Blind adaptive beamforming is often used in communication systems to combat co-channel interference. Among a number of techniques, the constant modulus algorithm (CMA) has proven to be an e ective tool for blind beamforming of uncorrelated signals. Unfortunately, CMA beamformers encounter problems for correlated signals and interferences. In this paper, we consider correlated co-channel input s...

Multi-beam massive multiple-input–multiple-output (MIMO) configurations that utilize high-power beam selection in the analog parts and blind algorithms such as the constant modulus algorithm (CMA), which do not require channel state information (CSI), in the digital parts, have been proposed in the literature to improve the transmission rates and efficiency. In this paper, we evaluate the trans...

This paper proposes two nonlinear blind equalizers: the nonlinear constant modulus algorithm (NCMA) and the nonlinear modified constant modulus algorithm (NCMA) by applying a nonlinear transfer function (NTF) into constant modulus algorithm (CMA) and modified constant modulus algorithm (MCMA), respectively. The effect of the NTF on CMA and MCMA is theoretically analyzed, which implies that the ...

In this paper, we investigate adaptive blind source separation and equalization for multiple-input/multiple-output (MIMO) systems. We first analyze the convergence of the constant modulus algorithm (CMA) used in MIMO systems (MIMOCMA). Our analysis reveals that the MIMO-CMA equalizer is able to recover one of the input signals, remove the intersymbol interference (ISI), and suppress the other i...

CMA has been known as blind adaptive beamforming because it requires no knowledge about the signal except that the transmitted signal waveform has a constant envelope. But in practical applications, the constrained CMA degrades in the presence of both signal steering vector errors and interference nonstationarity. In this paper, we propose robust constrained CMA based on a Bayesian approach und...

In this paper, we propose novel blind separation techniques for multiple-input multiple-output systems based on least-squares constant modulus algorithm (LSCMA). To ensure that each output signal is extracted from different input signals, the proposed algorithms have been derived by using successive interference cancellation and Gram-Schmidt orthogonalization procedure. The performance is obser...

Foster F. Dai Auburn University Electrical and Computer Engineering Department 200 Broun Hall Auburn, Alabama 36849-5201 E-mail: [email protected] Abstract. This paper presents complete models for various fiber dispersions and their mitigations using electronic equalizers. A novel constantmodulus-adaptive CMA blind equalization technique is proposed for fiber dispersion compensation. Simulat...

introduction: nowadays , use of library software is a basic need for libraries and information centers. user interface is a part of computerized systems which is interacting to the user and it is an important factor in information searching process. this study aimed to compare librarian's satisfaction rate from library software interface in isfahan libraries in 2010. methods: this was a descrip...