High-mobility adaption and massive Multiple-input Multiple-output (MIMO) application are two primary evolving objectives for the next generation high speed train communication system. In this paper, we consider how to design a location-aware beam-forming for the massive MIMO system. We first analyze the tradeoff between beam directivity and beamwidth, based on which we present the sensitivity a...

This paper deals with the behaviour of acoustic cavities in the mid-high frequency range. The method proposed here is based on an energy flow method named Simplified Energy Method (MES). MES method is quite efficient in the mid-high frequency range but the directivity of the boundary sources is not well estimated. We propose a hybrid method which couples MES and the Boundary Element Method (BEM...

This paper examines the improvement that can be attained with perfect knowledge of the sound source directivity pattern and orientation in beamformer designs in the problem of speech acquisition. Data-independent beamformers are derived through formulation of a constrained optimization problem with a unity-gain constraint. Using computer simulation, these beamforming schemes are compared to the...

The use of microphone arrays for sound pickup in reverberant environments has been proposed by many authors. The observation on the M microphones can be decomposed into a spatially coherent and an incoherent part. The rst one is due to perfect (plane or spherical) sound waves caused by the direct path and specular re ections, whereas the latter is caused by di usion, di raction, non-perfect re ...

The surface mounted piezoceramic transducers and fiber optic sensor can detect signals in both symmetric and antisymmetric Lamb wave modes. Hanning windowed sine torn bursts were used for the piezoceramic transducer excitation signals. In order to overcome the difficulties in the signal processing of the simultaneous modes, the symmetric and antisymmetric modes were separated by using the two s...

Abstract The antenna height and directivity are used in the classification of statistical channel models for local multipoint distribution service (LMDS). When directional antennas are used and the antennas are sufficiently high providing a line-of-sight (LOS) propagation path between the transmitter and receiver, the statistics of the radio channel can be described by the lognormal or Nakagami...

A 3-D beam scanning antenna array design is proposed that gives a whole 3-D spherical coverage and also suitable for various radar and body-worn devices in the Body Area Networks applications. The Array Factor (AF) of the proposed antenna is derived and its various parameters like directivity, Half Power Beam Width (HPBW) and Side Lobe Level (SLL) are calculated by varying the size of the propo...

A novel fractal antenna-array type is proposed. The design is based on the Sierpinski rectangular carpet concept. However, the generator is a circular ring area, filled with radiating elements, so the higher stages of the fractal development produce large arrays of circular rings which, besides the high directivity, have the advantage of the almost uniform azimuthal radiation pattern, attribute...

We present cathodoluminescence experiments that quantify the response of plasmonic Yagi-Uda antennas fabricated on one-dimensional silicon nitride waveguides as function of electron beam excitation position and emission wavelength. At the near-infrared antenna design wavelength cathodoluminescence signal robustly is strongest when exciting the antenna at the reflector element. Yet at just sligh...

A theoretical method has been developed for predicting the directivity of the sound that is radiated from one side of a panel, or an opening, which is excited by sound incident from the other side of the panel, or the opening, from a room or duct. This directivity needs to be known when one is predicting the sound level at an external position which is due to the radiation of sound from the roo...