Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
  • H04W4/02—Services making use of location information
  • H04W4/023—Services making use of location information using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S11/00—Systems for determining distance or velocity not using reflection or reradiation
  • G01S11/02—Systems for determining distance or velocity not using reflection or reradiation using radio waves
  • G01S11/04—Systems for determining distance or velocity not using reflection or reradiation using radio waves using angle measurements
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S11/00—Systems for determining distance or velocity not using reflection or reradiation
  • G01S11/02—Systems for determining distance or velocity not using reflection or reradiation using radio waves
  • G01S11/06—Systems for determining distance or velocity not using reflection or reradiation using radio waves using intensity measurements
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W64/00—Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Definitions

• the invention relates generally to millimeter wave radio frequency (RF) systems and, more particularly, to estimating a distance between a first and second apparatus using training signals.
• RF radio frequency
• the 60GHz band is an unlicensed band which features a large amount of bandwidth and a large worldwide overlap.
• the large bandwidth means that a very high volume of information can be transmitted wirelessly.
• multiple applications each requiring transmission of large amounts of data, can be developed to allow wireless communication around the 60GHz band. Examples for such applications include, but are not limited to, game controllers, mobile interactive devices, wireless high definition TV (HDTV), wireless docking stations, wireless Gigabit Ethernet, and many others.
• An RF system typically comprises active and passive modules.
• the active modules e.g., a phased array antenna
• passive modules e.g., filters
• the various modules are fabricated and packaged as radio frequency integrated circuits (RFICs) that can be assembled on a printed circuit board (PCB).
• the size of the RFIC package may range from several to a few hundred square millimeters.
• the design of electronic devices should meet the constraints of minimum cost, size, power consumption, and weight.
• the design of the RF modules should also take into consideration the current assembled configuration of electronic devices, and particularly handheld devices, such as laptop and tablet computers, in order to enable efficient transmission and reception of millimeter wave signals.
• the design of the RF module should account for minimal power loss of receive and transmit RF signals and for maximum radio coverage.
• the first apparatus generally includes an interface for obtaining a plurality of training signals received in a plurality of directions from a second apparatus.
• the first apparatus may also include a processing system configured to estimate, based on the plurality of training signals, a distance between the first apparatus and the second apparatus.
• the first apparatus generally includes a first interface for outputting, for transmission, a plurality of training signals in a plurality of directions to a second apparatus, a second interface for obtaining, from the second apparatus, parameters corresponding to the training signals as received at the second apparatus, and a processing system configured to estimate, based on the parameters, a distance between the first apparatus and the second apparatus.
• Certain aspects of the present disclosure provide a method for wireless communication by a first apparatus.
• the method generally includes outputting, for transmission, a plurality of training signals in a plurality of directions to a second apparatus, obtaining, from the second apparatus, parameters corresponding to the training signals as received at the second apparatus, and estimating, based on the parameters, a distance between the first apparatus and the second apparatus.
• the first apparatus generally includes means for obtaining a plurality of training signals received in a plurality of directions from a second apparatus, and means for estimating, based on the plurality of training signals, a distance between the first apparatus and the second apparatus.
• the wireless station generally includes at least one receive antenna, a receiver for receiving, via the at least one receive antenna, a plurality of training signals received in a plurality of directions from a second apparatus, and a processing system configured to estimate, based on the plurality of training signals, a distance between the first apparatus and the second apparatus.
• the wireless station generally includes at least one receive antenna, a receiver for receiving, via the at least one receive antenna, a plurality of training signals received in a plurality of directions from a second apparatus, and a processing system configured to estimate, based on the plurality of training signals, a distance between the first apparatus and the second apparatus.
• FIG. 2 illustrates a block diagram of an example access point and user terminals, in accordance with certain aspects of the present disclosure.
• FIG. 3 illustrates a block diagram of an example wireless device, in accordance with certain aspects of the present disclosure.
• FIG. 5 illustrates sector level sweep during beamforming operations, in accordance with certain aspects of the present disclosure.
• FIG. 6 illustrates example operations that may be performed by a wireless device for determining a distance to another device, in accordance with certain aspects of the present disclosure.
• FIG. 6A illustrates example components capable of performing the operations shown in FIG. 6.
• FIG. 7 illustrates example signal propagation and reflection during beamforming operations, in accordance with certain aspects of the present disclosure.
• FIG. 8 is a graph of a standard deviation between receive powers of training signals as a function of distance, in accordance with certain aspects of the present disclosure.
• FIG. 9 illustrates example operations that may be performed by a wireless device for determining a distance to another device, in accordance with certain aspects of the present disclosure.
• FIG. 9A illustrates example components capable of performing the operations shown in FIG. 9.
• aspects of the present disclosure provide techniques for estimating a distance between a first apparatus and a second apparatus based on training signals.
• the training signals may be transmitted by the second apparatus in a plurality of directions using different antenna configurations.
• the first apparatus may receive at least one of the training signals transmitted by the second apparatus and estimate a distance to the second apparatus using the at least one received training signal.
• TX data processor 210 processes (e.g., encodes, interleaves, and modulates) the traffic data for each user terminal based on the rate selected for that user terminal.
• TX data processor 210 provides Ndn downlink data symbol streams for the Ndn user terminals.
• FIG. 3 illustrates various components that may be utilized in a wireless device 302 in which aspects of the present disclosure may be practiced and that may be employed within the MIMO system 100.
• the wireless device 302 is an example of a device that may be configured to implement the various methods described herein.
• the wireless device 302 may be an access point 110 or a user terminal 120.
• phased array antennas use training signals (e.g., during a BF training process) transmitted and received, for example, by phased array antennas to determine a distance between a first and second apparatus.
• a phased array antenna comprises multiple antennas that together are able to direct a signal in a particular direction. This may be accomplished by varying the antenna configuration or the relative phase of signals transmitted by each antenna in the array of antennas such that the signal is radiated in a particular direction.
• the antennas may be millimeter wave phased array antennas. Millimeter wave signals are highly directional and thus, lend themselves to beamforming.
• each station can sweep a sequence of transmissions, separated by a short beamforming interframe space (SBIFS) interval, in which the antenna configuration at the transmitter or receiver can be changed between transmissions.
• SIFS short beamforming interframe space
• beam refinement is a process where a station can improve its antenna configuration (or antenna weight vector) both for transmission and reception. That is, each antenna includes an antenna weight vector (AWV), which further includes a vector of weights describing the excitation (amplitude and phase) for each element of an antenna array.
• FIG. 5 illustrates a transmitting (TX) station 502 transmitting training signals (e.g., training signals 506) in various directions. These training signals may be used to estimate a distance d between the TX station 502 and a receiving (RX) station 504. As noted above, in some cases, the training signals 506 may be transmitted as part of a training procedure to help optimize communications between the two devices.
• training signals may be transmitted as part of a training procedure to help optimize communications between the two devices.
• each training signal may be separated from an adjacent training signal, direction-wise, by a certain angle.
• adjacent training signals may be separated by 10°.
• the training signals may be received by a RX station 504.
• the SLS phase typically concludes after an initiating station TX 502 receives sector sweep feedback from the RX station 504 and sends a sector acknowledgement (ACK), thereby establishing BF.
• ACK sector acknowledgement
• the feedback from the RX station 504 may indicate which of the signals transmitted by the TX station 502 was received with the highest receive power, which may help indicate a direction corresponding to a line of sight (LOS) between the devices.
• LOS line of sight
• signal L2 may be indicated as being received by the RX station 504 with the highest receive power among the plurality of training signals 506.
• the direction in which L2 was transmitted may then be used in subsequent communications between the TX station 502 and RX station 504.
• the training signals 506 may reflect off of obstructions (e.g., in a signal path of training signals 506) such as walls 508A and 508B, as will be discussed in more detail below.
• the operations 600 begin, at 602, by obtaining a plurality of training signals received in a plurality of directions from a second apparatus (e.g., TX station 502).
• a second apparatus e.g., TX station 502
• the RX station 504 may receive training signals 506 of FIG. 5, which may include training signals LI, L2 and L3.
• the RX station 504 may estimate, based on the plurality of training signals, a distance between the first apparatus and the second apparatus.
• Several techniques may be used to estimate the distance between the first apparatus and the second apparatus based on the training signals.
• distance between devices may be estimated based on knowledge of the direction of training signals when they depart the TX station and the path these training signals travel to reach the RX station 504.
• the RX station 504 may estimate the distance d based on characteristics of the training signals L2, LI and/or L3. For example, as illustrated in FIG. 7, an RX station 504 and a TX station 502 may be a certain distance r away from an obstruction such as a wall 508A. In this scenario, certain training signals (e.g., signals LI of training signals 506) may reflect off the wall 508 A. Therefore, signal LI may be directed towards the RX station 504 due to its reflection off the wall 508A.
• certain training signals e.g., signals LI of training signals 506
• signals LI may reflect off the wall 508 A. Therefore, signal LI may be directed towards the RX station 504 due to its reflection off the wall 508A.
• the RX station 504 may apply geometrical/trigonometric principles to estimate the distance d based on the distance r and the angle at which the reflected signal LI was received relative to signal L2 (having the highest receive power). For example, distance d may be estimated in accordance with the following equation:
• LI is the receive power of signal LI
• L2 is the receive power of signal L2
• L3 is the receive power of signal L3.
• estimating the distance between the first and second apparatuses may be based on differences in measured receive power for one or more pairs of the training signals (e.g., receive power of LI and L2). For example, differences in measured receive power for the one or more pairs of training signals may be compared to differences in previously measured receive power for the one or more pairs of training signals obtained at known distances.
• differences in measured receive power for the one or more pairs of training signals may be compared to differences in previously measured receive power for the one or more pairs of training signals obtained at known distances.
• FIG. 8 is a graph 800 of a standard deviation between the receive power of two training signals (e.g., signal LI and L2) as a function of distance.
• a standard deviation of 8 decibels (dB) between the receive power of LI and L2 corresponds with a distance of approximately 100cm between TX station 502 and RX station 504.
• the distance between the first and second apparatus may be determined by the RX station 504. That is, the distance between the first and second apparatuses may be estimated by comparing at least one difference in measured receive powers for one or more pairs of training signals to at least one difference in previously measured receive powers for the one or more pairs of training signals obtained at known distances.
• an inverse relationship may exist between the distance (d) and the deviation of the receive power of signal LI versus the receive power of signal L2.
• estimating the distance between the first and second apparatus may be based on a known beam-width of the training signals.
• the RX station may use the value (e.g., to optimize communications, decide whether to associate with the TX station etc.) and, in some cases, may transmit the estimated distance value (e.g., in a frame) back to the TX station for its use.
• the TX station may obtain a similar lookup table to that described above.
• the RX station may feedback information regarding the receive power of different training signals (or the difference itself), allowing the TX station to lookup an estimate of distance d from the lookup table.
• Parameters measured by the RX station or the standard deviation between the two received training signals may be sent to the TX station, and the TX station may use the lookup table to determine the distance between the first and second apparatuses.
• FIG. 9 illustrates example operations 900 for estimating a distance between a first apparatus (e.g., TX station 502) and second apparatus (e.g., RX station 504), in accordance with aspects of the present disclosure.
• the operations 600 may be performed, for example, by a first apparatus such as the TX station 502.
• the operations 900 begin, at 902, by outputting, for transmission, a plurality of training signals in a plurality of directions to a second apparatus.
• the TX station 502 may obtain, from the second apparatus, parameters corresponding to the training signals as received at the second apparatus.
• the TX station 502 may estimate, based on the parameters, a distance between the first apparatus and the second apparatus.
• the various operations of methods described above may be performed by any suitable means capable of performing the corresponding functions.
• the means may include various hardware and/or software component(s) and/or module(s), including, but not limited to a circuit, an application specific integrated circuit (ASIC), or processor.
• ASIC application specific integrated circuit
• operations 600 illustrated in FIG. 6 and operations 900 illustrated in FIG. 9 correspond to means 600A illustrated in FIG. 6A and means 900A illustrated in FIG. 9 A, respectively.
• a phrase referring to "at least one of a list of items refers to any combination of those items, including single members.
• "at least one of: a, b, or c" is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a- c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).
• the methods disclosed herein comprise one or more steps or actions for achieving the described method.
• the method steps and/or actions may be interchanged with one another without departing from the scope of the claims.
• the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims.
• a user interface e.g., keypad, display, mouse, joystick, etc.
• the bus may also link various other circuits such as timing sources, peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further.
• the processing system may be configured as a general-purpose processing system with one or more microprocessors providing the processor functionality and external memory providing at least a portion of the machine-readable media, all linked together with other supporting circuitry through an external bus architecture.
• the processing system may be implemented with an ASIC (Application Specific Integrated Circuit) with the processor, the bus interface, the user interface in the case of an access terminal), supporting circuitry, and at least a portion of the machine-readable media integrated into a single chip, or with one or more FPGAs (Field Programmable Gate Arrays), PLDs (Programmable Logic Devices), controllers, state machines, gated logic, discrete hardware components, or any other suitable circuitry, or any combination of circuits that can perform the various functionality described throughout this disclosure.
• ASIC Application Specific Integrated Circuit
• Computer- readable media include both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another.
• a storage medium may be any available medium that can be accessed by a computer.
• such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer.
• any connection is properly termed a computer-readable medium.
• certain aspects may comprise a computer program product for performing the operations presented herein.
• a computer program product may comprise a computer-readable medium having instructions stored (and/or encoded) thereon, the instructions being executable by one or more processors to perform the operations described herein.
• the computer program product may include packaging material.
• modules and/or other appropriate means for performing the methods and techniques described herein can be downloaded and/or otherwise obtained by a user terminal and/or base station as applicable.
• a user terminal and/or base station can be coupled to a server to facilitate the transfer of means for performing the methods described herein.
• various methods described herein can be provided via storage means (e.g., RAM, ROM, a physical storage medium such as a compact disc (CD) or floppy disk, etc.), such that a user terminal and/or base station can obtain the various methods upon coupling or providing the storage means to the device.
• storage means e.g., RAM, ROM, a physical storage medium such as a compact disc (CD) or floppy disk, etc.
• CD compact disc
• floppy disk etc.
• any other suitable technique for providing the methods and techniques described herein to a device can be utilized.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Radar, Positioning & Navigation (AREA)
• Remote Sensing (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Mobile Radio Communication Systems (AREA)
• Radio Transmission System (AREA)
• Radar Systems Or Details Thereof (AREA)

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• 2015
  • 2015-02-02 US US14/612,270 patent/US9936352B2/en active Active
• 2016
  • 2016-01-11 EP EP16705606.8A patent/EP3254137B1/en active Active
  • 2016-01-11 BR BR112017016576A patent/BR112017016576A2/pt not_active IP Right Cessation
  • 2016-01-11 WO PCT/US2016/012841 patent/WO2016126378A1/en not_active Ceased
  • 2016-01-11 JP JP2017540603A patent/JP6522767B2/ja not_active Expired - Fee Related
  • 2016-01-11 KR KR1020177021373A patent/KR101894376B1/ko not_active Expired - Fee Related
  • 2016-01-11 CN CN201680008062.4A patent/CN107209258A/zh active Pending
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