Filter
Top Products
xiv
List of terms
411-2021-111 Standard 01.01 June 1996
Modulation
The process of placing information on an RF carrier. The modulation technique
may involve changing the amplitude, frequency, or phase of the carrier
determined by the modulation index.
NES
Non-expanded Spectrum. The frequency spectrum initially assigned to the
cellular band. The Non-expanded Spectrum provides 333 channels to each of the
two bands, the A-Band and the B-Band.
Omni
An antenna design which permits radiation in essentially all H-Plane azimuths.
In cell sites, an Omni configuration means a single set of omni antennas is used
for all channels.
π
/4 DQPSK
Variation of Differential Quadrature Phase Shift Keying used in D_AMPS IS-54
TDMA for improved spectral characteristics and phase resolution. Permissible
phase changes are integral multiples of
π
/4 radians (45 degrees).
π
/4 is used to
reduce the peak to root mean square ratio requirements for linear PAs.
Return loss
A logarithmic relationship of the incident signal to the reflected signal as
expressed, in dB, by the following relationship:
where Pi = incident power in watts
Pr = reflected power in watts
The strength of the signal, expressed in dB, reflected by a load back into a
transmission line due to impedance mismatch. -14 dB corresponds to a VSWR of
1.5:1.
Reverse path
The path from cellular subscriber terminal to cell site.
RF
Radio Frequency. Electromagnetic energy of the frequency range just above the
audible frequencies and extending to visible light.
RIP
Rack Interface Panel. The RIP is the interface between the cell site power supply
and the cell site equipment.
P
r
10 log
P
i
Return Loss =