This distance is defined as the number of times that symbols with the same index differ in the two sequences.
As discussed in Section 3.1.1, the definition of sub-hops can exchange message among symbols with the same phase.
Below we assume that the pilot symbols are inserted as subcarrier channel symbols with the same energy as the data carrying channel symbols (i.e., no pilot boosting).
When we look at Figure 1, because a symbol can be converted to any other three symbols with the same probability, any symbol error will lead to the 1 2 ∗ 1 3 + 1 ∗ 1 3 + 1 2 ∗ 1 3 = 2 3 bit error.
Nevertheless, in the process of symbol matching and recognition, some symbols (especially polygon symbols) with the same style and different sizes cannot be automatically identified, and manual intervention is needed.
In summary, by selecting pilot nucleos such that the sum of the powers of their corresponding pilot symbols with the same indexes are equal, the bound on CRB is minimized.
If (mathcal {A}) and (tilde{mathcal {A}}) are both admissible symbols, with the same structural constants (mathcal {A}_0) and (mathcal {A}_1), then we say that the symbols are structurally similar.
It has also been noted that "media portrayals of the consumption and effects of alcohol do not comprise a neutral, scientific reality but rather signify a network of social knowledge, value systems, and symbols," with the same likely occurring for other substances [31].
To recognise a symbol, a pixel-by-pixel matching approach is proposed in which the symbols in a map, and those in the symbol library with the same mapping standard, are firstly transformed into BMP images, and then the symbol images within the map are matched with images from the library, to find out the correct symbol.
