NBI Suppression Technology Research On The Basis Of Improved SCR Algorithm

In the field of the civil communication, there is overlapping in the spectrum resources between the communication system occupying the wider band and narrow-band communication system. Thus such overlapping part makes the narrow-band interference overweigh the wide-band systems. In the military communication field, utilizing the high-power transmitter more easily realize the more narrow-band interference, and increase the interference bandwidth. The existence of the narrow-band interference will directly affect the quality of communication, degree of keeping secret, the ability of system, so it becomes an important research content to effectively suppress the narrow-band interference and keep the communication system steady.The narrow-band interference has such characteristics that the occupying bandwidth is narrow; spectrum energy is concentrated. Suppression algorithm consists of time domain and transform domain. The essay makes deep research on the transform domain suppression algorithm of the narrow-band interference on the basis of side correlation replacement algorithm, puts forward the improved algorithm, makes comparative analysis of the interference suppression of the improved algorithm and the ability of anti-noise, validates the effectiveness and advantage of the algorithm, and makes a design and validation about the realization of side correlation replacement algorithm.Side correlation replacement algorithm can effectively suppress the signals with the symmetrical spectrum including the signal QPSK. After confirming carrier frequency and interference centre frequency, replacing with un-interfered image spectrum in order to realize the suppression of narrow-band interference. This algorithm makes some improvements compared with the interference nulling algorithm in transform domain. Considering that the leaking out of spectrum brought by the lopping of statistics makes the effect on the capability of system, the essay puts forward the improved algorithm on the basis of overlap windowing, makes an emulation analysis of the improved algorithm of SCR on the basis of overlap windowing, and concludes the interference suppression capability and anti-noise capability of this algorithm. The result shows that the improved algorithm has a good effect and meets the advance theoretical analysis. Finally the essay gave the design plan of the realization of SCR, and validated the reliability and effectiveness of the design plan combining the emulation software with logic analysis on line. In virtue of the logic analysis on line to realize the observation of statistics and storage in a small amount, lowered the cost of validation and complexity. The virtual use indicates that the design plan is able to realize the algorithm better. Accomplishing the realization of side correlation replacement algorithm, provides the important evidence and reference to utilization forward.