Correction to "Crosscorrelation properties of pseudorandom and related sequences"
Correction to "Crosscorrelation properties of pseudorandom and related sequences"
复制标题
对“伪随机和相关序列的互相关特性”的更正
DOI：
10.1109/proc.1980.11910
复制
发表时间：
1980
期刊：
影响因子：
--
通讯作者：
M. Pursley
中科院分区：
文献类型：
--
作者：
D. Sarwate;M. Pursley
注意表达因果关系的精确零。这个变换的关键点是 A (wo) 的被积函数的行为。本质上，我们的程序改变了阻尼和振荡的作用，即，与原始情况相反，被积函数现在在积分实际起作用的区域中仅经历几次振荡。因此不会遇到数值问题。显式解析表达式可以通过 Hn (6 z)=-2i/n (&er,(z)+ i keidz)) 用开尔文函数编写。图中给出了一些数值示例。对于海水，我们使用 p= 0.25 am 和 9= 4%。 lo-’Vs/am 且电缆半径 ro= 0.1 m。在图 1 中，绘制了不同距离 r 和 0.8 ms 脉冲速率的场强 e,(t, r)。这些值指的是 1A 电流。有两个主要特征引起了人们的关注。首先，当输入脉冲实际上达到其最大值时，场强会改变符号，至少在不太远的 r 值处是如此。其次，输入脉冲之后有一个明显的拖尾。造成这种影响的原因是磁场的衰减。与实验数据[图1中星号所示的SI]的比较表明，这些效果实际上是观察到的。作为每单位长度时间的函数消耗的功率由下式给出
Note the exact zero which expresses causality. The crucial point of this transformation is the behavior of the integrand of A (wo). Essentially, our procedure switched the rBles of damping and oscillation, ie, in contrast to the original case, the integrand now undergoes only a few oscillations in the area where the integral actually makes a contribution. No numerical problems are therefore encountered. The explicit analytic expression can be written in terms of Kelvin functions via Hn (6 z)=-2i/n (&er,(z)+ i keidz)). In the diagrams a few numerical examples are presented. For seawater we used p= 0.25 am and 9= 4%. lo-’Vs/am and for the radius of the cable ro= 0.1 m. In Fig. 1 the field strengths e,(t, r) have been plotted for various distances r and for a pulse rate of 0.8 ms. The values refer to 1A current.Two main features attract attention. Firstly, the field strength changes sign at a time when the input pulse virtually reaches its maximum, at least at not too distant r-values. Secondly, there is an ap preciable tail after the input pulse. The cause of this contribution is the decaying magnetic field. A comparison with experimental data [SI indicated by asterisks in Fig. 1 shows that these effects are in fact ob-served. The power dissipated as a function of time per unit length is given by