Weak OFDM subcarrier number estimation method based on random resonance

Abstract

The invention belongs to the field of communication technology, and particularly to a weak OFDM subcarrier number estimation method based on random resonance. The method comprises the steps of settinga sampling frequency, wherein the sampling frequency is N times of a lowest sampling frequency, wherein N is not less than 50; selecting a bistable random resonance system parameter; for aiming at asignal which passes a bistable random resonance system, calculating a cepstrum and / or performing Haar wavelet transformation, and calculating an actual subcarrier number. The method of the invention is based on a cepstrum method and a wavelet improvement method. A random resonance method is used for reinforcing the weak OFDM signal. Compared with a traditional method, the weak OFDM subcarrier number estimation method has advantages of increasing an output peak value, improving detecting performance, reducing signal-to-noise ratio threshold, exerting an advantage on the condition of severe channel environment, improving estimation precision, improving algorithm performance for estimating the number of OFDM signal subcarriers to a relatively high extent, performing certain advantage on the condition of low signal-to-noise ratio, realizing better effectiveness and robustness, and performing an important function for restoring information of the OFDM signal on the condition of low signal-to-noise ratio, etc.

Description

technical field [0001] The invention belongs to the technical field of communication, in particular to a method for estimating the number of weak OFDM subcarriers based on random resonance. Background technique [0002] Orthogonal Frequency Division Multiplexing (OFDM) technology has become one of the key technologies in the fields of underwater acoustic communication, mobile communication, and short-wave communication due to its high spectrum utilization rate, strong anti-multipath ability, and convenient implementation. . Under non-cooperative communication conditions, estimating the number of subcarriers received by OFDM signals is an important prerequisite for accurate recovery of information. Therefore, effectively estimating the number of subcarriers actually used has always been a concern of researchers. At present, some important achievements have been made. results. Generally speaking, when the signal becomes weaker, the performance of the existing methods will be...

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Problems solved by technology

Generally speaking, when the signal becomes weaker, the performance of the existing methods will be degraded to varying degrees. How to realize the effective estimation of the number of subcarriers of the weak OFDM signal under the condition of low signal-to-noise ratio has become an urgent problem to be explored in this field. research topic

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