CPC H04W 56/0015 (2013.01) [H04W 56/0035 (2013.01)] | 17 Claims |
1. A control method of a distributed antenna system (DAS) including a baseband modem comprises the steps of:
calculating frequency offsets for each RF path in the baseband modem; controlling an oscillator clock of a central unit (CU) on the basis of an average of the frequency offsets;
determining an operation mode of the baseband modem;
controlling oscillator clocks of each distributed unit (DU) on the basis of the frequency offsets for each RF path when the operation mode of the baseband modem is a tracking mode; and
transmitting the oscillator clock of the central unit (CU) to each distributed unit (DU) when the operation mode of the baseband modem is an acquisition mode,
wherein in the tracking mode, oscillator clock errors of each distributed unit (DU) are individually controlled to have different values, and in the acquisition mode, the oscillator clock errors of each distributed unit (DU) are commonly controlled to have the same value.
|