Blind direction of arrival estimation systems and methods

A method comprises:

• receiving a signal from each of a plurality of antenna elements of an antenna array, the signal corresponding to a radio frequency signal received at the antenna array;
• determining at least two samples of the signal over a symbol period for each of the plurality of antenna elements;
• determining error estimates for each antenna element of the plurality of antenna elements;
• determining a line or a plane that fits each of the error estimates;
• determining a direction of arrival for the radio frequency signal by performing a lookup based on one or more parameters associated with the line or the plane;
• and
• determining an element delay for each element of the antenna array based on the direction of arrival.

A circuit comprising:

• an input to receive a signal corresponding to a radio frequency signal received at each element of an antenna array;
• a beamforming circuit configured to:
• determine two or more samples of a symbol period of the signal from each antenna element;
• square a power value of each of the two or more samples;
• add the squared power values for each of the two or more samples to produce a sinusoidal signal;
• correlate the sinusoidal signal to one or more second sinusoidal signals to determine an error estimate for each element of the antenna array;
• determine one of a line or a plane that best fits the error estimates;
• determine a direction of arrival of the radio frequency signal by looking up the direction of arrival from direction of arrival data in a memory based on one or more parameters of the line or the plane;
• and
• determine a fractional delay for each antenna element based on the determined direction of arrival of the radio frequency signal.