Orthogonal wavelet constant modulus blind equalization method based on IWPA (Improved Wolf Pack optimization Algorithm)

Abstract

The invention discloses an orthogonal wavelet constant modulus blind equalization method based on an IWPA (Improved Wolf Pack optimization Algorithm). According to the invention, A CM (Complex Method) with high local searching capacity is embedded into a WPA with high global optimizing capacity; an update mechanism of a wolf pack is improved to obtain an excellent IWPA; the new method promotes optimizing capacity of the WPA; a reciprocal of a cost function in the constant modulus blind equalization method CMA is used as a fitness function of the IWPA; an input signal of the CMA is used as an input of the IWPA; a leader wolf position captured by utilizing the IWPA is used as an initial weight vector of the CMA; then signal correlation is reduced by a wavelet; signals are output in an equalizing mode by the CMA; and an excellent equalizing effect can be obtained. Compared with the prior art, the orthogonal wavelet constant modulus blind equalization method has the advantages that correlations between the signals and between the signals and noise can be reduced; an algorithm convergence speed is improved; a steady state error is reduced; balancing quality is improved; and the orthogonal wavelet constant modulus blind equalization method has a certain practical value.

Description

Technical field: [0001] The invention relates to the technical field of data acquisition and signal processing, in particular to an orthogonal wavelet norm blind equalization method based on improved wolf group optimization. Background technique: [0002] When the signal is transmitted in the underwater acoustic digital system, due to factors such as limited bandwidth and multipath propagation, Inter-Symbol interference (ISI) will occur, resulting in serious distortion. If the blind equalization technology is introduced at the receiving end, it can be effectively Eliminate and reduce ISI, improve communication quality. The constant modulus blind equalization method (CMA) has a simple structure and stable performance, and is widely used at present, but there are problems such as slow convergence speed and large steady-state error; the orthogonal wavelet transform (WT) is introduced into the traditional constant modulus blind equalization method ( CMA), the preprocessing oper...

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Problems solved by technology

The constant modulus blind equalization method (CMA) has a simple structure and stable performance, and is widely used at present, but there are problems such as slow convergence speed and large steady-state error; the orthogonal wavelet transform (WT) is introduced into the traditional constant modulus blind equalization method ( CMA), the preprocessing operation is performed on the input signal of the equalizer carrying noise, the correlation between signals and the signal and noise is reduced, and the convergence speed of the method can be accelerated, but the gradient idea is still used when minimizing the non-convex cost function , so it is easy to fall into local extremum and affect the balance effect

Since the wolf pack optimization method (WPA) was proposed in 2013, it has been successfully used to solve many optimization problems of non-convex functions, but there are still problems such as low search accuracy. The complex method (CM ) to embed WPA, and improve the update mechanism of wolf packs, and obtain an improved wolf pack optimization method (IWPA) with high search precision and avoid falling into local optimum, which can better optimize high-dimensional non-convex functions and solve complex question

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