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utilizing physical layer information to improve rfid tag

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Figure 6.8. Strong and weak <strong>tag</strong> collision I-Q plot.<br />

An experiment was carried out by using some standard RFID <strong>tag</strong>s <strong>to</strong> find the<br />

distribution function of their random number genera<strong>to</strong>rs. Pearson’s chi-square test<br />

was carried out for all the 4 <strong>tag</strong>s as well as a data set generated using a uniform pdf.<br />

The results are summarized in table 6.5<br />

Table 6.5. Random number genera<strong>to</strong>r performance of common <strong>tag</strong>s<br />

6.5 Effect of non-uniform PDF<br />

Tag Mean Square Error<br />

bow-tie 41.43<br />

excalibur 31.25<br />

squiggle 22.53<br />

TI 20.77<br />

Reference data set 26.22<br />

Tag random number genera<strong>to</strong>rs have a uniform distribution for the output val-<br />

ues and they are distributed between 0 and 2 Q -1. In this section we analyze the<br />

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