5,990 research outputs found
Hybrid beamforming for single carrier mmWave MIMO systems
Hybrid analog and digital beamforming (HBF) has been recognized as an
attractive technique offering a tradeoff between hardware implementation
limitation and system performance for future broadband millimeter wave (mmWave)
communications. In contrast to most current works focusing on the HBF design
for orthogonal frequency division multiplexing based mmWave systems, this paper
investigates the HBF design for single carrier (SC) systems due to the
advantage of low peak-to-average power ratio in transmissions. By applying the
alternating minimization method, we propose an efficient HBF scheme based on
the minimum mean square error criterion. Simulation results show that the
proposed scheme outperforms the conventional HBF scheme for SC systems.Comment: IEEE GlobalSIP2018, Feb. 201
Ds+ -- Ds- Asymmetry in Photoproduction
Considering of the possible difference in strange and antistrange quark
distributions inside nucleon, we investigate the Ds+ -- Ds- asymmetry in
photoproduction in the framework of heavy-quark recombination mechanism. We
adopt two distribution models of strange sea, those are the light-cone
meson-baryon fluctuation model and the effective chiral quark model. Our
results show that the asymmetry induced by the strange quark distributions is
distinct, which is measurable in experiments. And, there are evident
differences between the predictions of our calculation and previous estimation.
Therefore, the experimental measurements on the Ds+ -- Ds- asymmetry may impose
a unique restriction on the strange-antistrange distribution asymmetry models.Comment: 11 page, 5 figure
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