Patent ID: 6307896
Filing Date: 2001-10-23
Classification: H04B,H04N

Abstract:
An instrumentation receiver for generating a digitally modulated intermediate frequency signal from a digitally modulated radio frequency input signal, the digitally modulated radio frequency input signal being modulated by digital data generated at a symbol frequency and having a pilot signal coherent with the radio frequency carrier, comprising:a mixer having as inputs the digitally modulated radio frequency input signal and a local oscillator signal and having as an output the digitally modulated intermediate frequency signal;a local oscillator having as an input a control signal and having as an output the local oscillator signal, the control signal adjusting the frequency of the local oscillator signal such that in the digitally modulated intermediate frequency signal the pilot signal is coherent with the intermediate frequency carrier signal and equal to an integer multiple of the symbol frequency where the integer multiple is equal to or greater than one; anda wide bandwidth low pass filter having as an input the digitally modulated intermediate frequency signal from the mixer and having as an output the digitally modulated intermediate frequency signal with mixer sum products and local oscillator feed through from the mixer removed.