US Patent 10305540 Measuring angle of incidence in an ultrawideband communication system

In an RF system comprising a first transceiver (96) and a second transceiver (98), a first transmission, T1, by the first transceiver (96) allows the second transceiver (98) to determine two possible valid angles of arrival, ±θ1, of T1. A second transmission, T2, from the second transmitter (98) to the first transmitter (96) containing θ1 and a bearing, α1, of a known fixed anchor relative to the second transmitter (98), allows the first transmitter (96) to determine two possible valid angles of arrival, ±θ2, of T2. From θ1, α1, θ2, and a bearing, α2, of the known fixed anchor relative to the first transmitter (96), the first transceiver (96) can determine the valid angle of arrival of T2.