Optical disc drive high frequency modulation signal detection

摘要

In a method of correcting a channel bit pattern that violates bi-phase modulation constraint in a bi-phase modulated portion of a high frequency modulation (HFM) signal, a sequence of channel bits is recovered from the HFM signal. The recovered sequence of channel bits is analyzed to generate a bi-phase modulation compliant sequence of channel bits based on the recovered sequence of channel bits, wherein the bi-phase modulation compliant sequence of channel bits does not violate the bi-phase modulation constraint in the bi-phase modulated portion of the HFM signal. Bi-phase modulated HFM bits are recovered from the bi-phase modulation compliant sequence of channel bits to generate a detection output corresponding to the recovered bi-phase modulated HFM bits.

主权项

1. A method of correcting a channel bit pattern that violates a bi-phase modulation constraint in a bi-phase modulated portion of a high frequency modulation (HFM) signal, the method comprising:
recovering a sequence of channel bits from the HFM signal; analyzing the recovered sequence of channel bits to generate a bi-phase modulation compliant sequence of channel bits based on the recovered sequence of channel bits, wherein the bi-phase modulation compliant sequence of channel bits does not violate the bi-phase modulation constraint in the bi-phase modulated portion of the HFM signal, wherein analyzing the recovered sequence includes
determining that a sub-sequence of the recovered sequence of channel bits violates the bi-phase modulation constraint,determining which bit in the sub-sequence of the recovered sequence of channel bits corresponds to a least reliable bit, andflipping the bit in the sub-sequence of the recovered sequence of channel bits that corresponds to the least reliable bit; and recovering bi-phase modulated HFM bits from the bi-phase modulation compliant sequence of channel bits to generate a detection output corresponding to the recovered bi-phase modulated HFM bits.