An Anti-jamming Method Of Frequency-hopping Based On Errors-and-erasures Correcting RS-turbo Concatenated Codes

Since short brust frequency-hopping communication systems have superior performances because of its concealment and increasing equipment interference tolerance, so it is widely used in anti-jamming military communication. It’s required to provide services based on high data rates burst-mode packet-data transmission, operate at very low Signal-to-Noise Ratio and large Doppler frequency offset conditions.In practice interference measures for short brust frequency-hopping emerge in endlessly, the partial band interference is the most typical mode. In order to achieve the purpose of reliable communication, short brust frequency-hopping communication systems not only need to realize high precision carrier synchronization with short pilot symbols at low Signal-to-Noise Ratio,but also need to use forward error correction code which has strong error correcting ability for data protection.Based on research of channel coding and carrier synchronization algorithms at home and abroad.Firstly,we introduce the encoding and decoding algorithms of Turbo code,the main factors affecting the decoding performance and the "error-floor" phenomenon; Secondly this paper detailed studies algebra knowledge of RS codes, analyses the principle of RS codes, mainly discusses the algebraic decoding principle. Thirdly, for the requirements of QPSK carrier synchronization Rotating Periodogram Averaging(RPA) algorithm is utilized to perform carrier estimation and Costas algorithm is used to track carrier phase. Finally, in order to use RS codes performance advantages in the high Signal-to-Noise Ratio and Turbo codes performance advantages in the low Signal-to-Noise Ratio to improve the "error-floor" phenomenon as well as to against partial band jamming, we put forward the symbol-frequency point frame structure and combine it with errors-and-erasures correcting RS codes. The variable erasure algorithm of RS codes is proposed on this basis, and simulated in AWGN and partial band interference channel. The concatenated codes can also keep normal work in which about 60% frequency points are stained by simulation.