Abstract: The present invention relates to a method for synchronizing the signals coming from a set of data channels of a two dimensional optical read-out system. Said synchronization method comprises a step of cross-correlating the signals of a pair of adjacent channels for determining a relative phase delay between said adjacent channels. It also comprises a step of iterating the cross-correlation step for the different pair of adjacent channels of the set of data channels. It finally comprises a step of compensating for the relative phase delays thus obtained in order to align the signals from adjacent channels with each other. The present invention is based on, for example, the use of the optical cross talk existing between adjacent channels in a cross correlator that is able to determine the relative phase between two adjacent channels.

Abstract: The present invention relates to a bit detection method for detecting the bit values of bits of a channel data stream stored on a record carrier, wherein the channel data stream resides on an N-dimensional lattice of bits and comprises a plurality of contiguous bit units, each bit unit comprising at least one bit, wherein bit detection for the channel data stream is performed by an iterative procedure, each iteration being carried out on the basis of said bit units, wherein the bit values of the bits of a bit unit are detected by said iterative procedure based on the received HF signal values of the bits of said bit unit. The proposed method comprises an initialisation step, an updating step and an iteration such the method the bits are detected in an iterative but non-recursive way which allow for a high level of parallel processing in the implementation.