| 摘要 |
A mobile unit of a digital mobile communications system includes a diverse antenna receiver arrangement comprising a main antenna branch (1), a second diverse antenna branch (2), and a diverse antenna switch (3) for switching between the two antenna branches. A channel acquisition controller (11) runs a channel acquisition process which causes the mobile unit to scan plural frequencies of the radio system in turn and take successive signal samples on each frequency, in which scan two signal samples are taken on each carrier frequency, one on the main antenna branch (1), and then one from the diverse antenna branch (2), before the receiver retunes to the next frequency to be sampled. After all the frequencies have been dual-sampled in this way, the process is redone a number of times and after a selected overall sampling period the mean signal strength of each frequency is determined from the samples taken. The mobile unit then, for example, selects the frequency with the greatest signal strength as the frequency (radio channel) to use. |
