Source: https://patents.google.com/patent/TW201507503A/en
Timestamp: 2020-02-22 14:38:38
Document Index: 775957499

Matched Legal Cases: ['Application No. 61', 'Application No. 61', 'arts\n404', 'arts\n1154', 'arts\n1160', 'arts\n1164', 'arts\n1210']

TW201507503A - High efficiency WLAN preamble structure - Google Patents
High efficiency WLAN preamble structure Download PDF
TW201507503A
TW201507503A TW103123021A TW103123021A TW201507503A TW 201507503 A TW201507503 A TW 201507503A TW 103123021 A TW103123021 A TW 103123021A TW 103123021 A TW103123021 A TW 103123021A TW 201507503 A TW201507503 A TW 201507503A
TW103123021A
TWI660639B (en
Nee Didier Johannes Richa Van
2013-07-05 Priority to US201361843228P priority Critical
2013-07-05 Priority to US61/843,228 priority
2013-10-31 Priority to US201361898397P priority
2013-10-31 Priority to US61/898,397 priority
2013-12-10 Priority to US201361914272P priority
2013-12-10 Priority to US61/914,272 priority
2014-07-02 Priority to US14/322,048 priority patent/US9780919B2/en
2014-07-02 Priority to US14/322,048 priority
2015-02-16 Publication of TW201507503A publication Critical patent/TW201507503A/en
2019-05-21 Publication of TWI660639B publication Critical patent/TWI660639B/en
Aspects of the present invention provide an example preamble signal format with a repeating signal (SIG) field that can help provide legacy compatibility and help address larger of various wireless bands (eg, WiFi bands). The effect of delay spread.
High efficiency WLAN preamble signal structure [Cross-reference to related applications]
This patent application claims US Provisional Application No. 61/843,228 filed on July 5, 2013, US Provisional Application No. 61/898,397, filed on October 31, 2013, and filed on December 10, 2013 The priority of U.S. Provisional Application Serial No. 61/914,272, which is assigned to the assignee of the present application, is hereby incorporated by reference.
Some aspects of the present invention are generally related to wireless communications, and in particular to information in the preamble signals using data packets to support larger delay spreads, for example, in the 2.4 GHz band and the 5 GHz band.
In order to address the growing bandwidth requirements of wireless communication systems, different approaches are being developed to allow multiple user terminals to communicate with a single access point via shared channel resources while achieving high data throughput. Multiple Input Multiple Output (MIMO) technology represents one such approach, which is a recent popular technology for next generation communication systems. MIMO technology has been adopted in several emerging wireless communication standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard. IEEE 802.11 is represented by the IEEE 802.11 committee for short A standard set of wireless local area network (WLAN) air intermediaries developed by Cheng Communications (for example, tens of meters to hundreds of meters).
MIMO system employs multiple (N T) transmit antennas and multiple (N R) receive antennas for data transmission. MIMO channel formed by the N T transmit antennas and N R receive antennas may be decomposed into N S independent channels is also referred to as spatial channels, where N S ≦ min {N T, N R}. Each of the N S independent channels corresponds to one dimension. If additional dimensions created by the multiple transmit and receive antennas are utilized, the MIMO system can provide improved performance (e.g., higher throughput and/or greater reliability).
In a wireless network with a single access point (AP) and multiple subscriber stations (STAs), it can occur on multiple channels to different stations (in both the uplink and downlink directions) Concurrent transmission. There are many challenges in such systems.
Some aspects of the present invention provide a method for wireless communication. The method generally includes generating a packet having a preamble signal that can be decoded by a first type of device having a first set of capabilities and a second type of device having a second set of capabilities, wherein the preamble signal includes at least one Repeated signal (SIG) field; and transmit the packet.
Some aspects of the present invention provide a method for wireless communication. The method generally includes receiving a packet having a preamble signal that can be decoded by a first type of device having a first set of capabilities and a second type of device having a second set of capabilities, wherein the preamble signal includes at least one Duplicate signal (SIG) field; and handle the duplicate SIG field.
Various aspects also provide various devices, program products, and devices (e.g., access points and other types of wireless devices) that are capable of performing the operations of the methods described above.
100‧‧‧Multiple Access Multiple Input Multiple Output (MIMO) System
110‧‧‧Access Point (AP)
120a‧‧‧User Terminal (UT)
120b‧‧‧User Terminal (UT)
120c‧‧‧User Terminal (UT)
120d‧‧‧user terminal (UT)
120e‧‧‧User Terminal (UT)
120f‧‧‧User Terminal (UT)
120g‧‧‧user terminal (UT)
120h‧‧‧User Terminal (UT)
120i‧‧‧User Terminal (UT)
150‧‧‧HEW packet
208‧‧‧Source
210‧‧‧TX data processor
220‧‧‧TX space processor
222a‧‧‧transmitter unit
222ap‧‧‧transmitter unit
224a‧‧‧Antenna
224ap‧‧‧Antenna
228‧‧‧channel estimator
234‧‧‧ Scheduler
240‧‧‧RX Space Processor
244‧‧‧ data slot
252ma‧‧‧Antenna
252xa‧‧‧Antenna
252xu‧‧‧Antenna
254m‧‧‧ receiver unit
254mu‧‧‧ Receiver unit
254xa‧‧‧ Receiver unit
254xu‧‧‧ Receiver unit
260m‧‧‧RX space processor
260x‧‧‧RX Space Processor
270m‧‧‧RX data processor
270x‧‧‧RX data processor
272m‧‧‧ data slot
272x‧‧‧ data slot
278m‧‧‧channel estimator
278x‧‧‧channel estimator
280m‧‧‧ controller
280x‧‧ ‧ controller
282m‧‧‧ memory
282x‧‧‧ memory
286m‧‧‧Source
286x‧‧‧Source
288m‧‧‧transmit (TX) data processor
288x‧‧‧transmit (TX) data processor
290m‧‧‧TX space processor
290x‧‧‧TX space processor
304‧‧‧Wireless equipment
312‧‧‧ Receiver
316‧‧‧ transmit antenna
318‧‧‧Signal Detector
320‧‧‧Digital Signal Processor (DSP)
322‧‧‧ busbar system
400‧‧‧ preamble signal
402‧‧‧All traditional parts
404‧‧‧Precoding 802.11ac VHT (Ultra High Delivery) section
406‧‧‧Traditional Short Training Field (L-STF)
408‧‧‧Traditional long training field
410‧‧‧Traditional Signal (L-SIG) field
412‧‧‧VHT Signal A (VHT-SIG-A) field with two OFDM symbols
414‧‧‧VHT Signal A (VHT-SIG-A) field with two OFDM symbols
416‧‧‧ group identifier (group ID) field
418‧‧‧Ultra high throughput short training field (VHT-STF)
420‧‧‧Super High Transport Long Training Field 1 (VHT-LTF1)
422‧‧‧Super High Transport Long Training Field (VHT-LTF)
424‧‧‧Super High Volume Signal B (VHT-SIG-B) field
426‧‧‧Information section
500‧‧‧HEW preamble signal format
504‧‧‧Repeated HE-SIG0 field section
506‧‧‧General (non-repetitive) HE-SIG1 field
510‧‧‧HEW preamble signal format
516‧‧‧Repeated HE-SIG1 field section
520‧‧‧HEW preamble signal format
526‧‧‧HE-SIG1 field
610‧‧‧VHT preamble signal format
612‧‧‧A point
620‧‧‧HEW preamble signal format
622‧‧‧L-SIG field
624‧‧‧HE-SIG0 field
626‧‧‧HE-SIG1 field
630‧‧‧ structure
640‧‧‧ structure
650‧‧‧ structure
660‧‧‧ empty structure
700‧‧‧ operation
700A‧‧‧ device
702A‧‧‧ square
800‧‧‧ operation
800A‧‧‧ device
802A‧‧‧ square
804A‧‧‧ square
900‧‧‧Preamble signal structure
910‧‧‧Preamble signal structure
922‧‧‧Repeated L-SIG field
1000‧‧‧Preamble signal structure
1026‧‧‧Repeated HE-SIG1 field
1030‧‧‧ Structure
1040‧‧‧ structure
1050‧‧‧ structure
1100‧‧‧Preamble signal structure
1124‧‧‧Repeated HE-SIG0 field
1126‧‧‧Repeated HE-SIG0 field
1150‧‧‧Preamble signal structure
1152‧‧‧Repeating parts
1154‧‧‧Repeating parts
1160‧‧‧ Preamble signal structure
1162‧‧‧Repeating parts
1164‧‧‧Repeating parts
1210‧‧‧Preamble signal structure
1212‧‧‧Instructions
1220‧‧‧Preamble signal structure
1222‧‧‧Instructions
1224‧‧‧ square
1226‧‧‧ square
1228‧‧‧ square
1230‧‧‧ square
1232‧‧‧ square
1234‧‧‧ square
1236‧‧‧ square
To more clearly understand the manner in which the above-described features of the present disclosure are used, the above briefly summarized aspects may be more specifically described with reference to the various aspects, some of which are illustrated in the drawings. It should be noted, however, that the drawings illustrate only some typical aspects of the present invention and should not be construed as limiting the scope of the invention, as this description may permit other equivalents.
FIG. 1 illustrates a diagram of a wireless communication network in accordance with certain aspects of the present disclosure.
2 illustrates a block diagram of an example access point and user terminal in accordance with certain aspects of the present disclosure.
4 illustrates an example structure of a preamble signal transmitted from an access point in accordance with certain aspects of the present disclosure.
FIG. 5 illustrates an example preamble signal structure having at least partially repeated signal fields in accordance with certain aspects of the present disclosure.
6A-6C illustrate example preamble signal structures having different forms of repeated signal fields in accordance with certain aspects of the present disclosure.
FIG. 7 illustrates example operations that may be performed by an access point (AP) in accordance with certain aspects of the present disclosure.
FIG. 7A illustrates an example component capable of performing the operations illustrated in FIG. 7. .
FIG. 8 illustrates example operations that may be performed by a station in accordance with certain aspects of the present disclosure.
FIG. 8A illustrates example components capable of performing the operations illustrated in FIG.
9A and 9B illustrate an example preamble signal structure with repeated L-SIG fields in accordance with certain aspects of the present disclosure.
10A and 10B illustrate an example preamble signal structure having different forms of repeated HE-SIG1 fields in accordance with certain aspects of the present disclosure.
11A-11C illustrate an example preamble signal structure having signal fields that are repeatable in the frequency domain, in accordance with certain aspects of the present disclosure.
12A-B illustrate an example preamble signal structure with signal delivery indicating delay spread protection for SIG fields, in accordance with certain aspects of the present disclosure.
12C illustrates an example technique for signaling an indication of delay spread protection for a SIG field in accordance with certain aspects of the present disclosure.
Aspects of the present invention provide techniques that can account for the large delay spread effects in certain frequency ranges, such as the WiFi band.
Aspects of the present invention provide a preamble signal structure for wireless transmission. As will be described herein, by designing a portion of the preamble signal structure to be capable of being decoded by devices having different capabilities (eg, following different standards), the first type of device that is not the transmission target or can be based on the decodable portion. Retreat and avoid transmission on the media.
According to some aspects, in one or more fields of the preamble signal structure Some or all (such as signal (SIG) fields) can be repeated. In some cases, repeating the SIG field in the preamble signal structure may provide one or more benefits. For example, a duplicate SIG field can provide Delay Extended Protection (DSP). As used herein, delay spread generally refers to the difference between the arrival time of the earliest multipath component and the arrival time of the latest multipath component. Repeating the SIG field also indicates that the device distinguishes between different types of packet formats (for example, between HEW and non-HEW packets). In such cases, the device may decide whether to process the remainder of the packet or to stop processing, and possibly to retire the specified duration indicated in the decoded portion of the persistent packet.
In some cases, the signal field may only be partially repeated, rather than repeating the entire signal field. For example, in some cases, some of the tonality of repeated signal fields may be punctured. This partial repetition can be used to avoid false alarms when detecting the preamble signal structure. For example, a partial repetition may illustrate that the decoding station avoids confusing the new preamble signal structure with other existing (so-called conventional) preamble signal structures, such as 802.11 ah preamble signal structures.
Various aspects of the present invention are described more fully hereinafter with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and should not be construed as being limited to any specific structure or function. Rather, these are provided to make the present invention thorough and complete, and which will fully convey the scope of the present invention to those skilled in the art. Based on the teachings herein, those skilled in the art will appreciate that the scope of the present invention is intended to cover any aspect of the present disclosure as disclosed herein, regardless of whether it is implemented independently or in combination with any other aspect of the present invention. For example, any number of aspects set forth herein can be used to implement an apparatus or a method of practice. In addition, the scope of this case is intended to cover the use of this Such an apparatus or method of practicing the various aspects of the present invention as set forth herein or in addition to other structural, functional, or structural and functional aspects. It should be understood that any aspect of the present disclosure disclosed herein may be implemented by one or more elements of the claim.
The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous.
Although specific aspects are described herein, numerous variations and permutations of these aspects are within the scope of the present disclosure. Although some of the benefits and advantages of the preferred aspects are mentioned, the scope of the present invention is not intended to be limited to a particular benefit, use, or objective. Rather, the various aspects of the present invention are intended to be broadly applicable to different wireless technologies, system configurations, networks, and transmission protocols, some of which are illustrated by way of example in the drawings and the description of the preferred aspects. The detailed description and drawings are merely illustrative of the invention, and the scope of the invention
The techniques described herein can be used in a variety of broadband wireless communication systems, including communication systems based on orthogonal multiplexing schemes. Examples of such communication systems include sub-space multiplex access (SDMA), time division multiplex access (TDMA), orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiplexing access (SC) -FDMA) system, etc. SDMA systems can utilize multiple different directions to simultaneously transmit data belonging to multiple user terminals. The TDMA system can allow multiple user terminals to share the same frequency channel by dividing the transmission signal into different time slots, each time slot being assigned to a different user terminal. OFDMA system utilizes positive Crossover Frequency Multiplexing (OFDM), a modulation technique that divides the overall system bandwidth into multiple orthogonal subcarriers. These secondary carriers may also be referred to as tones, frequency bands, and the like. Under OFDM, each subcarrier can be independently modulated with data. SC-FDMA systems can be transmitted over sub-carriers distributed across system bandwidth using interleaved FDMA (IFDMA), transmitted on blocks consisting of adjacent subcarriers using localized FDMA (LFDMA), or using enhanced FDMA (EFDMA) Transmitted on multiple blocks consisting of adjacent subcarriers. In general, modulation symbols are transmitted in the frequency domain under OFDM and in the time domain under SC-FDMA.
The teachings herein may be incorporated into (eg, implemented within or performed by) various wired or wireless devices (eg, nodes). In some aspects, a wireless node implemented in accordance with the teachings herein can include an access point or an access terminal.
An access point ("AP") may include, be implemented as, or be referred to as a Node B, a Radio Network Controller ("RNC"), an evolved Node B (eNB), a Base Station Controller ("BSC") , Base Transceiver Station ("BTS"), Base Station ("BS"), Transceiver Function ("TF"), Radio Router, Radio Transceiver, Basic Service Set ("BSS"), Extended Service Set ("ESS "), radio base station ("RBS"), or some other term.
An access terminal ("AT") may be included, implemented as, or referred to as a subscriber station, subscriber unit, mobile station, remote station, remote terminal, user terminal, user agent, user equipment, use Equipment, user station, or some other terminology. In some implementations, the access terminal can include a cellular phone, a cordless phone, a Session Initiation Protocol ("SIP") phone, a Wireless Area Loop ("WLL") station, a Personal Digital Assistant ("PDA"), with wireless A handheld device, station ("STA"), or some other suitable processing device connected to a wireless data modem. Thus, one or more aspects taught herein can be incorporated into a telephone (eg, a cellular or smart phone), a computer (eg, a laptop), a portable communication device, a portable computing A device (eg, a personal data assistant), an entertainment device (eg, a music or video device, or a satellite radio), a global positioning system device, or any other suitable device configured to communicate via wireless or wired media. In some aspects, the node is a wireless node. Such wireless nodes may provide connectivity or provide connectivity to the network (eg, a wide area network (such as the Internet) or a cellular network), such as via a wired or wireless communication link.
FIG. 1 illustrates a multiplexed access multiple input multiple output (MIMO) system 100 having an access point and a user terminal.
As illustrated, the AP 110 and the user terminal (UT) 120 can communicate via an exchange of packets 150 (referred to herein as high efficiency WiFi or high efficiency WLAN (HEW) packets). The HEW packet 150 can have a preamble signal structure in which at least a portion of the signal field is repeated, as will be described in more detail below.
For simplicity, only one access point 110 is shown in FIG. An access point is typically a fixed station that communicates with each user terminal and may also be referred to as a base station or some other terminology. A user terminal can be fixed or mobile and can also be referred to as a mobile station, a wireless device, or some other terminology. Access point 110 can communicate with one or more user terminals 120 on the downlink and uplink at any given time. The downlink (ie, the forward link) is the communication link from the access point to the user terminal, and the uplink (ie, the reverse link) is from The communication link from the user terminal to the access point. The user terminal can also communicate peer-to-peer with another user terminal. System controller 130 is coupled to each access point and provides coordination and control of these access points.
Although portions of the following disclosure will describe user terminals 120 that are capable of communicating via sub-space multiplex access (SDMA), for some aspects, user terminal 120 may also include some user terminals that do not support SDMA. . Thus, for these aspects, AP 110 can be configured to communicate with both SDMA user terminal communications and non-SDMA user terminals. This approach may facilitate allowing older versions of user terminals ("legacy" stations) to remain deployed in the enterprise to extend their useful life while allowing the introduction of newer SDMA user terminals where deemed appropriate.
System 100 employs multiple transmit antennas and multiple receive antennas for data transmission on the downlink and uplink. Access point 110 is equipped with N ap antennas and represents multiple inputs (MI) for downlink transmissions and multiple outputs (MO) for uplink transmissions. The set with K selected user terminals 120 collectively represents multiple outputs for downlink transmissions and multiple inputs for uplink transmissions. For pure SDMA, if the data symbol stream for K user terminals is not multiplexed in code, frequency, or time by some means, then N ap is expected. K 1. K may be greater than N ap if the data symbol stream can be multiplexed using TDMA techniques, using different code channels under CDMA, using disjoint sets of subbands under OFDM, and the like. Each selected user terminal transmits user-specific data to the access point and/or receives user-specific data from the access point. In general, each selected user terminal may be equipped with one or multiple antennas (i.e., N ut 1). The K selected user terminals may have the same or different number of antennas.
System 100 can be a time division duplex (TDD) system or a frequency division duplex (FDD) system. For TDD systems, the downlink and uplink share the same frequency band. For FDD systems, the downlink and uplink use different frequency bands. The MIMO system 100 can also utilize single or multiple carriers for transmission. Each user terminal can be equipped with a single antenna (eg, to suppress cost) or multiple antennas (eg, where additional cost can be supported). System 100 may also be a TDMA system if user terminals 120 share the same frequency channel by dividing transmission/reception into different time slots, each time slot being assigned to a different user terminal 120.
As illustrated, in FIGS. 1 and 2, an AP may transmit an HEW packet 150 having a preamble signal format as described herein (eg, according to the example formats illustrated in FIGS. 5-6 and 9-12) one).
2 illustrates a block diagram of an access point 110 and two user terminals 120m and 120x in a MIMO system 100. Access point 110 is equipped with N t antennas 224a through 224t. User terminal 120m is equipped with N ut, m antennas 252ma through 252mu, and user terminal 120x is equipped with N ut, x antennas 252xa through 252xu. Access point 110 is the transmitting entity for the downlink and the receiving entity for the uplink. Each user terminal 120 is a transmitting entity for the uplink and a receiving entity for the downlink. As used herein, a "transport entity" is an independently operated device or device capable of transmitting data via a wireless channel, and a "receiving entity" is an independently operated device or device capable of receiving data via a wireless channel. In the following description, the subscript "dn " indicates the downlink, the subscript " up " indicates the uplink, N up user terminals are selected for simultaneous transmission on the uplink, and N dn user terminals are selected. For simultaneous transmission on the downlink, N up may or may not be equal to N dn , and N up and N dn may be static values or may vary with each scheduling interval. Beam steering or some other spatial processing technique can be used at the access point and user terminal.
On the uplink, at each user terminal 120 selected for uplink transmission, a transmit (TX) data processor 288 receives traffic data from data source 286 and control data from controller 280. Transmit data processor 288 processes (e.g., encodes, interleaves, and modulates) the traffic data of the user terminal and provides a stream of data symbols based on a coding and modulation scheme associated with the rate selected for the user terminal. TX spatial processor 290 of the information symbol stream and performs spatial processing on N ut, m antennas provide N ut, m transmit symbol streams. Each transmitter unit (TMTR) 254 receives and processes (e.g., converts to analog, amplifies, filters, and upconverts) respective transmit symbol streams to produce an uplink signal. N ut, m transmitter units 254 provide N ut, m uplink signals for 252 emitted from the N ut, m antennas to the access point.
N up user terminals can be scheduled for simultaneous transmission on the uplink. Each of these user terminals performs spatial processing on its own data symbol stream and transmits its own set of transmitted symbol streams to the access point on the uplink.
At access point 110, N ap antennas 224a through 224ap receive uplink signals from all N up user terminals transmitting on the uplink. Each antenna 224 provides a received signal to a respective receiver unit (RCVR) 222. Each receiver unit 222 performs processing complementary to that performed by the transmitter unit 254 and provides a received symbol stream. The RX spatial processor 240 performs receiver spatial processing on the N ap received symbol streams from the N ap receiver units 222 and provides N up recovered uplink data symbol streams. Receiver spatial processing is performed based on channel correlation matrix inversion (CCMI), minimum mean square error (MMSE), soft interference cancellation (SIC), or some other technique. Each recovered uplink data symbol stream is an estimate of the data symbol stream transmitted by the respective user terminal. RX data processor 242 processes (e.g., demodulates, deinterleaves, and decodes) the recovered uplink data symbol stream based on the rate used for each recovered uplink data symbol stream to obtain Decoded data. The decoded data for each user terminal can be provided to data slot 244 for storage and/or to controller 230 for further processing.
On the downlink, at access point 110, TX data processor 210 receives traffic data from data source 208 for N dn user terminals scheduled for downlink transmission, from controller 230 Control data, and possibly other materials from scheduler 234. Various types of data can be sent on different transmission channels. TX data processor 210 processes (e.g., encodes, interleaves, and modulates) the traffic data for the user terminal based on the rate selected for each user terminal. The TX data processor 210 provides N dn downlink data symbol streams for N dn user terminals. The TX spatial processor 220 performs spatial processing (such as precoding or beamforming, as described in this context) on the N dn downlink data symbol streams and provides N ap transmit symbol streams for the N ap antennas. Each transmitter unit 222 receives and processes a respective transmitted symbol stream to generate a downlink signal. N ap transmitter units 222 provide N ap downlink signals for transmission from N ap antennas 224 to user terminals.
At each user terminal 120, N ut, m antennas 252 receive the N ap downlink signals from access point 110. Each receiver unit 254 processes the received signal from the associated antenna 252 and provides a received symbol stream. RX spatial processor 260 from N ut, m receivers 254 N ut unit, m is a received symbol streams, and perform receiver spatial processing of downlink data symbol stream to provide the user terminal is recovered. Receiver spatial processing is performed according to CCMI, MMSE, or some other technique. The RX data processor 270 processes (e.g., demodulates, deinterleaves, and decodes) the recovered downlink data symbol stream to obtain decoded data for the user terminal.
At each user terminal 120, channel estimator 278 estimates the downlink channel response and provides a downlink channel estimate, which may include channel gain estimates, SNR estimates, noise variances, and the like. Similarly, channel estimator 228 estimates the uplink channel response and provides an uplink channel estimate. Controller 280 for each user terminal typically based on the user terminal downlink channel response matrix H dn, m derives the spatial filter matrix for the user terminal. The controller 230 response matrix H up based on the effective uplink channel, eff derives the spatial filter matrix for the access point. The controller 280 of each user terminal can send feedback information (eg, downlink and/or uplink feature vectors, eigenvalues, SNR estimates, etc.) to the access point. Controllers 230 and 280 also control the operation of various processing units at access point 110 and user terminal 120, respectively.
3 illustrates various elements that may be employed in wireless device 302 that may be utilized within a wireless communication system (e.g., system 100 of FIG. 1 utilizing HEW packet 150 having a preamble signal structure as described herein). Wireless device 302 is an example of a device that can be configured to implement the various methods described herein. Wireless device 302 can be access point 110 or user terminal 120.
Wireless device 302 can include a processor 302 that controls the operation of wireless device 304. Processor 304 may also be referred to as a central processing unit (CPU). Memory 306, which may include both read-only memory (ROM) and random access memory (RAM), provides instructions and data to processor 304. A portion of the memory 306 may also include non-volatile random access memory (NVRAM). The processor 304 typically performs logical and arithmetic operations based on program instructions stored in the memory 306. The instructions in memory 306 may be executable to implement the methods described herein.
The wireless device 302 can also include a housing 308 that can include a transmitter 310 and a receiver 312 to allow for the transfer and reception of data between the wireless device 302 and a remote location. Transmitter 310 and receiver 312 can be combined into transceiver 314. Single or multiple transmit antennas 316 can be attached to the housing 308 and electrically coupled to the transceiver 314. Wireless device 302 can also include (not shown) multiple transmitters, multiple receivers, and multiple transceivers.
The wireless device 302 can also include a signal detector 318 that can be used to attempt to detect and quantize the level of signals received by the transceiver 314. Signal detector 318 can detect signals such as total energy, energy per symbol per symbol, power spectral density, and other signals. Wireless device 302 can also include a digital signal processor (DSP) 320 for use in processing signals.
The various components of the wireless device 302 can be coupled together by a busbar system 322 that can include, in addition to the data busbars, a power busbar, a control signal busbar, and a status signal busbar.
Example High Efficiency WLAN (HEW) Preamble Signal Structure
FIG. 4 illustrates an example structure of a preamble signal 400. For example, preamble signal 400 can be accessed from a wireless network (such as system 100 illustrated in Figure 1). Point (AP) 110 is transmitted to user terminal 120.
The preamble signal 400 can include an all-traditional portion 402 (i.e., a non-beamforming portion) and a pre-encoded 802.11ac VHT (Ultra High Conveyance) portion 404. The legacy portion 402 can include: a conventional short training field (L-STF) 406, a conventional long training field 408, a legacy signal (L-SIG) field 410, and a VHT signal A (VHT-SIG-A) field. Two OFDM symbols 412, 414. The VHT-SIG-A fields 412, 414 may be transmitted omnidirectionally and may indicate the allocation of the number of spatial streams to the STA combination (set). For some aspects, the group identifier (group ID) field 416 can be included in the preamble signal 400 to communicate to all supported STAs that the particular set of STAs will receive the spatial stream of MU-MIMO transmissions.
The precoded 802.11ac VHT portion 404 may include a very high throughput short training field (VHT-STF) 418, an ultra high throughput long training field 1 (VHT-LTF1) 420, and a super high throughput long training field ( VHT-LTF) 422, Super High Traffic Signal B (VHT-SIG-B) field 424, and data portion 426. The VHT-SIG-B field may include one OFDM symbol and may be precoded/beamformed for transmission.
Robust MU-MIMO reception may involve an AP (Access Point) transmitting all VHT-LTF 422 to all supported STAs (stations). The VHT-LTF 422 may allow each STA to estimate the MIMO channel from all AP antennas to the antenna of the STA. The STA may perform effective interference nulling on interference from MU-MIMO streams corresponding to other STAs using the estimated channel. In order to perform robust interference cancellation, it is expected that each STA knows which spatial stream belongs to the STA and which spatial streams belong to other users.
Large delay spread support for the WiFi band
Outdoor wireless networks with high access point (AP) elevations (e.g., on the pico/macro cell service tower) may experience channels with high delay spread (preferably over 1 [mu]s). Various wireless systems utilizing orthogonal frequency division multiplexing (OFDM) physical layers (PHYs) in the 2.4 GHz and 5 GHz bands, such as those according to 801.11a/g/n/ac, have a cyclic prefix of only 800 ns ( CP) length, almost half of the CP is consumed by the transmit and receive filters. Therefore, these types of systems are generally considered unsuitable for such deployments because WiFi packets with higher modulation and coding schemes (MCS) (eg, beyond MCS0) are difficult to decode in high latency extension channels.
According to various aspects of the present invention, a packet format (PHY waveform) compatible with such legacy systems and legacy versions and supporting a cyclic prefix longer than 800 ns is provided, which allows for use in an outdoor deployment with a high AP. 2.4GHz and 5GHz WiFi systems.
According to some aspects of the case, the traditional short training field (L-STF), the traditional long training field (L-LTE), the traditional signal field (L-SIG), and the super in the preamble signal of the PHY waveform. Embedding a new device in one or more of the High Traffic Signal (VHT-SIG) and the Ultra High Traffic Short Training Field (VHT-STF) can decode but does not affect the legacy (eg, 802.11a/g/n /ac) The decoded one-bit or multi-bit information of the receiver. Figure 5 illustrates an existing example preamble frame structure for 802.11a/g, 802.11n, and 802.11ac.
The L-SIG is modulated by binary shift phase keying (BPSK). The HT-SIG is modulated with orthogonal BPSK (Q-BPSK). The second OFDM symbol of the VHT-SIG is modulated with Q-BPSK. The "Q" rotation allows the receiver to distinguish between 11a/g, 11n and 11ac waveforms.
For some aspects, embedding a new device in one or more of L-STF, L-LTF, L-SIG, VHT-SIG, and VHT-STF can decode but does not affect the legacy 11a/g/n/ac The decoded one-bit or multi-bit information of the receiver. The one-bit or multi-bit information is compatible with the legacy preamble signal, ie, the 11a/g/n/ac device is capable of decoding the preamble signal and then relinquishes until the end of the transmission.
Depending on certain aspects, for delay spread tolerance, different transmission parameters can be used to increase the symbol duration (eg, down-convert to actually reduce the sampling rate, or increase the FFT length while maintaining the same sampling rate). The symbol duration can be increased, for example, by a factor of 2 to 4 to increase the tolerance for higher delay spread. This increase can be achieved via down-conversion (using a lower sampling rate with the same FFT length) or via increasing the number of sub-carriers (same sampling rate but increased FFT length).
The use of increasing symbol duration can be considered a physical layer (PHY) transmission mode that can be signaled in the SIG field, which can allow for maintaining a normal symbol duration mode. Keeping the "normal" symbol duration mode may be desirable (even for devices that can use this mode), because the increased symbol duration usually means an increased FFT size, which gives sensitivity to frequency errors. Increase and increase in PAPR. Moreover, not every device of the network will need this increased delay spread tolerance, and in such cases, the increased FFT size may actually compromise performance.
Depending on the particular implementation, such OFDM symbols may increase over time (eg, via an increase in the number of subcarriers) may occur after the SIG field in all packets or may only signal some packets. SIG field can be high Efficiency SIG (HE-SIG) field (as defined by the IEEE 802.11 High Efficiency WLAN or HEW Research Group) or VHT-SIG-A field (eg, according to 802.11ac).
If not applied to all packets, the OFDM symbol duration increases (eg, via an increase in the number of secondary carriers) may occur only after the information in the SIG field signals the SIG field in the changed packet. This information can be conveyed via bits in the SIG field, Q-BPSK rotation via SIG field symbols, or hidden information in the orthogonal track (virtual axis) of any SIG field.
The increased symbol duration can also be used for UL transmission. For UL transmissions, it is possible for the AP to indicate via the DL message that it wishes the next transmission to have an increased symbol duration. For example, in UL OFDMA, the AP may send a tone allocation message that, along with the distribution tone allocation, tells the user to use a longer symbol duration. In this case, the UL packet itself does not need to carry an indication of this digital change. This is because the AP is the one that first initiates the transmission and decides the duration of the symbol used by the STA in the UL. As will be described in more detail below (e.g., with reference to Figures 12A-12C), in some cases, a portion of the preamble signal may provide for some type of delay spread protection to be applied to a later portion of the preamble signal. Instructions.
The indication may be conveyed in the preamble signal (as described above) or may be conveyed via one or more bits in the data payload of the DL frame. Such payloads will only be understood by devices that support the increased symbol duration. In addition, the increased symbol duration in the UL can also be applied to the entire UL packet. Alternatively, the indication can also be communicated separately from the DL frame. E.g The use of the increased symbol duration on the UL may be semi-persistently scheduled, wherein the STA is signaled whether an increased symbol duration is used on the UL transmission. This approach allows the AP to not have to signal in each DL frame.
Example HEW preamble signal structure with at least partially repeated signal fields
As mentioned above, aspects of the present disclosure provide a preamble signal structure that can be decoded by devices having different capabilities (eg, compatible with different standards), wherein one or more signal fields of the preamble signal structure are repeated Some or all parts of the bit.
The preamble signal structure provided herein can be used in advanced systems such as HEW (High Efficiency WiFi or High Efficiency WLAN). These preamble signal formats can be considered to be based on some of the ideas provided above. The preamble signal structure provided herein provides a solution in which the SIG field of the HEW device can have delay spread protection while maintaining the current mechanism for performing automatic detection of 802.11n, 802.11a, and 802.ac packets.
The preamble signal format provided herein may retain L-SIG based concessions, as in the 11ac (mixed mode preamble) discussed above. A conventional section with preamble signals (which can be decoded by an 802.11 a/an/ac station) can facilitate mixing of legacy and HEW devices in the same transmission. In high data rate situations, devices can often see preamble signals. The preamble signal format provided in this article can help provide protection on the HEW SIG, which can indicate robust performance (eg, 1% SIG error rate in a relatively rigorous standard test scenario).
Figure 5 illustrates an example HEW preamble in accordance with various aspects of the present disclosure. Packets of signal formats 500, 510, and 520. As illustrated, the example format 500 can include a repeated HE-SIG0 field portion 504 followed by a general (non-repeating) HE-SIG1 field 506. As illustrated, the example format 510 can include a repeated HE-SIG0 field portion 504, and a repeated HE-SIG1 field portion 516. As described above, for example, all signal fields may be repeated or only a portion may be repeated, with certain tones of the repeated portions being punctured. As illustrated, the example format 520 can include delay extended protection, for example, using one of the mechanisms described above (eg, having a longer cyclic prefix for the HE-SIG1 field 526 relative to HE-SIG0) DSP) HE-SIG1 field 526.
FIG. 6 illustrates an example HEW preamble signal format 620 as compared to VHT preamble signal format 610. As illustrated, the HEW preamble signal format 620 can include one or more signal (SIG) fields that can be decoded by a first type of device (eg, an 802.11a/ac/n device) and can be of a second type One or more SIG fields (eg, HE-SIG0 and HE-SIG1) decoded by the device (eg, HEW device). Some devices, such as 802.111/ac/n devices, may be backed up based on the diachronic fields in the L-SIG 622. The L-SIG can be followed by a repeated high efficiency SIG0 (HE-SIG0) field 624. As illustrated, at some point 612, after the repeated HE-SIG0 field 624, the device may already know if the packet is a VHT packet, so the device can know if it needs to decode the rest of the packet.
As illustrated in FIG. 6B, various mechanisms may be used to repeat some or all of the HE-SIG0 fields to construct a repeated HE-SIG0 field 624. For example, a structure 630 can be constructed by repeating the HE-SIG0 field, where each HE-SIG0 field is preceded by a normal guard interval (GI), and the GI gives HE-SIG0 protection for each HEW device. As another example, structure 640 can be The HE-SIG0 field surrounded by the normal guard interval (GI) is repeated, and the other structure 650 can be repeated via the HE-SIG0 column with the extended GI (eg, double length/duration relative to the normal GI). Bit to construct.
In some cases, a duplicate SIG0 field may not be necessary. Thus, as another example illustrated, "empty structure 660" may indicate that there are no duplicate SIG0 fields. The resulting preamble signal structure 670 is shown in Figure 6C, which lacks a repeated HE-SIG0 portion 624. As illustrated, in the example preamble signal structure 670, the HE-SIG1 field 626 can follow the L-SIG field 622.
Repeating one or more signal fields can have various advantages. For example, the repetition gain on HE-SIG0 can reduce the SNR operating point and thus make HE-SIG0 more robust to inter-symbol interference (ISI). The L-SIG can still carry 6 Mbps because the group type detection based on the Q-BPSK check of the 2 symbols after the L-SIG can be unaffected.
Various techniques can be used to signal the HEW packet to the HEW device. For example, the HEW packet can be signaled via placing a quadrature track indication in the L-SIG, an autocorrelation of HE-SIG0 repetition, or based on a CRC check in HE-SIG0.
There are also various options for providing delay spread protection on the HE-SIG1. For example, HE-SIG1 can transmit on 128 tones (in 20MHz) to provide additional delay spread protection that can provide 1.6us GI on HE-SIG1, but needs to be calculated on L-LTE Interpolation of channel estimates. As another example, HE-SIG1 may have the same symbol duration, but may be sent with a 1.6 us CP. This may result in (more than 25% of the general value) CP management burden, but can not be interpolated.
In some cases, for delay spread protection, HE-SIG1 can be designed to have a longer CP. This may for example be via: (1) extending the CP up to 25% of the duration of the symbol while maintaining the same tone width as the conventional 802.11 system; and/or (2) halving the tone width and thus extending the entire symbol over time Two times the original (other factors are also possible) to get.
If the BW bit is placed in HE-SIG0, then HE-SIG1 can potentially be transmitted on all BWs (without having to repeat every 20 MHz).
Repeating HE-SIG0 (where the second HE-SIG0 has a GI at the end) after the L-SIG as shown in the structure 640 of FIG. 6B may give the HEW device protection for HE-SIG0. It may be noted that the middle portion of the HE-SIG0 sector may appear as a HE-SIG0 symbol with a relatively large CP. In this example, the Q-BPSK check of the first symbol after the L-SIG may not be affected. A Q-BPSK check of the second symbol can provide a random result (because the GI is at the end), but this may not have any adverse effect on the VHT device. In other words, when the device classifies the packet as 802.11ac, the VHT-SIG CRC will fail and the device will relinquish based on the L-SIG, which is exactly the same as when the device classifies the packet as 802.11a.
The L-SIG can still carry 6 Mbps, as overall auto-detection still works well in this way. As mentioned above, various techniques can be used to signal HEW packets to HEW devices. For example, the HEW packet can be signaled via placing a quadrature track indication in the L-SIG, an autocorrelation of HE-SIG0 repetition, or based on a CRC check in HE-SIG0.
Place a repeated HE-SIG0 with a double GI after the L-SIG (eg The HEW device can be protected from HE-SIG0 by the structure 650 of Figure 6B. However, a DGI with repetition may affect the detection based on the Q-BPSK check of the first 2 symbols after the L-SIG. As a result, the L-SIG may have to carry a rate of 9 Mbps.
In any of the structures 630, 640 or 650, the GI may be the same or different for each approach, and further, the HE-SIG0 field may even be different (eg, for a partial repetition) Truncated duplicate fields or some punctured tones).
In some cases, for joint frequency and time repetitions, the duration of HE-SIG1 may not be limited to 2 symbols. For example, if copying of both time and frequency is used, the HE-SIG1 duration can be 4 symbols. This design may be beneficial for low MCS modes.
Various optimizations can be provided for the preamble signal formats, such as those shown in Figures 5-6. For example, it may be possible to truncate the second HE-SIG0 symbol and start the next symbol earlier to save administrative burden. Furthermore, having SIG-B after HE-LTF can have some benefits, which can provide per-user bits for MU-MIMO.
Various bit allocations are possible for the HE-SIG 0 field. For example, there may be a 2-3 bit for bandwidth (BW) indication, an 8-bit length indication, a bit indicating that a longer symbol is used, 2-3 reserved bits, a 4-bit for CRC And 6 tail parts. If the longer symbol open bit is provided in HE-SIG0, this can be used to signal any of the following: HE-SIG has delay extended protection and any field after HE-SIG1 uses an increased FFT size, or Any field after HE-SIG1 has an increased FFT size. In the latter In this case, HE-SIG1 can always have delay spread protection.
FIG. 7 illustrates example operations 700 that may be performed, for example, by an access point (AP), in accordance with certain aspects of the present disclosure. As illustrated, at 702, the AP can generate a packet having a preamble signal that can be decoded by a first type of device having a first set of capabilities and a second type of device having a second set of capabilities, wherein The preamble signal includes at least one repeated signal (SIG) field. At 704, the AP can transmit the packet.
FIG. 8 illustrates example operations 800 that may be performed, for example, by a station, in accordance with certain aspects of the present disclosure. Operation 800 can be considered a complement of operation 800 performed at the AP.
At 802, a station can receive a packet having a preamble signal that can be decoded by a first type of device having a first set of capabilities and a second type of device having a second set of capabilities, wherein the preamble signal includes at least A repeated signal (SIG) field. At 804, the station processes the duplicate SIG field (eg, to decide if the remainder of the packet is to be processed).
In some cases, as shown in FIG. 9A, the preamble signal structure 900 can have duplicate L-SIG fields 922 (repeat some or all of the L-SIG field 622) (eg, have time ordinary The symbol level repeats or a type of repetition shown in Figure 5-6 for HE-SIG0 to provide protection for the L-SIG field. The L-SIG can be repeated all or partially. Partial L-SIG repetitions may be achieved, for example, by repeating the L-SIG only on even tones, odd tones, or some combination thereof. This can be equivalent to puncturing some of the tones in the repeated L-SIG 922. In some cases, in order to make the time domain power constant over multiple symbols, power boosting can be applied on repeated tones. For example, if in the second Only the even tones are repeated on the L-SIG, and the 3dB power boost can be applied to those repeated even tones (for example, the power used to guide the frequency modulation is unchanged).
The L-SIG repetition can be achieved similarly to the time repetition of the HE-SIG field described above, and in some cases the HE-SIG0 field 624 can also be repeated with any of the options described above with respect to Figure 6B for repetition. As illustrated in FIG. 9B, in some cases, the preamble signal structure 910 may lack duplicate HE SIG0 field 624.
Repeating the L-SIG field can have various benefits. As an example, this may allow the duration field in the L-SIG to be used for the HEW device. In addition, multiplexing the L-SIG to detect HEW packets can solve the potential problem, where the first two symbols after the L-SIG of the 802.11a packet look similar and if HE-SIG0 is used as in the previous proposal To detect HEW, you may never reach the HEW device. Repeating the L-SIG field in this manner can be used in combination with any type of repeated HE-SIG0 (and/or HE-SIG1) format, and can still allow automatic (based on the rotated second SIG field) Detection, and can also work with the HE-SIG field with an increased CP.
As illustrated in FIG. 10A, as a replacement for some or all of the repeated HE-SIG0 fields (or in addition to replacing some or all of the HE-SIG0 fields), the preamble signal structure 1000 may include repeating Repeated HE-SIG1 field 1026 constructed by some or all of the HE-SIG1 fields. As illustrated in FIG. 10B, the repeated HE-SIG1 fields can be constructed using the various options described above for the repeated HE-SIG0 fields. For example, some or all of the HE-SIG1 fields may be repeated (where each part has a normal GI (structure 1030) in front of it), via "inverted repetition" (where the repeated part is normal GI) A repeating HE-SIG1 field 1026 is constructed around the (structure 1040), or repeated portion, with a double GI (structure 1050).
As shown in FIG. 11A, preamble signal structure 1100 can have one or both of repeated HE-SIG0 field 1124 and HE-SIG1 field 1124 constructed using frequency domain and/or time domain repetition. For example, FIG. 11B illustrates an example preamble signal structure 1150 in which repeated HE-SIG0 field 1124 is generated using portions 1152 and 1154 (using different frequency resources) that are repeated in frequency. Similarly, FIG. 11C illustrates an example preamble signal structure 1160 in which repeated HE-SIG0 field 1126 is generated using portions 1162 and 1164 that are repeated in frequency. In these examples, for example, when compared to the time domain repeat described above, twice the tone can be used but the time duration is halved.
For example, frequency domain repetition may be performed in generally any suitable manner, where the data on the carrier is repeated once on some other secondary carrier. As an example, according to certain aspects (although not explicitly shown in Figure 11B or 11C), the even number of subcarriers may be filled with data, with a copy of the data on the odd number of carriers. While this may be excessive in some situations, there may be certain scenarios in which it is desirable to perform duplication in both the time domain and the frequency domain (for HE-SIG01 and/or HE-SIG1).
In some cases, a portion of the preamble signal may be transmitted at a lower data rate (eg, a lower MCS) than other portions. This can provide benefits such as better detection and better channel estimation. In some cases, non-repeating SIG fields (eg, HE-SIG1 fields) may be transmitted at a lower rate. In some cases, the transmit power for each low-latency packet and/or each L-STF with a longer L-STF segment and/or each L-LTE may be boosted (eg , up to 3dB) to enhance detection. In some cases, more short training fields can be added. In addition, the preamble signal can signal an indication of whether the packet is a low rate packet (a portion of which is transmitted at a lower rate). This indication can be signaled, for example, in the HE-SIG0 field.
In packets in which the low rate mode is indicated, various other characteristics may exist in addition to the data segment being transmitted at a lower rate. For example, the HE-SIG1 field may be transmitted at a lower MCS (this may be achieved via a repetition or a lower code rate) and/or an increased number of LTFs may be added after HE-SIG1 for data decoding.
The techniques described herein, for example, provide various options for HE-SIG1 transmission, where HE-SIG1 is transmitted on 128 tones (in 20 MHz) to provide additional delay spread protection or HE-SIG1 has (and normal) The same symbol lasts but is sent with a longer CP. As another example, HE-SIG1 may transmit on 256 tones (in 20 MHz). Various other possibilities are also available for transmitting the HE-SIG1. For example, as illustrated in FIGS. 10A and 10B, HE-SIG1 may also be repeated whenever increased delay spread protection is required, as described above with reference to HE-SIG1.
As mentioned above, all options for HE-SIG0 Delay Extended Protection can also be used for HE-SIG1. The benefits of the techniques provided herein for repeating SIG fields (eg, HE-SIG0 and/or HE-SIG1) in time and/or frequency may, for example, include improved delay spread along with lower SINR performance (allowing low) The lower SINR set point required for the rate mode) and the less stringent processing isochron, where the HE-SIG1 delay spread protection remains the same as HE-SIG0 (eg, this allows for consistency of the phase tracking loop and the like) .
Option to signal delayed extension protection
The aspects of the presently described above provide for one or more of repeating, for example, via time domain repetition, inverse GI based repetition (cyclic copy), and/or frequency domain repetition of SIG symbols. A technique to increase the detectability of certain SIG fields (eg, HE-SIG0).
Various techniques may be used to signal an indication of delay spread protection to be applied to subsequent portions of the preamble signal within a portion of the preamble signal or at least before the end of a portion of the preamble signal. In other words, such signal delivery can provide information on how to transmit certain fields, such as after a repeated SIG field. For example, as shown in the example preamble signal structure 1210 of FIG. 12A, after repeating the SIG field (eg, HE-SIG0, which may be repeated in time and/or frequency as described above), the normal SIG The structure can be used for subsequent SIG fields (e.g., without HE-SIG1 506 having a general 4us symbol, as in the example preamble signal structure 500 shown in Figure 5). However, in some cases, it may be desirable to increase the delay spread protection for the SIG field after the repeated SIG field. The delay spread protection may be, for example, via a repeating SIG field (eg, repeated HE-SIG1 516 in the example preamble signal structure 510 as shown in FIG. 5) or via having a longer CP for the SIG field (eg, Provided as HE-SIG1 526 with an increased CP relative to a normal CP in the example preamble signal structure 520 shown in FIG. An increased CP can be thought of as a form of partial repetition because a portion of the signal is repeated.
Since such delay spread protection (of the HE-SIG1 field) may not exist in every packet, it may be necessary to signal the structure of HE-SIG1 (whether it has delay spread protection). Therefore, as illustrated in FIG. 12A You can provide delay extended protection (DSP) for the HE-SIG1 field (and possibly which type of DSP) in the repeated HE-SIG0 field (or at least before the end of the repeated HE-SIG0 field). Instructions 1212. In some cases, an earlier indication of the structure may be desirable where the location of the sample may (due to the increased CP) be different than a normal packet. In some cases, an indication of the type of packet may be provided via a checksum in a repeated SIG field.
In a similar manner, as illustrated in the example preamble signal structure 1220 with repeated L-SIG fields as shown in Figure 12B, may be within the repeated L-SIG field (or at least in duplicate). An indication 1222 as to whether to provide Delay Extended Protection (DSP) for subsequent HE-SIG0 and/or HE-SIG1 fields is provided before the end of the L-SIG field.
One option for the DSP indication may be to signal the structure using the pilot frequency adjustment of the repeated SIG field (earlier). However, using conventional conventional pilot tone modulation (eg, (-21, -7, 7, 21) of HE-SIG0 in a 20 MHz tone plan - all other tones can be considered as non-pilot frequency modulation) signal transmission May be harmful to performance. For example, if the pilot tone of the first symbol is used for this signal transmission, it may cause false alarms (eg, 802.11n false alarms) when detecting certain types of packets, as some devices may automatically perform after phase correction. Detection (this phase correction may be experienced using traditional pilot frequency modulation).
As a general note, in some cases, non-lead frequency tones (eg, in repeated L-SIG or HE-SIG0) may be used to convey that the packet is an HEW packet (eg, utilizing various features provided herein) One or more ).
In some cases, the adverse effects of using pilot tone can be avoided by transmitting signal transmission information in other ways. For example, depending on certain aspects, this signal delivery information can be sent on even-tone tones of repeated SIG fields (eg, HE-SIG0) or any other non-legacy pilot tone, while still being able to (in some bootstraps) The frequency is adjusted to transmit a normal pilot frequency (or at least a subset of the normal pilot frequency). In some cases, for example, if the device performs maximum ratio combining (MRC) for the phase estimate and gives the pilot frequency to a smaller weight without sending anything, then the subset of the pilot tone is correctly filled possible. In some cases, signal transmission may be sent on the general pilot frequency adjustment of the second HE-SIG0 symbol (while simultaneously transmitting the normal pilot frequency on those pilot frequencies of the first symbol). This may be possible because the effect of the random Q-BPSK check (on the group type detection) on the second symbol after the L-SIG may not be very severe.
Other options for delay extended protection signal transfer include using explicit bits in repeated HE-SIG fields (eg, as described above), or using orthogonal tracks of HE-SIG0 across two symbols (eg, Signal delivery of out-of-phase components (eg, where detection of the use of orthogonal rails indicates delay extended protection). In some cases, for the option shown in Figure 12A, the joint encoding of HE-SIG0 and HE-SIG1 can be used for signal passing such that HE-SIG1 autocorrelation can be used to detect delay spread protection. Under this option, the receiving device can detect the delay spread protection by calculating the autocorrelation of the two symbols after the first repeated SIG field. In other words, does HE-SIG1 repeatedly tell us the type of delay extended protection. Use such a mechanism and do not use one of the explicit bits A potential secondary benefit is that the first and second SIG fields (both repeated) can be jointly encoded.
Various example techniques for signaling a DSP indicator are outlined in Figure 12C. For example, as described above, may be via an even tone of HE-SIG0 (or L-SIG) as shown at 1224, a non-legacy pilot tone as shown at 1226, HE- as shown at 1228 The general pilot frequency of the second symbol of SIG0 (or L-SIG), the orthogonal rail of the symbol across HE-SIG0 (or L-SIG) as shown at 1230, or the non-boot as shown at 1232 Frequently tune to signal the DSP indicator. Additionally, as shown at 1234, in some cases, how to repeat the signal field can be used as an indication. For example, the inverted ("flip") bit of the repeating portion (relative to the first portion) can be used as an indication that the DSP is applied to subsequent fields, while the non-inverted phase of the repeating portion indicates that no DSP is applied to the subsequent Field. As shown at 1236, in some cases, an explicit bit can be included. Such explicit bits can be used, for example, as DSP indications in repeated HE-SIG0 fields. However, there may be no such bits available for providing an explicit indication in the L-SIG field.
The various operations of the methods described above can be performed by any suitable means capable of performing the corresponding functions. These devices may include various hardware and/or software components and/or modules including, but not limited to, circuitry, special application integrated circuits (ASICs), or processors. In general, where there are operations illustrated in the figures, those operations may have corresponding pairing means functional elements with similar numbers. For example, operations 700 and 800 illustrated in Figures 7 and 8 may correspond to devices 700A and 800A illustrated in Figures 7A and 8A.
For example, the means for transmitting may include a transmitter, such as Figure 2 The transmitter unit 222 of the access point 110 illustrated in FIG. 2, the transmitter unit 254 of the user terminal 120 illustrated in FIG. 2, or the transmitter 310 of the wireless device 302 illustrated in FIG. The means for receiving may comprise a receiver, such as the receiver unit 222 of the access point 110 illustrated in Figure 2, the receiver unit 254 of the user terminal 120 illustrated in Figure 2, or in Figure 3 Receiver 312 of wireless device 302 is shown. The means for processing, the means for determining, the means for changing, the means for generating, the means for correcting, and/or the means for inspecting may comprise a processing system, which may include one or A plurality of processors, such as the receiving data processor 270 and/or controller 280 of the user terminal 120 illustrated in FIG. 2 or the receiving data processor 242 and/or controller 230 of the access point 110.
As used herein, the term "decision" encompasses a wide variety of actions. For example, a "decision" may include calculations, calculations, processing, derivation, research, inspection (eg, viewing in a table, database, or other data structure), detection, and the like. Moreover, "decision" may include receiving (eg, receiving information), accessing (eg, accessing data in memory), and the like. Moreover, "decision" may also include analysis, selection, selection, establishment, and the like.
As used herein, a phrase referring to "at least one of" a list of items refers to any combination of these items, including a single member. As an example, "at least one of a, b, or c" is intended to encompass: a, b, c, a-b, a-c, b-c, and a-b-c.
Various illustrative logic blocks, modules, and circuits described in connection with the present disclosure can be used with general purpose processors, digital signal processors (DSPs), special application products. An integrated circuit (ASIC), field programmable gate array (FPGA) or other programmable logic device (PLD), individual gate or transistor logic, individual hardware components, or designed to perform the functions described herein. Any combination to implement or execute. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
The steps of the method or algorithm described in connection with the present disclosure can be implemented directly in the hardware, in a software module executed by a processor, or in a combination of the two. The software modules can reside in any form of storage medium known in the art. Some examples of storage media that may be used include random access memory (RAM), read only memory (ROM), flash memory, EPROM memory, EEPROM memory, scratchpad, hard disk, removable magnetic Disc, CD-ROM, and more. The software module can include a single instruction, or many instructions, and can be distributed over several different code segments, distributed among different programs, and distributed across multiple storage media. The storage medium can be coupled to the processor such that the processor can read and write information from/to the storage medium. Alternatively, the storage medium can be integrated into the processor.
The methods disclosed herein comprise one or more steps or actions for achieving the methods described. These method steps and/or actions may be interchanged without departing from the scope of the claims. In other words, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims.
The functions described can be in hardware, software, firmware or any combination thereof. Implemented in . If implemented in hardware, the example hardware settings can include a processing system in the wireless node. The processing system can be implemented with a bus architecture. The bus bar can include any number of interconnect bus bars and bridges depending on the particular application of the processing system and overall design constraints. Busbars connect various circuits including processors, machine readable media, and bus interfaces. The bus interface can be used to connect a network interface card or the like to a processing system via a bus bar. The network interface card can be used to implement the signal processing function of the PHY layer. In the case of access terminal 120 (see FIG. 1), a user interface (eg, a keypad, display, mouse, joystick, etc.) can also be connected to the busbar. The busbars can also be coupled to various other circuits, such as timing sources, peripherals, voltage regulators, power management circuits, and the like, which are well known in the art and will therefore not be further described.
The processor is responsible for managing the bus and general processing, including executing software stored on machine readable media. The processor can be implemented with one or more general purpose and/or special purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuitry that can execute software. Software should be interpreted broadly to mean instructions, materials, or any combination thereof, whether referred to as software, firmware, mediator, microcode, hardware description language, or otherwise. As an example, the machine readable medium may include RAM (random access memory), flash memory, ROM (read only memory), PROM (programmable read only memory), EPROM (erasable program) Design read-only memory), EEPROM (Electrically Erasable Programmable Read Only Memory), scratchpad, diskette, optical disk, hard drive, or any other suitable storage medium, or any combination thereof. Machine readable media can be implemented in a computer program product. The electricity Brain program products can include packaging materials.
In a hardware implementation, the machine readable medium can be part of the processing system separate from the processor. However, as will be readily appreciated by those skilled in the art, the machine readable medium, or any portion thereof, can be external to the processing system. By way of example, a machine readable medium can include a transmission line, a carrier modulated by the data, and/or a computer product separate from the wireless node, all of which can be accessed by the processor via the bus interface. Alternatively or additionally, the machine readable medium, or any portion thereof, may be integrated into the processor, such as cache memory and/or general purpose register files.
The processing system can be configured as a general purpose processing system having one or more microprocessors that provide processor functionality, and external memory that provides at least a portion of the machine readable media, both of which are externally coupled The row architecture is linked to other supporting circuitry. Alternatively, the processing system may use an ASIC with a processor integrated in a single chip, a bus interface, a user interface (in the case of an access terminal), a support circuitry, and at least a portion of machine readable media ( Special application integrated circuit), or use one or more FPGAs (field programmable gate array), PLD (programmable logic device), controller, state machine, gate logic, individual hardware components, or Any other suitable circuitry, or any combination of circuitry capable of performing the various functionalities described throughout the present invention, can be implemented. Depending on the particular application and the overall design constraints imposed on the overall system, those skilled in the art will recognize how best to implement the functionality described with respect to the processing system.
Machine readable media can include several software modules. These soft phantoms A group includes instructions that, when executed by a processor, cause a processing system to perform various functions. The software modules can include a transmission module and a receiving module. Each software module can be resident in a single storage device or distributed across multiple storage devices. As an example, when a trigger event occurs, the software module can be loaded into the RAM from the hard drive. During execution of the software module, the processor can load some instructions into the cache to increase access speed. One or more cache memory lines can then be loaded into the general purpose scratchpad file for execution by the processor. In the following discussion of the functionality of a software module, it will be appreciated that such functionality is implemented by the processor when the processor executes instructions from the software module.
If implemented in software, the functions can be stored on or transmitted as computer readable media as one or more instructions or codes. Computer readable media includes both computer storage media and communication media including any media that facilitates the transfer of a computer program from one location to another. The storage medium can be any available media that can be accessed by the computer. By way of example and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, disk storage or other magnetic storage device, or can be used to carry or store instructions or data structures. Any other medium of the form of expected code that can be accessed by a computer. Any connection is also properly referred to as computer readable media. For example, if the software is using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technology (such as infrared (IR), radio, and microwave) from a web site, server, or other remote source Transmitted, the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies (such as infrared, radio, and microwave) are included in the definition of the media. Disks and discs as used herein include compact discs (CDs), laser discs, compact discs, digital versatile discs (DVDs), floppy discs , and Blu-ray discs , where disks are often magnetic. The data is reproduced, and the disc uses laser to optically reproduce the data. Thus, in some aspects, computer readable media can include non-transitory computer readable media (eg, tangible media). Additionally, for other aspects, computer readable media can include transient computer readable media (eg, signals). The above combinations should also be included in the scope of computer readable media.
Accordingly, certain aspects may include a computer program product for performing the operations provided herein. For example, such a computer program product can include computer readable media having stored thereon (and/or encoded) instructions executable by one or more processors to perform the operations described herein. For some aspects, computer program products may include packaging materials.
In addition, it should be appreciated that modules and/or other suitable means for performing the methods and techniques described herein can be downloaded and/or otherwise obtained by a user terminal and/or base station where applicable. For example, such a device can be coupled to a server to facilitate the transfer of means for performing the methods described herein. Alternatively, the various methods described herein can be provided via a storage device (eg, RAM, ROM, physical storage media such as a compact disc (CD) or floppy disk, etc.) such that once the storage device is coupled or provided to The user terminal and/or the base station can obtain various methods. Moreover, any other suitable technique suitable for providing the methods and techniques described herein to a device can be utilized.
It should be understood that the claims are not limited to the precise configurations and elements illustrated above. Layout, operation of the methods and devices described above Various changes, changes, and modifications are made to the details and details without departing from the scope of the claims.
A method for wireless communication, comprising the steps of: generating a packet having a preamble signal, the preamble signal being capable of being a first type of device having a first set of capabilities and a first having a second set of capabilities A type 2 device for decoding, wherein the preamble signal includes at least one repeated signal (SIG) field; and transmitting the packet.
The method of claim 1, wherein the repeated SIG field can be decoded by the second type of device, but cannot be decoded by the first type of device.
The method of claim 2, wherein: the preamble signal further comprises a SIG field that can be decoded by the first type of device; and one of the SIG fields that can be decoded by the first type of device The orthogonal track provides an indication of a type of packet to the second type of device.
The method of claim 1, wherein the repeated SIG field is repeated in a manner that allows the first type of device to detect a type of the packet.
The method of claim 1, wherein an indication of a type of the packet is provided via a orthogonal track of a SIG field that can be decoded by the device of the first type.
The method of claim 1, wherein an indication of a type of the packet is provided via a checksum in the repeated SIG field.
The method of claim 1, wherein at least one of the repeated SIG fields is rotated relative to the SIG field that can be decoded by the first type of device.
The method of claim 1, wherein at least a first portion of the repeated SIG field is preceded by a guard interval.
The method of claim 8, wherein a second portion of the repeated SIG field is preceded by a guard interval.
The method of claim 8, wherein a second portion of the repeated SIG field is truncated relative to a first portion of the repeated SIG field.
The method of claim 1, wherein an increasing symbol duration or an increased cyclic prefix relative to one or more fields of the preamble signal is used to transmit the preamble signal in the repeated SIG column At least a portion after the bit to provide delay spread protection.
The method of claim 11, wherein an indication of a type of delay spread protection is signaled prior to the end of the repeated SIG field.
The method of claim 1, wherein the at least one repeated SIG field is repeated in time.
The method of claim 1, wherein the at least one repeated SIG field is repeated in frequency.
The method of claim 1, wherein the at least one repeated SIG field comprises: a repeated first SIG field that can be decoded by the second type of device but cannot be decoded by the first type of device; and A repeating second SIG field that can be decoded by at least the first type of device.
The method of claim 15 wherein at least a first portion of the repeated first SIG field is preceded by a guard interval.
The method of claim 1, wherein at least a portion of the packet is transmitted at a rate that is lower than at least a portion of the preamble signal.
The method of claim 1, wherein the preamble signal includes at least two repeated SIG fields.
The method of claim 18, wherein at least one of the SIG fields in the repeated SIG field is repeated in time.
The method of claim 18, wherein at least one of the SIG fields in the repeated SIG field is repeated in frequency.
The method of claim 18, wherein the repeated SIG field includes at least one repeated high efficiency (HE)-SIG0 field and at least one repeated HE-SIG1 field.
The method of claim 1, wherein the at least one repeated signal (SIG) field includes a portion of the repeated SIG field.
The method of claim 22, wherein the partially repeated SIG field is transmitted by using a tone set to transmit a first symbol of the at least one repeated SIG field and transmitting using a limited subset of the tone set The at least one repeated SIG field is transmitted in the form of a second symbol.
A method for wireless communication, comprising the steps of: receiving a packet having a preamble signal, the preamble signal being capable of being a first type of device having a first set of capabilities and a first having a second set of capabilities A type 2 device for decoding, wherein the preamble signal includes at least one repeated signal (SIG) field; and processing the repeated SIG field.
The method of claim 24, wherein the repeated SIG field can be Two types of devices are decoded, but cannot be decoded by the first type of device.
The method of claim 25, wherein: the preamble signal further comprises a SIG field that can be decoded by the first type of device; and one of the SIG fields that can be decoded by the first type of device The orthogonal track provides an indication of a type of packet to the second type of device.
The method of claim 24, wherein the repeated SIG field is repeated in a manner that allows the first type of device to detect a type of the packet.
The method of claim 24, wherein an indication of a type of the packet is provided via a orthogonal track of a SIG field that can be decoded by the device of the first type.
The method of claim 24, wherein an indication of a type of the packet is provided via a checksum in the repeated SIG field.
The method of claim 24, wherein at least one of the repeated SIG fields is rotated relative to the SIG field that can be decoded by the first type of device.
The method as recited in claim 24, further comprising the step of determining a type of the packet via the correlation of the repeated portion of the repeated SIG field.
The method of claim 24, wherein at least a first portion of the repeated SIG field is preceded by a guard interval.
A method as recited in claim 24, wherein the use of an increased symbol duration or an increased cyclic prefix relative to one or more fields of the preamble signal to transmit the preamble signal in the repeated SIG column At least a portion after the bit to provide delay spread protection.
The method of claim 33, wherein the repeated SIG field of the packet is transmitted with a larger cyclic prefix relative to one or more fields of the preamble signal At least a portion of the subsequent, and transmitting at least a portion of the at least a portion over a longer symbol duration.
The method of claim 33, wherein the portions of the packet that are transmitted with an added symbol duration or an increased cyclic prefix are located after the at least one portion are transmitted in a normal symbol duration.
The method of claim 33, wherein an indication of a type of delay spread protection is signaled prior to the end of the repeated SIG field.
The method of claim 36, wherein the at least one repeated SIG field is repeated in time.
The method of claim 36, wherein the at least one repeated SIG field is repeated in frequency.
The method of claim 24, wherein the at least one repeated SIG field comprises: a repeated first SIG field that can be decoded by the second type of device but cannot be decoded by the first type of device; A repeating second SIG field that can be decoded by at least the first type of device.
The method of claim 39, wherein at least a first portion of the repeated first SIG field is preceded by a guard interval.
The method of claim 24, wherein at least a portion of the packet is transmitted at a rate that is lower than at least a portion of the preamble signal.
The method of claim 24, wherein the preamble signal comprises at least two repeated SIG fields.
The method of claim 24, wherein: a tone set of a first symbol of the repeated SIG field is used for pilot frequency; and a same tone set of a second symbol of the repeated SIG field At least a subset is used to signal a type of delay spread protection.
The method of claim 24, wherein a type of delay spread protection is signaled using a quadrature track of a repeated SIG field spanning at least two symbols.
A method as recited in claim 24, wherein a non-leading frequency tone of a repeated SIG field is used to signal a type of delay spread protection.
The method as recited in claim 24, further comprising the step of detecting a type of delay spread protection by calculating an autocorrelation of two symbols following a repeated first SIG field.
The method of claim 24, wherein a non-leading frequency tone of a repeated SIG field is used to signal a high efficiency WLAN type of the packet.
The method of claim 24, wherein the at least one repeated signal (SIG) field comprises a portion of the repeated SIG field.
The method of claim 50, wherein the partially repeated SIG field receives a first symbol of the at least one repeated SIG field using a tone set and receives using a limited subset of the tone set The at least one repeated SIG field is received in the form of a second symbol.
An apparatus for wireless communication, comprising: means for generating a packet having a preamble signal, the preamble signal being capable of being a first type of device having a first set of capabilities and having a second set of capabilities Decoding a second type of device, wherein the preamble signal includes at least one repeated signal (SIG) field; and means for transmitting the packet.
An apparatus for wireless communication, comprising: means for receiving a packet having a preamble signal, the preamble signal being capable of being a first type of device having a first set of capabilities and having a second set of capabilities A second type of device to decode, wherein the preamble signal includes at least one repeated signal (SIG) field; and means for processing the repeated SIG field.
An apparatus for wireless communication, comprising: a processing system configured to generate a packet having a preamble signal, the preamble signal being capable of being a first type of device having a first set of capabilities and having a first A second type of device of the second set of capabilities is decoded, wherein the preamble signal includes at least one repeated signal (SIG) field; and a transmitter configured to transmit the packet.
An apparatus for wireless communication, comprising: a receiver configured to receive a packet having a preamble signal, the preamble signal being capable of being a first type of device having a first set of capabilities and having a first A second type of device of the second set of capabilities is decoded, wherein the preamble signal includes at least one repeated signal (SIG) field; and a processing system configured to process the repeated SIG field.
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