Unmanned aerial vehicle wireless image transmission system based on 340 MHz multi-carrier modulation technology

Abstract

The invention provides an unmanned aerial vehicle wireless image transmission system based on a 340 MHz multi-carrier modulation technology, which comprises an audio and video A / D conversion module, an AES encryption module, an MPEG2 coding module, a COFDM modulation module and a storage module; a real-time AV video signal passes through the audio and video A / D module and is converted into a digital signal, the digital signal is encrypted through the AES encryption module and the MPEG2 coding module and modulated into a radio frequency signal through the COFDM modulation module after being compressed and processed, and the radio frequency signal is sent out through an antenna. According to the wireless image transmission system in the invention, multi-carrier modulation technology is adopted, so that multi-path interference is reduced, and the bit error rate is reduced; the wireless image transmission system has the advantages of being long in transmission distance, high in winding capability and the like and is particularly suitable for non-light-of-sight transmission in an urban building blocking environment and high-speed movement.

Description

technical field [0001] The invention relates to the field of wireless communication, in particular to an unmanned aerial vehicle wireless image transmission system based on 340MHz multi-carrier modulation technology. Background technique [0002] At present, the technical system adopted by wireless image transmission can be roughly divided into: GPRS / CDMA / 3G (mobile communication), LMDS (spread spectrum microwave), WLAN (wireless local area network), DBS (satellite), COFDM (orthogonal frequency division multiplexing) Each technology has its own advantages and disadvantages. GPRS / CDMA / 3G (mobile communication) has the advantages of low network construction cost and high resource utilization rate, but the transmission rate is generally at 100Kbps level, which makes it difficult to transmit high-quality images; LMDS (spread spectrum microwave) can provide bandwidth above 1GHz. Two-way high-speed video transmission can be realized in a visual environment, but it cannot be used ...

AI Technical Summary

Problems solved by technology

GPRS / CDMA / 3G (mobile communication) has the advantages of low network construction cost and high resource utilization rate, but the transmission rate is generally at 100Kbps level, which makes it difficult to transmit high-quality images; LMDS (spread spectrum microwave) can provide bandwidth above 1GHz. Two-way high-speed video transmission can be realized in a visual environment, but it cannot be used in blocking environments and mobile; WLAN (Wireless Local Area Network) is flexible in networking and easy to expand. It uses OFDM multi-carrier modulation in the physical layer, but the number of carriers is small and the frequency band High, the use effect is not ideal in blocking and mobile environments; DBS (satellite) frequency bandwidth, large capacity, long communication distance, large coverage area and not limited by geographical conditions, but the rental price is expensive due to the lack of satellite channels

[0003] None of the above wireless transmission technologies are suitable for UAVs. At present, UAVs mostly use microwave transmission for real-time image transmission, usually using three frequency bands of 1.2GHz, 2.4GHz or 5.8GHz, but there are still problems that the transmission distance is not far enough and is easily affected by the ground. Building interference, lack of necessary encryption protection and other shortcomings, it is difficult to meet the long-distance high-definition real-time transmission of audio and video in public security, armed police, fire protection, electric power, radio and television and other industries, especially for high-speed information transmission on the way or in blocking environments Require

Images