Low-complexity radio frequency front-end adjacent channel interference suppression device

Abstract

The invention discloses a low-complex radio frequency front-end adjacent channel interference suppression device, which includes a transmitting branch, a receiving branch and an auxiliary branch. The device performs nonlinear parameter estimation through a memory polynomial with filter fitting, and finally reconstructs and To counteract adjacent channel interference, the interference suppression process includes: up-conversion, parameter estimation, filter fitting, filtering, down-conversion and interference cancellation; parameter estimation, interference reconstruction and cancellation are completed in the digital domain, and the circuit structure of the cancellation method in the radio frequency domain is obtained. Effective simplification, compared with the RF domain offset method, the circuit structure is simplified, and the signal processing can be performed more flexibly, which is convenient for engineering implementation; and the digital signal output by the ADC of the receiving branch can be directly used for parameter estimation, and the required ADC sampling bandwidth and baseband signal Similarly, the requirements for system processing performance are effectively reduced.

Description

technical field [0001] The invention relates to the technical field of receiver signal processing methods, in particular to a low-complex radio frequency front-end adjacent channel interference suppression device. Background technique [0002] Nowadays, duplex filters are increasingly used in wireless communication devices such as cellular phones to achieve frequency-division duplex (FDD) communication. In these FDD applications, both uplink and downlink provide Good transceiver isolation remains a serious challenge. In fact, in order to get smaller and cheaper duplexers, people often have to sacrifice isolation at the expense of isolation, resulting in traditional duplexers that can provide 45-55dB isolation in the transmit channel, but can only provide about 45dB in the receive channel. 20-30dB isolation, at this time, the transmitted signal leaked to the receiving branch through the duplexer will still cause serious interference to the received signal, so the suppression...

AI Technical Summary

Problems solved by technology

However, the above method needs to use multiple adjustable bandpass filters and couplers in the implementation of the specific circuit, and the implementation structure of the radio frequency circuit is relatively complicated; in addition, it is easy to introduce noise interference in the radio frequency signal processing, thereby affecting the interference suppression effect; and the isolation bandwidth Restricted by antenna frequency domain changes and balanced reflection coefficients, the complexity of the radio frequency (RF) balance network will further increase, and high-order RF signal processing will not only increase the size and cost of the RF front-end, but often require high-order Multidimensional optimization to tune circuit parameters

[0004] There is also an existing technology that directly reconstructs and cancels the interference signal in the digital domain, and finally achieves about 20dB interference suppression

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