METHOD AND ARRANGEMENT FOR RECOVERING A BINARY DC-FREE CODE FROM A FREQUENCY MODULATED SIGNAL

摘要

The invention is related to a method and an arrangement for recovering a binary DC-free code from a frequency-modulated signal, without any analog signal demodulation of the frequency-modulated signal. The invention relates more particularly to an ATIP bi-phase channel bit and timing recovery in a deteriorated wobble channel as e.g. required for high speed recording on optical storage media. The arrangement comprises a digital phase lock loop (DPLL) and a phase detector (12) uses a phase trellis and a maximum likelihood detection is applied to the phase trellis for providing a bi-phase channel bit signal (16) and a bi-phase clock signal (15), which is in time with the sampling point for the bi-phase channel bit signal (16) for recovering said binary code. The invention is also applicable for further data transmission systems based on frequency modulation as e.g. modem or wireless data communication systems.