Patent ID: 8139693

Claim:
An estimation method, for use in a receiver of an orthogonal frequency division multiplexing (OFDM) system to estimate inter-carrier interference (ICI) power and noise power in a channel, the method comprising: receiving a first pilot signal and a second pilot signal carried on a first subcarrier and a second subcarrier, respectively, from the channel, wherein the first subcarrier and the second subcarrier are adjacent and differ by a first phase angle; obtaining a first channel estimation value and a second channel estimation value according to the first pilot signal and the second pilot signal; and determining a first channel response by performing a smooth process on the first channel estimation value and the second channel estimation value; obtaining a first expected value according to the difference between the first channel expected value and the first channel response; receiving a third pilot signal and a fourth pilot signal carried on a third subcarrier and a fourth subcarrier, respectively, from the channel, wherein the third subcarrier and the fourth subcarrier are adjacent and differ by a second phase angle; obtaining a third channel estimation value and a fourth channel estimation value according to the third pilot signal and the fourth pilot signal; and determining a second channel response by performing the smooth process on the third channel estimation value and the fourth channel estimation value; obtaining a second expected value according to the difference between the third channel expected value and the second channel response; and individually estimating the ICI power and the noise power according to the first phase angle, the second phase angle, the first expected value, and the second expected value.