Method for estimating phase error in MIMO OFDM communications system

A method for estimating a phase error in a receiver of a MIMO OFDM communications system, the method comprising:

• executing Hermitian transpose on a channel coefficient matrix of the MIMO OFDM communications system for generating a Hermitian-transposed channel coefficient matrix;
• multiplying a received signal matrix of the receiver with the Hermitian-transposed channel coefficient matrix for generating converted signals;
• summing products of the converted signals and complex conjugates of pilot signals corresponding to the converted signals for generating a sum result, wherein the pilot signals are extracted from the received signal matrix;
• and
• generating the phase error according to the sum result, the converted signals, and the complex conjugates of the pilot signals.

A method for estimating a phase error in a receiver of a MIMO OFDM communications system, the method comprising:

• executing Hermitian transpose on a channel coefficient matrix of the MIMO OFDM communications system for generating a Hermitian-transposed channel coefficient matrix;
• multiplying the Hermitian-transposed channel coefficient matrix with the channel coefficient matrix for generating a product channel coefficient matrix;
• inversing the product channel coefficient matrix for generating an inversed product channel coefficient matrix;
• adding a real constant to each element on diagonal of the inversed product channel coefficient matrix for generating a constant-added inversed product channel coefficient matrix;
• multiplying the constant-added inversed product channel coefficient matrix with the Hermitian-transposed channel coefficient matrix for generating a diversity gain matrix;
• and
• generating the phase error according to the diversity gain matrix, a received signal matrix, and a pilot signal matrix.