Interference cancelation has been mainly performed using arrays, in an important issue in communication both array and spatial cancelation and time domain approach were used. In array applications, depth of cancelation may dependent on the interferences to background power ratio and their spatial distributions. Also, array cancelers are inadequate when the signals are less than an array beamwidth apart. The latter was dealt with using supperesolution and eigenanalysis methods. Different time domain methods were used in the past. Among them what is termed Cross-Coupled PEL. It is an arrangement of two PLL each one is locked on and tracking one signal of the two at the input. In fact the output of such a system is dependent on one signal or the other. In a way Cross-Coupled IPLL is a signal separator. For the case of more than two signals we proposed in this thesis the N-Cross Coupled PLL. It is used to receive and process one of the N signals while suppressing the others which could be looked upon as interchannel interference. N-Cross Coupled PLLs consist of N PLLs interconnected using amplitude control loops that estimate the instantaneous amplitude of each signal. N-i signals are then subtracted from the input to leave, as clear as possible, one signal to be handled by the corresponding PLL. If the PLLs are used as FM demodulators then we get at the output the information contained in each signal regardless of the signal's relative powers and or their modulation content. Thus N-Cross Coupled PLLs behaves as N signals separator.