
2. Non-Linearity of modulation (EDGE)
• with EDGE, overcome non-linearity by using (1) feedback or
(2) pre-distortion or (3) both
• most techniques require a complex mixer...
• which requires a duplexer...
• which was actively designed out of GSM handsets to remove
size, weight, cost and power inefficiency!
DESIGN TIPS (GSM/GPRS/EDGE phone)
•careful design of the transmit path is needed
•new power control-loop is required
EGPRS design considerations (Modulation)
There are also new test considerations for EDGE
• New 8PSK modulation format requires validation
• Modulation Quality – EVM/Phase error/Frequency error
• 8PSK Power measurement changes
• Power Vs Time – New mask definition
• ORFS – More challenging to meet the same specification
• Testing under multiple TX timeslots
EGPRS TEST considerations
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