Locally generated spreading sequence can be reconstructed from a known chaotic system parameter [16].
Correlation properties give a numerical description of the quality of generated spreading sequences.
The DS-CDMA network uses randomly generated spreading codes of length N=16.
The DS-CDMA network uses randomly generated spreading codes of length N=32 and N=16; it also employs L p =3 independent paths with the power profile [0,−3,−6 dB] for the transmission link.
The principle of the necessity of generating spread nulls has been explained in [25].
It can be seen from Figure 4 that PODB method with NB generates spread nulls around ϕ = 30° with the width of W = 20° and depth about -20 dB. Figure 4 Average Beampatterns of PODB methods.
However, one simple way of generating spread nulls is to add N virtual LU sources ϕ i, i = 1,2,..., N around each direction of existing LU with the angle range of W/2, e.g. |ϕ i -ϕ m | ≤ W/2, m = 1,2,...,M.
First we assume W = 0, where W is the width of the spread nulls towards each LU, which requires only a point null at each LU direction, and then we give further results of how to generate spread nulls by modifying the angles.
Sensitivity to initial conditions and system parameter makes chaotic maps ideal for generating spreading sequences of the appropriate length.
Examining tissue from the animals' brain stems in the lab, Noebels and Aiba found that they could generate spreading depolarization far more easily in the mutant animals than in normal ones.
