An optical isolator system comprises an electrical-to-optical converter apparatus for receiving an input electrical signal from a system of an aircraft and converting the input electrical signal into an optical signal which is representative of the input electrical signal. The optical isolator system further comprises an optical-to-electrical converter apparatus for receiving the optical signal from the electrical-to-optical converter apparatus, for converting the received optical signal into an output electrical signal which is representative of the received optical signal, and for transmitting the output electrical signal to a portable server for the wireless distribution of content such as visual content, web content, video content, audio content, games, services, information and/or advertising content to clients in the aircraft. Associated methods are also described.

Joint estimation of the framer index and the frequency offset in an 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. By identifying the beginning of the header portion of a data frame, the receiver can then process data received from the transmitter in a manner synchronous to the manner in which the data was transmitted by the transmitter.

An optical communication system includes: a plurality of optical transmission devices converting a first data signal that is an electrical signal into an optical packet signal; an optical coupler coupling optical packet signals; an optical coupler branching the optical transmission signal generated through coupling; a plurality of optical reception devices converting the optical transmission signal generated through branching into a second data signal that is an electrical signal; and a control unit controlling operation of the optical transmission devices and the optical reception devices. The optical transmission devices allocate a communication resource to avoid collision with the optical packet signal transmitted from another optical transmission device, and transmit the optical packet signal, and the optical reception devices convert the optical transmission signal into an electrical transmission signal, select a designated signal portion from the electrical transmission signal, and output the designated signal portion as the second data signal.

Components, systems, and methods for determining propagation delay of communications in distributed antenna systems are disclosed. The propagation delay of communications signals distributed in the distributed antenna systems is determined. If desired, the propagation delay(s) can be determined on a per remote antenna unit basis for the distributed antenna systems. The propagation delay(s) can provided by the distributed antenna systems to a network or other system to be taken into consideration for communications services or operations that are based on communications signal delay. As another non-limiting example, propagation delay can be determined and controlled for each remote antenna unit to uniquely distinguish the remote antenna units. In this manner, the location of a client device communicating with a remote antenna unit can be determined within the communication range of the remote antenna unit.

An apparatus comprising a signal generator configured to produce a modulation signal, a filter coupled to the signal generator and configured to filter the modulation signal to produce a cancellation signal, and a reflective semiconductor optical amplifier (RSOA) coupled to the signal generator and the filter, wherein the RSOA is configured to generate an optical signal according to a difference between the modulation signal and the cancellation signal and transmit the optical signal towards a partial reflection mirror (PRM).

An optical and electrical hybrid beamforming transmitter, receiver, and signal processing method are provided. The transmitter includes, but is not limited to, two photoelectric converters, two adjusting circuits, and an antenna array. The photoelectric converter converts an optical signal into an initial electric signal, respectively. The adjusting circuit is coupled to the photoelectric converter, and are adapted for delaying the initial electric signal according to an expected beam pattern formed by the antenna array, respectively, to output an adjusted electric signal. The antenna array includes two antennas that are coupled to the adjusting circuit. The antenna radiates electromagnetic wave according to the adjusted electric signal. Accordingly, a phase of the signal may be adjusted, and the number of the elements may be reduced.

A moving body-mounted communication system includes an internal connector, a third transmission line and a first information transmitting and receiving device. The internal connector is mounted in a moving body and connected to an external connector which is connected to a second transmission line. The third transmission line is arranged in the moving body and connected to the internal connector. The first information transmitting and receiving device is connected to the third transmission line. Information is transferred between a first transmission line used in an information and communication network outside the moving body and the second transmission line, and is transferred between the second transmission line and the third transmission line, without performing conversion of the information form of the information between light and electricity.

Provided are a light transmission device and a control method of same which can switch a processing sequence according to a vendor of an optical module to be mounted thereon. The light transmission device, which is provided with ports on which optical modules which transmit an optical signal are mounted, is additionally provided with: a storage means for holding a table in which processing sequences respectively corresponding to pieces of identification information about the optical modules are stored; and a control means for acquiring pieces of identification information about the mounted optical modules, determining, with reference to the table, a processing sequence corresponding to the identification information about the acquired optical module, and executing the determined processing sequence for the optical module.

An optical fiber cable of a mobile fronthaul system based on a radio over fiber (RoF), which includes a control apparatus for monitoring an analog optical link according to an exemplary embodiment, may be monitored. The monitoring control apparatus may include an optical signal monitor to monitor an optical signal passing through an optical fiber cable, and a system controller to control the optical signal based on a result of the monitoring. The optical signal monitor may calculate an average optical power, carrier-to-noise ratio (CNR), and a size of a nonlinear component from an electrical signal, which has been acquired from the optical signal. Then, the optical signal monitor may control the calculated average optical power, CNR, and nonlinear component.

Disclosed is an electronic device (1) for converting a wireless signal (2) in the mm-wave or sub-THz range into at least one modulated optical signal (16). The electronic device (1) comprises an antenna element (11) for converting the wireless signal (2) into a guided electrical signal (12), wherein the antenna element (11) is arranged on a printed circuit board (10b′) or on a first integrated chip (10′)′ The electronic device (1) comprises an electrical signal converter (13) for converting the at least one guided electrical signal (12) into a conditioned electrical signal (14), wherein the electrical signal converter (13) is arranged on a second integrated chip (10″). The electronic device (1) comprises a modulator (15) for converting the conditioned electrical signal (14) into the modulated optical signal (16), wherein the modulator (15) is arranged on a third integrated chip (10′″), and wherein the modulator (15) comprises a waveguide (151) and a cladding (152) comprising a first cladding portion (1521) having a conductive material at an interface with the waveguide (151) and a second cladding portion (1522) having a conductive material at an interface with the waveguide (151).