US Patent 9774419 Inband spurious detection and processing within communication systems

A communication device receives a transmitted signal from another communication device. This transmitted signal is generated within the another communication device based on predetermined digital data. The communication device then generates a first reference signal based on a copy of the predetermined digital data and subtracts the first reference signal from the transmitted signal to generate a first residual signal. The communication device then identifies at least one adaptation parameter based on the first residual signal and adapts the first reference signal using the at least one adaptation parameter to generate a second reference signal so that a first characteristic of the transmitted signal and a second characteristic of the second reference signal are approximately equal. The communication device then subtracts the second reference signal from the transmitted signal to generate a second residual signal processes the second residual signal to characterize inband spurious emission within the transmitted signal.