Optical signals with different orbital angular momentum (OAM) modes are used to multiplex data directed to different receiver together using time division multiplexing. The OAM based multiplexing may be used in addition to other multiplexing schemes such as time division multiplexing, polarization multiplexing and so on. Capacity of existing optical network infrastructure can be increased significantly using OAM modulation, and data communication can be secured at the same time.

Optical signals with different orbital angular momentum (OAM) modes are used to multiplex data for different receiver together or a light signal. The OAM based multiplexing may be used in addition to other multiplexing schemes such as time division multiplexing, polarization multiplexing and so on. Capacity of existing optical network infrastructure can be increased significantly using OAM modulation, and data communication can be secured at the same time.

A multiplexed optical communication system comprising a carrier optical fiber, a plurality of launching light sources, and a matching plurality of multiplexer/demultiplexers and photodetectors is described and claimed. Optical communication channel separation by Spatial Domain Multiplexing (SDM), Optical Angular Momentum (OAM) multiplexing, and Wavelength Division Multiplexing (WDM) is used in combination to achieve significant increase in optical communication channel bandwidth over the prior art. The launching light sources may be positioned such that the light beams are incident on the receiving end of the carrier optical fiber at desired angles including complementary angles. Crosstalk between optical communication channels is minimal. The communication bandwidth of a TDM system may be increased by an order of magnitude due the layered WDM/SDM/OAM data multiplexing of the invention.

A system for enabling signal penetration into a building includes first circuitry, located on an outside of the building, that receives millimeter wave signals and converting the millimeter wave signals into a format that penetrates into an interior of a building for reception by wireless devices within the building. Second circuitry, located on an inside of the building and communicatively linked with the first circuitry, receives the millimeter wave signals in the format that penetrates into an interior of the building and converts the millimeter wave signals in the format to a second format for transmission to the wireless devices within the building.

A system for providing underwater communication using orbital angular momentum (OAM) includes a transmitter that processes input data to be transmitted using pre-coding information based on current transmission channel conditions to maximize data rate based on channel conditions. A receiver receives a transmitted multiplexed OAM optical signal and analyzes the received signal for channel state information. The channel state information is used to determine a set of pre-coding values that allow the transmitter to pre-code the input data to maximize the data rate based on current channel conditions. The pre-coding values are mapped to a codebook entry which identifies the pre-coding values. The codebook entry is transmitted from the receiver to the transmitter. The transmitter uses the received codebook entry to identify pre-coding values used to process subsequent input data to be transmitted in order to enhance data rate across the transmit channel.

Described herein is a multiplexer/demultiplexer optical device (100) comprising: a first beam-splitter cube (BS1); a second beam-splitter cube (BS2) optically coupled to the first splitter (BS1); a first Porro-prism reflector (PR1), which is optically coupled to the second splitter (BS2); and a second Porro-prism reflector (PR2), which is optically coupled to the second splitter (BS2) and is structured for introducing into optical beams that traverse it a phase delay depending upon an orbital angular momentum of the optical beams and upon an orientation of the second reflector. The device is a Michelson interferometer structured for obtaining constructive/destructive interference such as to multiplex/demultiplex on/from corresponding input/output ports, on the basis of values of orbital angular momentum, an optical beam comprising a plurality of concentric optical beams with cylindrical symmetry having different values of orbital angular momentum.

A system for enabling signal penetration into a building includes a transceiver located on an exterior of the building for receiving signals at a first frequency transmitted from a source outside of the building. An optical bridge receives the signals at the first frequency that experiences losses when penetrating an exterior surface of the building, converts the received signals at the first frequency into a first format that overcome losses caused by penetrating an exterior surface of the building and transmits the signals through the exterior surface of the building. A WiFi transceiver located on the interior of the building and connected to the optical bridge converts between the signals in the first format and WiFi signals and for transmitting the WiFi signals to the interior of the building and receiving the WiFi signals from the interior of the building.

A communications system includes transmitter circuit for receiving a plurality of input data streams and applying a different orthogonal function to each of the plurality of input data streams. The transmitter circuit processes each of the plurality of input data streams having the different orthogonal function applied thereto to spatially locate a first group of the plurality of input data streams having the different orthogonal function applied thereto onto a first carrier signal and to spatially locate a second group of the plurality of input data streams having the different orthogonal function applied thereto onto a second carrier signal. The transmitter circuit temporally locates the first carrier signal and the second carrier signal onto a third carrier signal and transmits the third carrier signal over a communications link. A receiver circuit receives the third carrier signal over the communications link and separates in time the third carrier signal into the first carrier signal and the second carrier signal. The receiver then separates the plurality of input data streams having the different orthogonal function applied thereto into the plurality of input data streams each having the different orthogonal function applied thereto. Finally, the receiver removes the orthogonal function from each of the plurality of input data streams and outputs the plurality of input data streams.

An apparatus for steering a beam includes a beamforming device for receiving electromagnetic (EM) waves and outputting, based on the received EM waves, EM waves having one or more orbital angular momentum (OAM) modes. The apparatus further includes phase shifters for modulating, based on one or more steering patterns, the EM waves outputted by the beamforming device. The apparatus further includes a radial waveguide divided into multiple waveguide sectors. Each waveguide sector has an input connected to one of the phase shifters, and one or more slot line antennas for transmitting the EM waves modulated by the phase shifter connected to the input, wherein the one or more slot line antennas are oriented differently to the one or more slot line antennas of each other waveguide sector.

Aspects of the disclosure relate to wireless communication including mode division multiplexing of data and reference signals using different orbital angular momentum (OAM) modes. An OAM transmitter may transmit a reference signal (RS) configuration information to an OAM receiver that indicates radio resources for a plurality of OAM modes. The OAM transmitter may further transmit data on a first OAM mode of the plurality of OAM modes using first radio resources of the radio resources indicated by the RS configuration information. The OAM transmitter may further transmit a reference signal on a second OAM mode of the plurality of OAM modes using the first radio resources of the radio resources indicated by the RS configuration information. The OAM receiver may receive the data on the first OAM mode and the reference signal on the second OAM mode. Other aspects, embodiments, and features are also claimed and described.