A wireless radio frequency conversion system is disclosed. The wireless radio frequency conversion system includes a wireless radio frequency transmit-receive device, a first conversion device, at least one optical fiber, a second conversion device, and a wireless radio frequency transmission device. The wireless radio frequency transmit-receive device performs a conversion and a transmit-receive manner to at least one radio frequency signal and at least one data signal. The first conversion device performs a conversion to the at least one data signal and at least one optical signal. The optical fiber transmits the at least one optical signal. The second conversion device performs a conversion to the at least one optical signal and the at least one data signal. The wireless radio frequency transmission device performs a conversion and a transmit-receive manner to the at least one data signal and the at least one terminal signal.

An optical receiving apparatus includes a decoupler, a voltage regulator, an optical-to-electrical converter, and an amplifier. The decoupler receives a first electrical signal, and performs direct current removal processing on the first electrical signal thereby obtaining a second electrical signal. The first electrical signal includes control information to control a working state of the amplifier. The electrical signal is a pulse signal and includes the control information. The voltage regulator receives the first electrical signal, and performs voltage regulation processing on the first electrical signal thereby obtaining a third electrical signal that has a constant amplitude and provides a voltage for the amplifier. The optical-to-electrical converter receives a burst optical signal, and converts the burst optical signal into a fourth electrical signal. The amplifier amplifies the fourth electrical signal based on the control information and a power supply of the third electrical signal, and outputs an amplified fourth electrical signal.

Disclosed is a radio-frequency-over-fiber (RFoF) transmission method using a directly modulated laser (DML). The RFoF transmission method to be performed by a head end includes combining a radio frequency (RF) carrier signal and a data signal having a lower frequency band than the RF carrier signal through an RF coupler, modulating the combined RF carrier signal and the combined data signal using a frequency response characteristic of a DML, and outputting an optical signal in which, of RF carrier signals and data signals being generated in a laterally symmetrical form based on an optical carrier frequency through the modulating, an RF carrier signal is suppressed.

Grid of beams (GoB) adaptation in a wireless communications circuit, particularly for a wireless communications system (WCS), is disclosed. The wireless communications circuit may be provided in the WCS to provide radio frequency (RF) coverage in a wireless communications cell. In this regard, an antenna array is provided in the wireless communications circuit to radiate the GoB, which includes a number of RF beams corresponding to an RF communications signal(s), in the wireless communications cell. In examples discussed herein, the wireless communications circuit can be configured to detect a coverage condition change in the wireless communications cell and modify the GoB accordingly. By adapting the GoB to the coverage condition change, it may be possible to reduce processing overhead and improve resource usage, data throughput, and system adaptability of the wireless communications circuit, thus helping to optimize RF coverage in the wireless communications cell.

Joint estimation of the framer index and the frequency offset in a optical communication system are described among various other features. A transmitter can transmit data frames using pilot and framer symbols. A receiver can estimate the framer index and frequency offset using the pilot and framer symbols, and identify the beginning of a header portion of a data frame. The estimation can be performed to compensate for delays such as half-symbol delays and differential group delays. By identifying the beginning of the header portion of a data frame while compensating for certain delays, the receiver can synchronize, with less error, the data transmitted by the transmitter and the data it received.

A method of RF signal processing comprises receiving an incoming RF signal at each of a plurality of antenna elements that are arranged in a first pattern. The received RF signals from each of the plurality of antenna elements are modulated onto an optical carrier to generate a plurality of modulated signals that each have at least one sideband. The modulated signals are directed along a corresponding plurality of optical channels with outputs arranged in a second pattern corresponding to the first pattern. A composite optical signal is formed using light emanating from the outputs of the plurality of optical channels. Non-spatial information contained in at least one of the received RF signals is extracted from the composite signal.

High-performance ultra-wideband Phased Array Antennas (PAA) are disclosed, having unique capabilities, enabled through photonic integrated circuits and novel optical architectures. Unique capabilities for PAA systems are enabled by photonic integration and ultra-low-loss waveguides. Novel aspects include optical multiplexing combining wavelength division multiplexing and/or a novel extension to array photodetectors, providing the capability to combine many RF photonic signals with very low loss. Architectures include tunable optical up-conversion and down-conversion systems, moving a chosen frequency band between baseband and a high RF frequency band with high dynamic range. Simultaneous multi-channel RF beamforming is achieved through power combining/splitting of optical signals.

A receiver (1) for a phased array antenna comprises a laser light source (2) arranged to provide an optical spectrum comprising a first spectral component having a first wavelength and a second spectral component having a second wavelength. The first wavelength is spaced from the second wavelength. A wavelength separator (4) is configured to separate the first spectral component from the second spectral component, such that the first spectral component is directed onto a first path (A) and the second spectral component is directed onto a second path (B). A first delay unit (16) is configured to add a controllable time delay to the first spectral component on the first path. A second delay unit (42) is configured to add the time delay to the second spectral component on the second path. A modulator (14) is configured to modulate the first spectral component on the first path with a received RF signal from the phased array antenna. A heterodyning device (50) is configured to heterodyne the resulting first and second spectral components.

A media converter has an electrical bus port for connecting a first electrical bus; and an optical bus port for connecting an optical bus. The media converter is configured to convert an electrical signal of the first electrical bus into an optical signal of the optical bus in such a way that, at a first value of an internal control signal of the media converter, the optical signal corresponds to the electrical signal and, at a second value of the internal control signal, the optical signal has an inverted shape corresponding to the electrical signal. In a transmission phase during which the internal control signal changes from the first value to the second value, the media converter is configured to emit the optical signal in such a way that the optical signal corresponds to the electrical signal until the end of the transmission phase.

Provided are: a photon detection light-receiving device with which it is possible to avoid malfunctions caused by the application of high voltages, and to shorten the delays in communication time in mesh-type network communication; and a communication apparatus equipped with the photon detection light-receiving device. The photon detection light-receiving device has a photon detection APD, a quenching resistor and a capacitor, with one end of the quenching resistor and one end of the capacitor being connected to one terminal of the photon detection APD. The optical wireless communication apparatus comprises: a housing; a photon detection light-receiving device that generates an electrical signal from received light; a receiving unit that generates a reception data signal using an electrical signal from the photon detection light-receiving device; a transmission unit that generates an electrical signal using a transmission data signal; a light emitting device into which the electrical signal from the transmission unit is input and generates transmission light; and an optical wireless communication controller that generates transmission data or reception data corresponding to the protocol of an external apparatus.