Apparatus and method for sampling timing compensation in multi-carrier system

A method for sampling timing compensation at a receiver of a communication system, wherein each of a first and a second symbol signals comprises two pilot signals transmitted via a first and a second pilot subchannels respectively, and the first and the second pilot subchannels comprise a first and a second pilot indexes respectively, the method comprising:

• generating first frequency responses of two of the pilot signals transmitted over the first pilot subchannel;
• generating second frequency responses of the other two of the pilot signals transmitted over the second pilot subchannel;
• generating a first difference between the first frequency responses of the first and second symbol signals;
• generating a second difference between the second frequency responses of the first and second symbol signals;
• calculating a timing offset according to a subtraction between the first and the second differences;
• and
• performing sampling timing compensation according to a phase rotation corresponding to the timing offset.

An apparatus for sampling timing compensation at a receiver of a communication system, wherein each of a first and a second symbol signals comprises transmitted via a first a second pilot subchannels respectively, and the first and the second pilot subchannels comprise a first and a second pilot indexes respectively, the apparatus comprising:

• a pre-FFT processing device for processing the first and the second symbol signals in a time domain;
• a FFT for transforming the first and the second symbol signals from the time domain to a frequency domain;
• a pilot subchannel estimator for generating first frequency responses of two of the pilot signals transmitted over the first pilot subchannel and generating second frequency responses of the other two of the pilot signals transmitted over the second pilot subchannel;
• a timing offset estimator, coupled to the pilot subchannel estimator, for calculating a timing offset according to a first difference between the first frequency responses of the first and second symbol signals, a second difference between the second frequency responses of the first and second symbol signals and a subtraction between the first and second differences;
• a phase rotator, coupled to the timing offset estimator, for performing sampling timing compensation according to a phase rotation corresponding to the timing offset;
• and
• a adjusting device for adjusting the operation of the pre-FFT processing device.

An method for sampling timing compensation at a receiver of a communication system, wherein each of a first and a second symbol signals comprises two pilot signals transmitted via a first and a second pilot subchannels respectively, and the first and the second pilot subchannels comprise a first and a second pilot indexes respectively, the method comprising:

• processing the first and the second symbol signals in a time domain;
• transforming the first and the second symbol signals from the time domain to a frequency domain;
• generating first frequency responses of two of the pilot signals transmitted over the first pilot subchannel;
• generating second frequency responses of the other two of the pilot signals transmitted over the second pilot subchannel;
• generating a first difference between the first frequency responses of the first and second symbol signals;
• generating a second difference between the second frequency responses of the first and second symbol signals;
• calculating a timing offset according to a subtraction between the first and second differences;
• performing sampling timing compensation according to a phase rotation corresponding to the timing offset;
• and
• adjusting the operation of the step of processing symbol signals in the time domain.