Digital radio paging communication system Patent #: 4194153
ApplicationNo. 06/339632 filed on 01/15/1982
US Classes:455/343.2, Battery saving based on received signal327/165, Regenerating or restoring rectangular (e.g., clock, etc.) or pulse waveform327/18, By presence or absence pulse detection327/72, Input signal compared to reference derived therefrom340/7.38, Time based455/343.5Battery saving based on detected power source level
ExaminersPrimary: Bookbinder, Marc E.
Attorney, Agent or Firm
International ClassesH03K 5/08 (20060101)
H04L 25/06 (20060101)
H04Q 7/18 (20060101)
Foreign Application Priority Data1981-01-26 JP
AbstractIn a pulse detector of a receiver for use in a digital radio communication system comprising a low pass filter supplied with an input signal, a first resistor and a capacitor which are connected in series between an output terminal of the low pass filter and ground to constitute a longer time constant integrating circuit, a second resistor connected in parallel with the first resistor through a switch controlled by a control input, the first and second resistors and the capacitor constituting a shorter time constant integrating circuit, and a comparator with one input connected to the output of the low pass filter and the other input to a juncture between the first and second resistors and the capacitor, the potential of the juncture being utilized as a reference potential of the comparator, there is provided a switch connected between the juncture and the ground in series with the capacitor. According to this invention, pulse detection can be made more accurately and power can be much more saved than a prior art pulse detecting circuit.