26
N:\mkt\MANUALS\HP8924C\APPMOD\BOOK\chapters\amcal.fb
Chapter 1, Calibrating the Test Set
Calibrating CDMA Channel Levels
Calibrating CDMA Channel Levels
Approximate time: 8 minutes
CDMA channel levels should be calibrated whenever any of the following events
occur:
•
After a 30-minute warm-up period
•
After firmware is upgraded
•
If a 5° C change in ambient temperature occurs
The Test Set optimizes the level accuracy of CDMA code channels and the
AWGN (Additive White Gaussian Noise) generator by measuring the analog I/Q
signals on an internal DSP-based voltmeter. Level correction factors are generated
by a ROM-based program named PCB_CAL and are applied to gain control
DACs, which control the fine level adjustment in the amplitude scaling path.
Calibrated channel power provides accurate values for Eb/Nt, the ratio between
Traffic channel power and AWGN. It is critical that these levels remain accurate.
A level accuracy error of 0.8 dB could alter FER from 0.5% to 5%.
Q Output
I Output
Diagnostic Mux
To DSP
Voltmeter
AWGN
Analog I
Analog Q
Level Correction
Factors
Gain Control
DAC
Σ
Σ
Содержание HP 8924C
Страница 21: ...Contents 21 N mkt MANUALS HP8924C APPMOD BOOK APPMOD TOC Table of Contents Index 351 ...
Страница 22: ...Contents 22 N mkt MANUALS HP8924C APPMOD BOOK APPMOD TOC ...
Страница 51: ...51 N mkt MANUALS HP8924C APPMOD BOOK chapters amcall fb Chapter 2 Setting Up a Call 2 Setting Up a Call ...
Страница 71: ...71 N mkt MANUALS HP8924C APPMOD BOOK chapters amrcvrt fb Chapter 3 CDMA Receiver Tests 3 CDMA Receiver Tests ...
Страница 139: ...139 N mkt MANUALS HP8924C APPMOD BOOK chapters amtxtst fb Chapter 4 CDMA Transmitter Tests 4 CDMA Transmitter Tests ...
Страница 199: ...199 N mkt MANUALS HP8924C APPMOD BOOK chapters amhoff fb Chapter 5 CDMA to Analog Handoff 5 CDMA to Analog Handoff ...
Страница 317: ...317 N mkt MANUALS HP8924C APPMOD BOOK chapters amsrq fb Chapter 10 Controlling Program Flow 10 Controlling Program Flow ...