Cambridge Positioning Systems Limited

Nujira Limited

Snaptrack Incorporated

James Brice

Peter James Duffett-Smith

Paul Hansen

Malcolm David MacNaughtan

John Christopher Clarke

Guy Albert Graube

Craig Andrew Scott

There is described a method of controlling signal alignment in a power amplifier, comprising: receiving an input signal to be amplified; receiving a supply voltage for the power amplifier, the supply voltage being derived in dependence on the signal to be amplified; amplifying the input signal to produce an output signal; comparing the output signal with a plurality of distorted versions of the input signal, each distorted version of the input signal being associated with a different time delay value; and adjusting the timing of either the input signal or the supply voltage by an amount in dependence on a time delay value determined to be associated with a distorted version of the input signal which most closely matches the output signal.

Timing alignment for power amplifier

There is disclosed a method for generating pre-emphasis coefficients for a pre-emphasis stage of a non-linear distorting device, the method comprising the steps of: capturing, for a given time period, samples of an input signal and samples of an output signal; determining the direction of an error between the captured samples; adjusting the input signal in a direction to reduce the error to generate an estimate of the pre-distorted input signal; generating updated pre-distortion coefficients in dependence on the estimate of the pre-distorted input signal and generated pre-distortion coefficients for one or more previous time periods.

Generation of pre-distortion coefficients

A method of calculating the position or state of motion of one or more terminals is proposed in which each has a receiver capable of making measurements of signals received from one or more transmission sources for use in calculating the unknown position or state of motion of the or each terminal. At least one transmission source has a known directional transmission pattern, and the bearing from one of the receivers of the or each of the transmission source having a known directional transmission pattern is estimated. Weights are assigned to the measurements made by the one receiver, the weights being calculated from the bearing or bearings and the known directional transmission pattern of the transmission sources.

Location systems and methods

The invention described relates to a radio positioning system primarily for a mobile telephone network, in which a list of offsets in time, phase, frequency, or derivatives thereof, or their equivalents expressed as offsets in distance or derivatives thereof, of a plurality of transmission source signals, received at a given location, relative to a common reference are generated. Data is acquired from one or more receivers, the positions of which may be known or determined. Such data are offsets in time, phase, frequency, or derivatives thereof, respectively of signals received from the transmission sources relative to a reference source in each receiver or to each other. The acquired data is combined for calculating the list of offsets relative to the common reference.

Radio positioning systems

A location measurement unitfor a radio location measuring system has two or more coupling devicesfor picking up the signals from a plurality of base transceiver stations (BTSs) of a cellular radio communication system. A switching device, is connected to the coupling devices, for switching between the signals picked up by the coupling devices and/or one/two or more receivers-are connected to respective coupling devices, for receiving the signals picked up by the coupling devices. A processoris connected to the or each receiver, for processing the signals output by the receiver. A communications linkis connected to the processor, for transferring the processed signals to a calculation node

Radio location system measurement unit

There is described a method of providing a positioning service for plural terminals operating in a communication network which may, for example be a GSM telephone network. The terminals have receivers for receiving signals from transmission sources. In the method measurements of the signals received from one or more of the transmission sources by the receivers are made and the measurements transferred to one or more data nodes. At the data node(s) one or more records of one or more of the measurements are created and at least some of the records are transferred to one or more computing nodes. At the computing node(s) a table of the records transferred to the computing node is maintained and a computation is carried out, using at least part of the table, from which the positions or states of motion or relative positions or relative states of motion of said plural terminals and the transmission time offsets of the transmission sources are extractable.

Positioning systems and methods

The invention concerns a method of determining the position or change in position or state of motion of a receiver or receivers, the position or change in position or state of motion of which is or are not already known, in a network of transmission sources some or all of whose positions are known. At a first time, the relative offsets in time, phase, frequency, or derivatives thereof with respect to each other, or with respect to a reference source, of the signals received by a first receiver from a plurality of the transmission sources are measured. At a selected second time, the respective offsets of the signals received by the same or a second receiver, whose position or state of motion is not already known, from the plurality of the transmission sources are measured. Then the position of the receiver or receivers at the first or second times or the change in position of the first receiver between the first and second times or the state of motion of either receiver is calculated from the relationship between the first and second sets of relative offsets.

Growing community of inventors

Cambridge, United Kingdom

James Brice