Abstract: A method and system for enabling the determination of a position of a receiver within a space includes transmitting a beacon signal from each of a plurality of beacon devices located at different locations within the space. The beacon signal transmitted from each beacon device has a unique information component and may have a unique frequency pattern of multiple frequencies. Each beacon signal can be distinguishable from the beacon signals transmitted from any other of the beacon devices based on the combination of its unique information component and its unique frequency pattern. The beacon signals are received at a receiver. At the receiver, for each beacon signal of a working subset, time-delay information of the received beacon signal is determined and multilateration is applied to determine the position of the receiver based on the location of each beacon device of the working subset.

Abstract: A method and system for enabling the determination of a position of a receiver within a space includes transmitting a beacon signal from each of a plurality of beacon devices located at different locations within the space. The beacon signal transmitted from each beacon device has a unique information component and may have a unique frequency pattern of multiple frequencies. Each beacon signal can be distinguishable from the beacon signals transmitted from any other of the beacon devices based on the combination of its unique information component and its unique frequency pattern. The beacon signals are received at a receiver. At the receiver, for each beacon signal of a working subset, time-delay information of the received beacon signal is determined and multilateration is applied to determine the position of the receiver based on the location of each beacon device of the working subset.

Abstract: A method of determining of a true time of arrival of an energy pulse in a positioning system using arrivals times of such pulses at a device after emission of the pulses from respective transmitters. A sampled signal is cross-correlated with the expected form of the energy pulse from the transmitter, and a highest peak in the correlated signal is located and selected to represent a possible time of arrival of the energy pulse. A sequentially preceding peak in the correlated signal is then selected has its magnitude compared with a threshold. This step is repeated until the magnitude of the currently selected peak is less than the threshold, at which point the last-selected peak whose magnitude exceeded the threshold marks the true time of arrival. This process avoids false time of arrival readings caused by reflected pulses.