To solve the problem of the large Doppler frequency offset in the LEO communication system, this paper studies a rapid PN code acquisition method based on the PMF-FFT architecture, which searches the phase and frequen...To solve the problem of the large Doppler frequency offset in the LEO communication system, this paper studies a rapid PN code acquisition method based on the PMF-FFT architecture, which searches the phase and frequency offset and at the same time reduces the acquisition time. It presents an improved method equivalent to windowing function and uses windowing process to overcome the attenuation of related peak envelope caused by partial matched filters.展开更多
The novel satellite Multiple Access scheme called Combined Free/Demand Assignment Multiple Access-Predictive Request (CFDAMA-PR) is proposed in this paper. In the CFDAMA-PR scheme, the ground station requests the dema...The novel satellite Multiple Access scheme called Combined Free/Demand Assignment Multiple Access-Predictive Request (CFDAMA-PR) is proposed in this paper. In the CFDAMA-PR scheme, the ground station requests the demand assignment slots by predicting the positive varying trend of the traffic source. The delay performances between CFDAMA-PR and CFDAMA-RR (Round Robin request) schemes were compared by computer simulation. Simulations were carried out with the Interrupted Poisson Process (IPP) and the Interrupted Fluid Process (IFP) traffic models. Simulation results demonstrate that compared to CFDAMA-RR protocol, the CFDAMA-PR scheme achieves a better delay/throughput of satellite channel.展开更多
文摘To solve the problem of the large Doppler frequency offset in the LEO communication system, this paper studies a rapid PN code acquisition method based on the PMF-FFT architecture, which searches the phase and frequency offset and at the same time reduces the acquisition time. It presents an improved method equivalent to windowing function and uses windowing process to overcome the attenuation of related peak envelope caused by partial matched filters.
文摘The novel satellite Multiple Access scheme called Combined Free/Demand Assignment Multiple Access-Predictive Request (CFDAMA-PR) is proposed in this paper. In the CFDAMA-PR scheme, the ground station requests the demand assignment slots by predicting the positive varying trend of the traffic source. The delay performances between CFDAMA-PR and CFDAMA-RR (Round Robin request) schemes were compared by computer simulation. Simulations were carried out with the Interrupted Poisson Process (IPP) and the Interrupted Fluid Process (IFP) traffic models. Simulation results demonstrate that compared to CFDAMA-RR protocol, the CFDAMA-PR scheme achieves a better delay/throughput of satellite channel.
