High density cellular mobile radio communications
Method and apparatus for assigning duplex radio channels and scanning duplex radio channels assigned to mobile and portable radio telephones in a cellular radiotelephone communications system Patent #: 4485486
ApplicationNo. 06/619251 filed on 06/11/1984
US Classes:455/436, Handoff455/69Transmitter controlled by signal feedback from receiver
ExaminersPrimary: Rubinson, Gene Z.
Assistant: Brady, W. J.
Attorney, Agent or Firm
International ClassH04Q 7/38 (20060101)
AbstractA cellular mobile radio-telephone system incorporates hand-off equipment for effecting a hand-off of communication links coupled to a mobile subscriber transceiver as the transceiver travels from one cell to an adjoining cell. The hand-off equipment includes a filter which smoothes voice channel signals received from the mobile transceivers so as to permit a more precise determination as to when a reduction in signal amplitude indicates the need for a hand-off. The operation of the filter includes long and short term averaging of a sequence of signal samples. Circuitry is also provided for predicting a time of signal fade-out based on differences in the amplitude of successive samples or groups of samples. Also disclosed is circuitry for commanding a change in transmitter gain in a transceiver as a function of signal fade-out.