摘要:
Aspects of the invention include a root node of a wireless communication infrastructure that buffers data packets for transmission by base stations over an air interface. The root node determines a time delay for transmission of a data packet from the root node to each base station, a maximum time delay of those time delays, and a timing latency based upon the maximum time delay. The root node transmits the timing latency to the base stations. In response, each base station initiates transmission of data packets received by the root node after expiration of the timing latency. Alternatively, the root node, instead of the base stations, may buffer the data packets, and transmit them so that they arrive at the base stations at substantially the same time.
摘要:
An Orthogonal Frequency Division Multiplex (OFDM) communication system comprises OFDM transmitters (103-109) and an OFDM receiver (101). The system comprises a subcarrier status data controller (200) for transmitting subcarrier status data to the OFDM receiver (101). The subcarrier status data indicates the active subcarriers of the OFDM transmitters (103-109). The OFDM receiver (101) comprises a receiver (201) which receives a signal comprising a desired signal component from a first OFDM transmitter (103) and interference from at least one interfering OFDM transmitter (105). The OFDM receiver (101) further comprises a subcarrier status processor (203) which receives the subcarrier status data and a channel estimator (205) which determines channel estimates for at least an air interface communication channel from the first OFDM transmitter (103) and an air interface communication channel from the interfering OFDM transmitter (105). An interference mitigation processor (207) performs interference mitigation of the interference in response to the subcarrier status data and the channel estimates thereby providing improved recovery of the data from the first OFDM transmitter (103).
摘要:
A communication device (60) for simultaneously transmitting independent information (82) on multiple channels comprises a modulator (66) and at least two matched filters (68-70). Each matched filter has a unique predetermined characteristic that is a time-reversed, complex conjugate of a complex waveform shape (72) produced by the modulator (66) in response to a channel encoder previously supplying known codeword vectors (75) to the modulator (66). Therefore, a composite signal envelope (82) produced for transmission by the communication device (60) of FIG. 4 has a reduced peak-to-mean envelope power ratio (PMEPR), since relatively large excursions in complex waveform shapes subsequently generated by the modulator (66) are unmatched by the unique filter characteristics while relatively small excursion are matched and therefore enhanced.
摘要:
A fender for sanitizing wheels of a wheelchair including a support frame and a fender housing. The support frame includes a mounting bracket for mounting the support frame on a vertical frame on the rear portion of the wheelchair. The fender housing is removably mounted on the support frame. The fender housing includes a plurality of Ultraviolet-C (UVC) light sources powered by a re-chargeable battery and a driver circuit. The plurality of UVC light sources are configured to sanitize a surface of a wheel of the wheelchair by virtue of illumination of surface of the wheel during rotation of the wheel.
摘要:
A method for non-invasively determining a chemical property of an aqueous solution is provided. The method provides the steps of providing a colored solute having a light absorbance spectrum and transmitting light through the colored solute at two different wavelengths. The method further provides the steps of measuring light absorbance of the colored solute at the two different transmitted light wavelengths, and comparing the light absorbance of the colored solute at the two different wavelengths to determine a chemical property of an aqueous solution.
摘要:
A broadband omni-directional bicone antenna. The antenna can comprise conductive surfaces of conical voids provided within a solid dielectric structure. The outside surface of the solid structure can support a radio frequency (RF) lens geometry operable for beam forming. The beam forming can modify the elevation pattern of the electromagnetic radiation from the bicone antenna. The solid dielectric structure may be machined or molded from a single piece of material. The conical voids provided within the solid structure can be metallized to provide conductive bicone radiators. The outer surface beam shaping lenses can be zoned or continuous and can provide elevation patterns with increased gain, cosecant squared falloff, or various other patterns. The beam shaping lens may be formed from any low-loss dielectric. Alternatively, the lens may be formed from a less dense material such as dielectric foam that can support radial conductive beam forming vanes.
摘要:
An apparatus is provided for predicting the future behaviour of an object such as a vehicle. A location and time determining system, such as a GPS receiver (6), determines the geographical location of the vehicle and the current time and supplies this to a processor, such as a computer (1) with a program memory (2). The processor periodically records the location and time to form a record of sightings of the vehicle. The processor (1, 2) compares a sequence of recent sightings waith earlier recorded sightings from the record to find matching sequences which represent journey segments which match over a predetermined minimum distance. The processor (1, 2) retrieves some of the sightings which follow the matching sequences and derives from these a prediction of the future behaviour, for example possible future routes and destinations of the vehicle.
摘要:
To generate course head assignments for a multihead composite material application machine having a set of heads, a set of paths for a ply for a composite part is received and it is determined whether each path of the set of paths complies with a head characteristic for the set of heads. In addition, a special head of the set of heads is assigned to a non-standard path of the set of paths in response to determining the non-standard path does not comply with the head characteristic and ones of the set of heads are assigned to corresponding ones of the set of paths in response to the ones of the set of paths being in compliance with the head characteristics. Furthermore, a constellation of head locations is calculated in response to the set of paths being in compliance with the head characteristic and the set of heads are assigned to the constellation of head locations in response to calculating the constellation of head locations.
摘要:
Apparatus for maintaining the temperature of a component of a gas turbine engine below a predetermined maximum working temperature comprises a reservoir for a cooling fluid having a boiling point below the working temperature and in which the component is immersed or with which it is in contact. At least two heat exchangers are associated with the reservoir and operable to effect condensation of vaporised cooling fluid and return of same to the reservoir. Preferably the apparatus is a closed system incorporating three heat exchangers respectively adapted to effect heat exchange with engine fuel, compressed air derived from A fan or low pressure compressor of the engine and ambient air. Means may advantageously be provided to ensure return of condensed cooling fluid to the reservoir when the attitude of the reservoir is altered as a result of aircraft manoeuvres.
摘要:
A method (400) and arrangement (200) for mitigation of intercell and intracell interference in a 3GPP cellular communication system (100) by, in a receiver in a cell of the system, deriving for a first channel in the cell a signal, representative of first channel transfer function (A(1)); deriving for at least a second channel originating in a different cell a signal (A(2 . . . M)), representative of second channel transfer function, based on: deriving a cell specific scrambling code (s), deriving a channel impulse response (h), and deriving a channelisation code (c); and performing multi-user detection using the first and second signals. Where the channelisation code is unknown, a substitute channelisation code is preferably substituted. It will be appreciated that the technique can be applied to both downlink and uplink. This provides the advantage that both intra-cell interference and intercell interference are mitigated.