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In this paper, a novel pilot extension scheme is proposed for massive MIMO uplink transmission, and its performance is evaluated analytically. Specifically, we divide the cell users into two groups, namely near users and far users, according to their distances to the service base stations. The far users are more motivated to mitigate the inter-cell interference than the near users at the price of...
In this paper, we propose an angle domain sparse code multiple access (ASCMA) scheme for the massive multiple-input multiple-output (MIMO) networks to enhance the access connectivity. The basic idea of ASCMA scheme is to construct a non-orthogonal transmission policy in the sparse angle domain channel of massive MIMO networks. Firstly, an angle domain mapping structure is presented, where both the...
This paper presents an orbit angular momentum (OAM) based wireless communication system combined with multi-input multi-ouput (MIMO) technique, where each MIMO branch multiplexes several OAM signals. The achievable sum-rate and array gain of the OAM-MIMO system relative to pure MIMO are analyzed. Results show that, when at near distance, e.g, the OAM beams are such collimated that each branch suffers...
In order to improve the simultaneous wireless information and power transfer (SWIPT) efficiency, we exploit the vertical domain by adjusting the base station (BS) antenna tilt. In this paper, the single-cell multiple-input multiple-output (MIMO) SWIPT system is studied where one BS employs three-dimensional (3D) directional antennas and users apply the power splitting (PS) technique. With zero-forcing...
Cell-free massive multiple-input multiple-output (MIMO), with a large number of distributed access points (APs) that jointly serve the user equipments (UEs), is a promising network architecture for future wireless communications. To reduce the cost and power consumption of such systems, it is important to utilize low-quality transceiver hardware at the APs. However, the impact of hardware impairments...
In this paper, we investigate the downlink of millimeter-wave multi-user massive MIMO systems, and propose a hybrid precoding scheme based on a sub-array architecture to achieve a better compromise between hardware cost and system performance. The proposed precoding scheme performs analog precoding and digital precoding at the transmitter with the generalized sub-array architecture. It implements...
In this paper, an antenna grouping assisted spatial modulation scheme is proposed for massive MIMO systems. Massive multiple-input-multiple-output (MIMO) systems are capable of offering abundant spatial capacity by deploying hundreds of antennas at the base station (BS). Spatial modulation (SM) is one of the key technologies in exploiting spatial capacity, which maps the information bits to the active...
Massive Multiple-Input Multiple-Output (MIMO) is one of the key technologies in the fifth generation (5G) wireless communication for much higher throughput. However, current detection algorithms for massive MIMO suffer from large computational complexity. The Neumann series based approximated matrix inverse is a good tradeoff between detection performance and computational complexity. In this paper,...
Wireless transmission over 15Gb/s data rate is reported using space diversity MIMO. Multi-diversity planar antennas are designed and fabricated to transmit and receive the radio frequency signal simultaneously in 2 radiation diversities. Reliable 15Gb/s indoor data transmission over 5m distance is demonstrated in the super high frequency band (SHF) of 11.6GHz to 20.4GHz. Low BER is achieved with 2×2...
In this paper a novel compact printed ultra wide band (UWB) multiple input multiple output (MIMO) antenna is presented with pattern diversity characteristic for portable devices. The MIMO configuration consists of two identical compact UWB antennas with a very simple decoupling circuit. To analyze the performance of antenna in UWB range the impedance bandwidth, isolation, radiation pattern, gain and...
In this paper, two planar inverted-F antennas on a slitted ground plane is proposed for MIMO mobile terminal. This antenna is designed to operate at 5 GHz with 1 GHz bandwidth. In simulation stage, the length and width of slitted are varied. The optimum slit's dimension is shown to be λ/4 length and 0.0333λ width, which produced reflection coefficient of −16.38 dB and isolation of −23.52 dB at 5 GHz,...
Two-dimensional Multiple Input Multiple Output (MIMO) array can form the high-resolution three-dimensional (3D) image of the near-filed target, Azimuth resolution of 3D imaging depends on angle of antennas and targets. The further distance between arrays is, the worse result of azimuth resolution we get. In this paper, we propose a method based on highresolution 3D imaging of depth compensation, which...
A direct spread spectrum (DSS) communication system is presented, which uses optimized spread spectrum sequence (SSS) and adaptive soft-iteration (Turbo) equalization (ASIE). The scheme using multiple receiver is similar to MIMO systems. The average cross-correlation of SSS is regarded as a critical factor to search optimized sequences used in under water acoustic (UWA) multi-access burst communication...
Multidimensional waveform encoding is a new multiple-input multiple-output (MIMO) technique for remote sensing. The orthogonality is acquired by digital beamforming in elevation. It has a potential to enhance ground moving target indication (GMTI) performance due to the larger along-track virtual array of the radar system. This paper proposed two modes for GMTI based on multidimensional waveform encoding:...
In this report, we investigate prediction accuracy of fading channels in line-of-sight (LOS) environment when using autoregressive (AR) model. We especially evaluate the accuracy of the predicted channel in LOS environment when applying the theoretical autocorrelation formula of the LOS environment to the AR model. The influence of the prediction methods on MIMO capacities is also investigated. The...
This paper presents a densely packed MIMO antenna array with high isolation. A compact resonator as a band-gap filter is designed between the two patch antennas to enhance the isolation. Thanks to this compact resonator, the isolation between two patches can reach 30dB, nearly 20dB higher than the MIMO antenna array without using decoupling network. Furthermore, he bandwidth and radiation pattern...
The Feature Selective Validation (FSV) Method has been developed as a standard technique to mimic an expert's opinion of concurrence between computational electromagnetics (CEM) and measurement datasets. In this paper, FSV is used to compare the design simulation and measurement of the microstrip antenna to verify the difference between the simulation data and the measured data. First, a typical patch...
This paper presents our preliminary considerations on SAR imaging using small platforms. The motivation, the approach and the key techniques are discussed. The designing of codes transmitted from multiple transmitters, the distribution of antennas to avoid frequency ambiguity and the imaging method are discussed.
This paper presents a systematic design of microstrip decoupling network to reduce the mutual coupling effect between a two-element antenna array. This design is based on the eigen-mode analysis method. The achieved microstrip decoupling network is simple and easy to fabricate. A reduction of more than 20 dB in mutual coupling is obtained for a two-element monopole array with element spacing of 0...
A very compact ultra-wideband (UWB) multiple-input-multiple-output (MIMO) ground linearly tapered slot Antenna (LTSA) is presented in this paper. On a cost-effective FR4 substrate, it consists of a ground plane and two microstrip feed lines. Its overall dimension is only 22×26 mm2. To miniaturize, two linearly tapered slots on the ground plane, acts as the main radiator. Then it does not need extra...
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