• 위성통신과 우주산업
• /
• 제7권3호통권17호
• /
• pp.4-9
• /
• 1999

• 위성통신과 우주산업
• /
• 제7권3호통권17호
• /
• pp.90-91
• /
• 1999

• 위성통신과 우주산업
• /
• 제3권1호
• /
• pp.48-57
• /
• 1995

• 위성통신과 우주산업
• /
• 제10권1호통권24호
• /
• pp.140-143
• /
• 2002

• Journal of Communications and Networks
• /
• 제12권6호
• /
• pp.529-532
• /
• 2010

Multi-carrier demultiplexer/demodulator (MCDD) in an on-board processing (OBP) satellite used for digital multimedia services has two typical architectures according to the channel demultiplexing procedure: Multistage multi-carrier demultiplexer (M-MCD) or poly-phase fast Fourier transform (PPF). During the channel demultiplexing, phase and quantization errors influence the performance of MCDD; those errors affect the bit error rate (BER) performance of M-MCD and PPF differently. In this paper, we derive the phase error variances that satisfy the condition that M-MCD and PPF have the same signal to noise ratio according to quantization bits, and then, with these results, analyze the BER performances of M-MCD and PPF. The results provided here may be a useful reference for the selection of M-MCD or PPF in designing the MCDD in an OBP satellite communications system.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1999년도 제14차 학술회의논문집
• /
• pp.238-243
• /
• 1999

Minimum-fuel and -time orbit transfer are two major goals of the satellite trajectory optimization. In this paper, we consider satellites in two coplanar elliptic orbits when the apsidal lines coincide, and analytically find the conditions for the two-impulse minimum-time transfer orbit using Lambert's theorem. The transfer time is a decreasing function of a variable related to the transfer orbit's semimajor axis in the minimum-time case. In the minimum-time case, there is no unique minimum-time solution, but there is a limiting solution. However, there exists a unique solution in the case of minimum-fuel transfer, fur which we find analytically the necessary and sufficient conditions. As a special case, we consider when the transfer angle is one hundred and eighty degrees. In this case, we show that we obtain the classical fuel-optimal Hohmann transfer orbit. We also derive the Hohmann transfer rime and delta-velocity equations from more general equations, which are obtained using Lambert's theorem. We note the tradeoff between minimum-time and - fuel transfer. An optimal coplanar orbit maneuver algorithm to trade off the minimum-time goal against the minimum-fuel goal is proposed. Finally, the numerical simulation results are given to demonstrate the derived theory and the algorithm.

• 위성통신과 우주산업
• /
• 제2권1호
• /
• pp.3-3
• /
• 1994

• 위성통신과 우주산업
• /
• 제7권3호통권17호
• /
• pp.12-12
• /
• 1999

• 위성통신과 우주산업
• /
• 제2권2호
• /
• pp.2-2
• /
• 1994

• 위성통신과 우주산업
• /
• 제3권1호
• /
• pp.3-3
• /
• 1995