摘要:
An oscillator unit for a base station or the like in a digital cellular radio network. The oscillator unit includes an adjustable oven stabilized crystal oscillator (21). The oscillator unit additionally includes a non-volatile memory (27), in which is stored a control information defining the frequency of the oven stabilized crystal oscillator (21) at the start of the oscillator unit, apparatus (30, 31, 32) for deriving a reference frequency from a fixed digital transmission connection, such as a PCM connection, between the base station and the remaining cellular radio network, a frequency control loop (21, 22, 23, 24) for maintaining a long-term stability for the oven stabilized crystal oscillator (21) on the basis of a long-term average of the difference between the frequency of the oven stabilized crystal oscillator and the reference frequency.
摘要:
For measuring gain error in a receiver of a base station of a cellular system and for improving field strength measurement, a signal received by the base station is measured before and after a receiver unit. The power level is corrected after the receiver unit to correspond to the power level of the signal determined before the receiver unit. For this purpose, before the receiver unit an accurate detector of the power level of the signal is provided, the power level of the signal detected by the detector being compared to the power level measured after the receiver.