| 摘要 |
In a mobile telephone system a base station communicates with a number of mobile units using a number of communication channels sharing the same radio frequency, using Time Division Multiplex (TDM). The system may be used in conjunction with frequency hopping, which has hitherto been restricted by the need for the base station to operate on more than one frequency, and the need to maintain a reserved channel for control purposes (the BCCH) which prevents channels on the corresponding timeslot on any other frequency in use by the base station from switching to the BCCH frequency. Each mobile unit uses a different timeslot in each successive frame. This arrangement reduces the effect of co-channel interference. By switching timeslots, using a sequence avoiding the BCCH, all channels can be interchanged, even if there are only one or two frequencies in use by the base station. |
