Hewlett-packard Development Company, L.p.

Powerwave Technologies, Inc.

Other

Ian Robert Johnson

Steven Andrew Wood

Christian G Luke

James Thomas Edward McDonnell

Mark Cope

Adrian Richard Mansell

Martin Warwick Beale

John Deryk Waters

David A Stafford

Robert Castle

Timothy Alan Heath Wilkinson

Michael Case Lawton

Amanda Richardson

Simon Haydn Baynham

Zhimin Shao

Robert A Hall

Adrian Mansell

A cellular communications service provider authenticates a provider of a location-dependent service, such as a wireless hotspot. Once the cellular communications service provider is aware of potential use of the service by the user, it authenticates the service provider and provides an authentication to the user. Users can thus avoid untrustworthy providers of local services.

Method and apparatus for authenticating service to a wireless communications device

A system and method for controlling the gain in the forward signal path of a digital predistortion linearizer is disclosed. The loop gain of the predistortion system is driven to unity, where a separately controlled constant-gain observation path allows accurate gain control of the forward path. This is divided into digital gain from the predistortion function and analog gain from a Voltage Variable Attenuator (VVA) in the transmitter. The invention balances the distribution between these two domains in order to maximize dynamic range and minimize noise in the forward signal path. In order to distribute the forward path gain accurately, the characteristic of the VVA must be well known. Since these devices tend to be non-linear, with variable characteristic over temperature and batch, the invention compensates for this non-linear behavior by tracking the varying transfer characteristic of the VVA, giving a predictable local characteristic. Another aspect of the disclosed invention is the ability to operate with very low transmit power and loop gain levels, allowing accurate gain control during such scenarios as cell initialization, that require operation over a wide dynamic range.

System and method for forward path gain control in a digital predistortion linearized transmitter

Access to a wireless data network to nodes located in a defined operational area is limited by transmitting a network signal within the defined operational area while transmitting a wave that can cause destructive interference with the network signal into a prohibited area adjacent to the defined operational area. The wave that can cause destructive interference is produced by phase and/or amplitude modulating the network signal. The modulation of the network signal includes sweeping the phase and/or amplitude.

Wireless data network security

A system and method for rapidly correcting the time difference between two signals is disclosed. In particular, a system and method for very rapidly correcting timing errors to the very high degree of accuracy required for digital predistortion adaptation is disclosed. The method is a signal processing technique, which can be performed in either hardware or software, which employs a correlation computation. The correlation results are processed in a manner that enables very rapid and accurate estimation of the time difference between the two signals.

System and method for digital timing error correction in a communications system utilizing adaptive predistortion

A system and method for compensating for the time delay between the in-phase I and the quadrature Q paths of a digitally modulated transmitter incorporating an analog quadrature modulator is disclosed. The time delay between the in-phase I and the quadrature Q paths is computed and used to calibrate a set of interpolation filters in the forward path that compensate for this delay, reducing the frequency dependent degradation in performance of the analog quadrature modulator. The disclosed system and method provides improved compensation of gain, phase and DC offsets in the analog quadrature modulator over a broader bandwidth. Fractional delay interpolation filters may be used to estimate the delay between the in-phase and quadrature paths. This eliminates the need for a factory calibration procedure, speeding up manufacture and reducing costs.

System and method for differential IQ delay compensation in a communications system utilizing adaptive AQM compensation

A method of communication between computing entities in a local area network operating an CSMA protocol in an environment where reflections of omni-directional transmissions from a plurality of objects cause multi-path fading includes data packets being transmitted having a header at a first, lower data rate, followed by transmission of payload data at a second, higher data rate. Where the packets are not confirmed to be received, the packet is retransmitted a predetermined number of times before the transmitting entity reduces the payload data rate of the packet and retransmits the packet. If the retransmitted lower payload data rate packet is not confirmed to be received within the predetermined number of transmissions at the lower rate, the packet is dropped.

Rate adaptive payload transmission for local area networks

A network adapter capable of receiving data from a network, said adapter arranged to receive data at at least a lowest and a highest rate; said adapter comprising: sampling means arranged to sample said data; an equalizer arranged to receive, and equalize, said data samples, and said equalizer capable of being trained to equalize data, at at least, each of said lowest and highest data rates; and training means capable of training said equalizer to equalize data; wherein; said adapter is initially arranged to train said equalizer to receive data at said lowest data rate allowing data to be decoded and if upon decoding said adapter determines that said equalizer has been trained to equalise data at the incorrect rate to retrain said equalize to equalize data at the correct rate.

Networking

A luminometer construction including means for supplying samples contained in respective cuvettes 20, in succession to be examined, the cuvettes being introduced into a carrier 10 having a cuvette gripper 19, the carrier 10 defining an examination chamber 21 into which the cuvettes are inserted, the carrier 10 being rotatable between a loading and a test position in which the examination chamber 21 is adjacent to a photo-multiplier device 25, whereby testing of a sample in a curvette 20 can be carried out, the examination chamber 21 having an edge in a plane inclined to the axis 11 of rotation of the carrier 10, and the photo-multiplier device 25 being arranged with its optical axis 26 perpendicular to such plane.

Growing community of inventors

Bristol, United Kingdom

Ian Robert Johnson