| 摘要 |
<p>A radio communications system in which analog voice signals (341) are transmitted and received via single sideband amplitude modulation, (346, 317) and digital data signals are transmitted and received via narrowband frequency modulation (353, 316) in a single trunked radio system having dedicated channel bandwidths. The base station (120) continuously transmits the FM signalling information on a dedicated control channel. The remote station (113, 118) transceiver initially acquires a lock to the data channel FM carrier, which is then demodulated to determine the frequency of an assigned voice channel. The remote station then acquires lock to the single sideband pilot carrier on the appropriate voice channel. The controller (130) incorporates a memory state (500) for holding AFC for the mobile transmit frequency.</p> |
