RF Calibration Introduction 1 整理版课件 Agenda What is RF calibration. Why calibration. NV items of RF calibration. Rx Calibration. Tx Calibration. 2 整理版课件 What is RF calibration • RF calibration is the process of measuring data to be used in the system for the purpose of compensation of non-linear characteristics and frequency variations, and to provide absolute power reference and temperature compensation to ensure performance of the Tx and Rx paths of a subscriber unit. • Output from the calibration process is stored in non-volatile (NV) memory items in AMSS. • AMSS uses calibration values during normal operation to ensure system performance is met. 3 整理版课件 Setup: What is RF calibration 4 整理版课件 Why calibration Subscriber units have differing RF characteristics Differences in design Part-to-part variations of components of the same design 5 整理版课件 Individual phones also change their own RF characteristics: over frequency channel over temperature Why calibration 6 整理版课件 Why calibration The subscriber unit must estimate the Rx power properly to maximize signal-to-noise ratios and to provide a basis for Tx power output. The subscriber unit must transmit at correct Tx power level over its large dynamic range. The Mobile Station Modem™ (MSM™) device and system software combination must know the RF and analog characteristics of the particular unit. Failure to compensate for differing RF/analog characteristics may cause the unit to fail minimum performance specifications 7 整理版课件 The compensation values are classified: Static RF NV items: Measured once per design. Calculated RF NV items: RF NV items that are calculated based on other parameters of the design configurations. Measured RF NV items: Is determined by the RF calibration process. NV items of RF calibration 8 整理版课件 Rx calibration Philosophy of Rx AGC(Automatic Gain control) loop. DVGA(Digital VGA) offset calibration. LNA(Low Noise Am