Study On The Adaptive Line Enhancement In Digital Timing Receiver

Adaptive Digital Filter is being an important tool in the field of Digital Signal Processing with the advancement of Digital Signal Processing. Adaptive Line Enhancer is linear system, BPL and BPM signal are all narrowband, the thesis analyse the signal emission format and signal transmission characteristic, study on the design and application of Adaptive Line Enhancer in Digital Timing Receiver. The content of this paper is as follows:Firstly, to solve the insufficiency of Adaptive Line Enhancer based on LMS algorithm, use the Adaptive Line Enhancer based on FTF algorithm to filter the random noise that interfere with the BPL signal. The method could get over the deficiency of Adaptive Line Enhancer based on LMS algorithm, and improve the Receiver performance. Comparing the two kinds of Adaptive Line Enhancer applicated in filtering random noise in BPL signal, the result shows that the Adaptive Line Enhancer based on FTF algorithm can converage more quickly, the output could superpose with the expectation and the error is small.These could meet the requirement of BPL Timing Receiver.Then, the Digital Signal Processing was studied in BPM Shortwave Digital Timing Receiver. Use the Notch Adaptive Line Enhancer to extract the useful signal on the base of using FIR Digital Band-pass Filter. Notch Adaptive Line Enhancer compared with FIR Filter in Digital Signal Processing of BPM Shortwave Timing Receiver, the result reveals that Notch Adaptive Line Enhancer can extract the useful signal better. The method could depress interference and noise more effectively, and NALE could increase Signal-to-Noise of output about 5dB than FIR digital filter.The BPL signal and BPM signal are both of single carrier signal, it's feasible to use adaptive line Enhancer for signal processing.The thesis makes use of the MATLAB to implement the application of some kinds of Adaptive Line Enhancer in Timing Receicer, and use the data sampling from the receiver. The result of simulink indicates Adaptive Line Enhancer could filter the interference and noise better than normal Digital Filter used in Digital Timing Receiver, and then improve the receiver performance more.