| 摘要 |
In a radio communication system having a command or base station and one or more controlled or mobile stations, the base station continuously transmits outbound function messages in binary bit form to the mobile stations Each outbound function message comprises a sequence of binary bits forming a first synchronizing word, a first address word transmitted three times, a second inverted synchronizing word, a second address word transmitted three times, a third inverted synchronizing word, and a command word transmitted three times. All mobile stations receive the outbound messages and synchronize on them, but only that mobile station whose address is transmitted responds. Each mobile station is synchronized when it properly receives two consecutive synchronizing words in sequence, and remains in synchronization unless five consecutive synchronizing word errors occur. The response from the mobile station to the base station is an inbound message also in binary bit form. each inbound message comprises a preamble followed by the first synchronizing word, the first address word transmitted three times, the second inverted synchronizing word, the second address word transmitted three times, the third inverted synchronizing word, and a response word transmitted three times. This inbound messsage or response has a bit rate that is 1? times the outbound message bit rate so that other mobiles can respond to their respective messages as they are transmitted by the base station. The base station anticipates each inbound message and uses the preamble and the first synchronizing word to synchronize itself with the inbound message. Thus, high spped binary function controls are reliably provided between a base station and one or more mobile stations in the environment of radio frequencies, particularly those in the land mobile service. |
