Patent ID: 8229045

Claim:
An apparatus for measuring a carrier-to-interference and noise ratio (CINR) from a pilot symbol in a digital communication system, the apparatus comprising: a pilot symbol acquisition unit implemented by a processor for acquiring the pilot symbol from a baseband frequency signal; a signal estimation unit for estimating a pilot signal and a data signal from the pilot symbol; a power calculation unit for calculating a power value of the estimated data signal and calculating a power value of a noise signal from a difference between the pilot symbol and the estimated pilot signal; and a CINR calculation unit for calculating the CINR on the basis of the power values of the data and noise signals, wherein the pilot symbol acquisition unit acquires the pilot symbol according to a channel mode included in a terminal, the channel mode selected from among Band adaptive modulation and coding (AMC), partial usage of sub-channels (PUSC), optional partial usage of sub-channels (OPUSC), and full usage of sub-channels (FUSC), wherein the signal estimation unit comprises a gain mapping unit for estimating the data signal by multiplying the estimated pilot signal by a weighting.