Method and apparatus for reducing the effect of AGC switching transients
AssigneeTelefonaktiebolaget L M Ericsson (publ)
InventorsPatrik Eriksson, Mats Eriksson
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Abstract
The present invention reduces automatic gain control (AGC) transients using first and second AGC processing branches to receive a signal. A gain is selectively adjusted (if desired) in the one of the AGC processing branches during a first time period. However, a gain is not adjusted in the other AGC processing branch during that first time period. The signals generated by the first and second AGC processing branches are then diversity processed to generate a received signal. The diversity processing effectively reduces the effect of any AGC transient.
Claims38
Apparatus for use in a receiver comprising:
- a first receiving branch for receiving a signal including a first amplifier and first automatic gain controlling circuitry configured to selectively adjust the gain applied to the signal by the first amplifier;
- a second receiving branch for receiving the signal including a second amplifier and second automatic gain controlling circuitry configured to selectively adjust a gain applied to the signal by the second amplifier;
- and
- control circuitry configured to select one of the first and second automatic gain controlling circuitry to adjust, if desired, the gain of a corresponding one of the first and second amplifiers for a period of time.
Apparatus for use in a diversity radio receiver, comprising:
- first diversity receiving branch for receiving a signal including a first amplifier and a first automatic gain controller (AGC) configured to selectively reduce the gain applied to the signal by the first amplifier;
- second diversity receiving branch for receiving the signal including a second amplifier and a second automatic gain controller configured to selectively reduce a gain applied to the signal by the second amplifier;
- and
- control circuitry configured to selectively enable one of the first and second automatic gain controllers for a holding time period and reduce, if desired, the gain of a corresponding one of the first and second amplifiers time based on an output from the comparison circuitry.
A method for reducing an effect of automatic gain control (AGC) adjustment transients, comprising:
- receiving a signal in a first AGC processing branch;
- receiving the signal in a second AGC processing branch;
- selectively adjusting a gain applied to one of the first and second branch signals during a first time period, where a gain applied to the other of the branch signals is not adjusted during the first time period;
- and thereafter
- diversity processing the first and second branch signals to generate a received signal.
Dependencies are inferred from the claim text.