Upstream frequency control for docsis based satellite systems

US7463707B2 · kind B2 · utility

Assignee

• Broadcom Corporation · US

Inventors

• Mark Dale · Laguna Hills, US
• Dorothy Lin · Irvine, US
• Alan Gin · Newport Beach, US
• David Hartman · Laguna Hills, US
• Rocco Brescia · Laguna Beach, US
• Ravi Bhaskaran · Irvine, US
• Jen-chieh Chien · Lake Forest, US
• Adel Fanous · Irvine, US

Key dates

• Filing date: Jan 28, 2003
• Grant date: Dec 9, 2008
• Expiry date: Dec 4, 2024

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04B7/18513
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

A system and method for minimizing the frequency error of satellite modem signals at a satellite gateway. The gateway downstream baud (symbol) clock and the elements that control the upstream frequency (i.e., local oscillators in the conversion chain, A/D sample clocks) are locked to a common frequency reference. The gateway sends upstream satellite frequency offset information, such as satellite ephemeris data from which to calculate Doppler offset, to the satellite modem. The satellite modem locks the frequency of the satellite modems master oscillator to the recovered baud rate using a frequency locked loop. The satellite modem uses its master oscillator as the carrier reference for the upstream frequency up conversion. The satellite modem uses or calculates the upstream satellite frequency offset and compensates for this offset by shifting its center frequency.