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Indexed by:期刊论文

Date of Publication:2009-09-01

Journal:INTERNATIONAL JOURNAL OF INNOVATIVE COMPUTING INFORMATION AND CONTROL

Included Journals:SCIE、EI、Scopus

Volume:5

Issue:9

Page Number:2907-2916

ISSN No.:1349-4198

Key Words:Constant modulus; Diagonal loading; Robust beamforming; Blind equalization

Abstract:The diagonal loading method is a simple and efficient method that can improve the robustness of beamformers. However, determining an ideal diagonal loading factor (DLF) is not a trivial problem. Maximizing the signal to interference-plus-noise ratio (SINR) can be one criterion for determining an ideal DLF. Unfortunately, the maximizing SINR is not realistic for practical applications. Although beamformers are widely used in radar, sonar and many other applications, in this paper, we consider a beamformer for PAM communication systems. In PAM communications, user information is coded into a sequence with the constant modulus (CM) in the baseband. Obviously, if the beamformer can cancel interference and noise sufficiently, the outputs of the beamformer should satisfy the CM condition more precisely. Therefore, minimizing the CM error (MCME) criterion can act as a reasonable substitution for maximizing the SINR criterion. In this paper, we present a cost function for the MCME criterion. We also propose a search algorithm for DLF determination by minimizing the cost function. Numerical experiments show the effectiveness of the proposed method.