US Patent 11550017 Angle of arrival estimation in a radio communications network

There is provided mechanisms for estimating angle of arrival of a radio signal in a radio communications network. A method is performed by a receiving radio transceiver device. The method comprises obtaining measurements of the radio signal as received in two receive beams covering a given angular sector. The two receive beams are created by analog beamforming in an antenna array. The receive beams have different complex beam patterns and at any angle within the given angular sector at most one of the complex beam patterns has gain below a threshold. The method comprises estimating the angle of arrival of the radio signal by comparing a complex amplitude of the measurements in the two receive beams to a discriminator function.