A fast and accurate class of carrier recovery schemes

This paper introduces a class of carrier recovery scheme based on simple trigonometric identities. We revisit carrier recovery schemes that have been in use for many years, and compare their relative performances using quantitative metrics. We show that trigonometric identities can be used to recover carriers faster and better than conventional control loop based schemes in special cases where there is a unique frequency locked relationship between the carriers and the pilot of the scheme. PLL and Costas loop based schemes have been carried over from analog systems and are now implemented on digital hardware without fully exploiting the advantages of digital systems, but we propose a simple scheme that can outperform these legacy methods in specific protocols, and be incorporated into modern receivers of any protocol having frequency-locked carriers of a pilot. We present results for the specific case of the FM-RDS protocol as an example.