PROBLEM TO BE SOLVED: To provide a communication device which is capable of reducing an operation amount required to separate multiple transmission signals based on multiple reception signals received through multiple antennas.SOLUTION: A communication device 3 obtains a residual component which is obtained by removing a component corresponding to other transmission signal candidates except a predetermined transmission signal among multiple transmission signals from a signal corresponding to any of multiple reception signals; by making the closest value to the residual component among values the predetermined transmission signal can take as a candidate of the predetermined transmission signal, and by making collection of a pair of the candidate of the predetermined transmission signal and a candidate of another transmission signal as a candidate group, obtains multiple candidate groups by changing the predetermined transmission signals; by selecting a pair of transmission signal candidates common to multiple candidate groups, and calculating a distance between a pair of estimated reception signals corresponding to the pair of transmission signal candidates and the multiple reception signals regarding each of selected pairs of transmission signal candidates, and estimates a pair of transmission signal candidates which has the shortest distance as multiple pairs of transmission signals.