Chirp-GFSK combined spectrum spreading modulation and demodulation system

Abstract

The invention discloses a Chirp-GFSK combined spectrum spreading modulation and demodulation system, and relates to the technical field of wireless communication. The system comprises a radio frequency part, a baseband modulator and a baseband demodulator; the baseband modulator comprises a data modulator, a frame synchronization header generator and a data frame forming module; and the data demodulator comprises a whitening module, a spectrum spreading module and a GFSK modulation module. At a transmitter, the system dynamically generates and sends a Chirp waveform to serve as a frame synchronization signal according to a GFSK spectrum spreading mode, and then data is sent by the GFSK modulation module; and at a receiver, a symbol and a frequency deviation of the signal in the channel transmission are estimated according to the frame synchronization signal Chirp by adopting a multi-threshold synchronization algorithm, a spectrum spreading GFSK signal is subjected to GFSK demodulationand signal dispreading after the frequency deviation of spectrum spreading GFSK is compensated, and a sending signal is obtained through recovery. According to the system, the advantages of the Chirpmodulation and the advantages of the spectrum spreading GFSK modulation signal are integrated, the complexity of signal synchronization is reduced, the synchronization time of a weak signal is shortened, the channel symbol and frequency deviation are overcome, and the signal demodulation complexity is reduced while low power consumption is achieved.

Description

technical field [0001] The invention relates to the technical field of wireless communication, in particular to a Chirp-GFSK joint spread spectrum modulation and demodulation system. Background technique [0002] At present, wireless communication has been developing rapidly all over the world, and has become a hot technology of common concern in the global communication and IT circles. Especially with the comprehensive development of the Internet of Things in the world, not only the basic technology of wireless communication has been continuously improved, developed and changed, Furthermore, various types of wireless communication systems and new wireless communication technologies emerge continuously, and the market demand for wireless communication technology also grows rapidly. Long-distance transmission, low complexity, and low power consumption have become the needs of the Internet of Things industry for wireless communication chips in the new era. The physical layer ...

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Problems solved by technology

However, the design of the GPS receiver is quite complicated, and the synchronization time for weak signals is very long

The communication system modulated by digitally synthesized chirp symbols used by LoRa transceivers has also reached a high level of coding gain, showing excellent long-distance anti-interference immunity, but LoRa transceivers use complex Fourier Transformation algorithm to realize signal reception and demodulation greatly increases the complexity of the receiving system

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