Firstly, the Earth＇s gravitational field from the past Challenging Minisatellite Payload （CHAMP） mission is determined using the energy conservation principle, the combined error model of the cumulative geoid heigh...Firstly, the Earth＇s gravitational field from the past Challenging Minisatellite Payload （CHAMP） mission is determined using the energy conservation principle, the combined error model of the cumulative geoid height influenced by three instrument errors from the current Gravity Recovery and Climate Experiment （GRACE） and future GRACE Follow-On missions is established based on the semi-analytical method, and the Earth＇s gravitational field from the executed Gravity Field and Steady-State Ocean Circulation Explorer （GOCE） mission is recovered by the space-time-wise approach. Secondly, the cumulative geoid height errors are 1.727 × 10^-1 m, 1.839 × 10^-1 m and 9.025 × 10^ -2 m at degrees 70,120 and 250 from the implemented three-stage satellite gravity missions consisting of CHAMP, GRACE and GOCE, which preferably accord with those from the existing earth gravity field models involving EIGEN-CHAMP03S, EICEN-GRACE02S and GO_CONS GCF 2 DIR R1. The cumulative geoid height error is 6.847 × 10 ^-2 m at degree 250 from the future GRACE Follow-On mission. Finally, the complementarity among the four-stage satellite gravity missions including CHAMP, GRACE, GOCE and GRACE Follow-On is demonstrated contrastively.展开更多
针对未编码的多输入多输出(MIMO,Multi-Input Multi-Output)系统,提出一种复杂度适中的分组全分集全码率(GFDFR,Group-wise Full Diversity Full Rate)空时编码方案。该方案通过在发送端进行天线分组,各组独立编码,减小全分集全码率(FDF...针对未编码的多输入多输出(MIMO,Multi-Input Multi-Output)系统,提出一种复杂度适中的分组全分集全码率(GFDFR,Group-wise Full Diversity Full Rate)空时编码方案。该方案通过在发送端进行天线分组,各组独立编码,减小全分集全码率(FDFR,Full Diversity FullRate)编码块的大小从而降低系统编解码复杂度;在频率选择性信道中,进一步对子载波分组进行独立编码,获得频率分集(或多径分集),以适中的复杂度在不降低系统分集度的情况下保证了信息的全码率传输,是一种在MIMO信道中极具实用价值的空时编码方案。展开更多
An iterative transmit power allocation (PA) algorithm was proposed for group-wise space-time block coding (G-STBC) systems with group-wise successive interference cancellation (GSIC) receivers. Group-wise interference...An iterative transmit power allocation (PA) algorithm was proposed for group-wise space-time block coding (G-STBC) systems with group-wise successive interference cancellation (GSIC) receivers. Group-wise interference suppression (GIS) filters are employed to separate each group's transmit signals from other interferences and noise. While the total power on all transmit symbols is constrained, all transmit PA coefficients are updated jointly according to the channel information at each iteration. Through PA, each detection symbol has the same post-detection signal to interference-and-noise ratio (SINR). The simulation results verify that the proposed PA algorithm converges at the equilibrium quickly after few iterations, and it achieves much lower bit error rates than the previous single symbol SIC PA and the fixed ratio PA algorithms for G-STBC systems with GSIC receivers .展开更多
A non-unitary non-coherent space-time code which is capable of achieving full algebraic diversity is proposed based on full diversity space-time block coding, The error performance is optimized by transforming the non...A non-unitary non-coherent space-time code which is capable of achieving full algebraic diversity is proposed based on full diversity space-time block coding, The error performance is optimized by transforming the non-unitary space-time code into unitary space-time code, By exploiting the desired structure of the proposed code, a grouped generalized likelihood ratio test decoding algorithm is presented to overcome the high complexity of the optimal algorithm, Simulation results show that the proposed code possesses high spectrum efficiency in contrast to the unitary space-time code despite slight loss in the SNR, and besides, the proposed grouped decoding algorithm provides good tradeoff between performance and complexity,展开更多
基金supported by the Main Direction Program of Knowledge Innovation of Chinese Academy of Sciences for Distinguished Young Scholar(KZCX2-EW-QN114)the National Natural Science Foundation of China(41004006,41131067,11173049 and 41274041)+7 种基金the Merit-based Scientific Research Foundation of the State Ministry of Human Resources and Social Security of China for Returned Overseas Chinese Scholars(Z01101)the Open Research Fund Program of the Key Laboratory of Geospace Environment and Geodesy,Ministry of Education,China(11-01-02)the Open Research Fund Program of the Key Laboratory of Geo-Informatics of National Administration of Surveying,Mapping and Geoinformation of China(201322)the Open Research Fund Program of the State Key Laboratory of Geoinformation Engineering,China(SKLGIE2013-M-1-5)the Main Direction Program of Institute of Geodesy and Geophysics,Chinese Academy of Sciences(Y309451045)the Research Fund Program of State Key Laboratory of Geodesy and Earth's Dynamics,China(Y309491050)the Research Fund of the National Civilian Space Infrastructure Project(Y419341034)the Research Fund of the Lu Jiaxi Young Talent and the Youth Innovation Promotion Association of Chinese Academy of Science(Y305171017)
文摘Firstly, the Earth＇s gravitational field from the past Challenging Minisatellite Payload （CHAMP） mission is determined using the energy conservation principle, the combined error model of the cumulative geoid height influenced by three instrument errors from the current Gravity Recovery and Climate Experiment （GRACE） and future GRACE Follow-On missions is established based on the semi-analytical method, and the Earth＇s gravitational field from the executed Gravity Field and Steady-State Ocean Circulation Explorer （GOCE） mission is recovered by the space-time-wise approach. Secondly, the cumulative geoid height errors are 1.727 × 10^-1 m, 1.839 × 10^-1 m and 9.025 × 10^ -2 m at degrees 70,120 and 250 from the implemented three-stage satellite gravity missions consisting of CHAMP, GRACE and GOCE, which preferably accord with those from the existing earth gravity field models involving EIGEN-CHAMP03S, EICEN-GRACE02S and GO_CONS GCF 2 DIR R1. The cumulative geoid height error is 6.847 × 10 ^-2 m at degree 250 from the future GRACE Follow-On mission. Finally, the complementarity among the four-stage satellite gravity missions including CHAMP, GRACE, GOCE and GRACE Follow-On is demonstrated contrastively.
文摘针对未编码的多输入多输出(MIMO,Multi-Input Multi-Output)系统,提出一种复杂度适中的分组全分集全码率(GFDFR,Group-wise Full Diversity Full Rate)空时编码方案。该方案通过在发送端进行天线分组,各组独立编码,减小全分集全码率(FDFR,Full Diversity FullRate)编码块的大小从而降低系统编解码复杂度;在频率选择性信道中,进一步对子载波分组进行独立编码,获得频率分集(或多径分集),以适中的复杂度在不降低系统分集度的情况下保证了信息的全码率传输,是一种在MIMO信道中极具实用价值的空时编码方案。
基金The National High Technology ResearchDevelopment Program of China (863 Pro-gram) (No003aa12331007)National Nat-ural Science Foudation of China ( No60572157,60332030)
文摘An iterative transmit power allocation (PA) algorithm was proposed for group-wise space-time block coding (G-STBC) systems with group-wise successive interference cancellation (GSIC) receivers. Group-wise interference suppression (GIS) filters are employed to separate each group's transmit signals from other interferences and noise. While the total power on all transmit symbols is constrained, all transmit PA coefficients are updated jointly according to the channel information at each iteration. Through PA, each detection symbol has the same post-detection signal to interference-and-noise ratio (SINR). The simulation results verify that the proposed PA algorithm converges at the equilibrium quickly after few iterations, and it achieves much lower bit error rates than the previous single symbol SIC PA and the fixed ratio PA algorithms for G-STBC systems with GSIC receivers .
基金Supported by the National Natural Science Foundation of China (Grant No. 60372055)the National Doctoral Foundation of China (Grant No. 20030698027)
文摘A non-unitary non-coherent space-time code which is capable of achieving full algebraic diversity is proposed based on full diversity space-time block coding, The error performance is optimized by transforming the non-unitary space-time code into unitary space-time code, By exploiting the desired structure of the proposed code, a grouped generalized likelihood ratio test decoding algorithm is presented to overcome the high complexity of the optimal algorithm, Simulation results show that the proposed code possesses high spectrum efficiency in contrast to the unitary space-time code despite slight loss in the SNR, and besides, the proposed grouped decoding algorithm provides good tradeoff between performance and complexity,
