The same hardware could also be used for different systems, for example, different tag
generations and different classes, since all the signal processing is performed in software.
The same software can be recompiled for a different processor and can be run on different
platforms such as in handheld terminals. Instead of implementing several RFID receivers
for different physical regions, one receiver could be used for all systems, and different
software packages could be used to switch between systems.
The requirements on the ADC in a software radio architecture are very high, as the
signal received by the antenna, for instance, does ?¬‚uctuate in amplitude by a large amount.
When such a wide dynamic range signal is converted in the ADC the dynamic range must
be high enough so that a weak tag reply can be separated from the harmonics and the
strong carriers. The SNR (signal to noise ratio) must also be high so that weak replies can
be seen above the noise ?¬‚oor.
5.1.6 Summary
This section has demonstrated a ?¬‚exible approach to implementation of an SDLR using
dynamic communication schemes. This platform provides a powerful solution for rapidly
building and testing new RFID communication systems and protocols, and it forms a basis
for developing highly ?¬‚exible RFID infrastructures.
The SDLR is an inexpensive and versatile solution to the collection of temporal and
spatial ?¬?eld data for numerous research and educational endeavors.
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