Abstract: A free space optical (FSO) communication node communicates via an FSO link with a remote FSO communication node that moves relative to the FSO node. The FSO node may be highly directional, and transmit (Tx) and receive (Rx) beams of the FSO node may share optical paths (at least in part). Instead of directing a Tx beam along a point ahead angle relative to a Rx beam (which may result in undesirable Rx coupling losses), the Tx beam is directed based on the point ahead angle and a point ahead offset angle. The point ahead offset angle modifies the point ahead angle to reduce Rx coupling losses while keeping Tx pointing losses at least low enough to maintain the FSO link. In some cases, due to the point ahead offset angle, the Tx direction minimizes a sum of the Rx coupling losses and the Tx pointing losses.

Abstract: Methods and systems are described for free space optical communication. An example device may comprise an optical beam separator configured to separate a first optical path into a receiving (Rx) optical path for signals received from free space and a transmitting (Tx) optical path for signals being transmitted into free space. The example device may comprise at least one positioner coupled to one or more of the Rx optical path or the Tx optical path. The example device may comprise a controller configured to control the at least one positioner to adjust one or more of the Rx optical path or the Tx optical path to facilitate communication with a remote communication device via free space.

Abstract: A free space optical (FSO) communication node communicates via an FSO link with a remote FSO communication node that moves relative to the FSO node. The FSO node may be highly directional, and transmit (Tx) and receive (Rx) beams of the FSO node may share optical paths (at least in part). Instead of directing a Tx beam along a point ahead angle relative to a Rx beam (which may result in undesirable Rx coupling losses), the Tx beam is directed based on the point ahead angle and a point ahead offset angle. The point ahead offset angle modifies the point ahead angle to reduce Rx coupling losses while keeping Tx pointing losses at least low enough to maintain the FSO link. In some cases, due to the point ahead offset angle, the Tx direction minimizes a sum of the Rx coupling losses and the Tx pointing losses.

Abstract: A free space optical (FSO) communication node communicates via an FSO link with a remote FSO communication node that moves relative to the FSO node. The FSO node may be highly directional, and transmit (Tx) and receive (Rx) beams of the FSO node may share optical paths (at least in part). Instead of directing a Tx beam along a point ahead angle relative to a Rx beam (which may result in undesirable Rx coupling losses), the Tx beam is directed based on the point ahead angle and a point ahead offset angle. The point ahead offset angle modifies the point ahead angle to reduce Rx coupling losses while keeping Tx pointing losses at least low enough to maintain the FSO link. In some cases, due to the point ahead offset angle, the Tx direction minimizes a sum of the Rx coupling losses and the Tx pointing losses.

Abstract: A positioning system and method includes a transmitter, a receiver, and a controller. The transmitter includes at least one energy source configured to emit an optical or quasi-optical electromagnetic signal as a channel communication. The receiver includes at least one detector element configured to receive the channel communication. The controller is connected to the receiver and configured to estimate a position of the transmitter within a space using a reference map of the space and one or more diffuse components of an impulse response of the channel communication.

Abstract: A free space optical (FSO) communication node communicates via an FSO link with a remote FSO communication node that moves relative to the FSO node. The FSO node may be highly directional, and transmit (Tx) and receive (Rx) beams of the FSO node may share optical paths (at least in part). Instead of directing a Tx beam along a point ahead angle relative to a Rx beam (which may result in undesiable Rx coupling losses), the Tx beam is directed based on the point ahead angle and a point ahead offset angle. The point ahead offset angle modifies the point ahead angle to reduce Rx coupling losses while keeping Tx pointing losses at least low enough to maintain the FSO link. In some cases, due to the point ahead offset angle, the Tx direction minimizes a sum of the Rx coupling losses and the Tx pointing losses.

Abstract: A positioning system and method includes a transmitter, a receiver, and a controller. The transmitter includes at least one energy source configured to emit an optical or quasi-optical electromagnetic signal as a channel communication. The receiver includes at least one detector element configured to receive the channel communication. The controller is connected to the receiver and configured to estimate a position of the transmitter within a space using a reference map of the space and one or more diffuse components of an impulse response of the channel communication.

Abstract: Optical wireless communication systems configured to provide Hadamard coded information are described. In some examples, the system includes a light fixture configured to encode communication information received from an area network as Hadamard coded information, and provide the Hadamard coded information as a first Hadamard coded modulated optical emission from a light emitting diode. An optical wireless communication device can receive and decode the optical emission and provide the decoded information to an electronic device coupled to the optical wireless communication device.

Abstract: Certain configurations of optical wireless communication devices that comprise a plurality of narrow beam width light emitting diodes to provide a wide-angle transmitter are described. The transmitter can be used, for example, in optical wireless communication systems. The transmitter can be designed to select one of the light emitting diodes that points towards the receiver for more reliable information exchange or data transmission. The particular light emitting diode used may change as a position of an end user changes.

Abstract: An expurgated pulse position modulation (EPPM) technique can be used to encode information for wireless transmission. Such an EPPM technique can be compatible with a simple receiver architecture, such as including a shift register and pulse position modulation (PPM) decoder. A multi-level EPPM (MEPPM) approach can increase the available symbols in the modulation constellation and can be used to accommodate multiple users or devices concurrently. Interleaving techniques can be used such as to reduce inter-symbol interference. An optical transmitter and an optical receiver can be used, such as including using energy in a visible range of frequencies. In an example, an optical source such as including one or more light emitting diodes can provide visible light for illumination, and the EPPM technique can include using codewords specified to provide a desired dimming level when such codewords are used to intensity modulate the optical source, without perceptible flicker.

Abstract: An expurgated pulse position modulation (EPPM) technique can be used to encode information for wireless transmission. Such an EPPM technique can be compatible with a simple receiver architecture, such as including a shift register and pulse position modulation (PPM) decoder. A multi-level EPPM (MEPPM) approach can increase the available symbols in the modulation constellation and can be used to accommodate multiple users or devices concurrently. Interleaving techniques can be used such as to reduce inter-symbol interference. An optical transmitter and an optical receiver can be used, such as including using energy in a visible range of frequencies. In an example, an optical source such as including one or more light emitting diodes can provide visible light for illumination, and the EPPM technique can include using codewords specified to provide a desired dimming level when such codewords are used to intensity modulate the optical source, without perceptible flicker.

Abstract: An expurgated pulse position modulation (EPPM) technique can be used to encode information for wireless transmission. Such an EPPM technique can be compatible with a simple receiver architecture, such as including a shift register and pulse position modulation (PPM) decoder. A multi-level EPPM (MEPPM) approach can increase the available symbols in the modulation constellation and can be used to accommodate multiple users or devices concurrently. Interleaving techniques can be used such as to reduce inter-symbol interference. An optical transmitter and an optical receiver can be used, such as including using energy in a visible range of frequencies. In an example, an optical source such as including one or more light emitting diodes can provide visible light for illumination, and the EPPM technique can include using codewords specified to provide a desired dimming level when such codewords are used to intensity modulate the optical source, without perceptible flicker.