High spectral efficiency distributed antenna systems （DAS） require vertical Bell-Labs layered space-time （V-BLAST） like spatial multiplexing schemes. However, unlike normal point-to-point multiple input multiple o...High spectral efficiency distributed antenna systems （DAS） require vertical Bell-Labs layered space-time （V-BLAST） like spatial multiplexing schemes. However, unlike normal point-to-point multiple input multiple output （MIMO） channels, DAS channels have different large-scale fadings from different transmit antennas, thus making equal power and rate transmission that is feasible in MIMO channels unrealistic in DAS channels. This paper proposes a novel transmit antenna selection scheme with power and rate allocation. The scheme is based on large-scale fading （shadow fading and path loss） and is suitable for VBLAST structures with zero-forcing and successive interference cancellation （ZF-SIC） receivers, ensuring balanced average symbol error rate （SER） performance in each layer. On the receiver side, a fixed detection order is used, which is obtained in the transmit antenna selection process. Simulation results show that the proposed scheme gives good performance gains over equal power and rate transmission systems without antenna selection.展开更多
Based on the new discrete particle swarm op-timization(NDPSO) and the mutation operation of the genetic algorithm,a hybrid discrete particle swarm op-timization(HDPSO) algorithm is proposed and applied to the signal d...Based on the new discrete particle swarm op-timization(NDPSO) and the mutation operation of the genetic algorithm,a hybrid discrete particle swarm op-timization(HDPSO) algorithm is proposed and applied to the signal detection of the Vertical Bell-Labs Layered Space-Time(V-BLAST)system.Then two detection ap-proaches that employ the HDPSO and parallel interfer-ence cancellation(PIC) algorithms in V-BLAST system are proposed.One of approaches is that the HDPSO algorithm is used as the first stage of the PIC to provide a good initial point for successive stages of the PIC,the other is that PIC is embedded into the HDPSO al-gorithm to improve further the fi tness of the population at each generation.Such a hybridization of the HDPSO with the PIC can speed up its convergence.In addition,a better initial data estimate supplied by the HDPSO algorithm improves the performance of the PIC,and the embedded PIC improves the performance of the HDP-SO.Analysis and simulation results show that the pro-posed detection approaches have lower computational complexity than the optimal ML detection approach and better detection performance than other conventional detection approaches.展开更多
为了缓解无线信道对图像传输的影响,综合考虑信源编码、信道编码及调制方式,提出了一种自适应VBLAST(vertical Bell labs layered space time)并行图像传输优化策略,该策略可根据信道环境,自适应选择信源编码、信道编码、调制和发送功...为了缓解无线信道对图像传输的影响,综合考虑信源编码、信道编码及调制方式,提出了一种自适应VBLAST(vertical Bell labs layered space time)并行图像传输优化策略,该策略可根据信道环境,自适应选择信源编码、信道编码、调制和发送功率以满足并行传输各层的误码率要求,从而综合协调系统资源来提高接收端图像重建质量。数值仿真结果表明,该策略比其他非自适应策略或部分自适应策略在性能上具有明显的优势。展开更多
As the combining form of the orthogonal frequency-division multiplexing (OFDM) technique and the vertical Bell Labs layered space-time (V-BLAST) architecture, the V-BLAST OFDM system can better meet the demand of next...As the combining form of the orthogonal frequency-division multiplexing (OFDM) technique and the vertical Bell Labs layered space-time (V-BLAST) architecture, the V-BLAST OFDM system can better meet the demand of next-generation (NextG) broadband mobile wireless multimedia communications. The symbols detection problem of the V-BLAST OFDM system is investigated under the frequency-selective fading environment. The joint space-frequency demultiplexing operation is proposed in the V-BLAST OFDM system. Successively, one novel half-rate rotational invariance joint space-frequency coding scheme for the V-BLAST OFDM system is proposed. By elegantly exploiting the above rotational invariance property, we derive one direct symbols detection scheme without knowing channels state information (CSI) for the frequency-selective V-BLAST OFDM system. Extensive simulation results demonstrate the validity of the novel half-rate rotational invariance joint space-frequency coding scheme and the performance of the direct symbols detection scheme.展开更多
文摘High spectral efficiency distributed antenna systems （DAS） require vertical Bell-Labs layered space-time （V-BLAST） like spatial multiplexing schemes. However, unlike normal point-to-point multiple input multiple output （MIMO） channels, DAS channels have different large-scale fadings from different transmit antennas, thus making equal power and rate transmission that is feasible in MIMO channels unrealistic in DAS channels. This paper proposes a novel transmit antenna selection scheme with power and rate allocation. The scheme is based on large-scale fading （shadow fading and path loss） and is suitable for VBLAST structures with zero-forcing and successive interference cancellation （ZF-SIC） receivers, ensuring balanced average symbol error rate （SER） performance in each layer. On the receiver side, a fixed detection order is used, which is obtained in the transmit antenna selection process. Simulation results show that the proposed scheme gives good performance gains over equal power and rate transmission systems without antenna selection.
基金supported by the Key Project of National Natural Science Foundation of China (No. 60496316)the National Science Fund for Distinguished Young Scholars (No. 60725105)+3 种基金the National Natural Science Foundation of China (No.60572146)The Re-search Fund for the Doctoral Program of Higher Educa-tion (No. 20050701007)the Fund of Teaching and Re-search Award Program for Outstanding Young Teachers in Higher Education Institute of Chinathe Key Project of Science and Technologies Research of MOE (No. 107103) and the 111 Project (B08038)
文摘Based on the new discrete particle swarm op-timization(NDPSO) and the mutation operation of the genetic algorithm,a hybrid discrete particle swarm op-timization(HDPSO) algorithm is proposed and applied to the signal detection of the Vertical Bell-Labs Layered Space-Time(V-BLAST)system.Then two detection ap-proaches that employ the HDPSO and parallel interfer-ence cancellation(PIC) algorithms in V-BLAST system are proposed.One of approaches is that the HDPSO algorithm is used as the first stage of the PIC to provide a good initial point for successive stages of the PIC,the other is that PIC is embedded into the HDPSO al-gorithm to improve further the fi tness of the population at each generation.Such a hybridization of the HDPSO with the PIC can speed up its convergence.In addition,a better initial data estimate supplied by the HDPSO algorithm improves the performance of the PIC,and the embedded PIC improves the performance of the HDP-SO.Analysis and simulation results show that the pro-posed detection approaches have lower computational complexity than the optimal ML detection approach and better detection performance than other conventional detection approaches.
文摘为了缓解无线信道对图像传输的影响,综合考虑信源编码、信道编码及调制方式,提出了一种自适应VBLAST(vertical Bell labs layered space time)并行图像传输优化策略,该策略可根据信道环境,自适应选择信源编码、信道编码、调制和发送功率以满足并行传输各层的误码率要求,从而综合协调系统资源来提高接收端图像重建质量。数值仿真结果表明,该策略比其他非自适应策略或部分自适应策略在性能上具有明显的优势。
文摘As the combining form of the orthogonal frequency-division multiplexing (OFDM) technique and the vertical Bell Labs layered space-time (V-BLAST) architecture, the V-BLAST OFDM system can better meet the demand of next-generation (NextG) broadband mobile wireless multimedia communications. The symbols detection problem of the V-BLAST OFDM system is investigated under the frequency-selective fading environment. The joint space-frequency demultiplexing operation is proposed in the V-BLAST OFDM system. Successively, one novel half-rate rotational invariance joint space-frequency coding scheme for the V-BLAST OFDM system is proposed. By elegantly exploiting the above rotational invariance property, we derive one direct symbols detection scheme without knowing channels state information (CSI) for the frequency-selective V-BLAST OFDM system. Extensive simulation results demonstrate the validity of the novel half-rate rotational invariance joint space-frequency coding scheme and the performance of the direct symbols detection scheme.
