US Patent 7280608 Real time dynamic correlator

Methods and systems are provided for evaluating electrical characteristics of a transmitter in real time using cross-correlation of a reference signal with a signal transmitted by the transmitter. A code generator is configured to generate reference code and test code that both include a plurality of frames of data. The reference code is output at a first rate and the test code is output at a second rate that is different from the first rate. A modulator is configured to modulate the reference code into a first modulated code. A correlator is configured to correlate the first modulated code with test code that has been modulated and transmitted by a transmitter.