在干扰信号相干的情况下,一般波束形成方法不能准确地对相干信号和期望信号进行到达角(DOA)估计,干扰抑制效果较差。通过对相干信号和加权矢量二次型性能函数的分析,提出了一种相干干扰抑制方法,即基于多约束最小均方(multiple constrai...在干扰信号相干的情况下,一般波束形成方法不能准确地对相干信号和期望信号进行到达角(DOA)估计,干扰抑制效果较差。通过对相干信号和加权矢量二次型性能函数的分析,提出了一种相干干扰抑制方法,即基于多约束最小均方(multiple constrained least mean square,MC-LMS)算法的空域调零抗干扰技术。该方法利用MC-LMS算法迭代计算权值,并对阵列信号自适应加权输出,通过频谱分析可以得到抑制干扰的效果。计算机仿真和工程实现表明该方法在复杂的电磁环境下能对相干干扰进行抑制,并通过抗干扰的数量和抗干扰性能验证了该方法的有效性。展开更多
To better remove the contamination on the surface of a heat-exchanger in urban sewage source heat pump system （USSHPS）, this paper analyzes the feasibility of strong self-flushing on the basis of experiments and pre...To better remove the contamination on the surface of a heat-exchanger in urban sewage source heat pump system （USSHPS）, this paper analyzes the feasibility of strong self-flushing on the basis of experiments and presents a new on-line self-flushing technique, which alternately flushes part of heat transfer tubes. In addition, operation principles and the structure of the new heat-exchanger are introduced and the feasible economi- cal and technological cleaning plans are given by design calculation and scheme comparison. The result shows that keeping each tube washed for one minute with 5 m/s, the operating cost is lower than ￥5 and when one flushing pump ahemately flushes 10-20 heat exchangers, the saved costs of flushing 10 tubes alternately are over 4 times of the increased costs.展开更多
文摘在干扰信号相干的情况下,一般波束形成方法不能准确地对相干信号和期望信号进行到达角(DOA)估计,干扰抑制效果较差。通过对相干信号和加权矢量二次型性能函数的分析,提出了一种相干干扰抑制方法,即基于多约束最小均方(multiple constrained least mean square,MC-LMS)算法的空域调零抗干扰技术。该方法利用MC-LMS算法迭代计算权值,并对阵列信号自适应加权输出,通过频谱分析可以得到抑制干扰的效果。计算机仿真和工程实现表明该方法在复杂的电磁环境下能对相干干扰进行抑制,并通过抗干扰的数量和抗干扰性能验证了该方法的有效性。
基金Sponsored by the National Natural Science Foundation of China (Grant No.50578048)
文摘To better remove the contamination on the surface of a heat-exchanger in urban sewage source heat pump system （USSHPS）, this paper analyzes the feasibility of strong self-flushing on the basis of experiments and presents a new on-line self-flushing technique, which alternately flushes part of heat transfer tubes. In addition, operation principles and the structure of the new heat-exchanger are introduced and the feasible economi- cal and technological cleaning plans are given by design calculation and scheme comparison. The result shows that keeping each tube washed for one minute with 5 m/s, the operating cost is lower than ￥5 and when one flushing pump ahemately flushes 10-20 heat exchangers, the saved costs of flushing 10 tubes alternately are over 4 times of the increased costs.
