Follower Jammer Research Articles

Joint power and hopping rate adaption against follower jammer based on deep reinforcement learning

AbstractAs an effective anti‐jamming approach, frequency‐hopping (FH) technology has been widely applied to tactical communication system, providing reliable communication guarantee and improving resilience against conventional interference under strong confrontation environment. Key challenges for tactical wireless communication network face are the smart follower jammer with responsive spectrum reconnaissance and intelligent decision‐making capabilities. In response, this article investigates a deep reinforcement learning based anti‐jamming scheme, with the aim of maximizing the system throughput. The interactions between a radio transmitter and a smart follower jammer are formulated as a hierarchical anti‐jamming dynamic game model, in which the radio terminal decides transmission power and hopping rate according to the state feedback information, and the jammer chooses spectrum scanning rate accordingly to minimizing the rewards of the FH communication system. We prove that there is a Nash equilibrium (NE) strategy for static and dynamic environment in the game. A double deep Q‐network with prioritized experience reply (PDDQN) based anti‐jamming scheme is proposed to approximating the optimal power control and hopping strategy without being aware of the environment and jamming parameters. Finally, simulation results demonstrate that the proposed algorithm efficiently provide better throughput and jamming resistance.

Evaluation of the Effect of Follower Jammer on the Mobile Bluetooth Network

Bluetooth wireless communication technology has spread rapidly in the past 20 years. It has made life much easier with all the devices that use Bluetooth technology around us such as mobile phones, laptops, and watches. With all the good and useful applications of Bluetooth technology, it has been used in harmful and bad ways such as cheating in an examination. In this article, parameter design considerations have been discussed for a follower jammer to interrupt a Bluetooth network, especially when it is used in unauthorized way. The effects of the follower jammer were studied and tested. The effects were calculated for time and jamming-over-signal ratio for three different distances (1, 5, and 10 m). The testing showed that the follower jammer designed was successful in disrupting the Bluetooth signal.

Anti-jamming Frequency Hopping System Using Multiple Hopping Patterns

This paper deals with the follower jamming (FJ) and partial-band jamming (PBJ) resistance for the frequency hopping (FH) communication system with low hopping rate over AWGN channel. To gain a comprehensive FJ and PBJ rejection capability, we propose a multi-pattern frequency hopping (MPFH) scheme. In MPFH, the data channel and complementary channel are hopped on separate frequency slots determined by their respective frequency patterns, which will lure the follower jammer out of aiming at the complementary channel, thus mitigating the effect of FJ. Besides, narrow-band receiver is employed to ensure its PBJ rejection capability. We further enhance the proposed scheme by employing convolutional coding and maximum-likelihood decoding. Its upper bounds on bit error rate (BER) are derived under FJ and PBJ, respectively. Effects of three FJ parameters (tracking success probability, jamming duration ratio and jamming bandwidth ratio) and one PBJ parameter (jamming bandwidth ratio) on BER performance of MPFH are investigated versus the conventional FH/BFSK and recently developed differential frequency hopping (DFH) system. Numerical and simulation results show that when under the worst-case FJ, the proposed MPFH performs as well as DFH, but outperforms the conventional FH/BFSK by more than 5 dB; on the other hand, when under worst-case PBJ, the MPFH has the similar BER performance as conventional FH/BFSK, but outperforms DFH by more than 5 dB. The proposed MPFH shows superior jamming rejection performance under both PBJ and FJ.

Performance Evaluation of the Effect of Noise Power Jammer on the Mobile Bluetooth Network

Network jammers can uncover the reliability of the wireless networks, where the position of the jammer node permit the network to cope with jamming leveraging varieties of defence strategies. Wireless Bluetooth network is a short range network, where the Bluetooth transceiver is operating in the 2.4 GHz ISM (industrial, scientific and medical) radio band, and a special type of frequency hopping pattern was included with the specification of the Bluetooth technology to offer the necessity requirement for the matching Radio Frequency RF channels. This paper calculates and evaluates the effect of noise power jammer and follower jammer on the Personal Area Network (PAN) Bluetooth network. The results prove that the effect on the Bluetooth network depends on many factors such as power density, distance and immunity technique, which is used in many Bluetooth networks.

Least squares symbol detection for two-antenna frequency hopping/M-ary frequency shift keying systems in the presence of follower jamming

The jamming robustness of frequency hopping systems with M -ary frequency shift keying (MFSK) modulation may be potentially neutralised by a follower partial-band jammer. To remove these harmful effects, a novel detection scheme for slow frequency hopping/MFSK systems, which use two receive antennas in a quasi-static flat fading channel, is proposed. The relative complex gain factor between the two jamming components is derived and is used to aid the symbol detection process. The improved performance of the new scheme is verified by using simulated bit error rate results.

Frequency-hopped spread spectrum in the presence of a follower partial-band jammer

A countermeasure to a partial-band follower jammer is proposed for frequency-hopped spread-spectrum communications. This technique randomizes the transmission technique used by the transmitter (and receiver). Either the information is carried by M tones which are transmitted in a frequency slot, or by M frequency slots which contain signal energy. As a counter-countermeasures, the jammer randomizes between jamming the same frequency slot being used by the communicator, or jamming a subset of the slots not being used by the communicator. The performance for randomized strategies for the communicator and jammer is investigated. It is shown that the proposed technique enhances the system's performance. >

Use of antenna nulling with frequency-hopping against the follower jammer

Antenna nulling is an effective ECCM (electronic counter countermeasures) asset that can be put in use with other ECCM techniques to obtain additional processing gain. Two antenna nulling schemes that can be used with frequency hopping to reduce the follower jammer threat are described. One of the schemes is only effective with uncorrelated signals. The second scheme is designed for coping with correlated jamming. Both schemes capitalize on the arrival time differences of the desired signal and the interference to isolate the interference for cancellation. The fast converging sample matrix inversion algorithm is considered in both schemes for improved effectiveness. The performance of the antenna nulling schemes, described in terms of the array output-signal-to-interference and noise ratio (OSINR), is evaluated by computer simulation. The OSINR of the array at a single frequency in the hop-set is presented for a range of desired signal-to-noise and jammer-to-noise ratios. The processing gain offered by the antenna nulling system was found to increase with increasing desired signal-to-noise ratio.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>