Le Minh Tuan

An MMSE-based beamforming algorithm for smart antenna applied to an MC-CDMA system with co-channel interference

This paper proposes an adaptive beamforming algorithm, called MC-MMSE, for adaptive antennas applied to an MC-CDMA system. A new method for updating the weight vector based on the MSE criterion is derived. Computer simulations show that the MC-MMSE algorithm is capable of rejecting co-channel interference that affects the MC-CDMA system. Thus, the BER performance of the MC-CDMA system is much higher than that of the MC-CDMA system without using adaptive antenna and that of the DS-CDMA system with adaptive antenna in multipath Rayleigh fading channel.

A new adaptive beamforming algorithm for MIMO smart antennas

We propose a new MIMO adaptive beamforming algorithm for smart antennas. The algorithm is based on the LMS, requiring no reference signal. Computer simulations, considering the multi-path Rayleigh fading channel, are presented to verify the performance.

A new RLS-based adaptive beamforming algorithm for smart antennas applied to an OFDM system

Considers an OFDM system with cochannel interference and the use of adaptive antenna arrays to suppress such interference. Based on the conventional RLS criterion, we derive a new recursive least square (RLS) adaptive beamforming algorithm for antenna arrays applied in an OFDM system. Computer simulation shows that when applied to the OFDM system, the proposed algorithm is capable of combating cochannel interference in both AWGN channel and multipath Rayleigh fading channel with AWGN.

A semi-blind LMS adaptive beamforming algorithm for smart antennas in an OFDM system

This paper proposes a semi-blind LMS adaptive beamforming algorithm for antenna arrays applied to an OFDM system. The OFDM system under consideration employs the fast Fourier transform (FFT) to efficiently generate the sub-carriers. The performance of the proposed algorithm is verified by computer simulation.

A new fuzzy logic application to variable step size LMS algorithm for adaptive antennas in CDMA systems

This paper proposes a new application of fuzzy logic to variable step size least mean square (VS-LMS) adaptive beamforming algorithm in CDMA systems. The proposed algorithm adjusts the step size of the least mean square (LMS) by using the application of fuzzy logic in which the increase or decrease of step size depends on the fuzzy inference results of the mean square error (MSE). Computer simulation results show that the proposed algorithm has a better capacity of tracking compared with the conventional LMS algorithms and other variable step size LMS algorithms.

An adaptive beamforming algorithm for antenna array applied to an MC-CDMA system with co-channel interference

In this paper, we propose an adaptive beamforming algorithm, called MC-LMS, for adaptive antenna applied to an MC-CDMA system. New method for updating the weight vector based on the MSE criterion is derived. Computer simulations show that MC-LMS algorithm is capable of rejecting co-channel interference that affects the MC-CDMA system. Thus, the BER performance of the MC-CDMA system is much higher than that of the MC-CDMA system without using adaptive antenna and that of the DS-CDMA system with adaptive antenna in multipath Rayleigh fading channel.

Semi-blind MMSE algorithm for adaptive antennas in OFDM/CDMA systems

This paper presents a semi-blind minimum mean square error (MMSE) beamforming adaptive algorithm used for OFDM/CDMA combined system. The proposed algorithm exploits the transmitting pilot signal in the initial period of the transmission to update the weight vector. Then it applies the blind adaptive period to update the weight vector, in which the pilot signal is no longer used. The derivation of the algorithm based on the mean square error (MSE) criterion is also presented. Computer simulation is carried out to verify the performance of the proposed approach.