4,606 research outputs found
Examining A Renormalizable Supersymmetric SO(10) Model
We examine a renormalizable SUSY SO(10) model without fine-tuning. We show
how to construct MSSM doublets and to predict proton decay. We find that in the
minimal set of Yukawa couplings the model is consistent with the experiments,
while including to fit the data there are inconsistencies.Comment: 18 page
Electromagnetic Lens-focusing Antenna Enabled Massive MIMO: Performance Improvement and Cost Reduction
Massive multiple-input multiple-output (MIMO) techniques have been recently
advanced to tremendously improve the performance of wireless communication
networks. However, the use of very large antenna arrays at the base stations
(BSs) brings new issues, such as the significantly increased hardware and
signal processing costs. In order to reap the enormous gain of massive MIMO and
yet reduce its cost to an affordable level, this paper proposes a novel system
design by integrating an electromagnetic (EM) lens with the large antenna
array, termed the EM-lens enabled MIMO. The EM lens has the capability of
focusing the power of an incident wave to a small area of the antenna array,
while the location of the focal area varies with the angle of arrival (AoA) of
the wave. Therefore, in practical scenarios where the arriving signals from
geographically separated users have different AoAs, the EM-lens enabled system
provides two new benefits, namely energy focusing and spatial interference
rejection. By taking into account the effects of imperfect channel estimation
via pilot-assisted training, in this paper we analytically show that the
average received signal-to-noise ratio (SNR) in both the single-user and
multiuser uplink transmissions can be strictly improved by the EM-lens enabled
system. Furthermore, we demonstrate that the proposed design makes it possible
to considerably reduce the hardware and signal processing costs with only
slight degradations in performance. To this end, two complexity/cost reduction
schemes are proposed, which are small-MIMO processing with parallel receiver
filtering applied over subgroups of antennas to reduce the computational
complexity, and channel covariance based antenna selection to reduce the
required number of radio frequency (RF) chains. Numerical results are provided
to corroborate our analysis.Comment: 30 pages, 9 figure
Energy translation and Proper-Time Eigenstates
The usual quantum mechanics describes the mass eigenstates. To describe the
proper-time eigenstates, a duality theory of the usual quantum mechanics was
developed. The time interval is treated as an operator on an equal footing with
the space interval, and the quantization of the space-time intervals between
events is obtained. As a result, one can show that there exists a zero-point
time interval.Comment: 15 pages, No figur
- …