An optical wireless communication (OWC) system comprising a first device comprising a transceiver apparatus and a plurality of further devices each comprising a respective further transceiver apparatus. The first device communicates via an optical channel with the plurality of further devices. The transceiver apparatus may comprise a receiver for receiving light representing optical wireless communication signals transmitted by the further devices, the receiver comprising a photodetector; receiver-side processing circuitry for processing optical wireless communication signals received by the receiver to extract data represented by the received optical wireless communication signals; a transmitter for transmitting further light representing optical wireless communication signals; transmitter-side processing circuitry for producing optical wireless communication signals for transmission by the transmitter; and an optical component for at least one of reflecting or guiding at least some light received from at least one of the further devices towards at least one of the further devices.

Methods of sensory input integrity attestation are provided. Artifacts included within devices under test inject a known noise signal into the output signal of one or more output devices that are detectable by one or more input devices (i.e., sensors) of an embedded device, and monitor the received input data. By comparing the received signal against the expected noise signal, attestation of the validity of sensory input data is possible. Such sensory input data attestation is capable either locally or using a remote attestation device with knowledge of the expected data stream.

An optical wireless communication device for transmitting data comprises a transmitter comprising a light source, a controller configured to control operation of the light source to produce modulated light comprising an optical wireless communication signal representative of said data, at least one proximity determining component configured to determine a proximity of an object, and a processing resource configured to determine whether the determined proximity is within a threshold distance, wherein the controller is configured to control operation of the transmitter and/or of at least one other component of the optical wireless communication device in dependence on whether the determined proximity is within the threshold distance.

An optical wireless communication device for transmitting data comprises a transmitter comprising a light source, a controller configured to control operation of the light source to produce modulated light comprising an optical wireless communication signal representative of said data, at least one proximity determining component configured to determine a proximity of an object, and a processing resource configured to determine whether the determined proximity is within a threshold distance, wherein the controller is configured to control operation of the transmitter and/or of at least one other component of the optical wireless communication device in dependence on whether the determined proximity is within the threshold distance.

A communication module includes: a transmitter and a receiver each disposed at an approximate center of a connection surface, the transmitter transmitting and the receiver receiving data by a data communication scheme with which the transmitter and the receiver are compatible; and a first electrode and a plurality of second electrodes, the first electrode having a polarity that is different from a polarity of the plurality of second electrodes, the first electrode and the plurality of second electrodes being disposed in an arrangement that is N-fold symmetric (where N is a natural number of 3 or more) in an outer periphery of the transmitter and the receiver, the transmitter and the receiver being disposed on the connection surface.

A communication module includes: a transmitter and a receiver each disposed at an approximate center of a connection surface, the transmitter transmitting and the receiver receiving data by a data communication scheme with which the transmitter and the receiver are compatible; and a first electrode and a plurality of second electrodes, the first electrode having a polarity that is different from a polarity of the plurality of second electrodes, the first electrode and the plurality of second electrodes being disposed in an arrangement that is N-fold symmetric (where N is a natural number of 3 or more) in an outer periphery of the transmitter and the receiver, the transmitter and the receiver being disposed on the connection surface.

This application provides a signal transmission method and apparatus. The method includes: obtaining, by a transmitter side, a first signal with N points; performing signal separation on the first signal with N points, to obtain two groups of signals (for example, a second signal with N points and a third signal with N points); combining the two groups of signals obtained through separation, to obtain a to-be-sent signal with 3N/2 points; and sending the signal with 3N/2 points to a receiver side, to enable the receiver to restore the first signal with N points from the received signal with 3N/2 points.

This application provides a signal transmission method and apparatus. The method includes: obtaining, by a transmitter side, a first signal with N points; performing signal separation on the first signal with N points, to obtain two groups of signals (for example, a second signal with N points and a third signal with N points); determining four signals with N/2 points based on the two groups of signals obtained through separation, and combining the four signals with N/2 points, to obtain a to-be-sent signal with 3N/2 points; and sending the signal with 3N/2 points to a receiver side, to enable the receiver to restore the first signal with N points from the received signal with 3N/2 points.

This application provides a signal transmission method and apparatus. The method includes: obtaining, by a transmitter side, a first signal with N points; performing signal separation on the first signal with N points, to obtain two groups of signals (for example, a second signal with N points and a third signal with N points); determining four signals with N/2 points based on the two groups of signals obtained through separation, and combining the four signals with N/2 points, to obtain a to-be-sent signal with 3N/2 points; and sending the signal with 3N/2 points to a receiver side, to enable the receiver to restore the first signal with N points from the received signal with 3N/2 points.

A transmission device includes a symbol generator that generates a modulation symbol by mapping transmission data to a signal point arranged in a two-dimensional or three-dimensional color space; and an outputter that outputs an optical signal modulated according to the modulation symbol.