US 2003/0169834 A1Published application

Random walk filter timing recovery loop

AssigneeThe Aerospace Corporation

InventorsTien M. Nguyen, James Yoh, Ashok Mathur, Gary W. Goo

Life of this patent

Estimating the term…

Loading patent…

Abstract

A timing recovery loop includes a random walk filter counter for counting early, nominal and late arrivals of data transitions pulses of an input baseband signal waveform encoding a digital bit stream, and provides magnitude counts that are compared to a threshold value that when exceeded by the magnitude counts results in a delay adjustment of the generated adjusted timing pulses then remaining synchronized with the actual bit timing for maintaining bit timing lock. The adjusted timing pulses can then be used by a data detector for reliable data detection and reconstruction of the digital bit stream. The threshold value can be adaptively adjusted for reducing drop lock rates in the presence of changing channel environments.

Claims8

Dependent claims

A timing recovery loop for generating adjusted timing pulses from a baseband signal waveform encoding a self clocking digital bit stream, the timing recovery loop comprising,

a pulse detector for generating data transition pulses from the baseband signal waveform, for comparing the data transition pulses with the adjusted timing pulses for generating early signals and lag signals
a random walk counter for counting the early signals and lag signals for generating a running count,
a threshold comparator for determining when the running count exceeds a predetermined threshold value, and
a timing pulse delay adjustor for delaying the adjusted timing pulses for synchronizing the adjusted timing pulses with the data transition pulses when the running count exceeds the predetermined threshold value.

1 more element

Dependencies are inferred from the claim text.