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Adaptive line enhancers for fast acquisition
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Yeh, H.-G. Nguyen, T. M. |
| Copyright Year | 1994 |
| Description | Three adaptive line enhancer (ALE) algorithms and architectures - namely, conventional ALE, ALE with double filtering, and ALE with coherent accumulation - are investigated for fast carrier acquisition in the time domain. The advantages of these algorithms are their simplicity, flexibility, robustness, and applicability to general situations including the Earth-to-space uplink carrier acquisition and tracking of the spacecraft. In the acquisition mode, these algorithms act as bandpass filters; hence, the carrier-to-noise ratio (CNR) is improved for fast acquisition. In the tracking mode, these algorithms simply act as lowpass filters to improve signal-to-noise ratio; hence, better tracking performance is obtained. It is not necessary to have a priori knowledge of the received signal parameters, such as CNR, Doppler, and carrier sweeping rate. The implementation of these algorithms is in the time domain (as opposed to the frequency domain, such as the fast Fourier transform (FFT)). The carrier frequency estimation can be updated in real time at each time sample (as opposed to the batch processing of the FFT). The carrier frequency to be acquired can be time varying, and the noise can be non-Gaussian, nonstationary, and colored. |
| File Size | 825211 |
| Page Count | 20 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19950010872 |
| Archival Resource Key | ark:/13960/t0jt4kp9w |
| Language | English |
| Publisher Date | 1994-11-15 |
| Access Restriction | Open |
| Subject Keyword | Computer Programming And Software Robustness Mathematics Fourier Transformation Signal To Noise Ratios Carrier To Noise Ratios Uplinking Bandpass Filters Batch Processing Fast Fourier Transformations Adaptive Control Real Time Operation Algorithms Least Squares Method Spectrum Analysis Line Spectra Target Acquisition Carrier Frequencies Adaptation Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
