Satellite-borne AIS conflicting signal separation method based on improved independent component analysis

Abstract

The invention discloses a satellite-borne AIS conflicting signal separation method based on improved independent component analysis. The method comprises the following steps: sampling by an analog-to-digital converter to form N channel receiving data; performing centralization processing and whitening processing on N paths of received observation signals; obtaining N paths of separation signals from the matrix preprocessed by the observation signals by using an improved ICA method based on the cuckoo algorithm and the Newton iterative algorithm; performing digital down-conversion, matched filtering and whitening filtering on the obtained N paths of separation signals; and decoding the N paths of separation signals after the whitening filtering by using the viterbi algorithm to obtain N AIS data frames. According to the satellite-borne AIS conflicting signal separation method disclosed by the invention, no frequency deviation, phase shift or amplitude estimation is required, a satellite-borne AIS receiver structure is simplified, and the satellite-borne load is relieved.

Description

Technical field [0001] The invention belongs to the technical field of ship automatic identification systems in wireless communication, and specifically relates to a spaceborne AIS conflict signal separation method based on improved independent component analysis. Background technique [0002] In the early 1990s, the Maritime Equipment Federation of the International Association of Lighthouse Navigation Organizations first proposed the development of a universal ship identification system. After that, the International Maritime Organization, the International Telecommunication Union and the International Electrotechnical Commission have all given great attention and support, and finally developed a new navigation system, the Automatic Ship Identification System (AIS). The main purpose of AIS is to facilitate the effective exchange of navigation data between ships and between ships and shores to improve the safety of maritime navigation and the real-time monitoring of maritime eve...

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Problems solved by technology

[0004] Invention patent 201310492497.9 discloses a signal processing method for solving AIS signal time slot conflicts. Aiming at the background that the number of AIS signals with time slot conflicts is the same as the number of receiving antennas, the signals received by multiple antennas are separated by phase processing. Restoring the AIS signal that needs to be separated, the AIS signal of other channels cannot be effectively separated

Invention patent 201410502475.0 discloses a co-channel interference suppression method for spaceborne AIS based on receiving blind beamforming, using the constant mode characteristic of the AIS signal to implement blind beamforming on the user signal through the constant mode algorithm, after separating the desired signal and the interference signal, the The desired signal is detected, but this technology is difficult to separate when the difference in direction of arrival of conflicting signals is small, and only one of the multiple signals is separated

Invention patent 201410228651.6 discloses a conflicting signal processing method that can be used in the spaceborne AIS system. It uses the known information in the frame structure to perform synchronization and channel estimation, and then detects a signal, subtracts it after reconstruction, and calculates the remaining signal Repeat this process to complete the signal separation. This method has the disadvantages of complex equipment and poor timeliness

Invention patent 201410608054.6 discloses a serial separation method of spaceborne AIS signals based on parameter estimation. It mainly estimates the time delay, frequency offset, phase and other parameters of mixed spaceborne AIS baseband signals. The coherently detected symbols are reconstructed to realize the separation of one signal, and then repeat this process for the remaining signals to achieve serial separation, and mainly analyze the separation effect of the main signal. This method also makes the equipment complicated and the separation Poor timeliness

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