Nortel Networks Corporation

Northern Telecom Limited

Apple Inc.

Rockstar Consortium US LP

Christopher John Reed

Simon John Gale

John Edward Hudson

David Damian Nicholas Bevan

Francis Giles Overbury

James Mark Naden

Dean Kitchener

Andrew Urquhart

Robin Paul Rickard

Graham Dolman

Steven Raymond Hall

David Neil Adams

William Waddoup

Simon Bates

John McNicol

Andrew P Winsor

Nicholas Hugh Latham

A base station including at least a transceiver switch is provided enabling the base station to transmit and receive data in either FDD or TDD mode from an antenna. The base station may be provided with a synthesizer which can be retuned from FDD to TDD mode or alternatively, an FDD and a TDD synthesizer and a switch enabling the transmitter and receiver of the base station to process FDD or TDD mode data respectively.

Dual mode base station

A broadband antenna structure has an electrically conductive enclosure with a closed end, over which a non-electrically conductive cover is placed. A radiating portion of an antenna feed layer comprising a conductive patch antenna element is placed in between the enclosure and the cover. The patch antenna element design is inherently broader band than that of conventional cavity-backed slot-radiating antennas, which are constrained in bandwidth by the need to keep the cavity formed in the enclosure small. The dielectric constant of the dielectric material of the cover reduces the required size of the conductive antenna element. The broadband antenna structure may be connected with an electronic device to form an antenna arrangement in which a portion of the antenna feed layer extends through an opening in a surface of an antenna housing, the portion being within an electronic device enclosure of the electronic device.

Antennas

A communications network comprises a plurality of linked nodes between a source and a destination. At each node the state of the network and its links are measured and stored with advertisements from other links. The node also performs a routing algorithm to define the instantaneously best path to the destination for the current network state. The routing algorithm responds to a plurality of metrics, including costs of links, and may use fuzzy logic which derives a fuzzy cost for candidate paths to derive a least fuzzy cost path to be followed. Traffic is shared between a path which is determined to be the best, at the current point in time, and a path which has previously been determined as the best path. The network can be a network which carries mobile cellular traffic.

Communication network route determination

In a cellular mobile telecommunications system the position of a mobile station can be estimated in terms of its bearing and range from a cell site. A multi-element direction finding antenna at the cell site receives signals from the mobile station and a receiver circuit estimates the bearing using the relative phase of signals received at different antenna elements and estimates the range by measuring round trip delay of signals to and from the mobile station. Motion of the mobile station can introduce errors into the bearing estimate due to frequency offset and frequency spread when element sampling is non-simultaneous. Compensation for these errors is introduced by using signal samples successively received at the same antenna element to estimate Doppler frequency offset and spread. It is necessary to ensure accurate calibration of the direction finding antenna and the receiver circuit. This is done by injecting calibration signals into the circuit near the antenna or into the antenna itself from a near field probe. Other aspects of calibration, such as antenna position, are calibrated using a remote beacon. A beacon emulating a mobile station but at a fixed, known location, or a beacon at an adjacent cell site may be used.

Position location method and apparatus for a mobile telecommunications system

Current telecommunications device transmission stages require a significant number of analogue (DAC) components. The present invention provides a digital to analogue converter implementation for coupling to the digital signal processing (DSP) stage of the device and comprises a DAC and means to nullify the output of the DAC over part of the DSP data output period to produce a series of pulses corresponding to this data. The pulses are bandpass filtered to produce an analogue output signal at an intermediate frequency.

Digital to analogue converter implementation

Method and apparatus of converting between digital and analogue signal formats, wherein dither signals are combined with information signals to be converted, the dither signals being as a predetermined plurality of particular discrete frequencies that are outside desired information signal bandwidth and have orderly relation including to signal conversion sampling rate, which orderly relation aids looping of sequences of patterns in a related data stream having pattern-to-pattern transitions similar to within-pattern transitions. Specifically, discrete dither signal frequencies have integral relation with their minimum separation or spacing and with said sampling rate, the lowest frequency and the minimum frequency separation each being whole number divisors or submultiples of higher dither frequencies andor of the signal conversion rate.

Digital/analogue conversion

A frequency selective noise reduction circuit and finds application in receiver demodulator arrangements in mobile telecommunication base stations. A receive signal is divided into two paths. One path includes a Phase Lock Loop circuit (PLL) which is employed to identify noise. The noise signal is inverted and then combined with the other signal.

Radio frequency noise reduction arrangement

A method and apparatus of reducing interference in a broadband radio frequency link is disclosed. Different signals are received by two antenna elements, in a first case the signals comprise differently polarized signals at the same or an offset frequency; in a second case the signals comprise a wanted signal and an interference signal, wherein the interfering signal is treated as an independent channel. The method comprises the steps of receiving radio frequency signals on two independent paths, selecting a portion of the radio frequency signal in each receive path or the desired signal path after demodulation where a predetermined frequency or band of frequencies is known to be absent; measuring the signal power; determining weights in a feedback path; and applying the feedback control signals to an algorithm which determines the weight(s) applied to the wanted signal such that the signal power in the summed signal(s) due to the interfering signal is reduced or cancelled.

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Potters Bar, United Kingdom

Christopher John Reed