Closed-loop antenna diversity in a cellular radio communication system

US7289769B2 · kind B2 · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Denis Brandes · Wendeburg, DE
• Bernhard Raaf · Hersbruck, DE
• Ralf Wiedmann · Birkenfeld, DE

Key dates

• Filing date: Apr 12, 2002
• Grant date: Oct 30, 2007
• Expiry date: Feb 14, 2024

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04B7/0689
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

A method is provided for operating a cellular radio communication system with a base station, which may be switched between an operating state without closed-loop antenna diversity and an operating state with closed-loop antenna diversity, emitting a downlink signal with a weighting vector and a user station, for receiving the downlink signal and transmitting an uplink signal to the base station, delivering back-coupling information to the base station in the operating state with closed-loop antenna diversity, representing a determined weighting vector. On transition of the radio communication system into the operating state with closed-loop antenna diversity, the user station delivers back-coupling information, representing a weighting vector determined and known before the transition into the operating state with closed-loop antenna diversity, to the base station until a current weighting vector is determined by measurement, and then delivers the back-coupling information representing the current weighting vector.