Method and apparatus for forming a remote beam

摘要

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 maximized 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.

主权项

1. An apparatus for forming a beam remotely at a plurality of spatially distributed antenna elements, the apparatus including:
a positioning-unit device coupled with a plurality of spatially distributed antenna elements, said positioning-unit device configured to generate a positioning signal and switch said antenna elements between first and second states in a predetermined switching sequence that is synchronised with said positioning signal wherein, in said first state, said antenna elements are configured to transmit said positioning signal; and a physically separate receiver configured to receive said positioning 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 the positioning signal from the antenna elements being switched to said first state in said switching sequence; mixing the received positioning signal with the modified reference signal to generate a mixed signal; and summing the mixed signal over a predetermined integration period to generate an accumulated signal that is indicative of the direction and magnitude of a beam formed remotely by said receiver at said antenna elements, wherein said switching sequence and its synchronisation with said positioning signal are known to said receiver.