专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

1. 发明授权

US4245325A Digital multifrequency signalling receiver 失效
标题翻译：数字多频信令接收机
公开(公告)号：US4245325A
公开(公告)日：1981-01-13
申请号：US12507
申请日：1979-02-15
申请人： Shiro Kikuchi , Hitoshi Imagawa , Yasumasa Iwase
发明人： Shiro Kikuchi , Hitoshi Imagawa , Yasumasa Iwase
IPC分类号： H04Q1/457 , G06F15/31
CPC分类号： H04Q1/457
摘要： Disclosed is a digital multifrequency signaling receiving system in which a first operation device executes an operation to multiply multifrequency signals composed of N samples as input signals by a window function including coefficients required for fast Fourier transform. An output produced at the first operation device, as a sample signal, is subjected to fast Fourier transformation at a second operation device which includes a subtractor and a logic circuit. In the subtractor, the sample signals are delayed N/2 samples to halve the number of sample signals. The logic circuit executes an operation for the sample signals, taking advantage of the fact that some frequencies of the outputs of the Fourier transform are represented as the conjugate complex of the other outputs of the Fourier transform. The sample signals fast-Fourier-transformed and produced at the second operation device are subjected discrete Fourier transformation in a processor, where an output for detecting the multifrequency signals is obtained.
摘要翻译：公开了一种数字多频信号接收系统，其中第一操作装置执行将由N个采样构成的多频信号乘以包括快速傅里叶变换所需的系数的窗函数作为输入信号的操作。在第一操作装置处产生的作为采样信号的输出在包括减法器和逻辑电路的第二操作装置上进行快速傅里叶变换。在减法器中，采样信号是延迟的N / 2采样，将采样信号的数量减半。利用傅里叶变换的输出的一些频率表示为傅里叶变换的其他输出的共轭复合的事实，逻辑电路对采样信号执行操作。在第二操作装置中快速傅立叶变换和产生的样本信号在处理器中进行离散傅里叶变换，其中获得用于检测多频信号的输出。

IPRDB

热门服务

关于我们

友情链接

联系方式