| 摘要 |
RECEIVER FOR LOCAL CALLS WITH LOW ENERGY CONSUMPTION This local call receiver or pager includes a circuit (3) for receiving and demodulating a call signal emitted by a central station and which contains synchronization code words, address code words and message code words. Such circuit is connected to the pager energy source (16) through switching means (3b) for cutting off the energy supply when it is not necessary to receive the call cignal. The pager also includes a decoder (4) intended to control the switching means as a function of the analysis of the call signal synchronization code words. Such analysis is effected bit-by-bit and the receiver circuit is disconnected as soon as the synchronization code word is recognized, in most cases following analysis of only a few bits of the code word. Application is in respect of pagers in which a satisfactory compromise must be obtained between dimensions and autonomy, as for instance in pagers combined with a timepiece to be worn on the wrist. |
