A 1090es signal expansion method based on phase modulation

Abstract

The invention discloses a 1090ES signal expansion method based on phase modulation, and relates to the field of civil aviation air traffic control surveillance. The signal processing process includes: collection of data information by the signal transmitter, dual modulation of PPM and sub-pulse phase, transmission of expansion signals, reception and synchronization of expansion signals by the signal receiver, demodulation of PPM information and phase information. The key technologies and effects are: 1. The modulation process adopts the segmented linear phase transition method to solve the spectrum expansion problem caused by the phase mutation, which effectively improves the bandwidth characteristics of the 1090ES signal after capacity expansion; 2. The carrier frequency synchronization process uses the leading pulse and 4-bit data The pulse is synchronized twice, which ensures the fast and accurate synchronization, and effectively solves the special multi-send and single-receive synchronization problem of the ADS-B receiver; 3. The demodulation process of the baseband phase information adopts a phase based on error forward feedback Judgment method effectively improves the accuracy of phase judgment.

Description

technical field [0001] The invention belongs to the field of air traffic control monitoring of civil aviation, and in particular relates to a capacity expansion technology for ADS-B 1090ES signals. Background technique: [0002] The new generation of air traffic control surveillance technology ADS-B (Automatic Dependent Surveillance-Broadcast) is gradually being promoted and applied in China, and may become the main surveillance means in my country's long-term planning. ADS-B realizes the monitoring function of the secondary radar, and also has the functions of navigation and communication, but due to the limited data carried by the signal, only a small amount of important information can be transmitted. The globally interoperable ADS-B extended message data link recommended by ICAO is 1090MHz Extended Squitter (1090ES), the signal length is 120μs, the first 8μs is the leading pulse, and the last 112μs is the data pulse. The data adopts pulse position modulation (PPM), one f...

AI Technical Summary

Problems solved by technology

Among them, the synchronization problem is particularly special. The ground or airborne ADS-B receiver repeatedly receives the 120μs signal broadcast by multiple airborne ADS-B transmitters. It is a burst communication of multiple transmissions and single reception, and the conventional synchronization method cannot be used.

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