Weak OFDM subcarrier number estimation method based on random resonance

A stochastic resonance and sub-carrier technology, applied in the field of communication, can solve problems such as performance degradation, achieve the effect of increasing peak value, improving algorithm performance, and improving estimation accuracy

Inactive Publication Date: 2018-10-19
PLA STRATEGIC SUPPORT FORCE INFORMATION ENG UNIV PLA SSF IEU
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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

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  • Weak OFDM subcarrier number estimation method based on random resonance
  • Weak OFDM subcarrier number estimation method based on random resonance
  • Weak OFDM subcarrier number estimation method based on random resonance

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Embodiment Construction

[0042] In order to make the purpose, technical solution and advantages of the present invention more clear and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and technical solutions.

[0043] OFDM uses overlapping subcarrier modulation technology to divide the channel into multiple orthogonal subchannels in the frequency domain. Parallel transmission is carried out on N sub-channels respectively; its specific implementation can be carried out by using discrete Fourier transform. Later, a fast algorithm of discrete Fourier transform was born, and IFFT / FFT is used for modulation and demodulation. In the signal modulation process, It can generate the same number of orthogonal parallel subcarriers as the number of IFFT points N, but in practical applications, only some subcarriers are selected to transmit signals. The principle is as follows: figure 1 As shown, the third-party reception needs to estimat...

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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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Application Information

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IPC IPC(8): H04L27/26G01R23/16
CPCG01R23/16H04L27/2601H04L27/2647
Inventor 张政马金全王学成彭华童莉王彬吴微孔德阳
Owner PLA STRATEGIC SUPPORT FORCE INFORMATION ENG UNIV PLA SSF IEU
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