【摘 要】
：
Channel estimation plays a significant role in the Inter-carrier interference (ISI) mitigation and symbol detection in Orthogonal frequency division multiplexin
【机 构】
：
College of Electronic Science and Technology,National University of Defense Technology,Changsha 4100
论文部分内容阅读
Channel estimation plays a significant role in the Inter-carrier interference (ISI) mitigation and symbol detection in Orthogonal frequency division multiplexing (OFDM) systems. As the speed of mobile terminal increases, the channel changes rapidly, causing fast fading which will degrade the system performance. In this paper, a low complexity fast fading channel estimation method suited for scattered pilot OFDM systems is proposed. This method is characterized by estimating channel matrix directly in the frequency domain, which can significantly reduce the channel estimation complexity with good system performance. Simulation results verify its superiority over the existing estimation methods.
其他文献
Accurate small traffic sign recognition is more important for the safety of intelligent transportation systems. A recognition framework named attentive context region-based detection framework(AC-RDF)
目的探讨氯吡格雷联合阿司匹林肠溶片治疗急性心肌梗死(AMI)的效果。方法94例AMI患者,按照编号单双数分为对照组(奇数)和观察组(偶数),每组47例。对照组采用阿司匹林肠溶片治疗,观察组在对照组基础上联合氯吡格雷治疗。比较两组临床疗效、冠状动脉(冠脉)再通情况、凝血指标、不良事件发生情况。结果观察组患者治疗总有效率为95.74%,高于对照组80.85%,差异具有统计学意义(P<0.05)。两组患者再通率比较差异无统计学意义(P>0.05);观察组患者再闭塞率2.13%(1/47)、血小板聚集
目的探讨慢性心力衰竭(心衰)经阿托伐他汀治疗的效果。方法94例慢性心衰患者,按照住院序号奇偶性分为对照组和观察组,各47例。对照组采用常规治疗,观察组采用阿托法他汀治疗。比较两组患者临床疗效以及治疗前后的心功能指标、血脂指标。结果观察组治疗总有效率95.74%高于对照组的82.98%,差异具有统计学意义(P<0.05)。治疗后,观察组患者左室射血分数(LVEF)(40.26±5.38)%、左室收缩末期容积指数(LVESVI)(46.25±7.69)ml/m2、左室舒张末期容积指
Hundreds of Megabit per second (Mb/s) data transmission over a moderate range (10m) underwater optical wireless channel is implemented with 4-level pulse amplit
Video-driven animation has always been a hot and challenging topic in the field of computer animation. We propose a method of mapping a sequence of human skeletal keypoints in a video onto a two-dimen
近年来随着用户对供能形式的需求不断丰富,传统的以单一电能为形式的供能系统已经无法满足能源用户的需求。考虑了冷热电联供系统(combined cooling heating and power,CCHP)对不同能源协同供应的特点,对以风能、太阳能、天然气和储能协同供能的冷热电联供优化问题进行研究。综合考虑不同费率结构以及可再生能源带来的功率波动,以经济成本和环境成本为目标,构建了含燃气发电机、燃气锅炉、电制冷机、蓄电池组等机组的冷热联供能源协同优化模型。采用粒子群算法对多目标进行求解优化,结果表明该算法能够
目的探讨溶栓与单纯抗凝治疗中危急性肺栓塞(PE)患者效果差异,为实际应用提供参考依据。方法80例中危急性PE患者,随机分为研究组和对照组,每组40例。对照组在绝对卧床、吸氧机止痛等治疗基础上,予以单纯抗凝治疗,研究组加用溶栓治疗。比较治疗前、治疗后2周的血气指标,临床疗效,并发出血情况。结果治疗后,研究组患者动脉血氧分压(PaO2)、动脉血二氧化碳分压(PaCO2)、肺泡-动脉血氧分压差[P(A-a)O2]分别为(87.1±10.6)、(30.5±8.2)、(25.5±6.0)mm Hg(1 mm Hg=
The federated learning method based on model aggregation can balance data and protect privacy, but the existing methods are difficult to achieve the effectivene
目的探究对老年慢性心功能不全患者行沙库巴曲缬沙坦钠片治疗的临床疗效。方法80例老年慢性心功能不全患者,依据随机数字表法分为观察组及对照组,每组40例。对照组患者接受常规治疗,观察组患者在对照组基础上加用沙库巴曲缬沙坦钠片治疗。比较两组治疗效果、6 min步行距离、左室射血分数(LVEF)、堪萨斯城心肌病患者生活质量量表(KCCQ)评分及不良反应发生情况。结果观察组治疗总有效率97.50%高于对照组的75.00%,差异具有统计学意义(P<0.05)。治疗后,观察组患者6 min步行距离(343.01±
目的探究超声引导下髂筋膜阻滞对膝关节置换术后的镇痛效果。方法62例预接受膝关节置换术的患者,随机分为甲组和乙组,每组31例。甲组患者在手术前进行股神经阻滞麻醉,乙组患者在手术前进行超声引导下髂筋膜阻滞。比较两组患者镇痛效果、镇静和舒适度及不良反应发生率。结果术后1、2 h,两组视觉模拟评分法(VAS)评分比较差异无统计学意义(P>0.05);术后6、12、24、48 h,乙组VAS评分分别为(3.01±0.85)、(2.01±0.52)、(1.29±0.34)、(0.64±0.11)分,低于甲组的(