Geometrical closed loop line of sight (LOS) multiple-input-multiple-output (MIMO). Singular value decomposition (SVD) processing for a LOS communication channel into respective channel matrices, and appropriate processing of signals within transmitter and/or receiver communication devices operate to support very high data throughput, including approaching or converging to the Shannon limit channel capacity (e.g., bits/sec/Hz). Certain communication systems operate with multi-antenna communication devices, and sometimes, the optimal spacing between those respective antennae cannot be achieved. Appropriate processing can recover most, if not all, of any performance degradation as may be incurred by a deviation from the perfectly optimal spacing between those respective antennae. In addition, any deleterious effects of phase noise among the antennae may be mitigated by driving the antennae using a common or singular local oscillator, or tracking the communication channel (e.g., channel estimation, tracking, etc.) and updating the respective SVD channel matrices based upon such phase noise.