Methods and apparatus for interference cancelation in a radio frequency communications device are described. In various embodiments a signal to be transmitted in converted into an optical signal and processed using an optical filter assembly including one or more optical filters to generate an optical interference cancelation signal. The optical interference cancelation signal is converted into an analog radio frequency interference cancelation signal using an optical to electrical converter prior to the analog radio frequency interference cancelation signal being combined with a received signal to cancel interference, e.g., self interference. The optical filter assembly can include a large number of taps, e.g., 30, 50, 100 or more. Each tap may be implemented as a separate optical filter or series of optical filters. Delays and/or gain of the optical filters can be controlled dynamically based on channel estimates which may change due to changes in the environment and/or communications device position.

Methods and apparatus for reducing and/or canceling signal interference between receiver and transmitter components of a wireless communications device are described. The methods and apparatus are well suited for use in a wide range of devices including user equipment devices such as cell phones as well as in network equipment such a base stations. Opto-mechanical devices are used in some embodiments as part of an apparatus which performs interference cancelation on RF (Radio Frequency) signals.

Embodiments relate to providing simultaneous digital and analog services in optical fiber-based distributed radio frequency (RF) antenna systems (DASs), and related components and methods. A multiplex switch unit associated with a head-end unit of a DAS can be configured to receive a plurality of analog and digital downlink signals from one or more sources, such as a service matrix unit, and to assign each downlink signal to be transmitted to one or more remote units of the DAS. In one example, when two or more downlink signals are assigned to be transmitted to the same remote unit, a wave division multiplexer/demultiplexer associated with the multiplex switch unit can be configured to wave division multiplex the component downlink signals into a combined downlink signal for remote side transmission and to demultiplex received combined uplink signals into their component uplink signals for head-end side transmission.

The present application relates to devices and components related to a direct detection and photonics receiver.

Provided is a phased array antenna which can be used in the millimeter wave band and whose cost is lower than that of a conventional phased array antenna. The phased array antenna (1) includes: an optical modulator (OM) configured to generate a signal light beam SL by carrying out intensity modulation on a carrier light beam CL by use of a sum signal V.sub.IF+LO(t), the sum signal V.sub.IF+LO(t) being obtained by adding an intermediate frequency signal V.sub.IF(t) and a local signal V.sub.LO(t); and a time delay device (TD) configured to generate delayed signal light beams SL′1, SL′2, . . . and SL′n by imparting time delays Δt1, Δt2, . . . and Δtn to the signal light beam SL. Each feeding circuit (Fi) generates, from a corresponding delayed signal light beam SL′i, a delayed radio frequency signal V.sub.RF(t−Δti) to be supplied to an antenna element (Ai).

The application provides an optical network apparatus and an optical module. The optical network apparatus is configured to: convert, by a processing chip, the received N electrical signals from a board interface chip into a first electrical signal and a second electrical signal; and send the above two electrical signals to a first optical transmission component and a second optical transmission component, respectively; convert, by the first optical transmission component, the first electrical signal into a first optical signal; and convert, by the second optical transmission component, the second electrical signal into a second optical signal. The N to-be-sent electrical signals are combined, and only two optical transmission components are connected to the processing chip. Therefore, the processing chip does not need to be connected to four optical transmission components, fewer optical transmission components are required, and costs are reduced.

Optical network systems are disclosed, including a transmitter comprising a digital signal processor that receives data; circuitry that generate a plurality of electrical signals based on the data; a plurality of filters, each of which receiving a corresponding one of the plurality of electrical signals, a plurality of roll-off factors being associated with a respective one of the plurality of filters; a plurality of digital-to-analog converter circuits that receive outputs from the digital signal processor, the outputs being indicative of outputs from the plurality of filters; a laser that supplies light; and a modulator that receives the light and outputs from the digital-to-analog converter circuits, the modulator supplying a plurality of optical subcarriers based on the outputs of the digital-to-analog converter circuits, such that one of the plurality of optical subcarriers carrying information for clock recovery.

A method for receiving a modulated receive signal, with a transmission unit having a laser and an electro-absorption modulator. The received optical receive signal is directed towards the laser; due to the irradiance of the optical receive signal onto the laser, the optical frequency of the light radiated from the laser is adapted to and/or aligned with the optical frequency of the received optical receive signal; the light radiated from the laser and the optical receive signal received via the optical waveguide are overlapped in the electro-absorption modulator; the thus-created overlapping signal from the electro-absorption modulator is converted into an electrical receive signal, in particular into an electrical current signal; and a receive signal is provided which corresponds to the electrical receive signal or is derived from same.

Optical network systems and components are disclosed, including a transmitter comprising a digital signal processor receiving a plurality of independent data streams, and supplying a plurality of digital subcarrier outputs, based on the plurality of independent data streams, and configurable to vary the frequency spacing between two or more of the plurality of digital subcarrier outputs; the transmitter configured to output a modulated optical signal including a plurality of optical subcarriers based on the digital subcarrier outputs wherein based on first ones of the plurality of digital outputs, the first one of the plurality of subcarriers is spectrally spaced from the second one of the plurality subcarriers by a first gap, and based on second ones of the plurality of digital outputs, the first one of the plurality of subcarriers is spectrally spaced from the second one of the plurality of subcarriers by a second gap different than the first.

Software Defined Networking concepts apply to access, fronthaul, backhaul and core networks of 5G mobile networks and beyond. Such network components currently have individual/segmented control planes and associated controllers to provide configurability, provisioning, and network slicing. This is because of technology disparity between these network components: access is wireless/cellular, backhaul and fronthaul are optical/fiber, and core is electrical/wire-line. A system/method is detailed that enables a coordinated and unified end-to-end slicing, wherein the coordination is provided in the system/method that (a) attaches to the respective controllers of these network components in real-time, (b) collects the connectivity topology of each network segment as the network evolves, (c) passes the slice-profile information (translating according to capabilities of that network segment to configure an end-to-end slice with a specified bandwidth requirement and service quality level), and (d) passes across a VLAN tag to be used across network segments to associate with the same slice.