Edge (Option 202 Only) - Agilent Technologies ESG Series User And Programming Manual

ESG Family Signal Generators Overview of Modulation Formats
Options UN8 and 202

EDGE (Option 202 Only)

EDGE (Option 202 Only)
The Enhanced Data Rates for GSM Evolution (EDGE) digital communications standard
defines a voice and data over-air interface between a mobile radio and the system
infrastructure. This standard was designed as the basis for a private radio
communications system. A central control center is linked to multiple base station sites
which provide the required coverage.
The EDGE digital communications standard employs a 8:1 Time Division Multiple Access
(TDMA) allowing eight channels to use one carrier frequency simultaneously. The
812.5 kbits/second raw bit rate is modulated with 3π/8 rotating 8PSK. This standard
defines the channel separation as 200 kHz at carrier frequencies between 935 and
960 MHz (downlink transmissions) and 890 to 915 MHz (uplink transmissions) at a power
level ranging between 3.7 mW and 20 W. The standard specifies a physical traffic channel
(TCH) with two logical components: a logical TCH and the slow associated control channel
(SACCH).
The EDGE framing structure is based on a hierarchical system consisting of timeslots,
TDMA frames, multiframes, and hyperframes. One traffic channel consists of either 468 or
471 modulated bits including tail, encryption, training sequence, and guard time bits.
Eight of these bursts make up one TDMA frame. Twenty-six TDMA frames make up one
multiframe. Frames 12 and 25 in the multiframe are dedicated to control channel
signaling (SACCH).
Guard time appears in the visual representation of the timeslot as a 24.75-bit field. In the
actual implementation, the guard time field in timeslots 0 and 4 are 27 bits long and the
remaining timeslots contain 24-bit fields.
Real-Time I/Q Baseband Generator User's and Programming Guide 1-7