Nokia RM-626 Service Manual page 221

RM-626
System Module
• GSM mode
• GSM TX data bits are sourced from baseband via RFBus to Älli
In GMSK mode, the output level of Älli is kept high with all power levels, and the output power is adjusted
by altering the collector voltage of PA. In practice, the output level of Älli is also slightly changed (optimized)
in the highest power level to keep the PA compression level more constant, which results in better overall
efficiency and performance.
In WCDMA and EDGE mode, the output power is tuned by output level of Älli. The supply voltage in WCDMA
mode is adjusted in power levels to optimize the current consumption.
Issue 1 COMPANY CONFIDENTIAL Page 6 – 33
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