Design And Implementation Of Suppression Of Narrowband Interference In WCDMA Repeater

With the development of mobile communication, coverage is becoming more and more important. The major technique being used for enhancing wireless network's coverage is repeater. Repeater, a type of relaying equipment, is used to provide wider coverage. In this thesis, AIC technology is implemented in WCDMA repeater to combat its inherent co-channel interference.This dissertation first introduces WCDMA repeater, AIC and the basic theory of Spread spectrum and perturbation. And then analyze some kind of spread spectrum of communication systems with narrowband interference suppression, linear forecast technology and nonlinear, MATLAB platform to simulate AIC designs. Therein, the algorithms of different convergence performance of are analyzed. After comparing the computational complexity, it shows that the algorithms, i.e., P-NLMS in the time domain, instead of the division use the LUT based structure, is adopted for the coefficients updating, which is significantly applicable in hardware systems. Even under the SIR of-5dB, the resulted EVM can be reduced to 12.7687%, which satisfies the requirement of WCDMA repeater.Last, with a comprehensive consideration of work environment, interference suppression requirements and available hardware resources and other factors in the actual WCDMA communication systems, P-NLMS algorithms are implemented in FPGA. The system testing indicates the actual anti-interference ability and theoretical analysis results were consistent, such as jitters in-band removed, suppression out of band increased and EVM restricted within 16.75%. Generally speaking, AIC technology guarantees a significant improvement, which is of great practical applicability for the practical projects.