High-speed wavelet multi-carrier spread-spectrum communication system and method suitable for 5G network

Abstract

The invention discloses a high-speed wavelet multi-carrier spread-spectrum communication system and method suitable for a 5G network. The system comprises a plurality of communication devices which are in mutual communication and are arranged in a wireless network. The communication devices comprise the signal emission device and the signal receiving device. The signal emission device comprises a coding unit, a spread-spectrum unit, a carrier modulation unit and a parallel-serial conversion unit which are sequentially connected. The signal receiving device comprises a series-parallel conversion unit, a wavelet filtering unit, a dispreading unit, a data demodulation unit and a decoding unit which are sequentially connected. High adaptability is achieved to a time-frequency selectivity wireless channel. Meanwhile, due to the facts that spreading codes with different lengths are used for corresponding to various wavelet subcarriers with different bandwidths, and the spreading codes with the same length are further arranged, so that multiple choices are achieved, the high-speed wavelet multi-carrier spread-spectrum communication system can obtain more higher data rates than that of a conventional multi-carrier spread-spectrum communication system in which fast Fourier transformation is used, and thus the high-speed wavelet multi-carrier spread-spectrum communication system and method are suitable for the high-speed 5G network.

Description

technical field [0001] The present invention relates to the technical field of wireless communication, in particular to a high-rate wavelet multi-carrier spread spectrum communication system and method suitable for 5G networks, in particular to high-rate wavelet multi-carrier spread spectrum communication that can vary with channel time-frequency changes. Background technique [0002] The wireless channel has the characteristics of time-frequency selective attenuation and is affected by the multipath effect. In the existing wireless communication technology, in order to overcome the above problems, multi-carrier modulation technology is mainly used, that is, orthogonal frequency division multiplexing technology and spread spectrum The combination of technologies, that is, the use of multi-carrier spread spectrum communication systems to achieve data transmission. However, although the existing technical solutions of multi-carrier spread spectrum communication systems have hi...

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Problems solved by technology

However, although the existing technical solutions of multi-carrier spread spectrum communication systems have high modulation efficiency, the receiving mechanism of OFDM is complicated, the required protocol is also complicated, and the construction cost is high, and at the same time Since OFDM is implemented by fast Fourier transform, the frequency interval between subcarriers is fixed and minimum, so it is extremely sensitive to carrier frequency errors.

If there is any error in the carrier frequency caused by the Doppler effect and clock deviation caused by the relative motion between the transmitter and the receiver, the carrier frequency will lose its orthogonality and generate large inter-carrier interference, making the communication system reliable Unsatisfactory sex and adaptability

In addition, for frequency-selective channels, OFDM adopts a method of frequency dispersion, and its operation performance can achieve better results; for time-selective channels or time-frequency selective channels, Orthogonal frequency division multiplexing cannot cope with channel changes, and its operating performance often cannot achieve better results

In addition, OFDM is extremely sensitive to strong noise interference, and its reliability and adaptability are unsatisfactory in the case of large impulse noise interference

In order to overcome the problem of performance degradation caused by channel time-frequency variation in multi-carrier spread-spectrum communication systems, it is necessary to develop new multi-carrier spread-spectrum communication that can change with channel time-frequency variation and can simultaneously deal with strong noise interference However, the methods developed so far have high computational complexity and are difficult to implement in real-time communication systems.

At the same time, with the research and implementation of 5G networks, higher requirements are put forward for the data rate. Fast Fourier transform is used to realize multi-carrier modulation. Because Fourier transform is limited by only one-dimensional frequency transform, the data rate is difficult. Further improved in the frequency domain

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