Apparatus for estimating phase error and phase error correction system using the same

A phase error correcting system for correcting a carrier phase error, comprising:

• a phase error estimating apparatus which includes:
• a probability value estimating means for estimating a negative log probability value for each transmission symbol by transforming a soft output information transferred from the outside to a log A posterior probability ratio (LAPPR) value;
• an APP value calculating means for calculating a posterior probability (APP) value by applying a negative exponential function to the transmission symbol;
• an average value deciding means for deciding an average value for each transmission symbol using the probability information entirely, partially, or selectively according to a probability information type;
• and
• a symbol phase estimating means for estimating a phase of a symbol based on the decided average value,
• wherein the phase error estimating apparatus repeatedly corrects a phase error based on probability information of a transmission signal outputted from a turbo decoder to correct a phase error at a low signal-to-noise ratio.