Page 308 - Fundamentals of Radar Signal Processing

instead of the 1/20 that would be obtained if a 20-bit Barker code existed. A

code that obtains a PSL = 2 for N = 20 is discussed momentarily.

FIGURE 4.49 Autocorrelation of combined B ⊗ B code.
5
4

Another technique uses pseudorandom noise sequences to generate much
P
longer biphase codes. Pseudorandom sequences have length N = 2 – 1 for some
P and generally exhibit range sidelobes on the order of –10 log (N). For
10
example, the matched filter output for a typical N = 1023 (P = 10) code, shown
in Fig. 4.50, has peak sidelobes just above –30 dB.