Method and apparatus for forming a remote beam
AssigneeLocata Corporation Pty Ltd
InventorDavid Small
Life of this patent
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Abstract
A device and method are provided for forming a beam of a transmit antenna array in the direction of a positioning receiver. Since the beam of the transmit antenna array is formed remotely by the positioning receiver, the received gain of the incoming positioning signal is maximised while signals from other directions are attenuated, thereby mitigating any unwanted effects of multipath. Depending on the number of elements in the transmit antenna array and their physical distribution, the width of the beam can be made finer such that the positioning receiver only requires a simple omni-directional antenna to achieve an accurate positioning solution.
Claims20
An apparatus for manipulating a signal received from a plurality of spatially distributed antenna elements, the apparatus including:
- a transmitter coupled with a plurality of spatially distributed antenna elements, said transmitter being configured to generate a signal and switch said antenna elements between first and second states in a predetermined switching sequence that is synchronised with said signal wherein, in said first state, said antenna elements are configured to transmit said signal;
- and
- a physically separate receiver configured to receive said signal transmitted from said antenna elements, said receiver having a processor for:
- generating a reference signal;
- modifying said reference signal in substantial synchronisation with the receipt of said signal from said antenna elements being switched to said first state in said switching sequence;
- mixing the received signal with the modified reference signal to generate a mixed signal;
- and
- summing said mixed signal over a predetermined integration period to generate an accumulated signal,
- wherein said switching sequence and its synchronisation with said signal are known to said receiver.
A method for manipulating a signal received from a plurality of spatially distributed antenna elements, the method including the steps of:
- a) generating said signal;
- b) switching said spatially distributed antenna elements from a second state to a first state in a predetermined switching sequence that is synchronised with said signal, wherein, in said first state, said antenna elements are configured to transmit said signal;
- c) receiving, at a physically separate receiver, the transmitted signal;
- d) generating, in a correlator of the receiver, a reference signal for correlation with the received signal;
- e) applying, in substantial synchronisation with the receipt of said signal from said antenna elements being switched to said first state in said switching sequence, a predetermined offset to said reference signal to create a modified reference signal;
- f) mixing said received signal with said modified reference signal to create a mixed signal;
- and
- g) accumulating said mixed signal over an integration period to create an accumulated signal,
- wherein said switching sequence and its synchronisation with said signal are known to said receiver.
An apparatus for manipulating a signal received from a plurality of spatially distributed antenna elements, the apparatus including:
- a transmitter coupled with a plurality of spatially distributed antenna elements, said transmitter being configured to generate a signal and switch said antenna elements between first and second states in a predetermined switching sequence that is synchronised with said signal wherein, in said first state, said antenna elements are configured to transmit said signal;
- and
- a physically separate receiver configured to receive said signal transmitted from said antenna elements, said receiver having a processor for:
- generating a reference signal;
- modifying said reference signal in substantial synchronisation with the receipt of said signal from said antenna elements being switched to said first state in said switching sequence;
- mixing the received signal with the modified reference signal to generate a mixed signal;
- and
- summing said mixed signal over a predetermined integration period to generate an accumulated signal,
- wherein said switching sequence and its synchronisation with said signal are known to said receiver,
- and wherein said receiver includes at least one receive channel having a correlator, wherein said correlator is configured to selectively manipulate the phase and/or gain of said reference signal in substantial synchronisation with the receipt of said signal from said antenna elements being switched to said first state.
Dependencies are inferred from the claim text.