Channel estimating method in wireless communication system and apparatus thereof

An apparatus for estimating a channel in a wireless communication system, the apparatus comprising:

• a calculating unit calculating an interference coefficient based on a known structure of a pilot prior to receiving a signal;
• a channel estimating unit estimating a channel value in a frequency domain for a received signal of a subcarrier;
• an IDFT unit obtaining a channel value in a time domain by transforming the channel value from the frequency domain;
• and
• an interference cancelling unit calculating channel delay values based on the calculated interference coefficient and cancelling interference by subtracting the calculated channel delay values from the channel value in the time domain.

An apparatus for estimating a channel in a wireless communication system, the apparatus comprising:

• a channel estimating unit for estimating a channel value in a frequency domain for a received signal of a subcarrier;
• an IDFT unit for obtaining a channel value in a time domain by transforming the channel value from in the frequency domain;
• and
• an interference cancelling unit for calculating channel delay values based on an interference coefficient calculated with a known structure of a pilot and cancelling interference by subtracting the calculated channel delay values from the channel value in the time domain,
• wherein
• the interference cancelling unit includes:
• a first interference cancelling module that calculates channel delay values for each tap on a delay path based on an interference coefficient when delay information of the received signal is known and subtracts the channel delay values from the channel value in the time domain;
• an estimating module that estimates the channel delay information of the received signal when the delay information is unknown;
• and
• a second interference cancelling module that calculates channel delay values for each tap on a delay path based on the estimated channel delay information and subtracts the channel delay values from the channel value in the time domain.

A method for estimating a channel in a wireless communication system, the method comprising:

• calculating an interference coefficient based on a known structure of a pilot prior to receiving a signal;
• calculating a channel frequency response by performing least squares (LS) channel estimation of a received signal of a subcarrier;
• obtaining a channel impulse response in a time domain by performing inverse discrete Fourier transform (IDFT) on the channel frequency response;
• calculating channel delay values for each tap on a path for the received signal based on channel delay information and the interference coefficient;
• adding the calculated channel delay values;
• and
• cancelling interference by subtracting the channel impulse response in the time domain from the added channel delay value.

A method for estimating a channel in a wireless communication system, the method comprising:

• calculating an interference coefficient based on a known structure of a pilot, prior to receiving a signal;
• estimating a channel value of the received signal having a subcarrier in a frequency domain;
• obtaining a channel value in a time domain by transforming the channel value from the frequency domain;
• calculating channel delay values for each tap on a delay path based on the interference coefficient when delay information of the received signal is known and cancelling interference by subtracting the channel delay values from the channel value in the time domain;
• estimating channel delay information of the received signal when the delay information is unknown;
• and
• calculating channel delay values for each tap on a delay path based on the estimated channel delay information and cancelling interference by subtracting the channel delay values from the channel value in the time domain.