摘要:
The present invention includes a method for dynamically updating a propagation model of communication signals in an area being subjected to earthworking operations which alter the topology of the terrain in which the method comprises the steps of dynamically updating a terrain map of the area as a function of the earthworking operations and dynamically updating the propagation model in response to updating the terrain map. An apparatus for dynamically updating a propagation model of communication signals in an area being subjected to a mobile geography-altering machine capable of altering the topology of the terrain, the apparatus comprises circuitry for storing a terrain map representative of the terrain prior to the terrain being subjected to alteration by the mobile geography-altering machine, circuitry for dynamically updating the terrain map as the terrain is being subjected to alteration by the mobile geography-altering machine, and circuitry for dynamically updating the propagation model in response to updating the terrain map.
摘要:
An apparatus and method for communicating between a first communication node and a second communication node in an area having a plurality of communication nodes is disclosed which comprises generating a propagation model of signals from selected communication nodes in the area. The communication nodes may be fixed or mobile. The propagation model is based on an environmental map that includes the topography of the terrain and structures in the area. The propagation model is generated at selected intervals to provide updated information for predicting the quality of communication at a location at a future time.
摘要:
A system and method for providing dynamic channel equalization in V2V and V2I communications systems. The method includes separating the channel bandwidth of a message into a plurality of subcarriers having different subcarrier frequencies, where the subcarriers include data subcarriers and pilot subcarriers. The method demodulates the message in the receiver to extract symbols from the message and determines channel estimation frequency responses using a least-squares estimation process and the extracted symbols for the pilot subcarriers. The channel estimation frequency responses of either the pilot subcarriers, the pilot subcarriers and some data subcarriers, or the pilot subcarriers and all data subcarriers are used to generate updated channel estimation frequency responses, and a new channel estimation frequency response is generated for each extracted signal using a previous channel estimation frequency response and the updated channel estimation frequency response. The extracted symbols are equalized using the new channel estimation frequency response.
摘要:
A system for transmitting wireless communications within ductwork. The system includes a plurality of transmitter devices for introducing electromagnetic radiation into the ductwork such that the ductwork acts as a waveguide for the electromagnetic radiation, said transmitter devices comprising a transmitter array, wherein the transmitter devices are configured to introduce the electromagnetic radiation using multiple propagation modes. The system also includes a plurality of receiver devices for detecting the electromagnetic radiation within the ductwork, said receiver devices comprising a receiver array.
摘要:
An optical frequency shifter that uses mode coupling of magnetostatic waves with light having frequency .omega..sub.o from a laser. A controllable external magnetic biasing field and a controlled microwave source are used to independently specify the frequency .omega..sub.q and wavenumber K.sub.q of the magnetostatic wave. As a result, the mode coupling can be maintained over a range of frequencies .omega..sub.q so a shifted beam of light .omega..sub.o .+-..omega..sub.q can be produced.
摘要:
An antenna that has a number of co-located elements, with no (or very small) coupling between the various elements. The antenna may comprise one or more electric dipole elements, such as an electric tripole, co-located with one or more magnetic dipole elements, such as a magnetic tripole. The antenna has the property that although all of the electric and magnetic dipole elements are co-located, there is substantially no coupling between the elements. Some of the antenna elements may operate as transmitters and the others may act as receivers. The antenna elements may be tuned to different frequencies. The antenna may comprise less than six antenna elements. Also disclosed are example devices and systems that may utilize the antenna structure, such as a handheld wireless communication device and an access point of a HVAC wireless communication system.
摘要:
A device for writing data to a recording medium and a method for fabricating the device is presented. According to one embodiment, the device includes an electrical conductor having a cross-track portion, wherein the cross-track portion includes first and second opposing surfaces, and wherein the cross-track portion defines an aperture extending from the first surface to the second surface. The device also includes a dielectric portion disposed in the aperture such that the dielectric portion defines a ridge waveguide having a lowest-order mode cut-off frequency that is less than the frequency of incident optical energy used to heat the recording medium.
摘要:
An integrated frequency conversion and scanner for converting the frequency of an input light beam and deflecting the converted light beam through an electronically controlled angle is disclosed. This structure includes an electrooptic crystal including a region formed for converting the frequency of the input light to a higher frequency; and a field changing structure associated with selected regions of the crystal arranged so that an electric field is created at least partially within the crystal to change its refractive index to thereby deflect the converted light beam through an electronically controlled angle.
摘要:
A system and method for providing dynamic channel equalization in V2V and V2I communications systems. The method includes separating the channel bandwidth of a message into a plurality of subcarriers having different subcarrier frequencies, where the subcarriers include data subcarriers and pilot subcarriers. The method demodulates the message in the receiver to extract symbols from the message and determines channel estimation frequency responses using a least-squares estimation process and the extracted symbols for the pilot subcarriers. The channel estimation frequency responses of either the pilot subcarriers, the pilot subcarriers and some data subcarriers, or the pilot subcarriers and all data subcarriers are used to generate updated channel estimation frequency responses, and a new channel estimation frequency response is generated for each extracted signal using a previous channel estimation frequency response and the updated channel estimation frequency response. The extracted symbols are equalized using the new channel estimation frequency response.
摘要:
An apparatus for producing an optical spot on the order of 25 nm in a recording media. The apparatus includes an optical transducer comprising a waveguide which defines an aperture adjacent to an air bearing surface of the transducer adjacent a recording media. The transducer includes a protrusion extending beyond the plane of the air bearing surface extending toward the recording media.