A system for enabling signal penetration into a building comprising a receiver located on an outside of the building for receiving millimeter wave signals. At least one frequency downconverter for downconverts the received millimeter wave signals to a frequency level that overcomes losses occurring when the millimeter wave signals are transmitted from the outside the building to an interior of the building. Transceiver circuitry transmits the downconverted millimeter wave signals from the outside the building to the interior of the building. At least one frequency upconverter upconverts the received downconverted millimeter wave signals from the frequency level that overcomes losses occurring when the millimeter wave signals are transmitted from the outside the building to the interior of the building. A second transceiver transmits the upconverted millimeter wave signal in a second format to wireless devices within the building.

A system for enabling signal penetration into a building includes first circuitry, located on an outside of the building, for receiving signals at a first frequency that experiences losses when penetrating into an interior of the building and converting the received signals at the first frequency into a first format that overcome the losses caused by penetrating into the interior of the building over a wireless communications link. The first circuitry further includes a first transceiver, implementing a first transmission chipset for RF transmissions in the first format that counteracts losses occurring when penetrating into the interior of the building, for receiving the signals at the first frequency and converting the received signals at the first frequency into the first format that overcomes the losses caused by penetrating into the interior of the building. Second circuitry, located on the interior of the building is communicatively linked with the first circuitry for receiving and transmitting the converted received signals in the first format. The second circuitry further includes a second transceiver, implementing the first transmission chipset, for receiving and transmitting the converted signals in the first format from/to the first transceiver on the exterior of the building.

Provided are a technique for providing focused Bessel beams having orbital angular momentum (OAM) to a plane to solve a problem of the related art in which Laguerre-Gaussian (LG) beams having OAM and used for multiplexing of a microwave transmission system are dispersed, and an electromagnetic wave generation apparatus and method for implementing the technique.

Systems and methods for orbital angular momentum (OAM)-based multidimensional signaling with multiple-input-multiple-output (MIMO). The wireless communication is achieved using a transmitter including a plurality of orthogonal pulse shapers of a multidimensional modulator, the plurality of orthogonal pulse shapers generating a multidimensional modulated signal by imposing one or more data sequences on corresponding mutually orthogonal filter impulse responses derived from multiple orthogonal basis functions including Slepian sequences. An OAM antenna array including OAM antenna elements is used such that each of the OAM antenna elements includes an azimuthal phase shifter for shifting an azimuthal phase term of a wavefront generated by an antenna element such that the OAM antenna elements impose the multidimensional modulated signal on pre-determined OAM modes of a carrier signal corresponding to the azimuthal phase term.

Systems and methods for quantum key distribution using orbital angular momentum (OAM)-modes-enabled secure multidimensional coded modulation. The quantum key distribution including symbols of a raw key across subcarriers and multiplexing the subcarriers to form an electrical carrier. Then optically modulating the electrical carrier with an electro-optical modulator using an optical signal. The optically modulated electrical carrier is then imposed on a pre-determined OAM mode using an optical OAM multiplexer, attenuated, and transmitted across a quantum channel. A receiver then receives the transmitted signal and demultiplexes it with an optical OAM demultiplexer to extract projections. The projections then undergo optical-to-electrical conversion using a coherent optical detector with an optical signal from a local oscillator. A resulting estimated electrical carrier is then demultiplexed into subcarriers. The subcarrier undergo phase noise cancellation and subsequent demodulation to extract estimated symbol constellation points corresponding the symbols of the raw key.

Systems and methods for orbital angular momentum (OAM)-based multidimensional wireless communication. The OAM-based multidimensional wireless communication is preformed with a transmitter for generating an RF modulated signal carrying a data sequence. Further included is an OAM antenna array including OAM antenna elements, each of which includes an azimuthal phase shifter and an antenna element. The azimuthal phase shifter shifts an azimuthal phase term of a wavefront generated by the antenna element such that the OAM antenna element imposes the multidimensional modulated signal on a pre-determined OAM mode of a carrier signal corresponding to the azimuthal phase term.

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 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.

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.

Methods, systems, and devices for data encoding and channel hopping. The system includes a signal source for providing a signal. The system includes an optical switch having an input port and multiple output paths. The optical switch is configured to receive, at the input port, the signal. The optical switch is configured to route the signal to an output path of the multiple output paths. The system includes a mode converter that is connected to the optical switch and configured to select an orbital angular momentum (OAM) mode. The mode converter is configured to encode or channel hop the signal using the OAM mode and combine the signal from each output path. The system includes a transmitter configured to propagate the signal.