Chen Yading

A Robust Acquisition Scheme for FH Signal in Adverse Environments

Partial-band jamming and multi- tone jamming have severe effect on acquisition of frequency-hopping (FH) signal in adverse environments. In this paper, an anti-jamming FH signal acquisition scheme based on cognitive correlation process is proposed and analyzed. The main idea of this scheme is make full use of a priori knowledge about FH speed and FH pattern. Theoretic analysis in detection probability and false probability is given to demonstrate the robust performance of the FH signal acquisition method compared to conventional acquisition scheme without any prior information on FH speed and pattern.

A new anti-jam receiver for MFSK/FFH system with multitone jamming

In this paper, a differential jamming rejection (DJR) receiver in fast frequency hopping (FFH) M-ary frequency shift keying (MFSK) systems with a worst-case band multitone jamming (MTJ) is introduced. This receiver, based on detecting frequency spectrum difference in forward-backward time slot while the FFH/MFSK signal arrive receiver, implements differential suppression of a worst-case band multitone jamming without any side information. Further analysis and data simulation indicate that this scheme possesses good efficiency.

Anti-jamming Performance and Implementation of Ultra-Fast Frequency Hop Test-bed

Fast frequency hopping (FFH) communications is an important technology of anti-jamming in military applications. In this paper, anti-jamming performance and implementation of ultra-fast frequency hopping (UFFH) test-bed are described. The system provides the highest hopping rate reported to date and keeps capability of communication under the condition in which the 60% of system working spectrum is stained. The test-bed capable of transmitting data at 96 kbps with hopping rates of up to 100 khops/s operates in the VHF/UHF band. Based on software defined radio technology (SDR), the architecture uses a direct digital frequency synthesizer (DDFS) to implement demodulation and modulation of frequency hopping (FH) signal. Furthermore, different arithmetic of digital signal processing and parameters could be software configured because of the high performance analog-to-digital converter (ADC) and the super-heterodyne architecture. Finally, it is showed by the result of measure and simulation that UFFH test-bed has a robust anti-jamming performance

Anti-jamming performance of CCPR in FFH/BFSK systems

Communication countermeasures technique is an important component of contemporary military wireless communication system. In this paper, an anti-jamming receiver, clipper cascaded product-combining receiver (CCPR) has been presented for the fast frequency-hopped binary frequency-shift-keying (FFH/BFSK) spread-spectrum communications system with two typical hostile jamming and the additive white Gaussian noise. Further analysis and simulation indicate that the system anti-jamming performance, using this method presented in this paper, could be improved about 10dB better than conventional product combining and self-normalizing combining when the signal-to-jamming ratio (SJR) less than −10dB. Furthermore, its low complexity makes it carry out easily.