Agilent Technologies ESG series, User And Programming Manual, Page: 26 / 446

1-10 Real-Time I/Q Baseband Generator User’s and Programming Guide
Overview of Modulation Formats ESG Family Signal Generators
PDC Options UN8 and 202
PDC
The Personal Digital Cellular (PDC) digital communications standard defines a voice and
data over-air interface between a mobile radio and the system infrastructure. A central
control center is linked to multiple base station sites which provide the required coverage.
The PDC digital communications standard employs a 6:1 Time Division Multiple Access
(TDMA) allowing six channels to use one carrier frequency simultaneously. The raw bit
rate, 42 kbits/second, is modulated using a system known as
π
/4 Differential Quadrature
Phase Shift Keying (
π
/4DQPSK). This standard defines the channel separation as 50 kHz
(25 kHz interleave) in two separate frequency bands: 810 to 826 MHz (downlink
transmission) 940 to 956 MHz (uplink transmission), as well as 1477 to 1501 MHz
(downlink transmission) 1429 to 1453 MHz (uplink transmission) at a power level of 0.8 W
(mobile station). The standard includes a control channel, multiple traffic channels, and
other logical channel types.
The PDC framing structure is based on a hierarchical system consisting of timeslots,
TDMA frames, multiframes, and hyperframes. One uplink traffic channel burst (from
mobile to base station) consists of 280 modulated bits including ramp, data, preamble,
synchronization word, color code, steal flag, slow associated access channel, and guard bits.
Six of these bursts make up one TDMA frame. Eighteen TDMA frames make up one
multiframe.