| 摘要 |
FIELD: radio engineering, communication.SUBSTANCE: apparatus for measuring the time of arrival of a two-position angle shift keyed signal has a means of receiving signals, an analogue-to-digital converter (ADC), a first fast Fourier transform (FFT) processor, a cross-spectrum computer, a second FFT processor, a device for determining arguments of the maximum of the discrete cross-correlation function (DCCF) of the signal, a third FFT processor as well as, connected in series between the output of the ADC and the input of the first FFT, a signal quadrature decomposition device, a first low-pass filter (LPF), read-only memory (ROM), and a modulo 2? subtractor; between the second output of the signal quadrature decomposition device and the second input of the ROM, there is a second LPF; the subtracting input of the subtractor is connected to the output of the ROM through a signal symbol delay unit, and the input of the third FFT processor is connected to the output of a two-level modulating signal generator through series-connected differential decoder and sampling frequency expander.EFFECT: high computational efficiency by eliminating receiving frequency uncertainty, which enables to avoid the search for the argument of the maximum of a one-dimensional discrete cross-correlation function.2 cl, 3 dwg |
