Distributed co-operating nodes using time reversal

摘要

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.

主权项

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 following 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, the time-reversed signal corresponding to said each node being such that when all nodes of the plurality of nodes synchronously transmit respective time-reversed signals, the time-reversed signals transmitted by all nodes of the plurality of nodes combine spatially and temporally to focus on a subject, the step of obtaining comprising steps of receiving at said each node one or more waveforms resulting from a sounding signal, and time-reversing at said each node the one or more waveforms resulting from the sounding signal; sending the trigger signal from the trigger node of the plurality of nodes; and transmitting the time-reversed signals from all nodes of the plurality of nodes, one of the time-reversed signals per corresponding node, so that a combination of the plurality of time-reversed signals is spatially and temporally focused on the subject, the step of transmitting being performed in response to expiration of the predetermined synchronization period following the step of sending the trigger signal; wherein the nodes of the plurality of nodes art untethered ad hoc nodes movable relative to each other, and each node of the plurality of nodes has a different physical clock.