Satellite-borne AIS collision signal separation method based on adaptive moment estimation

Abstract

The invention discloses a satellite-borne AIS collision signal separation method based on adaptive moment estimation. The method specifically comprises the steps of sampling received AIS collision signals to obtain N ways of receiving signals, and carrying out digital down conversion processing to obtain an observation signal matrix; preprocessing the observation signal matrix, and carrying out collision removal processing through combination of mutual information maximization and maximum adaptive moment estimation and a signal separation algorithm, thereby obtaining N ways of separated signals; carrying out frame header burst detection, frequency offset estimation, symbol timing synchronization and whitening filtering processing on the N ways of separated signals; and carrying out decoding processing through utilization of a Viterbi algorithm, thereby obtaining valid data frames. According to the method, the maximum adaptive moment estimation is introduced into the mutual informationmaximization algorithm, the estimation precision of a separation matrix is improved, moreover, the time required for matrix optimization and collision removal is reduced, the timeliness is relativelyhigh, and the method is relatively applicable to a satellite-borne AIS receiving system.

Description

technical field [0001] The invention belongs to the technical field of ship automatic identification system in wireless communication, and in particular relates to a space-borne AIS collision signal separation method based on adaptive moment estimation. Background technique [0002] Automatic Identification System (AIS) is a marine traffic monitoring and management system currently used to realize traffic control communication between ships and shores and between ships. It can obtain and process ship navigation information in nearby sea areas in real time, effectively Avoid collisions between ships, improve the safety of maritime navigation and the real-time monitoring of maritime events. [0003] Since the shore-based AIS system is constrained by the communication distance and its coverage is limited, it can only supervise ships within 50 nautical miles of the coast, and cannot detect, identify and track ships in distant sea areas. The satellites cover a wide area, and as ...

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Problems solved by technology

[0006] The patent application number is CN201410602546.4, and the invention title is "A Method and System for Reducing AIS Signal Aliasing". Based on updating its own time slot reservation table, the updated time slot reservation table is encapsulated and sent to the channel at the same time to reduce AIS signal aliasing. This method needs to be continuously updated, has poor real-time performance, and signals sent in different time slots Collisions may still occur due to different transmission paths, and the problem of signal collisions cannot be effectively solved

[0007] The patent application number is CN201410677035.9, and the Chinese patent titled "a satellite AIS signal detection and processing device and method under high conflict" allows the signal to pass through the radio frequency filter module and the baseband filter module in sequence. The group signal is further demodulated by using the interference elimination module to further demodulate the small signal. The successfully demodulated signal is re-modulated and compared with the original signal, and then the small signal demodulation is realized through baseband filtering. This method also cannot effectively solve the three-way and The above multi-channel signal collision separation problem

[0008] It can be seen from the above that there are still many deficiencies in the existing spaceborne AIS collision signal separation methods, which need to be further improved to achieve

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