High Resolution Wide Swath (HRWS) Synthetic Aperture Radar (SAR) often suffers from low Signal-to-Noise Ratio (SNR) due to small transmitting antenna, especially in phased array antenna systems. Digital Beam Forming (...High Resolution Wide Swath (HRWS) Synthetic Aperture Radar (SAR) often suffers from low Signal-to-Noise Ratio (SNR) due to small transmitting antenna, especially in phased array antenna systems. Digital Beam Forming (DBF) based on Single Input and Multiple Output (SIMO) achieves receiving array gain at the cost of increasing data rate. This letter proposes a new HRWS SAR method, which employs intra-pulse null steering to get receiving gain in elevation and decrease the data rate, and Multiple Input and Multiple Output (MIMO) using Space-Time Block Coding (STBC) in azimuth to get transmitting gain and receiving array gain simultaneously. The feasibility is verified by deduction and simulations.展开更多
A new architecture of null steering antenna based upon the technology of space-time adaptive processing（STAP） with optimized parameters is proposed. The new STAP antenna is comprised of multiple channels and each ch...A new architecture of null steering antenna based upon the technology of space-time adaptive processing（STAP） with optimized parameters is proposed. The new STAP antenna is comprised of multiple channels and each channel is a transversal filter. So separate sensor element for the reference signal is not required because the antenna gets the reference signal from the first sensor of the auxiliary array. Furthermore, the least mean square（LMS） algorithm is employed to calculate the weight vector. Detailed analysis about the relationship between noise power and output error is investigated. Compared with the traditional null steering antenna in space or space-time domain, the new approach obtains more freedom degrees and can suppress both the wideband and narrowband interferences more efficiently with deeper nulls. Simulation results shows that the proposed architecture outperforms the conventional STAP techniques for interference suppression.展开更多
To minimize transmitting power,an adaptive resource allocation algorithm is proposed for multi-user multiple input multiple output-orthogonal frequency division multiplexing(MIMO-OFDM)downlink with correlated channels...To minimize transmitting power,an adaptive resource allocation algorithm is proposed for multi-user multiple input multiple output-orthogonal frequency division multiplexing(MIMO-OFDM)downlink with correlated channels,which,based on the user’s grouping according to their spatial correlations,combines the shared manner and the exclusive manner to allocate sub-carriers.Between different groups the shared manner with a null steering method based on group marginal users is applied,whereas within a group the exclusive manner is applied.The simulations show that the power efficiency and spectral efficiency are improved;the base station transmitting antenna number and the computational complexity is decreased.展开更多
文摘High Resolution Wide Swath (HRWS) Synthetic Aperture Radar (SAR) often suffers from low Signal-to-Noise Ratio (SNR) due to small transmitting antenna, especially in phased array antenna systems. Digital Beam Forming (DBF) based on Single Input and Multiple Output (SIMO) achieves receiving array gain at the cost of increasing data rate. This letter proposes a new HRWS SAR method, which employs intra-pulse null steering to get receiving gain in elevation and decrease the data rate, and Multiple Input and Multiple Output (MIMO) using Space-Time Block Coding (STBC) in azimuth to get transmitting gain and receiving array gain simultaneously. The feasibility is verified by deduction and simulations.
基金supported by the China Academy of Space Technology (CAST) Fund in 2014 (CAST20140008)the Fundamental Research Funds for the Central University of China (106112013CDJZR160002)
文摘A new architecture of null steering antenna based upon the technology of space-time adaptive processing（STAP） with optimized parameters is proposed. The new STAP antenna is comprised of multiple channels and each channel is a transversal filter. So separate sensor element for the reference signal is not required because the antenna gets the reference signal from the first sensor of the auxiliary array. Furthermore, the least mean square（LMS） algorithm is employed to calculate the weight vector. Detailed analysis about the relationship between noise power and output error is investigated. Compared with the traditional null steering antenna in space or space-time domain, the new approach obtains more freedom degrees and can suppress both the wideband and narrowband interferences more efficiently with deeper nulls. Simulation results shows that the proposed architecture outperforms the conventional STAP techniques for interference suppression.
基金supported by the National Natural Science Foundation of China (Grant No.60572039).
文摘To minimize transmitting power,an adaptive resource allocation algorithm is proposed for multi-user multiple input multiple output-orthogonal frequency division multiplexing(MIMO-OFDM)downlink with correlated channels,which,based on the user’s grouping according to their spatial correlations,combines the shared manner and the exclusive manner to allocate sub-carriers.Between different groups the shared manner with a null steering method based on group marginal users is applied,whereas within a group the exclusive manner is applied.The simulations show that the power efficiency and spectral efficiency are improved;the base station transmitting antenna number and the computational complexity is decreased.
