Patent ID: 8019021

Claim:
A method for estimating a carrier to interference and noise ratio (CINR) when a preamble symbol transmit power is amplified in comparison with a data symbol transmit power, and there are subcarriers not transmitting a preamble at a receiver of an orthogonal frequency division multiplex (OFDM) system, the CINR estimating method comprising: (a) receiving a preamble symbol and transmit subcarrier transmitted from a base station and calculating an interference power, a transmit subcarrier noise power and a receive power, the receive power being given as a power value used to transmit a preamble and data symbol at a base station; (b) estimating a CINR value of the preamble using the interference power, the transmit subcarrier noise power, and the receive power; (c) calculating a non-transmit subcarrier noise power from a subcarrier not transmitting the preamble; and (d) calculating an average of the CINR using the CINR value of the preamble and the non-transmit subcarrier noise power.