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For the interference hidden in the expected multi-carrier signal, this paper proposes a novel detection and recognition algorithm. The algorithm cannot only detect the single-carrier interference (SCI) by the high-order cumulant, but also finds the multi-carrier signal based on spectrum character. Besides, the algorithm can distinguish the modulation types of the SCI. The algorithm does not depend on any prior knowledge and data-aided, which is propitious to practical applications. The analysis and simulation results demonstrate that the proposed algorithm is effective.

Markov Random Field (MRF) based design methodology presents a new approach to establish high noise-immune structure for ultra-low power circuit designs. The MRF design technique is able to significantly improve the reliability and interference tolerance of the logic circuits. The main idea of this methodology is that the circuit has the highest likelihood for correct logic states from the viewpoint of joint probability distribution. At present, the researches of MRF-based circuit designs focus on the circuit structure and noise tolerant performance analysis for ultra-low supply voltage applications. But there is no investigation on the timing performance of MRF-based circuits. In this paper, we simulated different well-known structures of the fundamental MRF-based elements with HSPICE, and measured the corresponding propagation delay and transition time to evaluate the timing performance of circuit. From the measurements, we find that the propagation delay of MRF-based circuits is one order bigger than that of the traditional (complementary metal oxide semiconductor) CMOS circuits, but MRF-based circuits can achieve similar transition time with traditional CMOS circuits.

To fulfill future airport capacity requirements, the proposed data link has to be a high capacity, high rate data link. Air-ground Data Link System can be used in orthogonal frequency division multiplexing (OFDM) systems to improve communication quality and capacity. A channel estimation design method for OFDM system by using correlation of pilot sequences has been proposed in this paper. The main point of this algorithm is the autocorrelation of the sequences. This paper presents a method for optimum training sequences design and the channel estimation implementation that follows. By using these training sequences, in frequency domain, we can get the channel frequency response easily; in time domain, we can get the data fading which are between the adjacent pilot training symbols by some means of interpolation. Simulation and implementation results indicates that this method can obtain good system performance and with low complexity.