Patent ID: 8774296

Claim:
An apparatus for calculating channel frequency domain correlation so as to calculate a minimum mean square error filter coefficient, comprising: a pilot channel preliminary estimation unit configured to preliminarily estimate a frequency domain channel response at pilot subcarriers of a receiving signal to obtain a pilot channel preliminary estimation value; a determination unit configured to determine, from channel frequency domain correlation values which can be estimated directly, a channel frequency domain correlation value which can be reliably calculate, and consider any of the remaining channel frequency domain correlation values which can be estimated directly and a channel frequency domain correlation value which cannot be estimated directly as a channel frequency domain correlation value which cannot be reliably calculated; a first channel frequency domain correlation value calculation unit configured to calculate the channel frequency domain correlation value which can be reliably calculated using the pilot channel preliminary estimation value to obtain a reliably calculated channel frequency domain correlation value; wherein the first channel frequency domain correlation value calculation unit is configured to calculate the channel frequency domain correlation value which can be reliably calculated according to the following formula: θ ⁢ Δ ⁢ ⁢ f ⁡ ( q ) = E { ( k 1 , l 1 ) , ( k 2 ⁢ l 2 ) } ∈ P q ⁢ { H k 1 , l 1 LS · ( H k 2 , l 2 LS ) * θ Δ ⁢ ⁢ t ⁡ ( l 2 - l 1 ) } wherein, θ Δƒ indicates the channel frequency domain correlation value which can be realiably calculated, q, k 1 , k 2 , l 1 and l 2 are integers, P q is a set composed of all of pairs of subscript {(k 1 l 1 )} meeting k 2 −k 1 =q, H k 1 ,l 1 LS is a pilot channle preliminary estimation value of the k 1 th subcarrier in the l 2 th OFDM symbol as a pilot subcarrier, H k 2 ,l 2 LS is a pilot channel preliminary estimation value of the k 2 th subcarrier in the l 2 th OFDM symbol as a pilot subcarrier, and θ Δt (l 2 −l 1 ) is a time domain correlation value; and a second channel frequency domain correlation value calculation unit configured to calculate the channel frequency domain correlation value which cannot be reliably calculated, using the reliably calculated channel frequency domain correlation value.