This thesis studies SRS noise estimation method with multi-users in the Long Term Evolution(LTE), and proposes a Discrete Fourier Transform (DFT) time-domain filtering algorithm based on interference cancellation. By calculating signal power in the system protecting band, decision threshold of time domain filtering can be denoted. Therefore, one can reduce the impact of noise on the useful signal within the window, and also obtain a more accurate noise estimation. Simulation results show that either in the case of single-user or multi-user, the proposed algorithm can get good performance. At the same time, the algorithm can accurately reflect the impact in neighborhood interference on each band channel quality, so as to achieve the frequency domain resource selective scheduling effectively.

Cleft palate is a kind of congenital defect, and nasal leak is one of common symptoms in cleft palate speech. The automatic detection of nasal leak in cleft palate speech can provide a certain auxiliary basis for clinical diagnosis. Aiming at the characteristics of nasal leak in cleft palate speech, an improved method based on group delay is proposed. Since group delay parameter can greatly characterize nonlinear signals. Gammatone filter combined with the characteristics of human auditory is used to demodulate speech signal, and group delay parameters are calculated for each frequency band. It is used as features to identify nasal leak in cleft palate speech. The proposed algorithm is tested on 351 speech samples provided by West China Hospital of Stomatology Sichuan University. Compared with the classical group delay method, the accuracy of this improved method is 91.74% for the detection of nasal leak in cleft palate speech.

Abstract. With the rapid development of the global electronic market, the filter has been greatly promoted. And the development of digital technology also create a good technical foundation for the filter. This paper introduces the basic concepts of digital filters, the brief introduction of MATLAB Software, and the design method of FIR low-pass filter. Taking MATLAB as working platform and development tools, the design and simulation of FIR low-pass filter are realized by MATLAB program. And the practicability of low-pass filter for audio processing is proved by tests.

Mobile communication has become the most promising and the most potential hot technology in contemporary communications. 4G is a comprehensive system for multiple access technologies that enable seamless links to various technologies based on a common platform. In this paper, the development of mobile communication and characteristics were summarized, and MATLAB simulation software is used to simulate the communication process in the wireless channel.