Method and apparatus for correlation detection of multi-level signals with non-standard deviations

• Main Authors: WADIN CRAIG P, CHANG CHUN-YE SUSAN, POWELL, II CLINTON C
• Format: Patent
• Language: English
• Published: 17.07.2001
• Edition: 7
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION

A method (200) of decoding a multi-level synchronous protocol having a first portion encoded as M/2-level signals and a subsequent portion encoded as M/2-level signal or M-level signals, wherein the M/2-level signals have expected larger than normal variation of deviations includes steps of decoding (202) the first portion using a biased mode which uses M correlators shifted (204) to adequately cover the frequency range of the expected larger than normal variation of deviations and determining (206) from decoding of the first portion whether the subsequent portion is the M/2-level or M-level signal. If a M/2-level signal is found, continue decoding (210) in the biased mode. If it's the M-level signal, then decoding continues in standard mode (214), which uses M correlators that are spaced in frequency to match M spectral deviations within a predetermined frequency range.