Parameter Estimation Of Multicarrier Signals

In the fourth generation,fifth generation and sixth generation mobile communication,OFDM technology is the core technology.therefore,this thesis takes ordinary multicarrier as the observation object,and also takes the OFDM signal as the observation object,aiming to improve the accuracy of OFDM time parameter and frequency domain parameter estimation and reduce the estimation error.The traditional parameter estimation algorithm is simulated and verified,and the estimation algorithm of OFDM time parameters and the number of sub-carriers is proposed and verified.First of all,the paper explains the principle and system model of OFDM technology,and introduces the extraction method of common feature quantities of OFDM signals.Using different feature quantities,the estimation of parameters such as carrier frequency,symbol time parameters,and bandwidth of OFDM signals is completed.Then,the paper studies the recovery effect of stochastic resonance on the time domain waveform of periodic signal.Aiming at the problem that the selection of stochastic resonance parameters is difficult and requires a high sampling rate under high-frequency signals,a new idea is proposed,which relaxes the limitations of the stochastic resonance method,and uses the improved stochastic resonance method to solve common problems.Carrier frequency estimation of multi-carrier signals is studied.Using the common spectrum to estimate the number of carriers is more accurate,and the signal after stochastic resonance is more accurate to estimate the carrier frequency.The two algorithms are combined.After simulation verification,it has better performance than the original algorithm under low SNR.The thesis also analyzes the influence of noise on OFDM signal oversampling rate estimation,and uses the mathematical relationship between OFDM symbol time length and OFDM useful symbol time length to estimate the total time length of OFDM symbol instead of the useful symbol time length,and completes the estimation of the number of subcarriers.Finally,the traversal method and substitution method proposed in this thesis are compared with the traditional subcarrier number and OFDM time parameter estimation algorithm.The proposed algorithm has obvious advantages after simulation.