Patent ID: 7733975

Claim:
A receiver of a Multiple Input Multiple Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) communications system, the receiver comprising: at least one receiving antenna for receiving radio frequency signals from at least one receiving path; wherein a pilot signal is extracted from each of the received radio frequency signals; a receiving signal transforming module coupled to the at least one receiving antenna for receiving the radio frequency signals and generating transformed signals accordingly; a signal converting device coupled to the receiving signal transforming module for converting the transformed signals to converted signals; a signal summation device coupled to the signal converting device for summing products of the converted signals and complex conjugates of pilot signals corresponding to the converted signals and accordingly generating a sum result, and a Phase Lock Loop (PLL) coupled to the signal summation device, for estimating a phase error according to the sum result, the converted signals, and the complex conjugates of the pilot signals.