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In this paper, massive MIMO measurements are carried out with a Massive MIMO testbed and a multi-antenna mobile terminal. The 8-antennas handset with a dimension of 15cm×7.5cm is used as the mobile station in order to mimic a smartphone. Measurements are successively undergone in a typical indoor scenario. The influence of antenna numbers in the handset on the indoor wireless channel characteristic...
A novel empirical, measurement-based massive MIMO channel matrix model under real indoor environment at 4.1 GHz is proposed. In this model, the channel matrix can be described as the sum of a fixed and a random matrices, furthermore, the random matrix can be decomposed into the product of four parts: the eigenvectors of the transmitting and receiving side correlation matrices, a coupling matrix, whose...
As a kind of special form of mobile ad hoc networks, VANET receives more and more attention for providing safety and entertainment news. The frequent changes of topology caused by high-speed mobile vehicles will cause routing unreachable, leading to loss of data packets eventually. So, routing protocols used in the VANET need to be improved to enhance the reliability and effectiveness. An improved...
The statistical characteristics of body obstruction (BO) and none-BO (NBO) cases for off-body channel under hospital environment at 6∼8.5 GHz are presented in this paper. It is seen that all the statistical parameters of off-body channel in BO and NBO cases share the same distributions except the RMS. It is also found that the relationship between RMS and coherence bandwidth under BO and NBO cases...
As physicists want to put more and more functionalities and algorithms into frontend ASICs, the logic design (of some ASICs) become more and more complicated. A reliable, robust functional verification testbench is one of the most important part during ASIC design. This paper presents a well-constructed testbench based on Universal Verification Methodology(UVM) research for ATLAS Phase-II upgrade...
The design approach of a loop-dipole combined antenna for wearable applications is proposed. In order to mitigate the antenna's performance deterioration caused by the human body, additional loops are incorporated with a wideband dipole. The loops can i) widen the impedance bandwidth by minimizing the reactance of the antenna, ii) increase the antenna's directivity and iii) act as wearable accessories...
The influence of the person density on the indoor MIMO channel models is experimentally investigated. The path loss is modeled as a log-distance function adding additional attenuations related to both of the distance and person density. Then, the shadowing, the root mean square delay spread, and the channel capacity are described as normal distributed random variables. Their mean value and the standard...
A complementary antenna for wearable applications is proposed. By introducing a loop-monopole combined structure, unidirectional beam is obtained and the interaction between the antenna and the human body can be potentially mitigated. The antenna's operation principle is analyzed and validated at first. Then, prototypes are designed and measured. When the antenna is placed in free space, an impedance...
The channel impulse response (CIR) under indoor stair environment is modeled. In this model, the amplitude and phase of the CIRs are described as Weibull and uniform distributed random variables, respectively. The CIRs can be simulated using the proposed model. Then, Orthogonal Frequency Division Multiplexing (OFDM) communication system is implemented on the measured and simulated channels. Based...
In this paper, a novel joint recursive least square (RLS) and least mean square (LMS) adaptive equalization algorithm for indoor, short range wireless communications under staircase environment is proposed. In this algorithm, the RLS is initially used to realize the fast convergence. Then, the LMS is adapted to rapidly optimize the receiving signals. Once the imbalance of the equalizer or severe channel...
Energy efficiency (EE) of wireless communications has attracted growing attention in recent years. In this paper, we focus on the EE optimization in cognitive radio networks (CRN) from a perspective of designing MAC frame structure, namely scheduling the sensing-then-transmission time slots. Considering secondary users adopting channel handoff to avoid collisions with primary users, the EE of CRN...
Conceptual design of a novel multi-resonated complementary antenna is proposed. By perpendicularly incorporating an offset microstrip-fed slot radiator and a symmetrical aperture-dipole element, the dominant one half-wavelength mode and two fractional-order dipole modes, i.e., the three quarters-wavelength mode and seven quarters-wavelength mode can be excited and triple-band operation can be obtained...
A compact wideband fractal loop-dipole composite antenna is presented. By introducing a Koch fractal structure, the antenna's size can be reduced while maintaining good pulse fidelity. It is demonstrated that an impedance bandwidth from 2.86 to 11.23GHz for |S11| lower than −10dB could be obtained. Furthermore, stable radiation pattern and pulse fidelity of 0.75 could be achieved in the same bandwidth.
Analyzing frequency selective surface (FSS) can be of great significance. FSS can present band-stop or band-pass properties at some specific frequency bands, and this is very helpful in designing practical electromagnetic and communication systems. The application of method of moments (MoM) in this field is very popular. However, when the electric size of FSS increases, huge in-core memory requirement...
Novel path loss and delay spread models with antenna height dependency under indoor stair environment are proposed. According to the persons' posture and location of the mobile device, the antenna height is categorized as three levels: low, medium and high. The path loss is modeled by using minimum mean square error (MMSE) method; meanwhile, both of mean excess delay and RMS delay spread are modeled...
Operation principle of a dual-band loop-monopole composite antenna is investigated in detail. The prototype antenna under investigation is composed of two monopoles and a sectored loop. Each mode of the antenna is numerically studied by analyzing its surface current distribution and radiation pattern. It is shown that the antenna has three operation modes.
A planar dual-band antenna using off-centered feed structure is proposed and investigated. The antenna consists of an off-centered dipole and an asymmetrical slot radiator. Design guidelines of the antenna are drawn and design principle is analyzed first. By properly selecting the feeding position, an operating frequency band of 2.47 to 2.53GHz and 4.14 to 13.76GHz for return loss larger than 10dB...
A novel empirical path loss model for indoor stairwell environment is presented. The model is based on the multiple-input-multiple-output (MIMO) measurements at 2.6 GHz. The model is divided into two scenarios, i.e., line-of-sight (LOS) and non-LOS (NLOS). In the case of LOS, the path loss exponent n is dependent with the increasing of frequency slightly and is fitted by the frequency using power...
In this paper, the efficient analysis of electromagnetic scattering from objects is performed utilizing the characteristic basis function method (CBFM) with the compressed sensing (CS) technique. CBFM generates sets of high-level basis functions, i.e. the characteristic basis function (CBF), defined over macro domains of the object under discussion, to significantly reduce the matrix size and storage...
Design concept of an implantable, balanced slot-dipole composite antenna is proposed and simulated. The antenna is composed of a tapered slot element and a symmetrical dipole and embedded in a planar stratified phantom. The reflection coefficiency, radiation pattern and gain of the antenna are simulated. It is shown that the antenna can operate at 402–405MHz, 433MHz, 902–928MHz and 2400–2500MHz bands...
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