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Method and device for eliminating direct current offset

A DC bias and straight line technology, applied in the direction of DC level restoration device/bias distortion correction, baseband system, electrical components, etc., can solve the problem of degradation of received signal demodulation performance

Inactive Publication Date: 2011-04-27
ST ERICSSON SEMICON BEIJING
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Problems solved by technology

[0002] In the wireless communication system, due to the time-varying nature of the transmission channel, there is a DC offset in the received signal output by the radio frequency circuit, which will have an adverse effect on the equalization and correct demodulation of the received signal, and even in serious cases. Leading to a sharp decline in the demodulation performance of the received signal

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  • Method and device for eliminating direct current offset

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Embodiment Construction

[0088] In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0089] refer to figure 1 , the method for eliminating the DC bias in the embodiment of the present invention includes the following steps:

[0090] Step 101: Calculate the Euclidean distance between two demodulation symbols in multiple demodulation symbols based on QPSK modulation;

[0091] The invention is aimed at processing the received signal based on QPSK modulation. First, perform channel estimation and signal equalization on the received signal to obtain demodulation symbols, and perform normalization processing on the demodulation symbols; then, after obtaining multiple demodulation symbols, calculate two of the multiple demodulation symbols Euclidean distance between two demodulated symbols.

[0092] Step 102: Determine 4 sets from the m...

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Abstract

The invention provides a method and a device for eliminating direct current offset. The method comprises the following steps of: calculating the Euclidean distance between every two of a plurality of quadrature phase shift keying (QPSK) modulation-based demodulation symbols; determining four sets from the plurality of demodulation symbols, wherein every set corresponds to a modulation direction of QPSK modulation; performing Euclidean distance weighted summation calculation on the four determined sets respectively and selecting a demodulation symbol which has a minimum weighted summation value and serves as a rough estimation point of QPSK modulation in every set; re-determining four sets from the plurality of demodulation symbols according to the Euclidean distance between each modulation symbol and the rough estimation point; performing Euclidean distance weighted summation calculation on the four re-determined sets respectively and selecting a demodulation symbol which has a minimum weighted summation value and serves as a precise estimation point of QPSK modulation in every set; and performing direct current offset calculation and compensation according to the precise estimation point. The demodulation performance of a system can be enhanced.

Description

technical field [0001] The present invention relates to the technical field of wireless communication, in particular to a method and device for eliminating DC bias. Background technique [0002] In the wireless communication system, due to the time-varying nature of the transmission channel, there is a DC offset in the received signal output by the radio frequency circuit, which will have an adverse effect on the equalization and correct demodulation of the received signal, and even in serious cases. This leads to a sharp decline in the demodulation performance of the received signal. [0003] Therefore, how to eliminate the DC offset in the received signal has become an urgent technical problem to be solved. Contents of the invention [0004] The technical problem to be solved by the present invention is to provide a method and device for eliminating DC offset, so as to accurately estimate and eliminate the DC offset in the received signal, thereby improving the demodula...

Claims

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Application Information

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IPC IPC(8): H04L25/06H04L27/20
CPCH04L25/061H04L27/22
Inventor 陈江杉马振国尹力勇
Owner ST ERICSSON SEMICON BEIJING
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