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A hybrid direct sequence and frequency hopping (DSFH) spread spectrum signal can greatly improve ranging precision and jamming resisting capability in spacecraft TT and C (Tracking, Telemetry and Command). The frequency hopping adds another searching dimension to acquisition and increases the acquisition complexity. Therefore, this paper designs a(More)
In order to reduce the complexity when adaptive coding and modulation (ACM) technique is applied in the low and medium-orbit remote sensing satellite with Ka band TT&C and communications systems, this paper presents a novel ACM technic optimization method based on system characteristics (e.g., the earth station location, trajectory of the satellite and(More)
We present a new interpolatory subdivision scheme based on PB-splines (point-based B-splines), over triangular meshes. Using the stencil of the interpolatory /spl radic/3-subdivision scheme, we propose a different refinement strategy by introducing a variable a to each regular vertex (valence = 6). By applying different a (locally or globally), the scheme(More)
The paper presents a new code acquisition method for usage in DSSS communication system with large frequency offset. A serial correlator combined with decimation filters, which outputs are then fed into FFT process. By using the FFT technique, the search over the frequency uncertainty can be omitted and the usage of decimation filter can improve frequency(More)
Since dynamic characteristics of low earth orbit (LEO) satellites will induce Doppler shift on carrier frequency and code rate. Therefore, most implementations of traditional receivers for LEO satellites adopt differential demodulation techniques, and the cost is a 3 dB demodulation threshold increment, which raises overall system budget and brings about(More)
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