Patent ID: 8559571

Claim:
A calibration system employed in a multi-input-multi-output (MIMO) system for receiving a plurality of streams comprising: a first calibration circuit responsive to inphase (I) and quadrature (Q) pairs of streams and operative to calibrate each of the I and Q pairs, the first calibration circuit is operative to calibrate and compensate for gain offsets, phase offsets, and group delays on a per stream basis by using reference signals, wherein the first calibration circuit is configured to calculate a gain offset between the I and Q of each of the I and Q pairs of a stream of the streams, over ‘n’ number of samples of I and Q wherein ‘n’ is an integer, and to compensate for the calculated gain offset and to generate a gain compensated I and a gain compensated Q for each of the I and Q pairs of the stream and is further operative to use the gain compensated I and gain compensated Q to calculate a phase offset between the I and Q of each of the I and Q pairs of the stream and to compensate for the calculated phase offset and to calculate and compensate for a group delay and to generate first calibrated I and Q pairs of streams; a second calibration circuit responsive to the first calibrated I and Q pairs of streams and operative to calibrate across the streams, the second calibration circuit operative to use the first calibrated I and Q pairs of streams to calculate and compensate for phase delay of I and Q pairs of streams across the streams to generate phase compensated I and Q pairs of streams and to compensate the phase compensated I and Q pairs of streams for a second group delay across the streams.