Establishment method for real virtual staggered quadriphase sequence, MSK/GMSK (Gaussian Minimum Shift Keying) synchronization method and spectrum spread system

Abstract

The invention discloses an establishment method for a real virtual staggered quadriphase sequence and a sequence set, an MSK / GMSK (Gaussian Minimum Shift Keying) synchronization method and an FBMC (Filter Bank Multicarrier)-OQAM spectrum spread system. The real virtual staggered quadriphase sequence and sequence set are established according to a binary sequence with high autocorrelation. The real virtual staggered quadriphase sequence can be generated by any binary sequence. The cycle of the generated real virtual staggered quadriphase sequence is two times of that of the original binary sequence. The maximum nontrivial autocorrelation function value of the generated real virtual staggered quadriphase sequence is two times of that of the original binary sequence. According to the real virtual staggered quadriphase sequence and sequence set obtained through adoption of above-mentioned establishment method, synchronization of a MSK / GMSK signal is realized; the optimum quadriphase sequence is applied to MSK / GMSK modulation, thereby obtaining the MSK / GMSK signal with an excellent autocorrelation characteristic; and the optimum quadriphase sequence can be applied to synchronization and channel estimation. The established real virtual staggered quadriphase sequence and sequence set also can be used as spectrum spread codes for spreading spectrum, a purpose of reducing a peak-to-average power ratio of an FBMC signal is achieved, a signal transmission rate is improved, and an FBMC-OQAM signal with the excellent autocorrelation characteristic is obtained.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, and more specifically relates to a construction of a real-virtual interleaved four-phase sequence and a sequence set, an MSK / GMSK synchronization method, a FBMC-OQAM spread spectrum system, and a FBMC-OQAM synchronization signal generation method. Background technique [0002] Pseudo-random sequences with good randomness and correlation characteristics close to white noise are widely used in communication systems and cryptographic systems; the four-phase sequence in the pseudo-random sequence is favored, and the four-phase optimal autocorrelation sequence is the most popular. focus on. Existing studies on four-phase sequences and sets of four-phase sequences are based on general four-phase sequences, and the research on real-virtual interlaced four-phase sequences is not sufficient. [0003] In the existing special communication system, the GMSK (Gaussian Minimum Shift Keying, Gau...

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Problems solved by technology

[0004] An existing method for adaptive demodulation of GMSK signals is to first perform inversion processing on the received I and Q signals, and then use a sliding correlation method for channel estimation on the inverted signals, and perform time delay synchronization according to the channel estimation value. Determine the timing advance, and determine the channel type according to the energy sum of the channel parameters, when the ratio E of the energy of the channel parameters at the maximum correlation position to the maximum energy sum ratio When it exceeds a certain threshold, the zero equalization method is used for demodulation, and a soft decision value is output at the same time; when E ratio When it is less than a certain threshold, the balanced demodulation method is used for demodulation; this method does not eliminate the interference caused by frequency offset and initial phase

[0005] Another GMSK signal receiving method is to "precode" the original information before GMSK modulation at the sending end, precode the double Chirp signal sent by the sending end, estimate the frequency difference and time delay at the receiving end, and then correct On the basis of a large frequency difference, the least square method is used to estimate the channel impulse response, and finally the residual frequency difference and phase deviation in the signal are corrected according to the channel impulse response; the calculation is complicated, and multiple thresholds need to be set. Sensitive to changes, not conducive to the actual use of the project;

[0006] To sum up, the defect of the existing correlation synchronization method is that the interference caused by frequency offset and initial phase is not eliminated, and the synchronization measurement is sensitive to the change of energy intensity, which is not conducive to engineering practice

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