Abstract: Embodiments of dual mode communication systems and methods are disclosed. On system embodiment, among others, comprises logic configured to perform spatial multiplexing and expanded bandwidth signaling to data.

Abstract: Methods and systems for transmitter diversity expansion are provided. The methods and systems include steps and modules for applying a number of data streams (K) to a larger number of antennas (N). This is performed by applying each of the data streams to a single base antenna, such that K data streams are applied to K base antennas, and by shifting and combining the K data streams to produce N-K data streams to apply to N-K extension antennas.

Abstract: Disclosed herein are various embodiments of methods, systems, and apparatus for increasing packet generation in a digital communication system. In one exemplary method embodiment, subcarriers are added to a packet in a wireless local area network transmission to increase the data rate.

Abstract: Embodiments of dual mode communication systems and methods are disclosed. On system embodiment, among others, comprises logic configured to perform spatial multiplexing and expanded bandwidth signaling to data.

Abstract: One or more nanotaper coupling waveguides formed within an optical substrate allows for straightforward, reproducible offset launch conditions to be achieved between an incoming signal and the core region of a multimode fiber (which may be disposed along an alignment fixture formed in the optical substrate), fiber array or other multimode waveguiding structure. Offset launching of a single mode signal into a multimode fiber couples the signal into favorable spatial modes which reduce the presence of differential mode dispersion along the fiber. This approach to providing single mode signal coupling into legacy multimode fiber is considered to be an improvement over the prior art which required the use of an interface element between a single mode fiber and multimode fiber, limiting the number of propagating signals and applications for the legacy multimode fiber. An optical switch may be used to select the specific nanotaper(s) for coupling into the multimode fiber.

Abstract: A silicon-on-insulator (SOI)-based tunable laser is formed to include the gain medium (such as a semiconductor optical amplifier) disposed within a cavity formed within the SOI substrate. A tunable wavelength reflecting element and associated phase matching element are formed on the surface of the SOI structure, with optical waveguides formed in the surface SOI layer providing the communication between these components. The tunable wavelength element is controlled to adjust the optical wavelength. Separate discrete lensing elements may be disposed in the cavity with the gain medium, providing efficient coupling of the optical signal into the SOI waveguides. Alternatively, the gain medium itself may be formed to include spot converting tapers on its endfaces, the tapers used to provide mode matching into the associated optical waveguides.

Abstract: A silicon-based optical modulator structure includes one or more separate localized heating elements for changing the refractive index of an associated portion of the structure and thereby providing corrective adjustments to address unwanted variations in device performance. Heating is provided by thermo-optic devices such as, for example, silicon-based resistors, silicide resistors, forward-biased PN junctions, and the like, where any of these structures may easily be incorporated with a silicon-based optical modulator. The application of a DC voltage to any of these structures will generate heat, which hen transfers into the waveguiding area. The increase in local temperature of the waveguiding area will, in turn, increase the refractive index of the waveguiding in the area. Control of the applied DC voltage results in controlling the refractive index.

Abstract: One embodiment of the present invention provides a system that facilitates dynamic delivery of service profiles to a client. During operation, the system performs a discovery operation to allow the client to discover new services on a network. If a new service is discovered for which the client does not possess a service profile, the client to obtains the service profile from the new service and subsequently installs it, thereby enabling the client to interact with the new service.

Abstract: Methods and systems for transmitter diversity expansion are provided. The methods and systems include steps and modules for applying a number of data streams (K) to a larger number of antennas (N). This is performed by applying each of the data streams to a single base antenna, such that K data streams are applied to K base antennas, and by shifting and combining the K data streams to produce N-K data streams to apply to N-K extension antennas.

Abstract: A silicon-insulator-silicon capacitive (SISCAP) optical modulator is configured to provide analog operation for applications which previously required the use of relatively large, power-consuming and expensive lithium niobate devices. An MZI-based SISCAP modulator (preferably a balanced arrangement with a SISCAP device on each arm) is responsive to an incoming high frequency electrical signal and is biased in a region where the capacitance of the device is essentially constant and the transform function of the MZI is linear.

Abstract: Embodiments of legacy compatible spatial multiplexing systems and methods are disclosed. One method embodiment, among others, comprises receiving long training symbols and cyclic shifted long training symbols corresponding to legacy preamble portions of packets corresponding to first and second transmit signals, receiving long training symbols and inverted cyclic shifted long training symbols corresponding to spatial multiplexing portions of packets corresponding to first and second transmit signals, and combining the symbols corresponding to the first and second transmit antennas to estimate the respective channels.

Abstract: An optical coupler is formed of a low index material and exhibits a mode field diameter suitable to provide efficient coupling between a free space optical signal (of large mode field diameter) and a single mode high index waveguide formed on an optical substrate. One embodiment comprises an antiresonant reflecting optical waveguide (ARROW) structure in conjunction with an embedded (high index) nanotaper coupling waveguide. Another embodiment utilizes a low index waveguide structure disposed in an overlapped arrangement with a high index nanotaper coupling waveguide. The low index waveguide itself includes a tapered region that overlies the nanotaper coupling waveguide to facilitate the transfer of the optical energy from the low index waveguide into an associated single mode high index waveguide. Methods of forming these devices using CMOS processes are also disclosed.

Abstract: Systems and methods of convergence beamforming are disclosed. One method embodiment, among others, comprises receiving N data streams from at least N+1 antennas, where N is an integer greater than 1; determining signal characteristics of each received data stream; and adjusting the signal characteristics of N data streams to be transmitted based on the determined signal characteristics of the received N data streams. The convergence beamforming may be achieved by the orthogonalization of received multipath channel vectors. The transmission signals from a station are adjusted corresponding to the channel characteristics of the signals received by that station.

Abstract: Embodiments of cyclic diversity systems and methods are disclosed. One system embodiment, among others, comprises a logic configured to cyclically advance, or perform the periodic equivalent of the same, one or more sections of an orthogonal frequency division multiplexing (OFDM) packet relative to the OFDM packet to be transmitted on a first transmit antenna, the packet having the one or more cyclically advanced sections to be transmitted on a second transmit antenna, the duration of the cyclic advance having a duration less than a guard interval.

Abstract: A decision directed flicker noise canceller for reducing flicker noise in a modulated input signal according to an embodiment of the present invention includes a decision circuit, a conversion circuit, first and second adders and a filter. The decision circuit provides signal decisions based on the input signal. The conversion circuit provides selected signal values based on the signal decisions. The first adder subtracts the selected signal values from signals based on the input signal to provide a flicker noise estimate. The filter receives and filters the flicker noise estimate and the second adder subtracts the filtered flicker noise estimate from the input signal and provides a corrected input signal. In a feedback configuration, the second adder is located in a feedback position before the decision circuit in the signal processing path. In a feed-forward configuration, the second adder is located in a feed-forward position after the decision circuit.

Abstract: Disclosed is a method of fabricating an optical waveguide device including the steps of forming a mask over a waveguide core material layer so as to leave a portion of the layer exposed, and exposing the structure to an oxidizing environment to form an oxide layer on the waveguide core material layer at least in the exposed portion thereby defining the lateral dimension of the waveguide core. The resulting waveguide core has extremely smooth surfaces for low optical losses.

Abstract: A plasma-based etching process is used to specifically shape the endface of an optical substrate supporting an optical waveguide into a contoured facet which will improve coupling efficiency between the waveguide and a free space optical signal. The ability to use standard photolithographic techniques to pattern and etch the optical endface facet allows for virtually any desired facet geometry to be formed—and replicated across the surface of a wafer for the entire group of assemblies being fabricated. A lens may be etched into the endface using a properly-defined photolithographic mask, with the focal point of the lens selected with respect to the parameters of the optical waveguide and the propagating free space signal. Alternatively, an angled facet may be formed along the endface, with the angle sufficient to re-direct reflected/scattered signals away from the optical axis.

Abstract: Systems and methods for enabling arbitrary components to transfer current, contextual data between each other without requiring prior knowledge of each other. The contextual data may include executable computer language instructions or a type, operating status, identity, location, administrative domain or environment information of the components or its users. The system includes a set of arbitrary components associated with one or more universal interfaces. The one or more universal interfaces may include mobile code, a contextual interface, a notification interface, a user interface and a data source interface. A first component at least has a universal contextual interface. A second component may invoke the universal contextual interface and execute associated instructions to transfer contextual data between the first component and the second component.

Abstract: A silicon-on-insulator (SOI)-based tunable laser is formed to include the gain medium (such as a semiconductor optical amplifier) disposed within a cavity formed within the SOI substrate. A tunable wavelength reflecting element and associated phase matching element are formed on the surface of the SOI structure, with optical waveguides formed in the surface SOI layer providing the communication between these components. The tunable wavelength element is controlled to adjust the optical wavelength. Separate discrete lensing elements may be disposed in the cavity with the gain medium, providing efficient coupling of the optical signal into the SOI waveguides. Alternatively, the gain medium itself may be formed to include spot converting tapers on its endfaces, the tapers used to provide mode matching into the associated optical waveguides.

Abstract: One or more nanotaper coupling waveguides formed within an optical substrate allows for straightforward, reproducible offset launch conditions to be achieved between an incoming signal and the core region of a multimode fiber (which may be disposed along an alignment fixture formed in the optical substrate), fiber array or other multimode waveguiding structure. Offset launching of a single mode signal into a multimode fiber couples the signal into favorable spatial modes which reduce the presence of differential mode dispersion along the fiber. This approach to providing single mode signal coupling into legacy multimode fiber is considered to be an improvement over the prior art which required the use of an interface element between a single mode fiber and multimode fiber, limiting the number of propagating signals and applications for the legacy multimode fiber. An optical switch may be used to select the specific nanotaper(s) for coupling into the multimode fiber.