Selectively called radio receiver with bit rate detection for battery at shorter than a frame period

摘要

In a selectively called radio receiver operable in a battery saving method in which frame synchronism is established after establishment of bit synchronism and in which a bit rate detection signal is produced by detecting a bit rate of an arriving radio signal to establish the frame synchronism before lapse of a frame synchronism establishing interval after establishment of the bit synchronism or restoration of bit synchronism subjected to a failure, repeated production of the bit rate detection signal at a regular interval is monitored by determining for the regular interval a unit time interval shorter than a frame period of the radio signal. Preferably, the unit time interval is equal to a four- codeword length of codewords, such as the frame period, when sixteen is the number of codewords in a typical frame.