Apparatus for receiving ranging signals
AssigneeParthus (UK) Limited
InventorAnthony R. Pratt
Life of this patent
Estimating the term…
Abstract
Apparatus for receiving ranging signals (e.g. signals from Global Positioning System satellites) has a receiver coupled to a plurality of spaced antennas. The receiver includes a signal combiner which receives, from a processing circuit, signal components individually representative of a characteristic of the received ranging signals (e.g. signal-to-noise ratio) at a respective antenna and weights the said components to produce a range estimate of improved accuracy in difficult reception conditions. In one embodiment receiver includes a common i.f. channel which filters a combination signal representative of all the incoming signals in order substantially to maintain phase coherence between the incoming signals, yielding improvements in carrier phase measurement and discrimination.
Claims76
A position-fixing receiver arranged to receive simultaneously ranging signals produced by a plurality of remote transmitters which include at least one satellite and which form part of a satellite-based universal ranging system, wherein the apparatus comprises a radio receiver unit having a plurality of radio frequency (r.f.) input connections, and a plurality of spaced-apart antennas each connected to a respective said input connection, and wherein the receiver unit includes:
- an antenna signal processing circuit responsive to the ranging signals for producing output signals including components each individually representative of at least one characteristic of the ranging signals received at a respective antenna a signal replica generator for generating replicas of the received ranging signals, and
- a signal combiner configured to receive the outout signals, to monitor, for each of a plurality of said remote transmitters, at least one characteristic of the ranging signals from that remote transmitter via the different antennas, and to weight one or more of said components to yield a range estimate.
A position-fixing receiver arranged to receive simultaneously ranging signals produced by a plurality of remote transmitters which include at least one satellite and which form part of a satellite-based universal ranging system, wherein the apparatus comprises a radio receiver unit having a plurality of radio frequency (r.f.) input connections, and a plurality of spaced-apart antennas each connected to a respective said input connection, and wherein the receiver unit includes:
- an antenna signal processing circuit responsive to the ranging signals for producing output signals including components each individually representative of at least one characteristic of the ranging signals received at a respective antenna, a code-tracking loop, and
- a signal combiner configured to receive the output signals, to monitor, for each of a plurality of said remote transmitters, at least one characteristic of the ranging signals from that remote transmitter via the different antennas, and to weight one or more of said components to yield a range estimate.
A position-fixing receiver arranged to receive simultaneously ranging signals produced by a plurality of remote transmitters which include at least one satellite and which form part of a satellite-based universal ranging system, wherein the apparatus comprises a radio receiver unit having a plurality of radio frequency (r.f.) input connections, and a plurality of spaced-apart antennas each connected to a respective said input connection, and wherein the receiver unit includes:
- an antenna signal processing circuit responsive to the ranging signals for producing output signals including components each individually representative of at least one characteristic of the ranging signals received at a respective antenna a signal replica generating replicas of the received ranging signals, and
- a signal selection arrangement configured to receive the output signals, to monitor, for each of a plurality of said remote transmitters, at least one characteristic of the ranging signals from that remote transmitter via the different antennas, and to select one or more of said components to yield a range estimate.
Apparatus arranged to receive ranging signals produced by a plurality of remote transmitters which form part of a universal ranging system, wherein the apparatus comprises a radio receiver unit having a plurality of r.f. input channels and a plurality of spaced-apart antennas each connected to a respective said input channel, wherein:
- the receiver unit includes at least one antenna signal processing circuit responsive to the carrier phases of the ranging signals received via at least one of the antennas,
- each input channel i includes a multiplying element arranged to combine a respective first multiplier signal Mi with an incoming signal in the channel, the multiplier signals constituting an orthogonal set of signals, and
- the receiver unit further includes a combining element for combining the multiplier output signals resulting from combining the incoming signals with the multiplier signals, a common intermediate frequency channel including common filtering means for receiving the multiplier output signals from the combining element, an analog-to-digital converter (ADC) coupled to an output of the common channel, and a processor for applying second multiplier signals to a digitized signal obtained from the ADC thereby substantially to isolate from each other signals representative of respective incoming signals from respective antennas, each second multiplier signal corresponding to or being the same as the first multiplier signal for the respective antenna,
- whereby phase coherence is maintained between the different signals associated with the different antennas.
Apparatus arranged to receive ranging signals produced by a plurality of remote transmitters which form part of a universal ranging system, wherein the apparatus comprises a radio receiver unit having a plurality of radio-frequency (r.f.) input channels, and a plurality of spaced-apart antennas each connected to a respective said input channel, wherein the receiver unit includes an arrangement for coherently combining, processing and separating signals representative of the ranging signals received by the antennas from each of a plurality of the transmitters, the arrangement including a common signal processing channel including common filtering means to maintain phase coherence between the separated signals associated with any one of said transmitters.
A position-fixing receiver arranged to receive simultaneously ranging signals produced by a plurality of remote transmitters which include at least one satellite and which form part of a satellite-based universal ranging system, wherein the apparatus comprises a radio receiver unit having a plurality of radio frequency (r.f.) input connections, and a plurality of spaced-apart antennas each connected to a respective said input connection, and wherein the receiver unit includes:
- an antenna signal processing circuit responsive to the ranging signals for producing output signals including components each individually representative of at least one characteristic of the ranging signals received at a respective antenna, a code-tracking loop, and
- a signal selection arrangement configured to receive the output signals, to monitor, for each of a plurality of said remote transmitters, at least one characteristic of the ranging signals from that remote transmitter via the different antennas, and to select one or more of said components to yield a range estimate.
Dependencies are inferred from the claim text.