Abstract: A GPS RF front-end is disclosed comprising an antenna for receiving GPS signals, an analog to digital converter for sampling received GPS signals and interface circuitry for outputting the GPS signal samples. The GPS RF front-end is configured to vary the sample resolution of GPS signal samples outputted. Also disclosed is a corresponding method of providing a position fix, storage medium and apparatus for the same.

Abstract: A GPS receiver (10) is disclosed comprising a GPS antenna and a GPS RF front-end including an analogue to digital converter for sampling received GPS signals; and a processor for outputting, including to an external device, the GPS signal samples together with ancillary information either directly or indirectly describing characteristics of the GPS signal samples and/or the GPS signals contained therein. Also disclosed is a corresponding method of providing a position fix and a computer program, computer-readable storage medium and apparatus for the same.

Abstract: The present invention provides for a method of receiving a signal spread over a frequency range, and in particular a direct sequence spread spectrum signals including the step of employing a Fast Fourier Transform (FFT) in the Doppler search. In particular, the invention relates to the receipt of spread spectrum signals such as those transmitted as part of a GPS system.

Abstract: A method of determining a GPS position fix. The method includes: (i) sampling received GPS signals and storing those samples; (ii) conducting preliminary processing of those GPS signal samples to determine the likelihood of being able to obtain a position fix during later, final processing of those GPS signal samples; and (iii) after step (ii), conducting final processing of those GPS signal samples to obtain a position fix.

Abstract: A communications system comprises at least one beacon device capable of wireless message transmission and at least one portable device capable of receiving such a message transmission. The beacon is arranged to broadcast a series of inquiry messages each in the form of a plurality of predetermined data fields arranged according to a first communications protocol, such as Bluetooth. For the delivery of additional data via broadcast, and in particular data including location information, the beacon adds to each inquiry message prior to transmission an additional data field carrying broadcast data, with the portable device receiving the transmitted inquiry messages including the location data and reading the broadcast data from the additional data field.

Abstract: A method of generating a map display for a graphical user interface (GUI) comprising the steps of displaying a map, highlighting a first area on the map surrounding a first position fix wherein the size of the area corresponds to the accuracy of the first position fix and highlighting a second area on the map surrounding a second position fix wherein the size of the second area corresponds to the accuracy of the second position fix. Either (a) when the first and second areas overlap, either (i) the one corresponding to the most recent or accurate position fix is displayed on top of the other or (ii) the highlighting of the overlapping area is different from that of those parts of the first and second areas which do not overlap, or (b) the manner in which at least one of the position fixes is obtained is indicated by the color of the highlight. The area highlighted on the map surrounding the position fix may be a shape other than a circle.

Abstract: A GPS RF front-end is disclosed comprising an antenna for receiving GPS signals, an analog to digital converter for sampling received GPS signals and interface circuitry for outputting the GPS signal samples. The GPS RF front-end is configured to vary the sample resolution of GPS signal samples outputted. Also disclosed is a corresponding method of providing a position fix, storage medium and apparatus for the same.

Abstract: A method of acquiring a received spread spectrum signal, especially a GPS signal, is disclosed together with a spread spectrum signal receiver and a cellular telephone incorporating such a receiver. The method comprises the steps of: providing a replica signal containing a pseudorandom noise code, corresponding to that of the spread spectrum signal; providing a subject signal containing two fragments of the spread spectrum signal initially received during respective time periods between which a further time period elapses; and coherently correlating the replica signal with the subject signal over the two fragments.

Abstract: In accordance with the present invention, a method of processing a sampled signal stream containing at least one spread spectrum signal is provided together with a receiver, computer, computer-readable storage medium and computer program for the same. The method comprises the steps of processing samples at a first bit level and, either in parallel or subsequently, processing samples at a second bit level, different from the first bit level.

Abstract: A method of determining a GPS position fix comprising the steps of: (i) sampling received GPS signals and storing those samples; (ii) conducting preliminary processing of those GPS signal samples to determine the likelihood of being able to obtain a position fix during later, final processing of those GPS signal samples; and (iii) after step (ii), conducting final processing of those GPS signal samples to obtain a position fix.

Abstract: A method of despreading GPS spread spectrum signals containing pseudorandom noise (PRN) code sequences and received by a GPS receiver (24) is disclosed together with a GPS receiver (24) and a mobile communications device (MS1) (especially a mobile cellular telephone) for the same. The method comprises the steps of providing Doppler information relating to an estimate of the variation in Doppler shift as observed on the target signal by the GPS receiver and which is attributable to the motion of the GPS satellite; and correlating the target signal with a reference signal containing corresponding PRN code sequences, wherein, in the course of a single dwell, the correlation is modified as a function of the Doppler information.

Abstract: Methods of providing an estimate of the location of a first device are discloses comprising the steps of determining the location of a separately housed, second device located near to the first device; providing the location of the second device to the first device; and using the location of the second device as an estimate of the location of the first device. Either the second device is arranged to perform a function based on its location other than providing its location as an estimate of the location of the first device, or the location of the second device is provided to the first device using a wireless communications link.

Abstract: A positioning system, apparatus and method include a transmitter (2), a receiver (4) and a plurality of reflectors (6). A signal is transmitted from transmitter to receiver both directly and via the reflectors (6). A location server (8) calculates the unknown position of the transmitter or receiver by identifying signal components (40) with reflectors (6).

Abstract: A GPS receiver is disclosed which has an omnidirectional antenna and a directional antenna and is configured to (i) acquire a first GPS signal from the output of the directional antenna, either alone or combined with the output of the omnidirectional antenna, and (ii) acquire a second GPS signal from the output of the omnidirectional antenna alone. Also, disclosed is a GPS receiver having an omnidirectional antenna and a directional antenna which is configured to acquire a GPS signal from the output of the directional antenna alone.

Abstract: A method of determining the position of a mobile unit (MS1) having a GPS receiver (24) is disclosed. The method comprising the steps of measuring mobile unit pseudoranges at the mobile unit (MS1) using the GPS receiver (24); providing reference pseudoranges corresponding to a reference location situated remote from the mobile unit (BS1); and determining the position of the mobile unit (MS1) relative to the reference location (BS1) as a function of both the reference pseudoranges and the mobile unit pseudoranges.

Abstract: A method of despreading a plurality of GPS spread spectrum signals received by a GPS receiver (24) is disclosed together with a GPS receiver (24) and a mobile communications device (MS1) (especially a mobile cellular telephone) for the same. The method comprises the steps of acquiring a first GPS signal from the stored samples; obtaining frequency information relating to variations in the frequency of the first acquired signal as measured by the GPS receiver; and using the frequency information to acquire a second GPS signal. The frequency information may be used to acquire the second GPS signal in the course of a single dwell and may also, for a digital GPS receiver, relate to variations in the frequency of the first acquired signal present in stored samples.

Abstract: A method of providing an estimate of the location of first and second devices MS1, MS2 comprising the steps of obtaining at least one range measurement from the first device MS1 to a known reference point BS1, GPS SVs; obtaining at least one range measurement from the second device MS2 to a known reference point BS1, GPS SVs, the second device MS2 being located near to the first device MS1; and calculating an estimate of the location of the devices MS1, MS2 using range measurements obtained with respect to both the first and second devices MS1, MS2.

Abstract: A method and apparatus for receiving a spread spectrum signal at a mobile communications terminal, including the step of processing the signal for the purposes of signal acquisition and signal tracking, monitoring movement of the mobile terminal and deriving a signal indicative of a characteristic of movement of the mobile terminal, and further including changing the mode of the processing of the incoming spectrum signal in response to the signal indicating the said characteristic of movement of the mobile terminal.

Abstract: A mobile device (MS) is disclosed comprising a GPS receiver (14) and an audible alarm (13, 15) configured to sound, during operation of the GPS receiver, in response to either adverse performance of the GPS receiver or to an event which is adverse or likely to be adverse to the performance of the GPS receiver. The alarm may sound in response to the inability of the GPS receiver to either acquire or track a GPS signal, or obtain or maintain a position fix. Also, the alarm may sound in response to movement of the GPS receiver, including acceleration and higher order movement of the GPS receiver, in so far as that movement is adverse to the performance of the GPS receiver.

Abstract: A method of despreading GPS spread spectrum signals containing pseudorandom noise (PRN) code sequences and received by a GPS receiver (24) is disclosed together with a GPS receiver (24) and a mobile communications device (MS1) (especially a mobile cellular telephone) for the same. The method comprises the steps of providing Doppler information relating to an estimate of the variation in Doppler shift as observed on the target signal by the GPS receiver and which is attributable to the motion of the GPS satellite; and correlating the target signal with a reference signal containing corresponding PRN code sequences, wherein, in the course of a single dwell, the correlation is modified as a function of the Doppler information.