Clock and Data Recovery Techniques

摘要

The Clock and Data Recovery Techniques (CDRT) contribute Inverse Signal Transformation (IST) reversing transmission channel transfer function to achieve a direct recovery of original data from and synchronization of receiver clock to received signals affected by deterministic and random distortions introduced by the channel. The CDRT include also Phase Frequency Recovery Techniques (PFRT) and Direct Synthesis of Receiver Clock (DSRC) presenting feed-forward phase control configurations using an oscillator clock for synthesizing a receiver clock synchronous to a received data carrying signal.

主权项

1. A method for direct synthesis of receiver clock (DSRC) using an oscillator clock for producing a synthesized clock synchronous to a referencing frame providing frequency and phase transmittal from a frame of a received orthogonal frequency division multiplexing (OFDM) signal, wherein a clock synthesis configuration comprises a phase detector measuring phase errors between the referencing frame and a corresponding frame of the oscillator clock, a programmable control unit (PCU) reading the measured phase errors in order to produce phase amendments, a phase synthesizer applying the phase amendments to the oscillator clock in order to produce the synthesized clock specified by the phase amendments without introducing uncontrolled phase transients; wherein the DSRC method comprises the steps of:
processing the received OFDM signal in frequency domain in order to recover selected tones from the received OFDM signal, using the recovered selected tones for detecting boundaries of the frame of the received OFDM signal, using the boundary detections for defining the referencing frame; using the phase detector for the measuring the phase errors between the referencing frame and the corresponding frame of the oscillator clock; using, by the PCU, preceding measured phase errors for calculating predicted phase amendments designed to compensate the measured phase errors; using, by the PCU, the measured phase errors and the predicted phase amendments for calculating phase tracking errors between a frame of the synthesized clock and the referencing frame; using, by the PCU, the phase tracking errors and following said predicted phase amendments for calculating following said phase amendments designed to minimize following said phase tracking errors; applying, by the phase synthesizer, the following phase amendments to the oscillator clock in order to minimize the phase tracking errors.