A novel SINR and mutual information based radar jamming technique

The improvements of anti-jamming performance of modern radar seeker are great threats to military targets. To protect the target from detection and estimation, the novel signal-to-interference-plus-noise ratio(SINR)-based and mutual information(MI)-based jamming design techniques were proposed. To interfere with the target detection, the jamming was designed to minimize the SINR of the radar seeker. To impair the estimation performance, the mutual information between the radar echo and the random target impulse response was used as the criterion. The spectral of optimal jamming under the two criteria were achieved with the power constraints. Simulation results show the effectiveness of the jamming techniques. SINR and MI of the SINR-based jamming, the MI-based jamming as well as the predefined jamming under the same power constraints were compared. Furthermore, the probability of detection and minimum mean-square error(MMSE) were also utilized to validate the jamming performance. Under the jamming power constraint of 1 W, the relative decrease of the probability of detection using SINR-based optimal jamming is about 47%, and the relative increase of MMSE using MI-based optimal jamming is about 8%. Besides, two useful jamming design principles are concluded which can be used in limited jamming power situations.

Strategies for Dense Optical CDMA Communication Systems

In this paper, we have formulated a strategy that the limited available codesequences in pure Direct-Sequence (DS) or Frequency-Hopping (FH) system can be reused to realizedense optical CDMA: the strategy of novel hybrid DS/FH system. In which, the case that there are nusers employing the same FH pattern but different DS code patterns is considered. On the conditionthat the impact of channel noises is neglected, the upper bound probability of error is evaluatedbased on the stationary random process theory. The results shout that the hybrid system is suitablefor Dense Optical CDMA (DOCDMA) communication. Moreover, the problems such as the link-impairment,dispersion of group velocity, etc. in the pure (DS or FH) system can be solved effectively.