In this paper we examine the robustness of two element transmit beamforming in the presence of feedback delay and quantization error. Specifically, we examine the robustness of two-element beamforming techniques in the presence of Ricean fading. We show that when the fading is Ricean, feedback methods are significantly more robust than when the fading is Rayleigh. This is significant since many...

Distributed beamforming is a transmitting technique in which a cluster of independent transmitter form an antenna array in order to increase signal strength in the receiver. Synchronization between transmitting antennas is implemented in an iterative fashion using feedback from the receiver. While interest toward distributed beamforming is growing rapidly, there are no working applications impl...

Recent work has shown that endfire beamforming of ocean noise can be used to produce images of the seabed layering [Siderius et al., J. Acoust. Soc. Am. 120, 1315-1323 (2006)]. This initial noise imaging technique used conventional beamforming and was later extended to adaptive beamforming that is theoretically optimal. However, there can be problems with adaptive methods, which include extreme...

The minimum variance distortionless response (MVDR) beamforming technique is applied to a spherical microphone array. Therewith optimal spatial filters are calculated. Besides, a freely chosen measure of stability in the calculation facilitates a tradeoff between directivity and noise sensitivity. The beamforming method is compared to the highly directive method of phase-mode processing and the...

Transmit beamforming with receive combining is a simple approach to exploiting the significant diversity provided by multiple-input multiple-output (MIMO) systems, and this technique can be easily extended to frequency selective MIMO channels by employing orthogonal frequency division multiplexing (OFDM). Optimal beamforming requires channel state information in the form of the beamforming vect...

In this paper, a new user-scheduling-and-beamforming method is proposed for multi-user massive multiple-input multiple-output (massive MIMO) broadcast channels in the context of two-stage beamforming. The key ideas of the proposed scheduling method are 1) to use a set of orthogonal reference beams and construct a double cone around each reference beam to select ‘nearly-optimal’ semi-orthogonal ...

Two Ways to Beamform The first point of clarity to make about Cisco’s paper—and any “beamforming” argument—is that there are different fundamental categories of beamforming, including chip-based beamforming and antenna-based beamforming (e.g. BeamFlex). Most vendors are limited to offering whatever their chip vendor has included in the Wi-Fi chipset. By contrast, Ruckus can support both methods...

COLLABORATIVE BEAMFORMING FOR WIRELESS AD-HOC NETWORKS A.H. Karode1, S.R. Suralkar2, Manoj Bagde3 1Dept. of Electronics and Telecommunication, SSBTCOET, Jalgaon, India, [email protected] 2Dept. of Electronics and Telecommunication, SSBTCOET, Jalgaon, India, [email protected] 3 Dept. of Electronics and Telecommunication, SSBTCOET, Jalgaon, India, [email protected] In this ...

Although underlay networks mitigate the dual problems of spectrum congestion and spectrum under-utilization, the bi-directional (primary-to-secondary and secondaryto-primary) interference issues must be addressed to improve their reliability, coverage and capacity. To address these problems, this thesis investigates beamforming and two-way relaying. Specifically, the two underlay configurations...