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Direct current (DC) offset correction using analog-to-digital conversion

A technology of digital converters and converters, applied in the field of reducing or eliminating DC offsets in the transmission path, can solve problems such as insufficient processing

Inactive Publication Date: 2011-06-29
QUALCOMM INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, previous attempts have not adequately dealt with the DC offset found in certain communication technologies (e.g., mobile cellular systems)

Method used

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  • Direct current (DC) offset correction using analog-to-digital conversion
  • Direct current (DC) offset correction using analog-to-digital conversion
  • Direct current (DC) offset correction using analog-to-digital conversion

Examples

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Embodiment Construction

[0015] The following detailed description, which references and incorporates drawings, describes and illustrates one or more particular embodiments. These embodiments have been shown and described in sufficient detail (provided not to be limiting, but merely to illustrate and teach) to enable those skilled in the art to practice what is claimed. Therefore, for the sake of brevity, the description may omit certain information known to those skilled in the art.

[0016] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or variation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments or variations. All embodiments and variations described in this description are exemplary embodiments and variations provided to enable persons skilled in the art to make and use the invention, and not necessarily to limit the scope of legal protection given to the appended...

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PUM

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Abstract

Techniques for reducing or eliminating DC (direct current) offset in transmitters are disclosed. An apparatus for DC offset reduction may include a converter, a digital engine, and a plurality of programmable current supplies. The converter is configured to provide digital representations of a plurality of DC currents associated, respectively, with a plurality of differential signal legs. The digital engine is configured to receive the digital representations and to produce instructions for generating compensating currents for the plurality of differential signal legs based on comparisons, respectively, between each of the digital representations and a calibration current. The programmable current supplies correspond, respectively, to the differential signal legs. The current supplies are configured to inject the compensating currents into the differential signal legs, respectively, to reduce DC offset between the differential signal legs, based upon the instructions. The instructions allow one-shot DC offset correction, instead of successive approximation for DC offset correction.

Description

technical field [0001] The present invention relates generally to wireless communications, and more particularly, to techniques for reducing or eliminating DC (direct current) offsets in transmit paths. Background technique [0002] Signal paths in radio frequency (RF) transmitters sometimes have undesirable DC offsets. DC offset generally refers to a relatively constant offset of a signal from zero. In other contexts, DC offset may alternatively refer to an offset that occurs between differential signals. The latter type of DC offset that occurs between differential signals can be particularly difficult to resolve in contemporary digital communication systems (eg, mobile cellular systems). For example, in a digital communication system that transmits in-phase (I) and quadrature (Q) signal components, in a differential signal representing the I and Q components (e.g., I p , I m , Q p and Q m Differential signals) can have undesirable DC offsets. Such DC offsets may ca...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L25/06H04L27/36
CPCH04L27/364H04L25/061H04B1/04H04L25/06
Inventor 巴赫曼·阿拉里李希求柯金书李桑奥
Owner QUALCOMM INC
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