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This paper presents a non-codebook based Multiple User Multiple Input Multiple Output (MU-MIMO) test-bed system for Time Division Duplexing (TDD) Long Term Evolution-Advanced (LTE-A), which has been implemented for verifying the performance of a dynamic precoding procedure. Using the parameter of propagation path gain, the proposed MU-MIMO system can adaptively switch the precoder to guarantee that...
We propose a novel method for joint probabilistic constrained robust beamforming and antenna selection used in cognitive radio (CR) networks. Assuming complex Gaussian distributed channel state information (CSI) errors, the Bernstein-type inequalities are used to transform the no closed-form probabilistic constrained into the deterministic forms. Moreover, l1-norm is introduced as the closest convex...
We propose a vehicle-to-infrastructure (V2I) communication system that utilizes a smart antenna technology to increase service coverage and system throughput. During contention-based channel access, a collision occurs when more than one vehicle selects the same minislot to transmit an access signal to an infrastructure. To solve this problem, we propose a group-based channel access scheme. Numerical...
In this paper, an electrically small square loop antenna with a capacitive SRR cover structure is built and tested. The size of the proposed antenna (ka 0.34) is much smaller than the corresponding Chu limit value. The experimental result shows that the resonant frequency and impedance bandwidth (VSWRles2) are 906 MHz and 5.8 MHz (901.7 - 907.5 MHz) respectively. The proposed antenna has maximum gain...
In this paper, the high gain electrically small loop antenna which is satisfied with the small antenna condition ka <1 and MNG MTM condition kreles0.5 is proposed. The proposed antenna is designed with the MNG MTM ground structure in order to match a high inductive reactance. Although it has a compact size, the high efficiency and gain are achieved. It will be available to apply to mobile UMTS...
In this paper, the proposed small antenna, which using negative permittivity meta-material structure is designed, achieves wide Q more than calculated QL of chu limits. The equivalent circuit of proposed antenna is realized by Ansoft designer. The proposed small antenna is optimized by 3-D field simulation tool, CST MWS(micro wave studio).
In this paper, the high gain and broadband antenna operating for SDMB (Satellite Digital Multimedia Broadcasting) system is proposed. The proposed antenna consists of the SAP (Shorted Annular Patch) structure, which inhibits surface-wave and the parasitic SAP element with spacing of 0.25 lambda0 in order to improve gain, bandwidth and directivity. The RHCP (Right Hand Circular Polarization) is generated...
In this paper, the reconfigurable annular ring slot antenna with circular polarization diversity is proposed for SDMB(satellite digital multimedia broadcasting) system. The proposed antenna consists of a ring slot with tuning stubs. Four PIN diodes are attached to achieve circular polarization diversity. By switching the diodes on or off, the proposed antenna can be operated either RHCP(right hand...
In this paper, two representing diodes, the PIN diode and the varactor, are used for the Macro-micro frequency tuning. The PIN diode in the antenna is used for switching wireless service bands (Macro-tuning). As well as the varactor in the antenna is used for tuning frequency band to obtain the constant antenna gain (micro-tuning). The proposed antenna newly realizes desirable broad and fine frequency...
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