User Manual

Architecture
Nortel Networks Confidential
3–50
PE/DCL/DD/0063
411–9001–063
Standard 12.07/EN September 2000
GSM/BSS V12
3.5 e–DRX functional architecture
The e–DRX board consist of (see Figure 3–15):
an e–LDRX digital board including a dc/dc converter, a frame processor TX
logic (GMSK and 8–PSK modulation), and a local time base, working for all
frequency bands
an e–RDRX radio board including a dc/dc converter, a low power driver and a
dual receiver
3.5.1 Modifications between the DRX and e–DRX
This chapter describes the modifications between the current DRX and the e–DRX.
The main features of the e–DRX are the following:
signal processing capacity improvement
8–PSK modulation compatibility
receive dynamic extension
TX output power dynamic reduction
packet backhaul readiness
3.5.1.1 E–LDRX board modifications
The main modifications concerning the e–LDRX board are the following:
the migration of BDT, AMNU, and TX into a single FPGA
the use of one PowerQuicc
the introduction of the 52 MHz frequency reference function
the use of two DSP
the extension of the memory capacity (8 Mb for SDRAM, 4 Mb for flash and
2 Mb for SRAM)
the size reduction and integration of the dc/dc converter on the e–LDRX board
the lower power consumption (<15W)