Abstract:
A communications system and method for exchanging spectrum usage information through a drop box (100) includes one or more central stations (101) that defines a region of operation. A central drop box (102) is associated with the central station (101) for providing a database of spectrum usage information. Stations (103, 105, 107) using the communications system may submit information regarding spectrum usage to the central drop box (102) that affects the region of operation (109, 115) for providing the most efficient and non-interfering uses of the frequency spectrum.
Abstract:
A communications system and method for exchanging spectrum usage information through a drop box (100) includes one or more central stations (101) that defines a region of operation. A central drop box (102) is associated with the central station (101) for providing a database of spectrum usage information. Stations (103, 105, 107) using the communications system may submit information regarding spectrum usage to the central drop box (102) that affects the region of operation (109, 115) for providing the most efficient and non-interfering uses of the frequency spectrum.
Abstract:
The present invention provides a method for computing the position of a mobile device ( 200,405 ) operating in a wireless network ( 100 ). The system includes a receiver, adapted to receive respective signals from each of at least four reference devices ( 410,415,420,425 ) at the mobile device ( 405 ), each respective signal including information representing a Time of Flight between the mobile device ( 405 ) and the associated fixed reference device. The system includes a processor ( 215 ), to estimate the location of the mobile device ( 200,405 ) by computing at least three Apollonius circles ( 500,600,700 ) between the mobile device ( 405 ) and each of the at least three different pairs of fixed reference devices, wherein the computed Apollonius circles are indicative of the distance between the mobile device ( 405 ) and each of the associated fixed reference devices of each pair; and calculating the location of the mobile device ( 405 ) as the intersection of the computed Apollonius circles.
Abstract:
The present invention provides a method for computing the position of a mobile device ( 200,405 ) operating in a wireless network ( 100 ). The system includes a receiver, adapted to receive respective signals from each of at least four reference devices ( 410,415,420,425 ) at the mobile device ( 405 ), each respective signal including information representing a Time of Flight between the mobile device ( 405 ) and the associated fixed reference device. The system includes a processor ( 215 ), to estimate the location of the mobile device ( 200,405 ) by computing at least three Apollonius circles ( 500,600,700 ) between the mobile device ( 405 ) and each of the at least three different pairs of fixed reference devices, wherein the computed Apollonius circles are indicative of the distance between the mobile device ( 405 ) and each of the associated fixed reference devices of each pair; and calculating the location of the mobile device ( 405 ) as the intersection of the computed Apollonius circles.
Abstract:
A method for measuring the Time Of Arrival of signals in a communications network is provided. A transmitter emits a beacon that is a digital message of known content, followed by timing information. The message is preceded by a pseudo-random binary phase-shift keying (BPSK) modulated sequence that allows the receiver to synchronize on the received signal using the autocorrelation method. During the synchronization process, are computed the approximated Time Of Arrival (TOA) and approximated frequency difference between the local oscillator and the received signal. The content of the beacon message is then used for correcting the approximated TOA and the frequency differences, providing results of very high precision of TOA. The timing information that follows the beacon is used for network clock synchronization and for computing the distances between network nodes.
Abstract:
The present invention provides a method for computing the position of a mobile device (200,405) operating in a wireless network (100). The system includes a receiver, adapted to receive respective signals from each of at least four reference devices (410,415,420,425) at the mobile device (405), each respective signal including information representing a Time of Flight between the mobile device (405) and the associated fixed reference device. The system includes a processor (215), to estimate the location of the mobile device (200,405) by computing at least three Apollonius circles (500,600,700) between the mobile device (405) and each of the at least three different pairs of fixed reference devices, wherein the computed Apollonius circles are indicative of the distance between the mobile device (405) and each of the associated fixed reference devices of each pair; and calculating the location of the mobile device (405) as the intersection of the computed Apollonius circles.
Abstract:
A method for measuring the time of arrival of radio signals within a network comprises receiving the received signals including at least a first pseudorandom code and a second pseudorandom code from at least one other node; identifying a frequency difference between the node and the other node using a phase difference between each of a maximum value of a cross-correlation provided by the first pseudorandom code and the second pseudorandom code; applying the frequency difference to the reception of the received signal; and calculating the time of arrival of the received signal comprising a time, measured with a local clock, when the cross-correlation has achieved the maximum value.
Abstract:
A method provides for identifying short radar signals in presence of interfering signals from various sources applicable to U-NII devices. The method includes collecting a set of information about received interfering signals until the End-Of-Burst (EOB) condition is identified. When the EOB is identified, the set information about the received train of interfering signals is processed. The algorithm selects the time interval between two pulses as a possible Pulse Repetition Interval (PRI) and checks if the same time interval or a multiple of it can be found between other pulses in the collected set, with some small acceptable error. Pulses matching the criteria are considered as potential radar pulses. When at least one pulse has been identified as a potential radar pulse for a number of times larger than a predefined limit, it is concluded that that pulse has been generated by a radar installation.
Abstract:
A wireless device for determining distances between other wireless communications devices in a wireless communication network The wireless device receives an incoming message signal from at least one other wireless device in the network The message signal includes a fame of arrival of a ranging signal previously transmitted by the wireless device Responsive to receiving the message signal, the wireless device receives one or more incoming ranging signals from the other wireless device Each ranging signal is received in a frequency range that is substantially less than the frequency range in which the messaging signal was received
Abstract:
A method for measuring the Time Of Arrival of signals in a communications network is provided. A transmitter emits a beacon that is a digital message of known content, followed by timing information. The message is preceded by a pseudo-random binary phase-shift keying (BPSK) modulated sequence that allows the receiver to synchronize on the received signal using the autocorrelation method. During the synchronization process, are computed the approximated Time Of Arrival (TOA) and approximated frequency difference between the local oscillator and the received signal. The content of the beacon message is then used for correcting the approximated TOA and the frequency differences, providing results of very high precision of TOA. The timing information that follows the beacon is used for network clock synchronization and for computing the distances between network nodes.