Interferences rejection by testing-telling spread spectrum systems

A new system for narrowband interference rejection using a two-way Spread Spectrum (SS) communication has been presented.¹ The system employs the inherent capability in a two-way Frequency Hopping (FH) channel to reject these hops hit by narrowband interference (intentional or unintentional). Following the initial acquisition of synchronization, the system undergoes a testing-telling process and, once these interference tones are detected, simple convolutional codes can be effectively used without interleaving or other sophisicated coding techniques. Error bounds are formulated for a noncoherent Frequency Shift Keying (FSK) channel under worst case jamming plus White Gausian noise. These bounds show the adequacy of the new technique for narrowband interference rejection in two-way SS channel.