An autonomous system with no Customer Network Investment is described, wherein the system is configurable to operate on in a band in addition to the LTE band. Such system allows the definition of hybrid operations to accommodate the positioning reference signals (PRS) of LTE and already existing reference signals. The system can operate with PRS, with other reference signals such as cell-specific reference signals (CRS), or with both signal types. As such, the system provides the advantage of allowing network operator(s) to dynamically choose between modes of operation depending on circumstances, such as network throughput and compatibility.

An autonomous system with no Customer Network Investment is described, wherein the system is configurable to operate on in a band in addition to the LTE band. Such system allows the definition of hybrid operations to accommodate the positioning reference signals (PRS) of LTE and already existing reference signals. The system can operate with PRS, with other reference signals such as cell-specific reference signals (CRS), or with both signal types. As such, the system provides the advantage of allowing network operator(s) to dynamically choose between modes of operation depending on circumstances, such as network throughput and compatibility.

In receiving radio waves from a transmitter by an array antenna, and estimating an arrival direction of a direct wave, delay times of the arriving waves are estimated (13) by means of a super-resolution process based on transmission channel estimation results, an arriving wave component corresponding to the delay time having been determined to be equal to or longer than a threshold value is removed (15) from the transmission channel estimation results, arriving wave components after the removal are separated from each other to extract direct wave components (17), and an arrival angle is estimated (19). The arrival direction of the direct wave can be accurately estimated in an environment where delayed waves of short delay times are present. Also, the amount of calculation is small even when the super-resolution process is performed.

An apparatus for estimating a direction of arrival includes an antenna, a beamforming network, and an evaluator. The antenna is configured to receive signals, is circularly polarized, and includes a plurality of different radiation patterns. The beamforming network is configured to provide based on signals received by the antenna decomposed signals that are received by associated radiation patterns of the plurality of radiation patterns. The evaluator is configured to estimate the direction of arrival based on the decomposed signals and based on information describing signal receiving characteristics of the antenna. The invention also refers to a corresponding method.

Disclosed is a position estimation method for estimating a position of an interference signal source and a position estimation system for performing the method. The position estimation method may implement an indoor delay-space analysis structure by transmitting and receiving a known signal and a virtual array structure-based direction finding algorithm in an indoor environment in which a plurality of reflected waves is present and may increase an estimation probability for the position of the interference signal source.

Disclosed is a position estimation method for estimating a position of an interference signal source and a position estimation system for performing the method. The position estimation method may implement an indoor delay-space analysis structure by transmitting and receiving a known signal and a virtual array structure-based direction finding algorithm in an indoor environment in which a plurality of reflected waves is present and may increase an estimation probability for the position of the interference signal source.

A radar apparatus includes: a transmitting portion including transmitter elements that emits a transmitting signal as a radar wave toward an object; a receiving portion including receiver elements receiving a reflection signal; and an estimation portion. The estimation portion generates a virtual receiving array including virtual receiver elements. The estimation portion divides the virtual receiving array into identical sub-arrays. The estimation portion generates covariance matrix data for each of the sub-arrays. The estimation portion averages the covariance matrix data for each of the sub-arrays to decorrelate a direct reflection signal from the object and multipath reflection signal among the reflection signal and spatially smooths the reflection signal. The estimation portion resolves the direct reflection signal from the object and the multipath reflection signal. The estimation portion determines the direction of the object.

A method of combined direction finding (DF) and fine timing measurement (FTM) positioning in a wireless location area network (WLAN) is proposed. A multiple antenna IEEE 802.11 transmitting device (AP) can transmit signal preamble containing multiple Long Training Field (LTF) symbols in a radio frame from multiple antennas, which allows a receiving device (STA) to resolve multiple DF sounding signals transmitted from the multiple antennas and thereby estimating angle of departure (AoD). On the other hand, the AP can estimate angle of arrival (AoA) from radio signals transmitted from the STA. When the radial resolution error of AoD or AoA positioning increases, DF positioning and fine-timing measurement (FTM) ranging can be jointly applied to reduce the radial resolution error and extends the AoD/AoA service area with positing accuracy.

A method of combined direction finding (DF) and fine timing measurement (FTM) positioning in a wireless location area network (WLAN) is proposed. A multiple antenna IEEE 802.11 transmitting device (AP) can transmit signal preamble containing multiple Long Training Field (LTF) symbols in a radio frame from multiple antennas, which allows a receiving device (STA) to resolve multiple DF sounding signals transmitted from the multiple antennas and thereby estimating angle of departure (AoD). On the other hand, the AP can estimate angle of arrival (AoA) from radio signals transmitted from the STA. When the radial resolution error of AoD or AoA positioning increases, DF positioning and fine-timing measurement (FTM) ranging can be jointly applied to reduce the radial resolution error and extends the AoD/AoA service area with positing accuracy.

A system and method for rank estimation of electromagnetic emitters is provided. One aspect of the disclosure provides creating a graph of angles of arrival (AoAs) versus range and using a polynomial curve fit against the graph to determine a rank estimation of electromagnetic emitters. Another aspect of the disclosure provides using a search over parameters of the multiple polynomial curve fits, for each hypothesized rank, to optimize the rank estimation results. This search may be a greedy search to improve speed of convergence. Another aspect of the disclosure provides a metric score to select the highest probability rank (number of emitters) based on the agreement between the multiple polynomial curve fits and residual AoA errors.