-division multiplexing (OFDM) quantity of symbols that is dependent upon whether the PPDU comprises a legacy short training field (L- STF) or an extended range short training field (ER-STF); when the STF is an !,- STF, the STF comprises 10 OFDM symbols; and when the STF is an ER-STF, the STF comprises 10 N OFDM symbols with N > 0; decoding an automatic gain control (AGC) setting to produce an AGC setting to an AGC; and utilizing a plurality of the STF OFDM symbols that includes a 10th OFDM symbol when the STF is an L-STF, and a 10+Nth OFDM symbol when the STF is an ER-STF to provide energy for packet detecting.

[0083] In Example 23, the subject matter of Example 22 optionally includes wherein a periodicity of the Symbols of the ER-STF is 0.8 8 and a duration of

[0084] In Example 24, the subject matter of any one or more of Examples 22-

23 optionally include wherein N is two or four.

[0085] In Example 25, the subject matter of any one or more of Examples 22-

24 optionally include wherein the AGC setting signal utilizes a first plurality of the L-STF or Symbols of the ER-STF to produce the automatic gain control (AGC) setting to the AGC,

[0086J In Example 26, the subject matter of any one or more of Examples 22-

25 optionally includes wherein the AGC setting signal has a period that differs

[0087] In Example 27, the subject matter of any one or more of Examples 22-

26 optionally includes further comprising configuring the receiver to utilize an integration duration longer than 0.8 LIS.

[0088] In Example 28, the subject matter of Example 27 optionally includes wherein the integration duration is 1.6 μ3 or 3.2 .

[0089] In Example 29, the subject matter of any one or more of Examples 22-

28 optionally includes wherein utilizing the plurality of the L-Symbois of the STF to provide energy for packet detection occurs when a signal-to-noise ratio (S R) is at or above a predefined SNR dB level.

[0090] In Example 30, the subject matter of any one or more of Examples 22-

29 optionally include wherein the ER-STF is provided after a repeated legacy signal field (RL-SIG) in the PPDU and is processed after packet detecting has been performed.

[0091] Example 31 is a method performed by a wireless communication device, the device comprising memory; and processing circuitry coupled to the memory, the method comprising: encoding a physical layer convergence protocol (PLCP) protocol data unit (PPDU) preamble comprising: a legacy short training field (L-STF); for packet detecting, a legacy long training field (L-LTF), a legacy signal field (L-SIG), and a repeated legacy signal field (RL-SIG); and for channel training, an extended range long training field (ER-LTF) that follows the RL-SIG.

[0092] In Example 32, the subject matter of Example 31 optionally includes encoding an extended range short training field (ER-STF) between the RL-SIG and the ER-LTF.

[0093] In Example 33 , the subj ect matter of any one or more of Examples 31 - 32 optionally includes wherein the ER-LTF has a 4x symbol duration.

[0094] In Example 34, the subject matter of any one or more of Examples 31- 33 optionally include decoding a received PPDU preamble comprising a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signal field (L-SIG), and an extended range long training field (ER-LTF); performing packet detecting using the L-LTF, the L-SIG, and the RL-SIG fields; and performing channel training using the ER-LTF.

[0095] In Example 35, the subject matter of Example 34 optionally includes decoding a repeated legacy signal field (R-LSIG) located between the L-SIG and the ER-LTF.

[00961 I¹¹ Example 36, the subject matter of any one or more of Examples 3 1 -

35 optionally include encoding a repeated L-LTF and a repeated L-SIG that follows the L-LTF and the L-SIG in the PPDU, wherein the L-LTF, the L-SIG, the repeated L-LTF, and the repeated L-SIG are used for the packet detecting.

[0097] In Example 37, the subject matter of any one or more of Examples 32-

36 optionally include encoding a repeated L-LTF, a repeated L-SIG, and a repeated RL-SIG that follows the L-LTF, the L-SIG, and the RL-SIG in the PPDU, wherein the L-LTF, the L-SIG, the RL-SIG, the repeated L-LTF, the repeated L- SIG, and the repeated RL-SIG are used for the packet detecting.

[0098] In Example 38, the subject matter of any one or more of Examples 32-

37 optionally includes wherein the L-LTF, L-SIG, and RL-SIG form a 16 long signal for the packet detection.

[0099] In Example 39, the subject matter of any one or more of Examples 34- 38 optionally include storing L-LTF symbols usable for channel training in a buffer,

[00100] In Example 40, the subject matter of any one or more of Examples 3 1 - 39 optionally includes further comprising configuring the receiver to utilize an integration duration longer than 0.8 μβ.

[00101] In Example 1, the subject matter of Example 40 optionally includes wherein the integration duration is 1.6 μ.3 or 3.2 [is.

[00102] Example 42 is a method performed by a wireless communication device, the device comprising memory; and processing circuitry coupled to the memory, the method comprising: decoding a physical layer convergence protocol (PLCP) protocol data unit (PPDU) preamble comprising: a legacy short training field (L-STF); a legacy long traimng field (L-LTF), a legacy signal field (L-SIG), and a repeated legacy signal field (RL-SIG) for packet detection, and an extended range long training field (ER-LTF) that follows the RL-SIG for a channel training operation; the method further comprising: performing packet detecting using the legacy long training field (L-LTF), the legacy signal field (L-SIG), and the repeated legacy signal field (RL-SIG); and performing channel training using the extended range long training field (ER-LTF) that follows the RL-SIG.

[00103] Example 43 is a computer-readable storage medium that stores instructions for execution by one or more processors, the instructions to configure the one or more processors to cause a wireless device to: decode a physical layer convergence protocol (PLCP) protocol data unit (PPDU) preamble comprising a short training field (STF) and a legacy long training field (L-LTF), wherein: the STF comprises an orthogonal frequency-division multiplexing (OFDM) quantity of symbols that is dependent upon whether the PPDU comprises a legacy short training field (L-STF) or an extended range short training field (ER-STF); when the STF is an L-STF, the STF comprises 10 OFDM symbols, and when the STF is an ER-STF, the STF comprises 10+N OFDM symbols with N > 0; decode an automatic gain control (AGC) setting to produce an AGC setting to an AGC; and utilize a plurality of the STF OFDM symbols that includes a 10th OFDM symbol when the STF is an L-STF, and a 10+Nth OFDM symbol when the STF is an ER- STF to provide energy for packet detection.

[00104] In Example 44, the subject matter of Example 43 optionally includes wherein a periodicity of the Symbols of the ER-STF is 0.8 μ8 and a duration of

[00105] In Example 45, the subject matter of any one or more of Examples 43- 44 optionally include wherein N is two or four.

[00106] In Example 46, the subject matter of any one or more of Examples 43- 45 optionally include wherein the AGC setting signal utilizes a first plurality of the L-STF or Symbols of the ER-STF to produce the automatic gain control (AGC) setting to the AGC.

[00107] In Example 47, the subject matter of any one or more of Examples 43-

46 optionally includes wherein the AGC setting signal has a period that differs from 0.8 [is.

[00108] In Example 48, the subject matter of any one or more of Examples 43-

47 optionally includes wherein the processor circuitry is further configured to configure the receiver to utilize an integration duration longer than 0.8 μβ. [00109] In Example 49, the subject matter of Example 48 optionally includes wherein the integration duration is 1.6 μ.3 or 3 ,2 [is.

[00110] In Example 50, the subject matter of any one or more of Examples 43-

49 optionally includes wherein the utilization of the plurality of the L-Symbols of the STF to provide energy for packet detection occurs when a signal-to-noise ratio

(SNR) is at or above a predefined SNR dB level.

[00111] In Example 51 , the subj ect matter of any one or more of Examples 43-

50 optionally include wherein the ER-STF is provided after a repeated legacy signal field (RL-SIG) in the PPDU and is configured to be processed after packet detection has been performed,

[00112] Example 52 is a computer-readable storage medium that stores instructions for execution by one or more processors, the instructions to configure the one or more processors to cause a wireless device to: encode a physical layer convergence protocol (PLCP) protocol data unit (PPDU) preamble comprising: a legacy short training field (L-STF); for packet detection, a legacy long training field (L-LTF), a legacy signal field (L-SIG), and a repeated legacy signal field (RL-SIG); and for a channel training operation, an extended range long training field (ER-LTF) that follows the RL-SIG.

[00113] In Example 53, the subject matter of Example 52 optionally includes wherein the processor circuitry is further configured to encode the PPDU to additionally include an extended range short training field (ER-STF) between the RL-SIG and the ER-LTF.

[00114] In Example 54, the subject matter of any one or more of Examples 52-

53 optionally includes wherein the ER-LTF has a 4x symbol duration.

[00115] In Example 55, the subject matter of any one or more of Examples 52-

54 optionally include wherein the processor circuitry is further configured to: decode a received PPDU preamble comprising a legacy short training field (L- STF), a legacy long training field (L-LTF), a legacy signal field (L-SIG), and an extended range long training field (ER-LTF); perform the packet detection using the L-LTF, the L-SIG, and the RL-SIG fields; and perform the channel training operation using the ER-LTF. [00116] In Example 56, the subject matter of Example 55 optionally includes wherein the processor circuitry is further configured to decode a repeated legacy signal field (R-LSIG) located between the L-SIG and the ER-LTF.

[00117] In Example 57, the subject matter of any one or more of Examples 52- 56 optionally include wherein the processor circuitry is further configured to encode a repeated L-LTF and a repeated L-SIG that follows the L-LTF and the L- SIG in the PPDU, wherein the L-LTF, the L-SIG, the repeated L-LTF, and the repeated L-SIG are used for the packet detection.

[00118] In Example 58, the subject matter of any one or more of Examples 53- 57 optionally include wherein the processor circuitry is further configured to encode a repeated L-LTF, a repeated L-SIG, and a repeated RL-SIG that follows the L-LTF, the L-SIG, and the RL-SIG in the PPDU, wherein the L-LTF, the L- SIG, the RL-SIG, the repeated L-LTF, the repeated L-SIG, and the repeated RL- SIG are used for the packet detection.

[00119] In Example 59, the subject matter of any one or more of Examples 53-

58 optionally includes wherein the L-LTF, L-SIG, and RL-SIG form a 16 long signal for the packet detection,

[00120] In Example 60, the subject matter of any one or more of Examples 55-

59 optionally include a buffer configured to store buffered L-LTF symbols usable for channel training.

[00121] In Example 61, the subject matter of any one or more of Examples 52-

60 optionally includes wherein the processor circuitry is further configured to configure the receiver to utilize an integration duration longer than 0.8 [is.

[00122] In Example 62, the subject matter of Example 61 optionally includes wherein the integration duration is 1.6 με or 3.2 μ8.

[00123] Example 63 is a computer-readable storage medium that stores instructions for execution by one or more processors, the instructions to configure the one or more processors to cause a wireless device to: decode a physical layer convergence protocol (PLCP) protocol data unit (PPDU) preamble comprising: a legacy short training field (L-STF); a legacy long training field (L-LTF), a legacy- signal field (L-SIG), and a repeated legacy signal field (RL-SIG); and an extended range long training field (ER-LTF) that follows the RL-SIG; the instructions are further to configure processor circuitry to: utilize the legacy long training field (L- LTF), the legacy signal field (L-SIG), and the repeated legacy signal field (RL- SIG) for packet detection, and utilize the extended range long training field (ER- LTF) that follows the RL-SIG for a channel training operation.

[00124] Example 64 is at least one machine-readable medium including instructions, which when executed by a machine, cause the machine to perform operations of any of the operations of Examples 22-42.

[00125] Example 65 is a computer program product comprising one or more computer readable storage media comprising computer-executable instructions operable to, when executed by processing circuitry of a device, configure the device to perform any of the methods of Examples 22-42.

[00126] Example 66 is an apparatus of a wireless communications device, comprising: means for decoding a physical layer convergence protocol (PLCP) protocol data unit (PPDU) preamble comprising a short training field (STF) and a legacy long training field (L-LTF); wherein: the STF comprises an orthogonal frequency-division multiplexing (OFDMF) quantity of symbols that is dependent upon whether the PPDU comprises a legacy short training field (L-STF) or an extended range short training field (ER-STF); when the STF is an L-STF, the STF comprises 10 OFDMF symbols; and when the STF is an ER-STF, the STF comprises 10+N OFDMF symbols with N > 0; means for decoding an automatic gain control (AGC) setting to produce an AGC setting to an AGC; and means for utilizing a plurality of the STF OFDMF symbols that includes a 10th OFDMF symbol when the STF is an L-STF, and a 10+Nth OFDMF symbol when the STF is an ER-STF to provide energy for packet detecting.

[00127] In Example 67, the subject matter of Example 66 optionally includes wherein a periodicity of the Symbols of the ER-STF is 0.8 \is and a duration of

[00128] In Example 68, the subject matter of any one or more of Examples 66- 67 optionally include wherein N is two or four.

[00129] In Example 69, the subject matter of any one or more of Examples 66- 68 optionally include wherein the AGC setting signal utilizes a first plurality of the L-STF or Symbols of the ER-STF to produce the automatic gain control (AGC) setting to the AGC. [00130] In Example 70, the subject matter of any one or more of Examples 66- 69 optionally include wherein the AGC setting signal has a period that differs from 0.8 με.

[00131] In Example 71, the subject matter of any one or more of Examples 66- 70 optionally include further comprising means for configuring the receiver to utilize an integration duration longer than 0.8 μ$,

[00132] In Example 72, the subject matter of Example 71 optionally includes wherein the integration duration is 1.6 or 3.2 .

[00133] In Example 73, the subject matter of any one or more of Examples 66- 72 optionally includes wherein the means for utilizing the plurality of the L- Symbols of the STF to provide energy for packet detection occurs when a signal- to-noise ratio (SNR) is at or above a predefined SNR dB level,

[00134] In Example 74, the subject matter of any one or more of Examples 66- 73 optionally include wherein the ER-STF is provided after a repeated legacy signal field (RL-SIG) in the PPDU and is processed after packet detecting has been performed.

[00135] Example 75 is an apparatus of a wireless communications device, comprising: means for encoding a physical layer convergence protocol (PLCP) protocol data unit (PPDU) preamble comprising: a legacy short training field (L- STF); for packet detecting, a legacy long training field (L-LTF), a legacy signal field (L-SIG), and a repeated legacy signal field (RL-SIG); and for channel training, an extended range long training field (ER-LTF) that follows the RL-SIG.

[00136] In Example 76, the subject matter of Example 75 optionally includes means for encoding an extended range short training field (ER-STF) between the RL-SIG and the ER-LTF,

[00137] In Example 77, the subject matter of any one or more of Examples 75-

76 optionally includes wherein the ER-LTF has a 4x symbol duration.

[00138] In Example 78, the subject matter of any one or more of Examples 75-

77 optionally include means for decoding a received PPDU preamble comprising a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signal field (L-SIG), and an extended range long training field (ER-LTF); means for performing packet detecting using the L-LTF, the L-SIG, and the RL-SIG fields; and means for performing channel training using the ER-LTF. [00139] In Example 79, the subject matter of Example 78 optionally includes means for decoding a repeated legacy signal field (R-LSIG) located between the L-SIG and the ER-LTF.

[00140] In Example 80, the subject matter of any one or more of Examples 75- 79 optionally include means for encoding a repeated L-LTF and a repeated L-SIG that follows the L-LTF and the L-SIG in the PPDU, wherein the L-LTF, the L~ SIG, the repeated L-LTF, and the repeated L-SIG are used for the packet detecting.

[00141] In Example 81, the subject matter of any one or more of Examples 76-

80 optionally include means for encoding a repeated L-LTF, a repeated L-SIG, and a repeated RL-SIG that follows the L-LTF, the L-SIG, and the RL-SIG in the

PPDU, wherein the L-LTF, the L-SIG, the RL-SIG, the repeated L-LTF, the repeated L-SIG, and the repeated RL-SIG are used for the packet detecting.

[00142] In Example 82, the subject matter of any one or more of Examples 76-

81 optionally includes wherein the L-LTF, L-SIG, and RL-SIG form a 16 is long signal for the packet detection.

[00143] In Example 83, the subject matter of any one or more of Examples 78-

82 optionally include means for storing L-LTF symbols usable for channel training in a buffer.

[00144] In Example 84, the subject matter of any one or more of Examples 75- 83 optionally includes further comprising means for configuring the receiver to utilize an integration duration longer than 0.8 μ3.

[00145] In Example 85, the subject matter of Example 84 optional ly includes wherein the integration duration is 1 .6 μ8 or 3.2 με.

[00146] Example 86 is a system comprising means to perform any of the methods of Examples 1-85.

[00147] Example 87 is an apparatus of a wireless communications device, comprising: means for decoding a physical layer convergence protocol (PLCP) protocol data unit (PPDU) preamble comprising: a legacy short training field (L- STF); a legacy long training field (L-LTF), a legacy signal field (L-SIG), and a repeated legacy signal field (RL-SIG) for packet detection; and an extended range long training field (ER-LTF) that follows the RL-SIG for a channel training operation, the apparatus further comprising: means for performing packet detecting using the legacy long training field (L-LTF), the legacy signal field (L- SIG), and the repeated legacy signal field (RL-SIG); and means for performing channel training using the extended range long training field (ER-LTF) that follows the RL-SIG.

[00148] Example 88 is an apparatus comprising means for performing any of the operations of Examples 1-87.

[00149] Example 89 is a system to perform any of the operations of Examples 1-87.

[00150] Example 90 is a method to perform any of the operations of Examples 1-87.

Claims

1. An apparatus of a wireless device, the apparatus comprising: memory; and processor circuitry coupled to the memory, the processor circuity configured to: decode a physical layer convergence protocol (PLCP) protocol data unit (PPDU) preamble comprising a short training field (STF) and a legacy long training field (L-LTF), wherein: the STF comprises a quantity of orthogonal frequency-division multiplexing (OFDM) symbols that indicates whether the PPDU comprises a legacy short training field (L-STF) or an extended range short training field (ER-STF), wherein when the STF is an L-STF, the STF comprises 10 OFDM symbols; and when the STF is an ER-STF, the STF comprises 10+N OFDM symbols with N > 0; decode an automatic gain control (AGC) setting from either the symbols of the L-STF or the symbols of the ER-STF; and utilize a plurality of symbols of the STF that includes a 0th OFDM symbol when the STF is an L-STF, and a 10+Nth OFDM symbol when the STF is an ER-STF for packet detection,

2. The apparatus of claim 1, wherein a periodicity of the symbols of the ER- STF is 0.8 μ8 and a duration of the ER-STF is > 8 μ .

3. The apparatus of claim 1, wherein the AGC setting signal utilizes a first plurality of the L-STF or Symbols of the ER-STF to produce the automatic gain control (AGC) setting to the AGC.

4. The apparatus of claim 1, wherein the AGC setting signal has a period that differs from 0.8 με.

5. The apparatus of claim 1, wherein the processor circuitry is further configured to configure a receiver to utilize an integration duration longer than 0.8 με.

6. The apparatus of claim 5, wherein the integration duration is 1.6 μ$ or 3.2

7. The apparatus of claim 1, wherein the utilization of the plurality of the L- Symbols of the STF to provide energy for packet detection occurs when a signal- to-noise ratio (S R) is at or above a predefined SNR dB level.

8. The apparatus of claim 1, wherein the ER-STF is provided after a repeated legacy signal field (RL-SIG) in the PPDU and is configured to be processed after packet detection has been performed.

9, An apparatus of a wireless device comprising: memory, and processor circuitry coupled to the memory, the processor circuity configured to: encode a physical layer convergence protocol (PLCP) protocol data unit (PPDU) preamble comprising: a legacy short training field (L-STF); for packet detection, a legacy long training field (L-LTF), a legacy signal field (L-SIG), and a repeated legacy signal field (RL-SIG); and for a channel training operation, an extended range long training field (ER-LTF) that follows the RL-SIG.

10. The apparatus of claim 9, wherein the processor circuitry is further configured to encode the PPDU to additionally include an extended range sh training field (ER-STF) between the RL-SIG and the ER-LTF. 11 The apparatus of claim 9, wherein the ER-LTF has a 4x symbol duration.

12, The apparatus of claim 9, wherein the processor circuitry is further configured to: decode a received PPDU preamble comprising an L-STF, an L-LTF, an L-SIG, and an ER-LTF; perform the packet detection using the L-LTF, the L-SIG, and the RL- SIG fields, and perform the channel training operation using the ER-LTF.

13. The apparatus of claim 12, wherein the processor circuitry is further configured to decode an RL-SIG) located between the L-SIG and the ER-LTF.

14. The apparatus of claim 9, wherein the processor circuitry is further configured to encode a repeated L-LTF and a repeated L-SIG that follows the L- LTF and the L-SIG in the PPDU, wherein the L-LTF, the L-SIG, the repeated L- LTF, and the repeated L-SIG are used for the packet detection.

15. The apparatus of claim 10, wherein the processor circuitry is further configured to encode a repeated L-LTF, a repeated L-SIG, and a repeated RL- SIG that follows the L-LTF, the L-SIG, and the RL-SIG in the PPDU, wherein the L-LTF, the L-SIG, the RL-SIG the repeated L-LTF, the repeated L-SIG and the repeated RL-SIG are used for the packet detection. 6. The apparatus of claim 10, wherein the L-LTF, L-SIG, and RL-SIG form a 16 μβ long signal for the packet detection,

17. The apparatus of claim 9, wherein the processor circuitry is further configured to configure the receiver to utilize an integration duration longer than 0.8 με.

18. A method performed by a wireless communication device, the device comprising memory; and processing circuitry coupled to the memory, the method comprising: decoding a physical layer convergence protocol (PLCP) protocol data unit (PPDU) preamble comprising a short training field (STF) and a legacy long training field (L-LTF); wherein: the STF comprises an orthogonal frequency-division multiplexing (OFDM) quantity of symbols that is dependent upon whether the PPDU comprises a legacy short training field (L-STF) or an extended range short training field (ER-STF); when the STF is an L-STF, the STF comprises 10 OFDM symbols; and when the STF is an ER-STF, the STF comprises 10+N OFDM symbols with N > 0; decoding an automatic gain control (AGC) setting from either the symbols of the L-STF or the symbols of the ER-STF; and utilizing a plurality of symbols of the STF that includes a 10th OFDM symbol when the STF is an L-STF, and a 10+Nth OFDM symbol when the STF is an ER-STF for packet detection. 9, The method of claim 18, wherein a periodicity of the Symbols of the ER- STF is 0.8 and a duration of the ER-STF is > 8 μ3.

20. The method of claim 18, wherein N is two or four.

21. The method of claim 18, wherein the AGC setting signal utilizes a first plurality of the L-STF or Symbols of the ER-STF to produce the automatic gain control (AGC) setting to the AGC.

22. The method of claim 18, wherein the AGC setting signal has a period that differs from 0.8 μβ.

23. The method of claim 18, wherein the ER-STF is provided only after a repeated legacy signal field (RL-SIG) in the PPDU and is processed after packet detecting has been performed,

24. A computer-readable storage medium that stores instructions for execution by one or more processors, the instructions to configure the one or more processors to cause a wireless device to: decode a physical layer convergence protocol (PLCP) protocol data unit (PPDU) preamble comprising a short training field (STF) and a legacy long training field (L-LTF), wherein: the STF comprises a quantity of orthogonal frequency-division multiplexing (OFDM) symbols that indicates whether the PPDU comprises a legacy short training field (L-STF) or an extended range short training field (ER-STF), wherein when the STF is an L-STF, the STF comprises 10 OFDM symbols, and when the STF is an ER-STF, the STF comprises 10+N OFDM symbols with N > 0; decode an automatic gain control (AGC) setting from either the symbols of the L-STF or the symbols of the ER-STF; and utilize a plurality of symbols of the STF that includes a 10th OFDM symbol when the STF is an L-STF, and a 10+Nth OFDM symbol when the STF is an ER-STF for packet detection.

25. The medium of claim 24, wherein the AGC setting signal utilizes a first plurality of the L-STF or Symbols of the ER-STF to produce the automatic gain control (AGC) setting to the AGC.