Systems Engineering and Electronics ›› 2021, Vol. 43 ›› Issue (12): 3709-3715.doi: 10.12305/j.issn.1001-506X.2021.12.35

• Communications and Networks • Previous Articles     Next Articles

Blind recognition algorithm of space frequency block codes based on frequency domain cross correlation sequence and peak detection

Wenjun YAN1, Yuyuan ZHANG1,*, Qing LING1, Keyuan YU2, Kaiwen TAN1, Hengyan LIU1   

  1. 1. Academy of Aeronautical Operations Service, Naval Aeronautical University, Yantai 264001, China
    2. Unit 92853 of the PLA, Xingcheng 125100, China
  • Received:2021-03-12 Online:2021-11-24 Published:2021-11-30
  • Contact: Yuyuan ZHANG

Abstract:

In order to solve the problems of difficult recognition of space-frequency block codes (SFBC) and high requirement of prior information in complex electromagnetic environment and non-cooperative communication, a blind recognition method of SFBC based on frequency cross-correlation sequence and peak detection is proposed. Firstly, by analyzing the coding characteristics of SFBC signals, the cross-correlation function of transmitter is calculated. Then, considering the influence of frequency selective channel, multipath propagation and noise, the cross-correlation function of the received signal is derived, and the frequency domain cross-correlation sequence is obtained by Fourier transform. Finally, based on the frequency domain cross-correlation sequence, the peak position is detected to identify the coding mode of the transmitter. The derivation and experimental results show that the algorithm has good recognition performance at low signal to noise ratio (SNR), strong adaptability to time deviation and frequency deviation, and has good recognition performance in complex electromagnetic environment. It can be applied to cognitive radio and spectrum detection. The algorithm does not need to know the priori information of channel and noise, the size of orthogonal frequency division multiplexing (OFDM) block and the synchronization information of receiver and transmitter, so it is very suitable for non-cooperative communication occasions such as electronic reconnaissance.

Key words: space-frequency block code (SFBC), cross-correlation sequence, peak detection, non-cooperative communication, blind signal recognition

CLC Number: 

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