针对Turbo码全并行译码算法译码迭代次数多、硬件消耗大的问题,提出了一种基于RADIX-4的改进译码算法。将译码算法中状态转移图的相邻两步状态合并为一步计算,译码时以"比特对"的形式操作进行迭代。在保留译码最大并行度同时...针对Turbo码全并行译码算法译码迭代次数多、硬件消耗大的问题,提出了一种基于RADIX-4的改进译码算法。将译码算法中状态转移图的相邻两步状态合并为一步计算,译码时以"比特对"的形式操作进行迭代。在保留译码最大并行度同时,译码计算单元使用量减少一半,显著降低了Turbo码全并行译码算法的运算复杂度和存储开销。仿真结果表明,在相同迭代次数条件下,该方法的译码性能较全并行译码算法平均提高约0.5 d B。展开更多
In this work, power efficient butterfly unit based FFT architecture is presented. The butterfly unit is designed using floating-point fused arithmetic units. The fused arithmetic units include two-term dot product uni...In this work, power efficient butterfly unit based FFT architecture is presented. The butterfly unit is designed using floating-point fused arithmetic units. The fused arithmetic units include two-term dot product unit and add-subtract unit. In these arithmetic units, operations are performed over complex data values. A modified fused floating-point two-term dot product and an enhanced model for the Radix-4 FFT butterfly unit are proposed. The modified fused two-term dot product is designed using Radix-16 booth multiplier. Radix-16 booth multiplier will reduce the switching activities compared to Radix-8 booth multiplier in existing system and also will reduce the area required. The proposed architecture is implemented efficiently for Radix-4 decimation in time(DIT) FFT butterfly with the two floating-point fused arithmetic units. The proposed enhanced architecture is synthesized, implemented, placed and routed on a FPGA device using Xilinx ISE tool. It is observed that the Radix-4 DIT fused floating-point FFT butterfly requires 50.17% less space and 12.16% reduced power compared to the existing methods and the proposed enhanced model requires 49.82% less space on the FPGA device compared to the proposed design. Also, reduced power consumption is addressed by utilizing the reusability technique, which results in 11.42% of power reduction of the enhanced model compared to the proposed design.展开更多
目的研究威灵仙多糖对非酒精性脂肪性肝炎(non-alcoholic steatohepatitis,NASH)大鼠胰岛素抵抗的干预作用,及实验性NASH大鼠血清视黄醇结合蛋白4(retinol binding protein 4,RBP4)与胰岛素抵抗的相关性。方法建模阶段:50只清洁级健康雄...目的研究威灵仙多糖对非酒精性脂肪性肝炎(non-alcoholic steatohepatitis,NASH)大鼠胰岛素抵抗的干预作用,及实验性NASH大鼠血清视黄醇结合蛋白4(retinol binding protein 4,RBP4)与胰岛素抵抗的相关性。方法建模阶段:50只清洁级健康雄性SD大鼠随机分为空白组(n=14)和造模组(n=36)。空白组用普通饲料饲养;造模组用高脂饲料饲养,建立NASH大鼠模型。干预阶段:将造模组大鼠(n=30)随机分为模型组、易善复组和威灵仙多糖组,每组各10只;空白组大鼠(n=8)作为对照组,依次分别给予0.9%NS、易善复溶液、威灵仙多糖溶液、0.9%NS灌胃干预,8周后4组大鼠下腔静脉取血检测空腹血糖、空腹胰岛素及RBP4的含量,统计分析各组上述指标的差异及胰岛素抵抗指数(HOMA-IR)与RBP4的相关性。结果与模型组相比,威灵仙多糖组NASH大鼠HOMA-IR、血清RBP4水平较低(P<0.05);NASH大鼠HOMA-IR与血清RBP4呈正相关(r=0.541,P=0.001)。结论威灵仙多糖可有效治疗NASH大鼠,其主要机制之一可能是通过降低NASH大鼠血清RBP4水平,改善NASH大鼠胰岛素抵抗。展开更多
文摘针对Turbo码全并行译码算法译码迭代次数多、硬件消耗大的问题,提出了一种基于RADIX-4的改进译码算法。将译码算法中状态转移图的相邻两步状态合并为一步计算,译码时以"比特对"的形式操作进行迭代。在保留译码最大并行度同时,译码计算单元使用量减少一半,显著降低了Turbo码全并行译码算法的运算复杂度和存储开销。仿真结果表明,在相同迭代次数条件下,该方法的译码性能较全并行译码算法平均提高约0.5 d B。
文摘In this work, power efficient butterfly unit based FFT architecture is presented. The butterfly unit is designed using floating-point fused arithmetic units. The fused arithmetic units include two-term dot product unit and add-subtract unit. In these arithmetic units, operations are performed over complex data values. A modified fused floating-point two-term dot product and an enhanced model for the Radix-4 FFT butterfly unit are proposed. The modified fused two-term dot product is designed using Radix-16 booth multiplier. Radix-16 booth multiplier will reduce the switching activities compared to Radix-8 booth multiplier in existing system and also will reduce the area required. The proposed architecture is implemented efficiently for Radix-4 decimation in time(DIT) FFT butterfly with the two floating-point fused arithmetic units. The proposed enhanced architecture is synthesized, implemented, placed and routed on a FPGA device using Xilinx ISE tool. It is observed that the Radix-4 DIT fused floating-point FFT butterfly requires 50.17% less space and 12.16% reduced power compared to the existing methods and the proposed enhanced model requires 49.82% less space on the FPGA device compared to the proposed design. Also, reduced power consumption is addressed by utilizing the reusability technique, which results in 11.42% of power reduction of the enhanced model compared to the proposed design.
文摘目的研究威灵仙多糖对非酒精性脂肪性肝炎(non-alcoholic steatohepatitis,NASH)大鼠胰岛素抵抗的干预作用,及实验性NASH大鼠血清视黄醇结合蛋白4(retinol binding protein 4,RBP4)与胰岛素抵抗的相关性。方法建模阶段:50只清洁级健康雄性SD大鼠随机分为空白组(n=14)和造模组(n=36)。空白组用普通饲料饲养;造模组用高脂饲料饲养,建立NASH大鼠模型。干预阶段:将造模组大鼠(n=30)随机分为模型组、易善复组和威灵仙多糖组,每组各10只;空白组大鼠(n=8)作为对照组,依次分别给予0.9%NS、易善复溶液、威灵仙多糖溶液、0.9%NS灌胃干预,8周后4组大鼠下腔静脉取血检测空腹血糖、空腹胰岛素及RBP4的含量,统计分析各组上述指标的差异及胰岛素抵抗指数(HOMA-IR)与RBP4的相关性。结果与模型组相比,威灵仙多糖组NASH大鼠HOMA-IR、血清RBP4水平较低(P<0.05);NASH大鼠HOMA-IR与血清RBP4呈正相关(r=0.541,P=0.001)。结论威灵仙多糖可有效治疗NASH大鼠,其主要机制之一可能是通过降低NASH大鼠血清RBP4水平,改善NASH大鼠胰岛素抵抗。
