Chip rate hopping provides low probability of detection for direct sequence signals
Electronics Letters , Volume 34 - Issue 7 p. 628- 629
Both analysis and measurements show that chip rate detection of a below-noise direct sequence spread spectrum communications signal can be countered by hopping the chip rate pseudorandomly.
McPherson, W.P., Hill, D.A., Mai, L., & Wight, J. S. (1998). Chip rate hopping provides low probability of detection for direct sequence signals. Electronics Letters, 34(7), 628–629.