Pulse or digital communications – Receivers – Interference or noise reduction
Reexamination Certificate
2006-07-04
2006-07-04
Vo, Don N. (Department: 2631)
Pulse or digital communications
Receivers
Interference or noise reduction
C375S345000
Reexamination Certificate
active
07072427
ABSTRACT:
Methods and apparatuses for reducing DC offsets in a communication system are described. In a first aspect, a feedback loop circuit reduces DC offset in a wireless local area network (WLAN) receiver channel. The frequency response of the feedback loop circuit can be variable. In a second aspect, a circuit provides gain control in a WLAN receiver channel. The stored DC offset is subtracted from the receiver channel. First and second automatic gain control (AGC) amplifiers are coupled in respective portions of the receiver channel. In a third aspect, a feedback loop circuit reduces DC offset in a WLAN receiver channel. The feedback loop circuit includes a storage element that samples and stores receiver channel DC offset. The loop is opened, and the DC offset stored in the storage element is subtracted from the receiver channel. Circuits for monitoring DC offset, and for providing control signals for controlling the frequency response of the DC offset reducing circuits are also provided.
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patent:
Brown Kevin
Rawlins Gregory S.
Rawlins Michael W.
Sorrells David F.
ParkerVision, Inc.
Sterne Kessler Goldstein & Fox PLLC
Vo Don N.
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