esourour
Newbie level 4
crystal frequency offset gsm
This is a question for specialists. I am designing a GSM algorithm for estiamting and tracking the frequency offset. According to the GSM specifications, the crystal offset must be < 0.1 PPM. This is normally achieved by locking to the Frequency Correction Channel, prior to a call.
A collegue in the field told me that the GSM chip must, in addition track a possible frequence offset during a call (or file download on GPRS mode) due possibe teperature variation or vibrations. According to him, this is done with the training sequence inside the GSM slot.
Any one knows if this is truly needed? If, yes, any reference for a method or algorithm?
Thanks
This is a question for specialists. I am designing a GSM algorithm for estiamting and tracking the frequency offset. According to the GSM specifications, the crystal offset must be < 0.1 PPM. This is normally achieved by locking to the Frequency Correction Channel, prior to a call.
A collegue in the field told me that the GSM chip must, in addition track a possible frequence offset during a call (or file download on GPRS mode) due possibe teperature variation or vibrations. According to him, this is done with the training sequence inside the GSM slot.
Any one knows if this is truly needed? If, yes, any reference for a method or algorithm?
Thanks