Abstract: A multipath signal is received comprising a PRN code used to determine time of arrival of a signal of interest. A correlated received signal is generated by filtering and correlating of the received multipath signal. Short-term accumulation segments are generated based on the correlated received signal. Doppler hypotheses are applied to each of the short-term accumulation segments to generate phase-corrected short-term accumulated blocks. The phase-corrected short-term accumulated blocks are accumulated to generate long-term accumulated blocks for each Doppler hypothesis. Alternatively, cross-correlation samples are generated for signal samples for each short-term accumulation segment, and the cross-correlation samples are accumulated to generate a long-term accumulated block.

Abstract: A method involves receiving cellular signals from multiple base stations at a signal monitoring unit. A first long-duration signal accumulation of the cellular signals is performed. First cells associated with the base stations are identified using the first accumulated signal. First cellular network parameters associated with the first identified cells are stored. A signal contribution of the first identified cells is removed from the first cellular signals. A second long-duration signal accumulation of the first cellular signals is performed. Second cells associated with the plurality of base stations are identified using the second accumulated signal, the second identified cells having been obscured by the first cells before the signal contribution of the first cells was removed from the first cellular signals. Second cellular network parameters associated with the second identified cells are stored. The first and second cellular network parameters of the first and second identified cells are then tracked.

Abstract: A method for location determination in a wireless communications system solves a minimization problem using estimated time-of-arrivals (TOAs) of reference signals [108, 110, 112] received by a receiving node [100] from transmitting nodes [102, 104, 106] and predetermined locations of the transmitting nodes, to produce an estimate of unknown receiving node location and/or an estimate of an unknown time of transmission (t) of the reference signals. The minimization problem is defined in terms of a theoretical system model of time-of-arrivals (TOAs), linearized globally as a function of the unknown receiving node location, the unknown time of transmission (t) of the reference signals, and an additional intermediate variable (u) that defines a non-linear quadratic constraint over position coordinates of the unknown receiving node location and the time of transmission (t) of the reference signals, wherein the minimization problem optimizes the additional intermediate variable (u).

Abstract: A method involves determining estimated positions for multiple cells within a region using cellular signals received by a receiver at multiple known receiver positions. Multiple first cell groups are determined using the multiple cells. Respective estimated positions are determined for each cell group of the first cell groups. Each cell group of the first cell groups is validated using the respective estimated position of each cell group and the known receiver positions. Multiple second cell groups are generated based on the cell group validation. An estimated position of each cell group of the second cell groups is used as an estimated position of a respective base station within the region, and a base station almanac is updated using a respective estimated position for each of the base stations.

Abstract: A wireless communications method synchronously transmits periodically from synchronized base stations of a single frequency network a common downlink synchronization signal (IoT-PSS) that underlays broadcasted signals transmitted in licensed bands of a cellular system, and a system frame number least significant bits signal (IoT-SFN-LSB) indicating timing of transmission of a system information block signal (IoT-SIB) that contains information related to downlink and uplink transmission schedules and allocations. An IoT device receives the common downlink synchronization signal and transmits uplink data only after receiving the synchronization signal and system frame number signal.

Abstract: A method involves receiving a ranging signal. A filtered ranging signal is generated using the ranging signal and used to determine a first estimated time of arrival (TOA) of the ranging signal. Multiple first time delay hypotheses of an actual TOA of the ranging signal are determined. A correlator vector is generated using the filtered ranging signal, a filtered local replica of the ranging signal, and the first time delay hypotheses. Multiple code phase discriminator vectors corresponding to second time delay hypotheses are generated, each code phase discriminator vector being based on estimated signal processing, filtering, and noise characteristics of the ranging signal for a respective second time delay hypothesis. A second estimated TOA of the ranging signal is generated using the correlator vector and the code phase discriminator vectors.

Abstract: A wireless communications method synchronously transmits periodically from synchronized base stations of a single frequency network a common downlink synchronization signal (IoT-PSS) that underlays broadcasted signals transmitted in licensed bands of a cellular system, and a system frame number least significant bits signal (IoT-SFN-LSB) indicating timing of transmission of a system information block signal (IoT-SIB) that contains information related to downlink and uplink transmission schedules and allocations. An IoT device receives the common downlink synchronization signal and transmits uplink data only after receiving the synchronization signal and system frame number signal.

Abstract: A method for estimating a time of arrival of a signal transmitted over a wireless channel, includes receiving the signal by a receiving device to produce a received signal; filtering by a filter either the received signal or a code sequence, wherein the filter is designed to produce a correlation output that is near causal; correlating the received signal with the code sequence to create the correlation output that is near causal; wherein near causal means that early side lobes and an early part of a main lobe of the correlation output are sufficiently suppressed in order to substantially reduce an impact of delayed multipath onto a first path component in the received signal, wherein the first path is in an operating region; identifying in the correlation output, an observation window associated with a main lobe in the correlation output; processing the observation window to determine a time of arrival of the first path component in the received signal.

Abstract: A method for estimating a time of arrival of a signal transmitted over a wireless channel, includes receiving the signal by a receiving device; correlating the received signal with a filtered code sequence to create a correlation output, identifying in the correlation output, an observation window associated with a main lobe in the correlation output; and processing the observation window to determine a time of arrival of a first path component in the received signal. The filtered code sequence is formed by incorporating a time of arrival matched filter (TOA-MF) inside predetermined shaped code sequence. The TOA-MF is matched to the predetermined shaped code sequence and is based upon a power delay profile of the wireless channel. The predetermined shaped code sequence is a convolution of a predetermined shaping sequence and a predetermined code sequence.

Abstract: A method for location determination in a wireless communications system solves a minimization problem using estimated time-of-arrivals (TOAs) of reference signals [108, 110, 112] received by a receiving node [100] from transmitting nodes [102, 104, 106] and predetermined locations of the transmitting nodes, to produce an estimate of unknown receiving node location and/or an estimate of an unknown time of transmission (t) of the reference signals. The minimization problem is defined in terms of a theoretical system model of time-of-arrivals (TOAs), linearized globally as a function of the unknown receiving node location, the unknown time of transmission (t) of the reference signals, and an additional intermediate variable (u) that defines a non-linear quadratic constraint over position coordinates of the unknown receiving node location and the time of transmission (t) of the reference signals, wherein the minimization problem optimizes the additional intermediate variable (u).

Abstract: A technique is provided for estimating time of arrival of a signal transmitted as a pulse and received as a sum of pulses. The received signal is filtered with a novel filter that lowers the early side lobes of the received signal to noise level. A first energy rise point is identified at a point of the main lobe of the filtered received signal, at which the energy is higher than the noise by a predetermined level. Starting from the identification of the first energy rise points, the time of arrival is estimated via curve matching, in which the shape of the filtered received signal is matched to the shape of a reference curve composed by a sum of one or more reference curves that are shifted both in time and in energy. The reference curves are found by applying to the transmitted signal the same filter applied to the received signal.

Abstract: A method for estimating a time of arrival of a signal transmitted over a wireless channel, includes receiving the signal by a receiving device; correlating the received signal with a filtered code sequence to create a correlation output, identifying in the correlation output, an observation window associated with a main lobe in the correlation output; and processing the observation window to determine a time of arrival of a first path component in the received signal. The filtered code sequence is formed by incorporating a time of arrival matched filter (TOA-MF) inside predetermined shaped code sequence. The TOA-MF is matched to the predetermined shaped code sequence and is based upon a power delay profile of the wireless channel. The computed shaped code sequence is a convolution of a predetermined shaping sequence and a predetermined code sequence.

Abstract: A time of arrival of a signal received by a receiving device over a wireless channel is estimated by identifying by the receiving device a location in the time domain of a first path component in a waveform of the received signal, which includes applying a filter to the waveform; identifying in the waveform an observation window associated with an energy rise in the waveform; correlating the identified observation window in the waveform with correlator sequences, and determining a time of arrival offset of the first path component from results of correlating the observation window with the correlator sequences. The properties of the correlator sequences depend on properties of the filter such that the correlator sequences account for the filtering of the waveform during the correlating, the correlator sequences reduce the effect of colored noise after hypothetical first path components; and the correlator sequences correspond to different time shifts of a hypothetical first path component.

Abstract: A technique is provided for estimating time of arrival of a signal transmitted as a pulse and received as a sum of pulses. The received signal is filtered with a novel filter that lowers the early side lobes of the received signal to noise level. A first energy rise point is identified at a point of the main lobe of the filtered received signal, at which the energy is higher than the noise by a predetermined level. Starting from the identification of the first energy rise points, the time of arrival is estimated via curve matching, in which the shape of the filtered received signal is matched to the shape of a reference curve composed by a sum of one or more reference curves that are shifted both in time and in energy. The reference curves are found by applying to the transmitted signal the same filter applied to the received signal.

Abstract: A technique is provided for estimating time of arrival of a signal transmitted as a pulse and received as a sum of pulses. The received signal is filtered with a novel filter that lowers the early side lobes of the received signal to noise level. A first energy rise point is identified at a point of the main lobe of the filtered received signal, at which the energy is higher than the noise by a predetermined level. Starting from the identification of the first energy rise points, the time of arrival is estimated via curve matching, in which the shape of the filtered received signal is matched to the shape of a reference curve composed by a sum of one or more reference curves that are shifted both in time and in energy. The reference curves are found by applying to the transmitted signal the same filter applied to the received signal.

Abstract: Positioning determination of a communication device in a wireless communication network is supported by a positioning device receiving [230] tight synchronization signals from a master positioning cell; determining [232] therefrom a plurality of time differences between their actual and theoretical times of arrival; synchronizing [234] a positioning cell clock based on the received tight synchronization signals adjusted by the time differences; and emitting [236] to the communication device a positioning signal at a time determined by the synchronization. The positioning signal includes an identifier of the positioning cell, and it is transmitted so as not to interfere with positioning pilot signals transmitted by the wireless communication network. The positioning device may alternatively receive synchronization signals from another positioning cell instead of a master positioning cell.

Abstract: Positioning determination of a communication device in a wireless communication network is supported by a positioning device receiving [230] tight synchronization signals from a master positioning cell; determining [232] therefrom a plurality of time differences between their actual and theoretical times of arrival; synchronizing [234] a positioning cell clock based on the received tight synchronization signals adjusted by the time differences; and emitting [236] to the communication device a positioning signal at a time determined by the synchronization. The positioning signal includes an identifier of the positioning cell, and it is transmitted so as not to interfere with positioning pilot signals transmitted by the wireless communication network. The positioning device may alternatively receive synchronization signals from another positioning cell instead of a master positioning cell.

Abstract: Positioning determination of a communication device in a wireless communication network is supported by a positioning device receiving [230] tight synchronization signals from a master positioning cell; determining [232] therefrom a plurality of time differences between their actual and theoretical times of arrival; synchronizing [234] a positioning cell clock based on the received tight synchronization signals adjusted by the time differences; and emitting [236] to the communication device a positioning signal at a time determined by the synchronization. The positioning signal includes an identifier of the positioning cell, and it is transmitted so as not to interfere with positioning pilot signals transmitted by the wireless communication network. The positioning device may alternatively receive synchronization signals from another positioning cell instead of a master positioning cell.

Abstract: A technique is provided for estimating time of arrival of a signal transmitted as a pulse and received as a sum of pulses. The received signal is filtered with a novel filter that lowers the early side lobes of the received signal to noise level. A first energy rise point is identified at a point of the main lobe of the filtered received signal, at which the energy is higher than the noise by a predetermined level. Starting from the identification of the first energy rise points, the time of arrival is estimated via curve matching, in which the shape of the filtered received signal is matched to the shape of a reference curve composed by a sum of one or more reference curves that are shifted both in time and in energy. The reference curves are found by applying to the transmitted signal the same filter applied to the received signal.

Abstract: Positioning determination of a communication device in a wireless communication network is supported by a positioning device receiving [230] tight synchronization signals from a master positioning cell; determining [232] therefrom a plurality of time differences between their actual and theoretical times of arrival; synchronizing [234] a positioning cell clock based on the received tight synchronization signals adjusted by the time differences; and emitting [236] to the communication device a positioning signal at a time determined by the synchronization. The positioning signal includes an identifier of the positioning cell, and it is transmitted so as not to interfere with positioning pilot signals transmitted by the wireless communication network. The positioning device may alternatively receive synchronization signals from another positioning cell instead of a master positioning cell.