A system for processing optical signals comprising a reference optical signal transmission structure configured to receive an optical signal at a first input and to provide the optical signal at a first output to a photodetector. A delay optical signal transmission structure configured to receive the optical signal at a second input and to provide a delayed optical signal at a second output to the photodetector. A signal processor configured to receive a first electric signal corresponding to the optical signal and a second electric signal corresponding to the delayed optical signal and to generate an output as a function of the first electric signal and the second electric signal.

Provided is an in-store dual-mode communication system in which shelves are disposed within a commercial space. A server is coupled to the Internet and/or a wide-area network and is configured to send and receive communications. Also provided are light-based messaging units that are located on and/or attached to such shelves, each: 1) having a light source, 2) receiving a communication from the server, and 3) in response to receipt of such communication, turning the light source on and off so as to broadcast a digital message that was included within such communication, as a binary-encoded digital signal corresponding to on/off states of the light source. A user device: (i) receives, via its light sensor, and then decodes the binary-encoded digital signal from a light-based messaging unit in order to obtain the digital message that corresponds to it; and also (ii) communicates with the server via its wireless interface.

Provided is an in-store dual-mode communication system in which shelves are disposed within a commercial space. A server is coupled to the Internet and/or a wide-area network and is configured to send and receive communications. Also provided are light-based messaging units that are located on and/or attached to such shelves, each: 1) having a light source, 2) receiving a communication from the server, and 3) in response to receipt of such communication, turning the light source on and off so as to broadcast a digital message that was included within such communication, as a binary-encoded digital signal corresponding to on/off states of the light source. A user device: (i) receives, via its light sensor, and then decodes the binary-encoded digital signal from a light-based messaging unit in order to obtain the digital message that corresponds to it; and also (ii) communicates with the server via its wireless interface.

An optical sensor includes at least two optical sensing pixels and at least two different grating elements. These grating elements are disposed above these optical sensing pixels correspondingly.

An optical sensor includes at least two optical sensing pixels and at least two different grating elements. These grating elements are disposed above these optical sensing pixels correspondingly.

Provided are, among other things, systems, methods and techniques for providing remote location-based customer service for in-store customers. One such system includes: (a) a central server; (b) wireless transceivers coupled to the central server at different locations within each of multiple different retail shopping sites; and (c) handheld wireless devices, carried by customers at such retail shopping sites and in wireless communication with such wireless transceivers. Each of the handheld wireless devices is configured with a user interface that allows a customer to designate a user-interface element to request a customer-service session. Upon designation of the user-interface element on one of such handheld wireless devices, the request is forwarded to the central server. The central server establishes a two-way real-time communication link between the handheld wireless device and a customer-service representative.

A method for determining a localization parameter of an object includes generating a plurality of estimates of a first frequency-domain amplitude of a baseband signal from the object, each estimate corresponding one of a plurality of temporal segments of the baseband signal. The method also includes determining the first frequency-domain amplitude as most common value of the plurality of estimates, and determining the localization parameter therefrom. A localization system includes a memory and a microprocessor. The memory stores instructions and is configured to store a baseband signal having a temporal frequency component and a corresponding first frequency-domain amplitude. The microprocessor is adapted to execute the instructions to: (i) generate a plurality of estimates of the first frequency-domain amplitude each corresponding to a respective one of a plurality of temporal segments of the baseband signal, and (ii) determine the first frequency-domain amplitude as the most common value of the estimates.

A detector (110) for determining a position of at least one object (112) is disclosed. The detector (110) comprises: at least one sensor element (118) having a matrix (120) of optical sensors (122), the optical sensors (122) each having a light-sensitive area (124), wherein each optical sensor (122) is configured to generate at least one sensor signal in response to an illumination of the light-sensitive area (124) by at least one light beam (116) propagating from the object (112) to the detector (110); at least one evaluation device (134) configured for evaluating the sensor signals, by a) determining at least one optical sensor (122) having the highest sensor signal and forming at least one center signal; b) evaluating the sensor signals of the optical sensors (122) of the matrix (120) and forming at least one sum signal; c) determining at least one combined signal by combining the center signal and the sum signal; and d) determining at least one longitudinal coordinate z of the object (112) by evaluating the combined signal.

In a method of determining the position of an object, raw image data of the sky is recorded using a celestial imaging unit. The last known position, orientation, date, and time data of the object are obtained, and the position of a celestial body is measured. A latitude and longitude of the object is determined by matching the measured celestial body position to the expected celestial body position based on the input parameters. A system for determining a new position of an object comprises a celestial imaging unit configured to record image data of the sky, a signal processing unit, and a signal processing unit configured to receive and store in memory the image data received from the celestial imaging unit. The signal processing unit filters the image to find the positions of celestial objects in the sky. The signal processing unit is further configured to use roll and pitch from an IMU, and date and time from a clock to determine the object's position (latitude and longitude).

In a method of determining the position of an object, raw image data of the sky is recorded using a celestial imaging unit. The last known position, orientation, date, and time data of the object are obtained, and the position of a celestial body is measured. A latitude and longitude of the object is determined by matching the measured celestial body position to the expected celestial body position based on the input parameters. A system for determining a new position of an object comprises a celestial imaging unit configured to record image data of the sky, a signal processing unit, and a signal processing unit configured to receive and store in memory the image data received from the celestial imaging unit. The signal processing unit filters the image to find the positions of celestial objects in the sky. The signal processing unit is further configured to use roll and pitch from an IMU, and date and time from a clock to determine the object's position (latitude and longitude).