Distributed-input OFDM angle-of-arrival scheme for location determination
First Claim
1. A method comprising:
- at a particular first wireless device having a plurality of antennas and that is part of a group of a plurality of first wireless devices at respective known locations, generating a location packet to be transmitted to a second wireless device, wherein the location packet is one of a plurality of location packets enabling a second wireless device to determine a location of the second wireless device by performing angle of arrival location determination with respect to the respective known locations of the plurality of first wireless devices;
determining a particular subset of subcarriers among a set of subcarriers available for use in transmitting the location packet, the particular subset of subcarriers associated with the particular first wireless device;
transmitting the location packet to the second wireless device across the particular subset of subcarriers using the plurality of antennas of the particular first wireless device, wherein the location packet is transmitted simultaneously with the plurality of location packets transmitted by a corresponding one or more of other first wireless devices in the group,wherein the plurality of location packets are simultaneously transmitted within a duration of a single location packet by the plurality of first wireless devices in the group to the second wireless device using respective different subsets of subcarriers to enable the second wireless device to perform angle of arrival location determination with respect to the respective known locations of the plurality of first wireless devices in the group.
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Accused Products
Abstract
A particular first wireless device having a plurality of antennas and that is part of a group of a plurality of first wireless devices, transmits to a second wireless device (whose location is to be determined) a packet across the plurality of antennas of the particular first wireless device simultaneously with a plurality of packets transmitted by a corresponding one of other first wireless devices in the group. The packet transmitted by the particular first wireless device uses a subset of a set of subcarriers available for use in the packet such that substantially the entire set of subcarriers are used in the aggregate across the plurality of packets simultaneously transmitted by the plurality of first wireless devices in the group to the second wireless device. The simultaneous reception of the plurality of packets at the second wireless device enables the second wireless device to determine its location.
60 Citations
20 Claims
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1. A method comprising:
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at a particular first wireless device having a plurality of antennas and that is part of a group of a plurality of first wireless devices at respective known locations, generating a location packet to be transmitted to a second wireless device, wherein the location packet is one of a plurality of location packets enabling a second wireless device to determine a location of the second wireless device by performing angle of arrival location determination with respect to the respective known locations of the plurality of first wireless devices; determining a particular subset of subcarriers among a set of subcarriers available for use in transmitting the location packet, the particular subset of subcarriers associated with the particular first wireless device; transmitting the location packet to the second wireless device across the particular subset of subcarriers using the plurality of antennas of the particular first wireless device, wherein the location packet is transmitted simultaneously with the plurality of location packets transmitted by a corresponding one or more of other first wireless devices in the group, wherein the plurality of location packets are simultaneously transmitted within a duration of a single location packet by the plurality of first wireless devices in the group to the second wireless device using respective different subsets of subcarriers to enable the second wireless device to perform angle of arrival location determination with respect to the respective known locations of the plurality of first wireless devices in the group. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus comprising:
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a plurality of antennas; a transmitter unit configured to generate a plurality of individual transmit signals, each for a corresponding one of the antennas; a receiver unit configured to detect signals received at one or more of the plurality of antennas; a modem configured to modulate signals for transmission by the transmitter unit and to demodulate one or more signals obtained by the receiver unit; a control unit coupled to the modem, the control unit configured to; generate a location packet for transmission by the transmitter unit across the plurality of antennas, the location packet being one of a plurality of location packets simultaneously transmitted by a particular first wireless device among a plurality of first wireless devices in a group, each of the plurality of first wireless devices associated with respective known locations, wherein the plurality of location packets enable a second wireless device to determine a location of the second wireless device by performing angle of arrival location determination with respect to the respective known locations of the plurality of first wireless devices; determine a particular subset of subcarriers among a set of subcarriers available for use in transmitting the location packet and cause the transmitter unit to transmit the location packet to the second wireless device such that the plurality of location packets are simultaneously transmitted within a duration of a single packet by the plurality of first wireless devices in the group to the second wireless device using respective different subsets of subcarriers to enable the second wireless device to perform angle of arrival location determination with respect to the respective known locations of the plurality of first wireless devices in the group. - View Dependent Claims (10, 11, 12, 13, 14)
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15. A method comprising:
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receiving from one of a plurality of first wireless devices at a second wireless device a message indicating that the plurality of first wireless devices at respective known locations are prepared to simultaneously transmit a plurality of location packets to the second wireless device, each location packet being transmitted from a plurality of antennas of respective ones of the first wireless devices, the message containing subcarrier mapping information indicating a respective subset of a set of subcarriers that each of the plurality of first wireless devices is to use in transmitting the respective location packets to the second wireless device; and receiving the plurality of location packets simultaneously transmitted by the plurality of first wireless devices; generating channel state information for reception of the plurality of location packets at the second wireless device and mapping the channel state information to respective ones of the plurality of first wireless devices; computing an angle-of-arrival estimate for each location packet received from each of the respective first wireless devices based on the channel state information and the subcarrier mapping information; and computing a location of the second wireless device based on the angle-of-arrival estimates for the plurality of first wireless devices and the respective known locations of the plurality of first wireless devices. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification