Modulation type independent carrier recovery for broadband wireless communication systems

In this paper we present a modulation type and baud rate independent synchronous receiver concept for millimeter-wave and sub-millimeter-wave transceivers. The synchronous receiver includes an analog feed-forward carrier recovery and a phase-locked-loop block. The carrier is recovered at the receiver employing a strong local oscillator signal transmitted along with the complex modulated data. The modulation type dependent amplitude and phase variations of the local oscillator signal are eliminated in the analog carrier recovery block of the synchronous receiver employing a frequency divider circuit. For a certain minimum ratio between the local oscillator power and the integrated data power over the entire bandwidth, a stable carrier can be recovered at the output of the frequency divider. The feasibility of this concept is validated through measurement utilizing an E-Band (71-76 and 81-86 GHz) direct conversion analog front end. The proposed synchronous receiver concept is carrier frequency independent and can be applied to communication systems working at higher carrier frequencies approaching THz domain as long as frequency dividers are available.