Training Sequence Design and Parameter Estimation of MIMO Channels with Carrier Frequency Offsets

This letter addresses the carrier frequency offsets and channel gains estimation problem for MIMO channels with multiple carrier frequency offsets that are not assumed to be equal for all transmit-receive antenna pairs. Training sequences are proposed for both flat fading and frequency selective fading MIMO channels. Under the proposed training sequences, sub-optimal performance of parameter estimation can be achieved by a subspace-based method with reasonable computational complexity. The method can also provide flexible tradeoff between complexity and performance