Summary

This chapter has presented some of the theory necessary to appreciate some of the ideas embedded in the ETSI noise model. In order to properly define the physical quantity being produced at the output of the model, some frequency metrology has been discussed. This was followed by a classification of noise types common in phaselock loops classified in terms of their power spectral density by use of the power-law model. The noise shaping function of filter A was then discussed. Finally, some theory of phaselock loops was presented. This material will subsequently used in chapter 5 in order to show that the ETSI noise model can be interpreted as a particular form of phaselock loop. In the next chapter, extensive discussion of the measures used to characterise clock performance is presented.