COMB JAMMING AS A STRATEGY FOR RCIED ACTIVATION PREVENTION

The main objective of this paper is the analysis of comb jamming as a technique for RCIED activation prevention. Presentation of three strategies for comb signal generation follows after comprehensive survey of various jamming techniques in the introduction. There are two paper original contributions. The first one is quantitative comparison for three signal generation techniques of their emission power in relation to barrage jamming under the condition of equal BER value. The second contribution is determination of exact BER value as a function of emission power in the case of barrage jamming. Until now we have made different analyses and comparisons starting from estimated emission power. The analysis procedure is performed for QPSK modulated RCIED activation signal. Power saving is evident for all three methods of jamming signal generation. It is proved that additional 2.5dB of power saving is achieved by equalization of frequency components level in comb signal. The analysis in this paper shows that comb jamming allows the same effects as barrage jamming, but with lower emission power

Successful Sweep Jamming Rate Determination of MPSK Modulated RCIED Activation Message Signals

This paper presents the development of the method for accurate successful jamming rate calculation when MPSK modulated RCIED activation message is jammed using sweep signal. Opposite to classical methods of error modelling where it is taken that only one bit in a symbol may be altered, it is supposed in this paper that any number of bits in a symbol is the subject of eventual modification. The derived formulas are achieved for QPSK, 8PSK and 16PSK modulated signals jamming. The results calculated by these formulas are verified and obtained by our originally developed simulation method. The results of calculation and simulation agree very well and the maximum difference between calculated and simulated successful jamming rate for any of three analyzed jamming methods and any level ratio between activation message signal and jamming signal does not overcome 1.1%. It is proved that successful jamming rate tends to maximum value 0.5 when jamming signal power increases and that only 20% lower successful jamming rate value is obtained for less than 7dB higher jamming signal level than it is the level of RCIED activation signal. These results point out that it is not necessary to apply too high emission power to achieve acceptable jamming effect. As a consequence, jammer practical implementation is easier and its dimensions are smaller

ANALYSIS OF JAMMING SUCCESSFULNESS AGAINST RCIED ACTIVATION WITH THE EMPHASIS ON SWEEP JAMMING

In this paper we first briefly compare the performances of active jamming remote controlled improvised explosive devices activation using wide-band noise and frequency sweep signal. Frequency sweep is the most widely used technique intended for active jamming and we analyze its characteristics: 1) sweep speed, 2) conditions for certainly successful jamming, 3) successful jamming probability if jamming is not certainly successful, and 4) step of frequency change when frequency sweep is applied. The separate paper section is devoted to the successful jamming probability calculation in general. The attention is also paid to jamming probability determination when starting and ending sweep signal frequencies are varied. The initial research has been upgraded and extended. The presented results refer to jamming equipment development in IRITEL, but it is important to add that they are also applicable to the other similar jamming systems realizations