This paper presents an adaptive beamforming application based on the capture of far-field speech data from a real single speaker in a real meeting room. After the position of a speaker is estimated by a speaker tracking system, we construct a subbanddomain beamformer in generalized sidelobe canceller (GSC) configuration. In contrast to conventional practice, we then optimize the active weight v...

This paper investigates how to efficiently charge sensor nodes in a wireless rechargeable sensor network (WRSN) with radio frequency (RF) chargers to make the network sustainable. An RF charger is assumed to be equipped with a uniform circular array (UCA) of 12 antennas with the radius λ, where λ is the RF wavelength. The UCA can steer most RF energy in a target direction to charge a specific W...

ABSTRACT We propose a new algorithm for blind source separation (BSS), in which independent component analysis (ICA) and beamforming are combined to resolve the low-convergence problem through optimization in ICA. The proposed method consists of the following three parts: (1) frequency-domain ICA with direction-of-arrival (DOA) estimation, (2) null beamforming based on the estimated DOA, and (3...

Blind beamforming based on the maximum signal-to-noise ratio (MSNR) can improve the performance of the array system only when the processing gain of the given code-division multiple-access (CDMA) system is high enough such that the desired signal can become dominant after the despreading [3], [15]. In this paper, we consider a maximum signal-to-(interference plus noise) ratio (MSINR) beamformin...

Beamforming techniques can be used to suppress co-channel interference in radio devices. In a cognitive setting, beamforming can be beneficial as it can be applied to cancel interference among co-located primary users and cognitive users. In this study, the authors propose an antenna selection algorithm combined with zero-forcing beamforming to improve the throughput of cognitive multiple-input...

.............................................................................................. 3 1 Theoretical Background ..................................................................... 5 1.1 What is an Active Phased Array Antenna? ............................................................... 5 1.1.1 Switched Beam Antenna ....................................................................

A peak to average power ratio (PAPR) reduction method is proposed that exploits the precoding or beamforming mode in WiMAX. The method is applicable to any OFDM/A systems that implements beamforming using dedicated pilots which use the same beamforming antenna weights for both pilots and data. Beamforming performance depends on the relative phase shift between antennas, but is unaffected by a p...

We compare space-time coding (transmit diversity) and random “opportunistic” beamforming in a SDMA/TDMA single-cell downlink system with random packet arrivals, correlated block-fading channels and non-perfect channel state information at the transmitter due to a feedback delay. Our comparison is based on system stability. The ability of accurately predicting the channel SNR dominates the perfo...

Antenna array beamforming and power control have been studied separately to increase the capacity in wireless communication networks. Recently, the two were considered jointly in a system with power control capabilities which uses antenna array at the receiver only or the transmitter only. In this paper we formulate and study the joint beamforming and power control problem in a system with ante...

Beamforming is a widely used method of provisioning high quality wireless channels that leads to high data rates and simple decoding structures. It requires feedback of Channel State Information (CSI) from receiver to transmitter, and the accuracy of this information is limited by rate constraints on the feedback channel and by delay. It is important to understand how the performance gains asso...