Two modified BP algorithms related to vertical and horizontal processes are proposed to accelerate iterative low-density parity- check （LDPC） decoding over an additive white Gaussian noise （AWGN） channel, where th...Two modified BP algorithms related to vertical and horizontal processes are proposed to accelerate iterative low-density parity- check （LDPC） decoding over an additive white Gaussian noise （AWGN） channel, where the newly updated extrinsic information is immediately used in the current decoding round. Theoretical analysis and simulation results demonstrate that both the modified approaches provide significant performance improvements over the traditional BP algorithm with almost no additional decoding complexity. The proposed algorithm with modified horizontal process offers even better performance than another algorithm with the modified horizontal process. The two modified BP algorithms are very promising in practical communications since both can achieve an excellent trade-off between the performance and decoding complexity.展开更多
针对中央处理器(CPU)平台中值滤波算法在实际应用中运算速率低且实时信号处理性能较差的问题,提出了一种基于图形处理器(GPU)的并行高速中值滤波算法。该算法采用统一计算设备架构(CUDA)并行架构对大规模数据处理进行了优化,从而有效提...针对中央处理器(CPU)平台中值滤波算法在实际应用中运算速率低且实时信号处理性能较差的问题,提出了一种基于图形处理器(GPU)的并行高速中值滤波算法。该算法采用统一计算设备架构(CUDA)并行架构对大规模数据处理进行了优化,从而有效提高了中值滤波算法的计算效率,实现了中值滤波的实时数据处理。通过构建GPU可任意伸缩的动态数组、优化多维索引的线性化方法解决了GPU动态显存空间分配问题。仿真试验结果表明:基于TITAN X GPU的5×5中值滤波,对4096像素×4096像素的图像处理计算速度比CPU平台提高了438倍。在同等计算规模条件下GPU高速中值滤波算法可大大提高计算性能。展开更多
为提高现有直接信息均匀压缩采样(Analog to information conversion,AIC)的观测效率和性能,在能量准则下,提出非均匀信息采集(Non-uniform information acquisition,NUIA),充分利用信息的重要性先验,即对信号随机调制后,依据能量进行...为提高现有直接信息均匀压缩采样(Analog to information conversion,AIC)的观测效率和性能,在能量准则下,提出非均匀信息采集(Non-uniform information acquisition,NUIA),充分利用信息的重要性先验,即对信号随机调制后,依据能量进行变速率的采集,能量越大的信号段采样速率越高,反之亦然。结合支撑域扩充、剪枝的思路提出变速匹配追踪(Variable rate matching pursuit,VRMP)算法,通过引入非均匀观测的先验支撑集,并在追踪过程中将其与迭代估计出的支撑集相并,提高了重构精度。理论分析和实验结果表明了NUIA-VRMP的有效性。特别地,相比于常规AIC的子空间追踪重构,NUIA-VRMP的组合能在低采样速率条件(如20%的Nyquist速率)下获得50dB的重构增益。展开更多
基金National Mobile Communication Research Laboratory,Southeast University(No.W200704),ChinaNatural Science foundation of Jiangsu Province (No.BK2006188),ChinaQuebec-China Joint Research Foundation by McGill University,Montreal,Quebec,Canada
文摘Two modified BP algorithms related to vertical and horizontal processes are proposed to accelerate iterative low-density parity- check （LDPC） decoding over an additive white Gaussian noise （AWGN） channel, where the newly updated extrinsic information is immediately used in the current decoding round. Theoretical analysis and simulation results demonstrate that both the modified approaches provide significant performance improvements over the traditional BP algorithm with almost no additional decoding complexity. The proposed algorithm with modified horizontal process offers even better performance than another algorithm with the modified horizontal process. The two modified BP algorithms are very promising in practical communications since both can achieve an excellent trade-off between the performance and decoding complexity.
文摘针对中央处理器(CPU)平台中值滤波算法在实际应用中运算速率低且实时信号处理性能较差的问题,提出了一种基于图形处理器(GPU)的并行高速中值滤波算法。该算法采用统一计算设备架构(CUDA)并行架构对大规模数据处理进行了优化,从而有效提高了中值滤波算法的计算效率,实现了中值滤波的实时数据处理。通过构建GPU可任意伸缩的动态数组、优化多维索引的线性化方法解决了GPU动态显存空间分配问题。仿真试验结果表明:基于TITAN X GPU的5×5中值滤波,对4096像素×4096像素的图像处理计算速度比CPU平台提高了438倍。在同等计算规模条件下GPU高速中值滤波算法可大大提高计算性能。
文摘为提高现有直接信息均匀压缩采样(Analog to information conversion,AIC)的观测效率和性能,在能量准则下,提出非均匀信息采集(Non-uniform information acquisition,NUIA),充分利用信息的重要性先验,即对信号随机调制后,依据能量进行变速率的采集,能量越大的信号段采样速率越高,反之亦然。结合支撑域扩充、剪枝的思路提出变速匹配追踪(Variable rate matching pursuit,VRMP)算法,通过引入非均匀观测的先验支撑集,并在追踪过程中将其与迭代估计出的支撑集相并,提高了重构精度。理论分析和实验结果表明了NUIA-VRMP的有效性。特别地,相比于常规AIC的子空间追踪重构,NUIA-VRMP的组合能在低采样速率条件(如20%的Nyquist速率)下获得50dB的重构增益。
