| 摘要 |
<p>The invention relates to an oscillator unit for a base station or the like in a digital cellular radio network. The oscillator unit comprises an adjustable oven stabilized crystal oscillator (21). The oscillator unit additionally comprises a non-volatile memory means (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, a means (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 said reference frequency.</p> |
