The Space Power Satellite(SPS) would be a huge spacecraft capturing the power of solar radiation in space and to supply electric power to the electric grid on the ground. The SPS concept was proposed by Dr. Peter Glas...The Space Power Satellite(SPS) would be a huge spacecraft capturing the power of solar radiation in space and to supply electric power to the electric grid on the ground. The SPS concept was proposed by Dr. Peter Glaser in 1968. SPS have been studied now for exactly fifty years by many scientists in various countries. It has been regarded as one of the most promising energy projects of the future and has been attracting more attention in recent years. More and more Chinese scholars and experts are paying attention to the development of SPS. Due to the huge size, immense mass and high power of such a satellite system, there are many technical difficulties which exist to realize SPS. In this paper, recent SPS research and development activities are reviewed first. Various SPS concepts are analyzed and compared. The primary scheme of the Multi-Rotary joint SPS(MR-SPS) is described. The main feature is that the huge solar array comprising many separate small solar sub-arrays and each solar sub-array has two middle power rotary joints. So, the most challenging technology, the high-power rotary joint, is simplified by using many middlepower rotary joints hence the possibility of a single-point failure of a single rotary joint is avoided. This enables easy assembly of the modular solar arrays. Finally some key technologies of MR-SPS are analyzed.展开更多
This paper proposes rate-maximized （MR） joint subcarrier pairing （SP） and power allocation （PA） （MR-SP＆PA）, a novel scheme for maximizing the weighted sum rate of the orthogonal-frequency-division multiplexi...This paper proposes rate-maximized （MR） joint subcarrier pairing （SP） and power allocation （PA） （MR-SP＆PA）, a novel scheme for maximizing the weighted sum rate of the orthogonal-frequency-division multiplexing （OFDM） relaying system with a decode-and-forward （DF） relay. MR-SP＆PA is based on the joint optimization of both SP and power allocation with total power constraint, and formulated as a mixed integer programming problem in the paper. The programming problem is then transformed to a convex optimization problem by using continuous relaxation, and solved in the Lagrangian dual domain. Simulation results show that MR-SP＆PA can maximize the weighted sum rate under total power constraint and outperform equal power allocation （EPA） and proportion power allocation （PCG）.展开更多
文摘The Space Power Satellite(SPS) would be a huge spacecraft capturing the power of solar radiation in space and to supply electric power to the electric grid on the ground. The SPS concept was proposed by Dr. Peter Glaser in 1968. SPS have been studied now for exactly fifty years by many scientists in various countries. It has been regarded as one of the most promising energy projects of the future and has been attracting more attention in recent years. More and more Chinese scholars and experts are paying attention to the development of SPS. Due to the huge size, immense mass and high power of such a satellite system, there are many technical difficulties which exist to realize SPS. In this paper, recent SPS research and development activities are reviewed first. Various SPS concepts are analyzed and compared. The primary scheme of the Multi-Rotary joint SPS(MR-SPS) is described. The main feature is that the huge solar array comprising many separate small solar sub-arrays and each solar sub-array has two middle power rotary joints. So, the most challenging technology, the high-power rotary joint, is simplified by using many middlepower rotary joints hence the possibility of a single-point failure of a single rotary joint is avoided. This enables easy assembly of the modular solar arrays. Finally some key technologies of MR-SPS are analyzed.
基金supported by the National Key Technology R&D Program (2008BAH30B10)the National Natural Science Foundation of China (60972070)+1 种基金the Chongqing Municipal Science & Technology Development Program,China (CSTC2010A-C2143)the Natural Science Foundation of Chongqing,China (CSTC2009B-A2090)
文摘This paper proposes rate-maximized （MR） joint subcarrier pairing （SP） and power allocation （PA） （MR-SP＆PA）, a novel scheme for maximizing the weighted sum rate of the orthogonal-frequency-division multiplexing （OFDM） relaying system with a decode-and-forward （DF） relay. MR-SP＆PA is based on the joint optimization of both SP and power allocation with total power constraint, and formulated as a mixed integer programming problem in the paper. The programming problem is then transformed to a convex optimization problem by using continuous relaxation, and solved in the Lagrangian dual domain. Simulation results show that MR-SP＆PA can maximize the weighted sum rate under total power constraint and outperform equal power allocation （EPA） and proportion power allocation （PCG）.
