Combination optimization self-adaptive frequency domain blind equalization method and system

Abstract

The invention discloses a combination optimization self-adaptive frequency domain blind equalization method and a system for achieving the method. Through combination of two frequency domain equalizers of two different types, automatic switching of two work modes can be achieved without error threshold selection; in the frequency domain blind equalization work mode, when the equalization beginning stage or channels suddenly change, intersymbol interference is eliminated; when the frequency domain blind equalization work mode obtains steady-state mean square error which is low enough, a frequency domain judging guiding mode is switched to. Combination output is obtained by combining the output of the two equalizers through combination parameters, the combination output is used for defining a time domain cost function of the whole combination optimization self-adaptive frequency domain blind equalization system to adjust the combination parameters; judging output of the combination output is used for adjusting the equalization performance of the frequency domain self-adaptive equalizers. Compared with a single frequency domain multi-mode blind equalizer and a single frequency domain self-adaptive equalizer, the method and system have good real-time tracking performance, the convergence rate is high, steady-state errors are low, and calculation complexity is greatly lowered.

Description

technical field [0001] The invention belongs to the technical field of digital communication, and in particular relates to an improved blind equalization method and a system for realizing the method. Background technique [0002] In the field of digital communication, time domain adaptive equalizer is widely used to suppress intersymbol interference. In order to avoid the transmission of the boot sequence and use the bandwidth more effectively, the time-domain constant mode blind equalization method CMA can be used. This type of time-domain blind equalization method needs to switch hard to the decision-guided through the steady-state error threshold when reaching a sufficiently low error. (DD) mode, but CMA cannot correct the signal phase rotation problem caused by channel distortion, so the time-domain multi-mode blind equalization method MMA has been developed. Compared with time-domain CMA, time-domain multimode blind equalization method MMA has many advantages, but it s...

AI Technical Summary

Problems solved by technology

When the mean square error threshold is inappropriate, it will affect the performance of the entire blind equalization system: if the mean square error threshold is too large, it will cause local convergence or even divergence of the equalization process; if the mean square error threshold is too small, It will cause the hard switching time during the equalization process to be too long or even impossible to switch

In order to overcome the defect that the hard handover between time-domain blind equalization mode and DD mode needs to select the mean square error threshold, researchers have given some soft handover methods, but these methods still cannot obtain better blind equalization performance, and the computational complexity high

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