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Применить Всего найдено 25. Отображено 22.
17-10-2017 дата публикации

Array-to-array beamforming and iterative time reversal techniques

Номер: US0009793969B2
Автор: David Smith, Mark Hsu, Maha Achour, Jeremy Rode, Anis Husain, Kris Gregorian, Jeremy Ward, SMITH DAVID, HSU MARK, ACHOUR MAHA, RODE JEREMY, HUSAIN ANIS, GREGORIAN KRIS, WARD JEREMY, Smith David, Hsu Mark, Achour Maha, Rode Jeremy, Husain Anis, Gregorian Kris, Ward Jeremy
Принадлежит: ZIVA CORP., ZIVA CORP, Ziva Corporation

In examples, two arrays of Radio Frequency nodes achieve enhanced beamforming for communications between the arrays by successively sending sounding signals from one array to the other array. Each sounding signal sent by the first of the two arrays is beamformed through time reversal of an immediately preceding sounding signal received by the first array from the second array, and each sounding signal (except the initial sounding signal) sent by the second array is beamformed through time reversal of an immediately preceding sounding signal received by the second array from the first array. The initial sounding signal sent by the second array may be omnidirectional, beamformed through a guesstimate, random, predetermined, or determined through a search of the area where the arrays are located. With sufficient beamfocusing, the arrays may communicate by sending and receiving data from one array to the other array.

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Номер записи: 1
17-01-2017 дата публикации

Distributed co-operating nodes using time reversal

Номер: US0009548799B2
Автор: Mark Hsu, David Smith, Jeremy Rode, Anis Husain, HSU MARK, SMITH DAVID, RODE JEREMY, HUSAIN ANIS, Hsu Mark, Smith David, Rode Jeremy, Husain Anis
Принадлежит: ZIV A CORP., ZIVA CORP, ZIV A CORP, Ziva Corporation

Dynamic, untethered array nodes are frequency, phase, and time aligned, and used to focus their transmissions of the same data coherently on a target, using time reversal. Alignment may be achieved separately for the radio frequency (RF) carriers and the data envelopes. Carrier alignment may be by phase conjugation. The data is distributed across the nodes. Data distribution and/or alignment may be performed by a Master node of the array. The nodes capture a sounding signal from the target, in the same time window. Each node converts the captured sounding signal to baseband, for example, using in-phase/quadrature downconversion. Each node stores the baseband samples of the sounding pulse. Each node convolves time-reversed samples of the sounding signal with the data, and upconverts the convolved data to radio frequency. The nodes emit their respective convolved and upconverted data so that the emissions focus coherently at the target.

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Номер записи: 2
31-10-2017 дата публикации

Wireless sensing with time reversal

Номер: US0009806846B2
Автор: David Smith, Jeremy Rode, Anis Husain, Mark Hsu, Maha Achour, SMITH DAVID, RODE JEREMY, HUSAIN ANIS, HSU MARK, ACHOUR MAHA, Smith David, Rode Jeremy, Husain Anis, Hsu Mark, Achour Maha
Принадлежит: ZIVA CORP., ZIVA CORP, Ziva Corporation

In examples, Radio Frequency Iterative Time-Reversal (RF-ITR) and singular value decomposition (SVD) are used by an array of nodes to characterize environment by identifying scatterer objects. The array may be ad hoc dynamic or stationary. The environment is cancelled from the RF-ITR by adjusting Time-Reversal (TR) prefilters, reducing illumination of the scatterer objects in the environment. This enables the RF-ITR process to focus on a moving target, which can then be sensed (discovered, identified, monitoring, tracked, and/or imaged). The moving target on which the RF-ITR process focuses may then be cancelled from the RF-ITR in the same way as the environment, allowing the RF-ITR to focus on another target. Multiple moving targets can thus be sensed. Defensive measures such as jamming may then be taken against the targets. The targets may be distinguished from the scatterer objects in the environment through differential, Doppler processing, and other classification techniques.

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Номер записи: 3
15-11-2016 дата публикации

Distributed co-operating nodes using time reversal

Номер: US0009497722B2
Автор: Anis Husain, Jeremy Rode, David Smith, Mark Hsu, Maha Achour, HUSAIN ANIS, RODE JEREMY, SMITH DAVID, HSU MARK, ACHOUR MAHA, Husain Anis, Rode Jeremy, Smith David, Hsu Mark, Achour Maha
Принадлежит: ZIVA CORP., HUSAIN ANIS, RODE JEREMY, SMITH DAVID, HSU MARK, ACHOUR MAHA, ZIVA CORP, Husain Anis, Rode Jeremy, Smith David, Hsu Mark, Achour Maha

Methods and systems for coherent distributed communication techniques using time reversal are disclosed. In one aspect, cooperating nodes of a cluster can move relative to each other and relative to an intended receiver of the nodes' data transmissions. The nodes are synchronized to a common time reference, and data for transmission from the cluster is distributed to the nodes. The intended receiver sends a sounding signal to the nodes. Each node receives the sounding signal, obtains the channel response between the intended receiver and itself, and time-reverses the channel response. Each node then convolves its time-reversed channel response with the data to obtain the node's convolved data. Each node waits a predetermined time following the time reference signal, as determined based on the common time reference. At the expiration of the predetermined time period, the nodes simultaneously transmit their convolved data.

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Номер записи: 4
17-10-2017 дата публикации

Synchronization of distributed nodes

Номер: US0009794903B2
Автор: David Smith, Anis Husain, Jeremy Rode, Mark Hsu, SMITH DAVID, HUSAIN ANIS, RODE JEREMY, HSU MARK, Smith David, Husain Anis, Rode Jeremy, Hsu Mark
Принадлежит: ZIVA CORP., ZIVA CORP, Ziva Corporation

Dynamic, untethered array nodes are frequency, phase, and time aligned/synchronized, and used to focus their transmissions of the same data coherently on a target or in the target's direction, using time reversal or directional beamforming. Information for alignment/synchronization may be sent from a master node of the array to other nodes, over non-RF links, such as optical and acoustic links. Some nodes may be connected directly to the master nodes, while other nodes may be connected to the master node through one or more transit nodes. A transit nodes may operate to (1) terminate the link when the alignment/synchronization information is intended for the node, and (2) pass through the alignment/synchronization information to another node without imposing its local clock properties on the passed through alignment/synchronization information. In this way, an end point node may be aligned/synchronized to the master node without a direct link between the two nodes.

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Номер записи: 5
18-10-2012 дата публикации

APPARATUS, METHODS, AND ARTICLES OF MANUFACTURE FOR WIRELESS COMMUNICATIONS

Номер: US20120263056A1
Автор: Achour Maha, Husain Anis, Rode Jeremy, Smith David
Принадлежит:

Selected embodiments are directed to methods, apparatus, and articles of manufacture for wireless radio frequency communications. Adjacent antenna array elements of a receiver antenna array are separated by less than the diffraction limit of the radio frequency communication band in which the apparatus and methods operate. A plurality or multiplicity of near-field scatterers are asymmetrically placed in the immediate vicinity of each of the antenna array elements, to perturb the pattern of each of the antenna elements, making the patterns different even below diffraction limit spacing. A transmitter spatially and temporally focuses simultaneous transmissions on each of the antenna array elements, using time reversal communication techniques. The transmitter may transmit through multiple antenna elements, and the channel from the transmitter to the receiver may be subject to multipath phenomena. 1. A radio antenna array , comprising:a plurality of antenna elements electrically insulated from each other, each antenna element of the plurality of antenna elements being configured to operate in a predetermined radio frequency (RF) band; anda plurality of near-field (NF) scatterers;wherein:the plurality of antenna elements comprises a first antenna element and a second antenna element, the first antenna element being separated from the second antenna element by a distance d, d being less than one-half wavelength at center frequency of the predetermined RF band; andthe NF scatterers of the plurality of NF scatterers arc distributed asymmetrically relative to the first and second antenna elements, each NF scatterer of a first subset of the NF scatterers of the plurality of NF scatterers is located nearer the first antenna element than d.2. A radio antenna array according to claim 1 , wherein:each NF scatterer of a second subset of the NF scatterers of the plurality of NF scatterers is located nearer the second antenna element than d; andeach antenna element of the array of ...

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Номер записи: 6
27-12-2012 дата публикации

Anti-geolocation

Номер: US20120328037A1
Автор: Anis Husain, David Smith, Jeremy Rode, Maha Achour, Mark Hsu
Принадлежит: Ziva Corp

Methods, apparatus, and articles of manufacture make Geolocation of a source transmitter more difficult or impossible. Scatterers common to a source transmitter and an intended receiver are identified using a variety of techniques, such as iterative time reversal (ITR) and Singular Value Decomposition (SVD) of a scatter matrix. The source transmitter then uses time reversal and knowledge of the signatures of the scatterers to focus its transmissions on one or more of the scatterers, instead of the intended receiver. The source transmitter may have multiple antennas or antenna elements. The source transmitter and/or the intended receiver may include antenna elements with Near-Field Scatterers to enable spatial focusing below the diffraction limit at the frequencies of interest. The source transmitter may be a plurality of ad hoc nodes cooperating with each other.

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Номер записи: 7
18-01-2018 дата публикации

Synchronization of distributed nodes

Номер: US20180020416A1
Автор: Anis Husain, David Smith, Jeremy Rode, Mark Hsu
Принадлежит: Ziva Corp

Dynamic, untethered array nodes are frequency, phase, and time aligned/synchronized, and used to focus their transmissions of the same data coherently on a target or in the target's direction, using time reversal or directional beamforming. Information for alignment/synchronization may be sent from a master node of the array to other nodes, over non-RF links, such as optical and acoustic links. Some nodes may be connected directly to the master nodes, while other nodes may be connected to the master node through one or more transit nodes. A transit nodes may operate to (2) terminate the link when the alignment/synchronization information is intended for the node, and (2) pass through the alignment/synchronization information to another node without imposing its local clock properties on the passed through alignment/synchronization information. In this way, an end point node may be aligned/synchronized to the master node without a direct link between the two nodes.

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Номер записи: 8
26-01-2017 дата публикации

WIRELESS SENSING WITH TIME REVERSAL

Номер: US20170026147A1
Автор: Achour Maha, Hsu Mark, Husain Anis, Rode Jeremy, Smith David
Принадлежит: ZIVA CORPORATION

In examples, Radio Frequency Iterative Time-Reversal (RF-ITR) and singular value decomposition (SVD) are used by an array of nodes to characterize environment by identifying scatterer objects. The array may be ad hoc dynamic or stationary. The environment is cancelled from the RF-ITR by adjusting Time-Reversal (TR) prefilters, reducing illumination of the scatterer objects in the environment. This enables the RF-ITR process to focus on a moving target, which can then be sensed (discovered, identified, monitoring, tracked, and/or imaged). The moving target on which the RF-ITR process focuses may then be cancelled from the RF-ITR in the same way as the environment, allowing the RF-ITR to focus on another target. Multiple moving targets can thus be sensed. Defensive measures such as jamming may then be taken against the targets. ii The targets may be distinguished from the scatterer objects in the environment through differential, Doppler processing, and other classification techniques. 1. A method of sensing one or more targets , the method comprising steps of:aligning a plurality of ad hoc nodes of an array in time and frequency;obtaining relative location of each node of the plurality of ad hoc nodes of the array, thereby obtaining relative layout of the array;characterizing environment of the array by identifying one or more clutter objects; andsearching for a first target using radio frequency iterative time reversal (RF-ITR) and clutter cancellation.2. The method of claim 1 , further comprising step of obtaining absolute geolocation of said each node of the plurality of ad hoc nodes of the array.3. The method of claim 1 , wherein the step of characterizing the environment comprises employing RF-ITR with singular value decomposition (SVD) and successive clutter object cancellation.4. The method of claim 3 , wherein at least one of the steps of characterizing and searching for the first target comprises step of performing signal classification.5. The method of ...

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Номер записи: 9
24-01-2019 дата публикации

TIME REVERSAL IN WIRELESS COMMUNICATIONS

Номер: US20190028304A1
Автор: Achour Maha, Gregorian Kris, Hsu Mark, Husain Anis, Rode Jeremy, Smith David
Принадлежит: ZIVA CORPORATION

In examples, Time-Reversal (TR) Orthogonal Frequency-Division Multiplexing (OFDM) communications employ adaptive filtering on a per-subcarrier basis. Matched filtering is used for subcarriers with poor transmission properties (such as relatively high channel attenuation), while inverse filtering is used for subcarriers with relatively good transmission properties (such as relatively low channel attenuation). Modulation order may be reduced for the subcarriers with poor properties (relative to the subcarriers with good properties). The discovery of subcarrier properties may be performed through the channel state information measured and reconciled from single- and/or bi-directional TR sounding signals. The discovery may be repeated, for example, performed continually. In response to changes in traffic and other environmental conditions, the system may be reconfigured dynamically with different subcarriers selected for matched and inverse filtering. In examples, a normalized signal-to-noise ratio threshold dividing good and poor transmission properties is computed based on an acceptable symbol error rate. 1. A method of wirelessly communicating between a first node and a second node using Radio Frequency (RF) Orthogonal Frequency-Division Multiplexing (OFDM) with a plurality of subcarriers and time-reversal , the method comprising:estimating channel between the first node and the second node for each subcarrier of the plurality of subcarriers, thereby obtaining a plurality of channel state information (CSI) estimates, a CSI estimate of the plurality of CSI estimates per subcarrier of the plurality of subcarriers, each subcarrier of the plurality of subcarriers being associated with a CSI estimate of the plurality of CSI estimates corresponding to said each subcarrier; andtransmitting data from the first node to the second node using inverse filtering for subcarriers of the plurality of subcarriers associated with CSI estimates that meet at least one channel quality ...

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Номер записи: 10
18-02-2016 дата публикации

Anti-geolocation

Номер: US20160047894A1
Автор: Anis Husain, David Smith, Jeremy Rode, Maha Achour, Mark Hsu
Принадлежит: Ziva Corp

Methods, apparatus, and articles of manufacture make Geolocation of a source transmitter more difficult or impossible. Scatterers common to a source transmitter and an intended receiver are identified using a variety of techniques, such as iterative time reversal (ITR) and Singular Value Decomposition (SVD) of a scatter matrix. The source transmitter then uses time reversal and knowledge of the signatures of the scatterers to focus its transmissions on one or more of the scatterers, instead of the intended receiver. The source transmitter may have multiple antennas or antenna elements. The source transmitter and/or the intended receiver may include antenna elements with Near-Field Scatterers to enable spatial focusing below the diffraction limit at the frequencies of interest. The source transmitter may be a plurality of ad hoc nodes cooperating with each other.

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Номер записи: 11
08-05-2014 дата публикации

DISTRIBUTED CO-OPERATING NODES USING TIME REVERSAL

Номер: US20140126567A1
Автор: Achour Maha, Hsu Mark, Husain Anis, Rode Jeremy, Smith David
Принадлежит:

Methods and systems for coherent distributed communication techniques using time reversal are disclosed. In one aspect, cooperating nodes of a cluster can move relative to each other and relative to an intended receiver of the nodes' data transmissions. The nodes are synchronized to a common time reference, and data for transmission from the cluster is distributed to the nodes. The intended receiver sends a sounding signal to the nodes. Each node receives the sounding signal, obtains the channel response between the intended receiver and itself, and time-reverses the channel response. Each node then convolves its time-reversed channel response with the data to obtain the node's convolved data Each node waits a predetermined time following the time reference signal, as determined based on the common time reference. At the expiration of the predetermined time period, the nodes simultaneously transmit their convolved data 1. A method of transmitting from a plurality of nodes , the method comprising steps of:synchronizing each node of the plurality of nodes to a common time reference of all nodes of the plurality of nodes, so that all nodes of the plurality of nodes are enabled to transmit synchronously a predetermined synchronization period after a trigger signal is sent from a trigger node of the plurality of nodes;obtaining at said each node of the plurality of nodes information sufficient to transmit from said each node a time-reversed signal corresponding to said each node, so that when all nodes of the plurality of nodes synchronously transmit respective time-reversed signals, the time-reversed signals combine spatially and temporally to focus on a subject;sending the trigger signal from the trigger node of the plurality of nodes; andtransmitting the time-reversed signals from all nodes of the plurality of nodes, a time-reversed signal per node, so that a combination of the plurality of time-reversed signals is spatially and temporally focused on the subject, the ...

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Номер записи: 12
26-03-2015 дата публикации

SYNCHRONIZATION OF DISTRIBUTED NODES

Номер: US20150085853A1
Автор: Hsu Mark, Husain Anis, Rode Jeremy, Smith David
Принадлежит: ZIVA CORPORATION

Dynamic, untethered array nodes are frequency, phase, and time aligned/synchronized, and used to focus their transmissions of the same data coherently on a target or in the target's direction, using time reversal or directional beamforming. Information for alignment/synchronization may be sent from a master node of the array to other nodes, over non-RF links, such as optical and acoustic links. Some nodes may be connected directly to the master nodes, while other nodes may be connected to the master node through one or more transit nodes. A transit nodes may operate to (2) terminate the link when the alignment/synchronization information is intended for the node, and (2) pass through the alignment/synchronization information to another node without imposing its local clock properties on the passed through alignment/synchronization information. In this way, an end point node may be aligned/synchronized to the master node without a direct link between the two nodes. 1. A method of synchronizing an array of at least three ad hoc nodes , the method comprising steps of:receiving from a master node of the array a first non-radio frequency (non-RF) signal carrying a first radio frequency (RF) signal, the step of receiving being performed at a first transit slave node of the array over a first non-RF side channel link, the first RF signal including properties of a local time reference of the master node;passing through at least a first portion of the first non-RF signal through the first transit slave to an end-point node without imposing clock properties of the first transit slave node on the first portion of the first non-RF signal, the first portion of the non-RF signal carrying at least a first portion of the first RF-signal, thereby enabling the end-point node to synchronize to the master node using the properties of the local time reference of the master node carried by the first portion of the first RF-signal.2. A method as in claim 1 , further comprising:terminating ...

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Номер записи: 13
23-03-2017 дата публикации

DISTRIBUTED CO-OPERATING NODES USING TIME REVERSAL

Номер: US20170086160A1
Автор: Achour Maha, Hsu Mark, Husain Anis, Rode Jeremy, Smith David
Принадлежит:

Distributed cooperating nodes of a cluster are used for communications, object location, and other purposes. The nodes can move relative to each other and an intended receiver. The nodes are synchronized and data for transmission from the cluster is distributed to the nodes. The intended receiver sends a sounding signal to the nodes. Each node receives the sounding signal, obtains the channel response between the intended receiver and the node, and time-reverses the channel response. Each node convolves its time-reversed channel response with the data to obtain the node's convolved data. A master node sends a time reference signal to the other nodes. Each node waits a predetermined time following the time reference signal, as determined based on a common time reference. At the expiration of the predetermined time period, the nodes simultaneously transmit their convolved data. The transmissions from the nodes combine coherently in time-space at the intended receiver. 1. A method of transmitting from a plurality of ad hoc nodes , the method comprising steps of:synchronizing each node of the plurality of ad hoc nodes to a common reference of all nodes of the plurality of ad hoc nodes so that said all nodes of the plurality of ad hoc nodes are enabled to transmit synchronously at a predetermined frequency;receiving at said each node one or more waveforms resulting from a sounding signal;generating a time-reversed signal at said each node, the step of generating comprising time-reversing the one or more waveforms received at said each node, thereby obtaining a plurality of time-reversed signals, a time-reversed signal of the plurality of time-reversed signals per said each node of the plurality of ad hoc nodes;sending a trigger signal from a trigger node of the plurality of ad hoc nodes; andtransmitting synchronously at the predetermined frequency the time-reversed signals from said all nodes of the plurality of ad hoc nodes, one of the time-reversed signals per node of ...

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Номер записи: 14
29-03-2018 дата публикации

ARRAY-TO-ARRAY BEAMFORMING AND ITERATIVE TIME REVERSAL TECHNIQUES

Номер: US20180091205A1
Автор: Achour Maha, Gregorian Kris, Hsu Mark, Husain Anis, Rode Jeremy, Smith David P., Ward Jeremy M.
Принадлежит: ZIVA CORPORATION

In examples, two arrays of Radio Frequency nodes achieve enhanced beamforming for communications between the arrays by successively sending sounding signals from one array to the other array. Each sounding signal sent by the first of the two arrays is beamformed through time reversal of an immediately preceding sounding signal received by the first array from the second array, and each sounding signal (except the initial sounding signal) sent by the second array is beamformed through time reversal of an immediately preceding sounding signal received by the second array from the first array. The initial sounding signal sent by the second array may be omnidirectional, beamformed through a guesstimate, random, predetermined, or determined through a search of the area where the arrays are located. With sufficient beamfocusing, the arrays may communicate by sending and receiving data from one array to the other array. 1. A method of radio frequency (RF) communication between arrays of nodes , the method comprising steps of:aligning/synchronizing nodes of a first array in time, frequency, and phase, the first array comprising a first plurality of nodes, the first plurality of nodes comprising at least two first array ad hoc nodes, each node of the first array comprising an RF receiver and an RF transmitter, whereby the first array is enabled to operate as a coherent array with coherent RF transmission properties and coherent RF reception properties;aligning/synchronizing nodes of a second array in time, frequency, and phase, the second array comprising a second plurality of nodes, the second plurality of nodes comprising at least two second array ad hoc nodes, each node of the second array comprising an RF receiver and an RF transmitter, whereby the second array is enabled to operate as a coherent array with coherent RF transmission properties and coherent RF reception properties; andsuccessively sending RF sounding signals from the first plurality of nodes to the second ...

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Номер записи: 15
30-03-2017 дата публикации

Array-to-array beamforming and iterative time reversal techniques

Номер: US20170093475A1
Автор: Anis Husain, David Smith, Jeremy Rode, Maha Achour, Mark Hsu
Принадлежит: Ziva Corp

In examples, two arrays of Radio Frequency nodes achieve enhanced beamforming for communications between the arrays by successively sending sounding signals from one array to the other array. Each sounding signal sent by the first of the two arrays is beamformed through time reversal of an immediately preceding sounding signal received by the first array from the second array, and each sounding signal (except the initial sounding signal) sent by the second array is beamformed through time reversal of an immediately preceding sounding signal received by the second array from the first array. The initial sounding signal sent by the second array may be omnidirectional, beamformed through a guesstimate, random, predetermined, or determined through a search of the area where the arrays are located. With sufficient beamfocusing, the arrays may communicate by sending and receiving data from one array to the other array.

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Номер записи: 16
01-06-2017 дата публикации

DISTRIBUTED CO-OPERATING NODES USING TIME REVERSAL

Номер: US20170156123A1
Автор: Hsu Mark, Husain Anis, Rode Jeremy, Smith David
Принадлежит: ZIVA CORPORATION

Dynamic, untethered array nodes are frequency, phase, and time aligned, and used to focus their transmissions of the same data coherently on a target, using time reversal. Alignment may be achieved separately for the radio frequency (RF) carriers and the data envelopes. Carrier alignment may be by phase conjugation. The data is distributed across the nodes. Data distribution and/or alignment may be performed by a Master node of the array. The nodes capture a sounding signal from the target, in the same time window. Each node converts the captured sounding signal to baseband, for example, using in-phase/quadrature downconversion. Each node stores the baseband samples of the sounding pulse. Each node convolves time-reversed samples of the sounding signal with the data, and upconverts the convolved data to radio frequency. The nodes emit their respective convolved and upconverted data so that the emissions focus coherently at the target. 1. A method of configuring a plurality of radio frequency (RF) nodes into a distributed RF time reversal mirror for transmitting to a target , the method comprising steps of:aligning phases of local clock references of all RF nodes of the plurality of RF nodes;aligning frequencies of the local clock references of all RF nodes of the plurality of RF nodes; andgenerating, by each RF node of the plurality of RF nodes, a time-reversed signal at carrier frequency using sample-reversal of a common time capture window of the plurality of RF nodes at baseband and phase-conjugation of a sounding signal at the carrier frequency, thereby obtaining a plurality of time-reversed signals, a time-reversed signal of the plurality of time-reversed signals per RF node of the plurality of RF nodes, the common time capture window being common to the plurality of RF nodes.2. The method of claim 1 , wherein modulation envelopes of the time-reversed signals of the plurality of time-reversed signals are not aligned by the plurality of RF nodes.3. The method of ...

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Номер записи: 17
18-06-2015 дата публикации

SYNCHRONIZATION OF DISTRIBUTED NODES

Номер: US20150173034A1
Автор: Hsu Mark, Husain Anis, Rode Jeremy, Smith David
Принадлежит: ZIVA CORPORATION

Dynamic, untethered array nodes with internal clocks are frequency, phase, and time aligned/synchronized, and used to focus their transmissions of the same payload data coherently on a target or in the target's direction, using time reversal or directional beamforming. Information for alignment/synchronization may be sent from a master node of the array to the slave nodes, over RF node-to-node links operating on different carrier or subcarrier frequencies. Additionally, the up- and down-communications on the RF links may use different frequencies. The RF links may also be used to distribute the payload data across the array. Because of frequency division on the RF links, interference is reduced or avoided, and the process of alignment/synchronization may be performed concurrently for several or all the slave nodes. The array may also operate collaboratively to receive data from the target. 1. A method of communicating between an array of ad hoc nodes and a target , the array comprising a master node and a plurality of slave nodes , the method comprising steps of:communicating between the master node and each slave node of the array to enable synchronization of said each slave node to the master node, the step of communicating with said each slave node being performed on a radio frequency (RF) side channel link associated with said each slave node, wherein a plurality of RF side channel links are established by the array, each RF side channel link operating on an upward frequency for transmissions to the master node and on a downward frequency for transmissions from the master node;performing frequency, time, and phase synchronization of said each slave node to the master node based on the step of communicating;distributing across the array common data for transmission to the target; andcoherently transmitting from said each node of the array to the target signals at a common RF frequency, the signals at the common frequency carrying the common data, so that the ...

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Номер записи: 18
09-10-2014 дата публикации

DISTRIBUTED CO-OPERATING NODES USING TIME REVERSAL

Номер: US20140301494A1
Автор: Hsu Mark, Husain Anis, Rode Jeremy, Smith David
Принадлежит: ZIVA CORPORATION

Dynamic, untethered array nodes are frequency, phase, and time aligned, and used to focus their transmissions of the same data coherently on a target, using time reversal. Alignment may be achieved separately for the radio frequency (RF) carriers and the data envelopes. Carrier alignment may be by phase conjugation. The data is distributed across the nodes. Data distribution and/or alignment may be performed by a Master node of the array. The nodes capture a sounding signal from the target, in the same time window. Each node converts the captured sounding signal to baseband, for example, using in-phase/quadrature downconversion. Each node stores the baseband samples of the sounding pulse. Each node convolves time-reversed samples of the sounding signal with the data, and upconverts the convolved data to radio frequency. The nodes emit their respective convolved and upconverted data so that the emissions focus coherently at the target. 1. A method of configuring a plurality of radio frequency transmission nodes into a distributed time reversal mirror for transmitting to a target , the method comprising:step for phase alignment of local clock references of all nodes of the plurality of radio frequency transmission nodes; andstep for frequency alignment of the local clock references of all nodes of the plurality of radio frequency transmission nodes.2. A method as in claim 1 , wherein modulation envelope of the nodes are not aligned.3. A method as in claim 1 , wherein the step for frequency alignment is based on repetitions of the step for phase alignment.4. A method as in claim 1 , wherein a first node of the plurality of radio frequency transmission nodes is designated as Master and the step for phase alignment is performed in a round-robin manner.5. A method as in claim 1 , wherein the step for phase alignment comprises sample reversal claim 1 , phase conjugation claim 1 , and Inter-node carrier phase alignment.6. A method of configuring a plurality of radio ...

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Номер записи: 19
19-10-2017 дата публикации

Node synchronization using time reversal

Номер: US20170302339A1
Автор: Anis Husain, David Smith, Jeremy Rode, Jeremy Ward, Kris Gregorian, Mark Hsu
Принадлежит: Ziva Corp

In examples, Radio Frequency nodes of an array are synchronized using Time-Reversal. A Master node (“Master”) of the array receives and captures a sounding signal emitted by a Slave node (“Slave”) of the array, downconverts it to baseband, Time-Reverses the downconverted signal, upconverts the Time-Reversed signal to the carrier frequency using the Master's clock so that the upconverted signal has phase property of the Master's clock, and transmits the resulting signal to the Slave. The Slave receives the signal from the Master, and adjusts the phase of the Slave's clock so that the phases of the two nodes are aligned. Once phases, frequencies, and time references of the array's nodes are aligned, the array may be used for coherent operation. In examples, the array is used to transmit Time-Reversed signals so that the signals from the array's nodes are spatially and temporally focused on a target.

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Номер записи: 20
12-03-2014 дата публикации

Distributed co-operating nodes using time reversal

Номер: EP2705726A1
Автор: Anis Husain, David Smith, Jeremy Rode, Maha Achour, Mark Hsu
Принадлежит: Ziva Corp

Methods and systems for coherent distributed communication techniques using time reversal are disclosed. In one aspect, cooperating nodes of a cluster can move relative to each other and relative to an intended receiver of the nodes' data transmissions. The nodes are synchronized to a common time reference, and data for transmission from the cluster is distributed to the nodes. The intended receiver sends a sounding signal to the nodes. Each node receives the sounding signal, obtains the channel response between the intended receiver and itself, and time-reverses the channel response. Each node then convolves its time-reversed channel response with the data, to obtain the node's convolved data. Each node waits a predetermined time following the time reference signal, as determined based on the common time reference. At the expiration of the predetermined time period, the nodes simultaneously transmit their convolved data.

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Номер записи: 21
22-05-2018 дата публикации

Distributed co-operating nodes using time reversal

Номер: US09980244B2
Автор: Anis Husain, David Smith, Jeremy Rode, Mark Hsu
Принадлежит: Ziva Corp

Dynamic, untethered array nodes are frequency, phase, and time aligned, and used to focus their transmissions of the same data coherently on a target, using time reversal. Alignment may be achieved separately for the radio frequency (RF) carriers and the data envelopes. Carrier alignment may be by phase conjugation. The data is distributed across the nodes. Data distribution and/or alignment may be performed by a Master node of the array. The nodes capture a sounding signal from the target, in the same time window. Each node converts the captured sounding signal to baseband, for example, using in-phase/quadrature downconversion. Each node stores the baseband samples of the sounding pulse. Each node convolves time-reversed samples of the sounding signal with the data, and upconverts the convolved data to radio frequency. The nodes emit their respective convolved and upconverted data so that the emissions focus coherently at the target.

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Номер записи: 22