[time-nuts] GLONASS receiver
magnus at rubidium.dyndns.org
Mon Aug 6 15:34:03 EDT 2012
On 08/06/2012 03:51 PM, Sylvain Munaut wrote:
>> GSM and derivates have +/- 50 ppb as frequency requirement, no time
> Note that GSM also have the constraint that all timing / frequencies
> in the system must be derived from the same reference.
> This way carrier freq / symbol rate / gsm time are all linked the same way.
It's a synchronous system. It's neat how the timing of the transmission
from the handsets is being steered (by quarter symbol solution) by the
base-station such that they occur in the middle of their time-slots as
being received by the base-station. The 13 MHz (actually 26 MHz or 52
MHz in modern handsets) clock of the hand-set is steered to the
frequency of the base-station. Thus, synthonisation and synchronisation
can be achieved.
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