Interference signal canceling apparatus and interference signal canceling method

A base station having an interference signal canceling apparatus, wherein said interference signal canceling apparatus comprises likelihood calculating means for calculating likelihoods of respective symbols included in an input signal;

• threshold value judging means for judging a threshold value by comparing a calculated likelihood with an appointed threshold value in terms of size;
• rank deciding means for deciding the rank of symbols, in which said likelihood is said threshold value or more, on the basis of said likelihood;
• demodulating means for demodulating said symbols on the basis of the decided rank;
• and removing means for removing the demodulated symbols from said input signal and making the same into a new input signal.

A method for canceling an interference signal, comprising the steps of:

• calculating likelihoods of respective symbols included in input signals;
• selecting symbols in which said calculated likelihood is a threshold value or more;
• deciding a rank of said selected symbols in the order that said likelihood is higher;
• demodulating said symbols on the basis of said decided rank;
• and
• removing said demodulated symbols from said input signal, and making the same into a new input signal.