Method and device for inhibiting local oscillator leakage

Abstract

The invention provides a method and a device for inhibiting local oscillator leakage, wherein the method comprises the steps of: overlying and digital-to-analogue converting a received first digital intermediate-frequency signal and a received first preliminary direct current offset signal and generating a first downlink receiving signal; frequency mixing and filtering the first downlink receiving signal and a downlink local oscillator signal and generating a first local baseband signal; frequency mixing and analogue-to-digital converting the local baseband signal and a feedback local oscillator signal and generating a first feedback sampling sequence; generating a second downlink receiving signal after waiting for a preset time; frequency mixing and filtering the second downlink receiving signal and the downlink local oscillator signal and generating a second local baseband signal; frequency mixing and analogue-to-digital converting the second baseband signal and the feedback local oscillator signal and generating a second feedback sampling sequence; calculating a local oscillator corrected value; and executing the method for inhibiting local oscillator leakage repeatedly by adopting the local oscillator corrected value as a new second preliminary direct current offset signal. The method and the device of the invention improve the effect of local oscillator leakage inhibition of dual-band wideband signals.

Description

technical field [0001] The invention relates to a local oscillator leakage suppression method and equipment, belonging to the technical field of wireless radio frequency. Background technique [0002] In a radio remote unit (Radio Remote Unit, RRU for short) transmission system, local oscillator leakage occurs due to modulation of an inherent direct current bias of a radio frequency (abbreviation: RF) link with a local oscillator signal. LO leakage may cause the radio frequency spurious index of the RRU air interface to fail to meet the standard. In addition, the leaked LO will also intermodulate with the useful signal, thereby interfering with the useful signal; for a zero-IF transmission system, if the LO leakage falls within the useful signal band If it is inside, it cannot be suppressed by the filter of the analog link, which will cause the error vector magnitude (abbreviation: EVM) to deteriorate and the emission spurious index will not meet the standard. Therefore, it ...

AI Technical Summary

Problems solved by technology

Since the adjustment process is highly dependent on experience, it brings great uncertainty to the automatic completion of the software calibration in the later stage, that is, the number of iterations of each local oscillator calibration is not certain, and the search range is also inconsistent. It needs to be done according to the specific product. Corresponding adjustments, in addition, due to the limited accuracy of the analog-to-digital conversion (abbreviation: ADC), when the leakage of the local oscillator is suppressed to a certain extent, it cannot converge, and the leakage suppression effect of the local oscillator cannot be further improved

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