A fast carrier cancellation method and device

Abstract

The present invention provides a fast carrier cancellation method and device. The method includes: keeping the amplitude of the cancellation signal unchanged, adjusting the phase shift of the controllable phase-shifting module separately by means of one-dimensional search, and determining the optimal phase of the cancellation signal , and record the ratio K of the in-phase component amplitude and the quadrature component amplitude of the baseband control signal at the optimal phase of the cancellation signal; keep the ratio K of the in-phase component amplitude and the quadrature component amplitude of the modulation module control signal unchanged and keep it controllable The phase shift of the phase shifting module is unchanged, and the one-dimensional search method is used to adjust the amplitude of the in-phase component and the quadrature component of the control signal within the amplitude range of the control signal of the modulation module by using the dichotomy method, and check the demodulation module. Whether the output satisfies the preset condition, if so, the optimal control signal is maintained, and the modulation module outputs the optimal cancellation signal to cancel the interference signal. The fast carrier cancellation method provided by the invention can quickly and accurately eliminate the carrier interference signal.

Description

technical field [0001] The invention relates to the technical field of radio frequency identification, in particular to a method and device for rapid carrier cancellation. Background technique [0002] In the UHF RFID reader system, affected by factors such as device isolation, the carrier leaked from the transmitting end to the receiving end will interfere with the receiving branch, which seriously affects the receiving sensitivity of the reading and writing equipment, resulting in the reading distance close. Therefore, it is necessary to use a carrier interference suppression scheme to eliminate the leaked carrier. In addition, due to the changeable working environment of the reader and the frequent operation in the frequency hopping mode, the interference signal is complex and changeable. If you want to improve the performance of the reader, the carrier cancellation module is required to quickly and accurately detect the interference signal. to eliminate. [0003] The ...

AI Technical Summary

Problems solved by technology

This method is a two-dimensional adjustment method. The number of adjustments is the product of the number of adjustments of the in-phase component and the number of adjustments of the quadrature component. There are many adjustment times and low efficiency.

[0005] The second is: use the cancellation signal generation circuit to adjust the reference signal. This method is a pure hardware method for carrier cancellation. It is difficult to achieve accurate phase adjustment, and there are defects that are difficult to debug and implement.

[0006] The third is: in the reflection module, the quadrature and in-phase components of the demodulated leakage signal are phase-rotated, and the method of controlling the reflection signal as a cancellation signal after the same and anti-phase integration is determined with the parameters of the anti-phase integration. Difficult, if the parameter is too small, it will lead to slow integration speed and low efficiency, if the parameter is too large, it will lead to poor adjustment accuracy

Images