1. The results show that DFH is not a LPI communication manner, and its security relies on the transition function.
2. Then a Viterbi algorithm is proposed and applied to frequency sequence decoding of DFH receiver, and it is further improved by the full use of the characteristics of transition function.
3. Cultural Revolution, naive we see: the resumption of classes in revolution, school name Dongfanghong primary, secondary DFH; work-based, agriculture-based when science; small business hawker when speculation; military propaganda team propaganda team work, agricultural promotion team admitted to the schools, factories; resorting to violence to a city is divided into two schools: the rebels, 110 conservative
4. The basic parameters, arrangment, as well as technical specification of DFH1854 articulated wheeled tractor are proposed.
5. Research about DFH Network Based on FH/DFH
6. A Kind of Shortwave Frequency Hopping Code Based on DFH Transform Function
7. In this paper, the characteristics of the DFH technologies are described, and the frequency transition function based on the recursive shift register is proposed.
8. The design of the G function (GF) is the core of the DFH system.
9. Situation and Development of Ultra-short Wave Communication in the Flood Control and Drought-resistant Research on Narrowband HF DFH Burst Communication
10. One method of hop detecting based on STFT is put forward, and the frequency features of HF DFH signal in one hop time is analyzed through it in this paper. Combining with the G function, it can detect the possible frequency.
11. Due to FFT demodulation of DFH communication system, an HF passive RTFS solution based on signal energy and ICF (Interference Centroid Frequency) is presented in detailed.
12. Simulation results showed that as the ideas of random coding and iterative decoding are used, the bit error rate performance of the turbo-DFH system is significantly better than that of the DFH system with the conventional error correction code and missed hop correction algorithm.
13. This paper introduced the production technology of linear low density polyethylene speciality resin DFH 2076 for communication cable sheathing in an all-density polyethylene plant. A comparison in performance between DFH 2076, its imported counterpart and the modified domestic resin of same kind was carried out.
14. The Differential Frequency Hopping (DFH) technology which combines modulation encoding and frequency hopping technology can highly improve the data transmission rate, anti-interference characteristic and anti-fading ability of the system.
15. This paper gives a brief description of the DFH-2A communication satellites which are the second generation of Chinese domestic communication satellites.
16. An antenna system for DFH-2A domestic telecommunications satellite
17. As an important direction for short wave frequency hopping technology, differential frequency hopping has been the concern of many researchers. This kind of correlated frequency hopping system can provide a data transfer speed faster than ever before, and better resistance to jamming and interception capabilities.
18. Reason Analysis and Improvement of Fracture Failure of Driving Shaft for DFH Middle Power Wheeled Tractor
19. Based on the encryption principle of affine cipher, a frequency transition function of DFH is designed.
20. This paper presents a new HF hopping system, which is called Differential Frequency Hopping (DFH) system. The frequency transition function and the method of signal detection are the key technologies in this system.