Automatic Gain Control in Multi-Carrier Wireless Systems

A method in a wireless receiver for processing a received multi-carrier signal, comprising:

• conditioning the received multi-carrier signal and converting the received multi-carrier signal into a digital signal, using a common analog signal path comprising an analog variable-gain circuit and an analog-to-digital converter;
• extracting first and second carrier-specific signals from the digital signal;
• adjusting gains applied to the first and second carrier-specific signals using first and second carrier-specific, digital variable-gain circuits, respectively;
• and
• allotting gain adjustments to the analog variable-gain circuit based on a difference between carrier signal levels for the first and second carriers.

A wireless user terminal comprising a receiver circuit for processing a received multi-carrier signal, the receiver circuit comprising:

• a common analog signal path for conditioning the received multi-carrier signal and converting the received multi-carrier signal into digital form, the common analog signal path comprising an analog variable-gain circuit and an analog-to-digital converter;
• first and second carrier-specific, digital variable-gain circuits corresponding to first and second carriers of the received multi-carrier signal, respectively;
• and
• a gain control circuit configured to control the analog variable-gain circuit and the digital variable-gain circuits and to allot gain adjustments to the analog variable-gain circuit based on a difference between carrier signal levels for the first and second carriers.