29

# It can be rewritten because E_{b }= P / R_{b }where R_{b}= bit rate and N_{j }= J/W. This can be tested by

running a simulation and calculating the BER for various ρ against E_{b}/N_{j}. This can be seen in

# Figure 14 below:

## BER vs. Eb/Nj for Pulsed Noise Jamming

10^{-1 }

theory simulation

10^{-2 }

# Worst-Case

10^{-3 }

BER

10^{-4 }

10^{-5 }

10^{-6 }

10^{-7 }

ρ = 0.2

ρ = 0.008

ρ = 0.00032

ρ = 1.0

ρ = 0.04

ρ = 0.0016

10^{-8 }

0

5

10

15

20

25 Eb/Nj (dB)

30

35

40

45

50

# Figure 14 – Worst-Case Jamming for Pulsed Noise in DSSS

# The worst-case can be approximated by the think black line is tangent to the curves of the

various ρ values. Figure 14 shows that the optimal jamming duty cycle is dependent on the E_{b}/N_{j }

of the transmitted signal. Assuming the E_{b}/N_{j }is at least 0.709, the worst-case line can be

approximated by the following equation (see [26] for math):