Patent ID: 7865158
Filing Date: 2011-01-04
Classification: H03J

Abstract:
1. A method of automatically correcting frequency of a local oscillator of a receiver, the method comprising: converting a received radio frequency (RF) signal to a baseband signal using a signal generated by the local oscillator, the frequency of the local oscillator being controlled by a control voltage signal; generating samples of the baseband signal; generating a pilot code sequence corresponding to a plurality of consecutive pilot symbols; generating a complex correlation of samples and a pilot code sequence for each of 4N consecutive pilot symbols, N being a positive integer; generating a phase vector corresponding to a phase difference between two consecutive pilot symbols, thereby generating 2N phase vectors; generating a combined phase vector by combining the 2N phase vectors, wherein when space time transmit diversity (STTD) is used, in-phase and out-of-phase components from two antennas are added to generate the combined phase vector, and when STTD is not used, two successive phase vectors corresponding to a single antenna are added to generate the combined phase vector; generating a phase error signal based on the combined phase vector; and generating the control voltage signal based on the phase error signal.