SINGLE-CARRIER QUADRATURE AMPLITUDE MODULATION (SC-QAM) DOWNSTREAM CHANNEL FAST PRE-SCANNING

• Main Authors: GUO, Jinji, LIU, Pingbo, FENG, Xing, LI, Feng
• Format: Patent
• Language: English
• Published: 29.09.2022
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION; WIRELESS COMMUNICATIONS NETWORKS

A network device for providing single-carrier quadrature amplitude modulation (SC-QAM) downstream channel fast pre-scanning. An orthogonal frequency-division multiplexing (OFDM) downstream (DS) channel scan in a foreground process and a single-carrier quadrature amplitude modulation (SC-QAM) DS channel scan in a background process are simultaneously performed. When a first OFDM downstream channel is locked onto, OFDM downstream channel is paused while scanning for SC-QAM downstream channels continues. SC-QAM DS channels identified in the background process are stored in a table. Based on a scan of all OFDM channels and failure to lock onto any OFDM DS channels, the SC-QAM DS channel scan in the background process is stopped and a normal SC-QAM DS channel scan is started. SC-QAM DS channels in the table are scanned first to provide fast pre-scanning. A modem becomes operational with a qualified SC-QAM DS channel obtained from the table.