Patent attributes
A first noise variance estimator calculates a first noise variance estimation value based on an channel estimation value of a received signal. A minimum mean squared error (MMSE) filter performs equalization on a residual interference component that is obtained by subtracting an interference component and desired signal component from the received signal. A second noise variance estimator calculates a second noise variance estimation value by using the equalized residual interference component that is output from the MMSE filter. A first noise variance selector and second noise variance selector select either one of the first or second noise variance estimation value, or selects a mean value of the two noise variance estimation values. A filter coefficient calculator calculates a filter coefficient based on a first selected noise variance value. An extrinsic LLR calculator calculates an extrinsic LLR by using a second selected noise variance value selected by the second noise variance selector.
