... Call
EXERCISES
287
2.
Consider a wideband radio that implements frequency hopping with a
fast-hopping LO. What steps are necessary to migrate that implementation
toward a software -radio architecture? What benefits ... context. A SPEAKeasy-like radio may have to operate within
a kilometer of a high-power (90 dBm) troposcatter communications system.
Metal structures may reflect some of th...
... to be radio- aware so that the radio s low data rates, high variability in
data transfer times, and occasional outages do not severely curtail user satis-
faction with the services. In the radio ... approaches, the radio applications and infrastructure software elements
are intricately interwoven. Open-architecture approaches now favor the use of
the industry-standard CORBA [216] in ra...
... algorithms and hardware can yield benefits (or cause problems)
for the analog parts of the software radio.
III. SDR APPLICATIONS
ADC and DAC applications are constrained by sampling rate and dynamic
range. ... A cellular uplink, for example, might consist of
25 MHz from 824 to 849 MHz. The ideal software radio would convert directly
from RF at a sampling rate of say 2.3 GHz. The Nyquist f...
... with
longer reach and greater reliability than analog radios. A first implementation
of an SDR may not perform as well as the equiv alent analog radio because in-
adequate attention is paid to the ... that general-purpose processors
cannot be used for software radio research. For example, MIT has used the
DEC Alpha chip for their virtual radio [178].
DSP teams apply skill in the use of...
... Interconnect), 316, 320
Radar, 74, 75
Radio applications (layer), 377, 380–380
Radio horizon, 83
Radio infrastructure, 164, 211, 363–368, 378,
380–381
Radio noise, 81, 397
Radio platform (reference model), ... Programmable Digital Radio (PDR) Case Studies 215
A. A Basic Commercial PDR 215
B. Multimode Conventional Radios 218
C. GEC’s Programmable Digital Radio 220
D. ITT Digital...
... other. Each radio has LOS access to a point in the troposphere from which
radio waves are scattered beyond LOS. Due to the weak coupling between
the radio waves and the troposphere, the radios employ ... programmable
digital radios. These radio suites also monitor emergency channels using ded-
icated transceivers. This includes simultaneous VHF and UHF operation.
Illustrative discrete...
... or more
radios each)
500–3000 National
Guard troops
50–300 squad radios, 12–80 company
radios, 3–10 high-level command network
radios, radio relays
with 20–50 aircraft 20–50 air mobile radio nodes ... characterizes the expected parameters
of that radio channel. All these are necessary in the analysis of software -radio
architecture.
A. Radio Resource Management
Radio resources cons...
... inheritance re-
lationships from the generic radio node class o f object. The domain (e.g.,
handset, cell site, vehicular radio) property of the radio node is therefore in-
herited by the function, ... interface. Layer 1 services are provided in the radio front end.
The architecture accommodates multiple layer 1 services corresponding to the
radio modes of the SDR. Thus, for example,...
... disaster-relief case study?
252
ANTENNA SEGMENT TRADEOFFS
bands. Using typical military radios such as SINCGARS, these radios will
jam each other. Operational steps may reduce the number of networks ... 7-1.
Due to the software radio s ability to concentrate energy, software constraints
may be required to preclude unacceptable exposure levels. For example, a
four-channel radio might be per...