Optimal Beam-Forming Design in Cognitive Relay Networks under Interference Threshold

2013 ◽  
Vol 850-851 ◽  
pp. 561-566
Author(s):  
Zi Jun Liu ◽  
Zhan Gao ◽  
Guo Xin Li ◽  
Hai Tao Zhang
Keyword(s):  
Multiple Input Multiple Output ◽  
Relay Networks ◽  
Primary User ◽  
Primary Data ◽  
Mimo Antenna ◽  
Cognitive Relay Networks ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Optimal Beam ◽  
Cognitive User

Recently, a new model for cognitive radio networks appears, in which a cognitive user (CU) can relay the primary data stream to improve the performance of the primary user s communication. Traditionally, the transmitter of the cognitive users will send data to the receiver of the cognitive users and relay the data sent from the primary user (PU) in different time slots. However, Multiple Input Multiple Output (MIMO) provides a remarkable increase in the spectral efficiency, which can transmit multiple independent data streams in a time slot with MIMO antenna. Based on the MIMO technique, we propose a novel framework, in which the cognitive user near by the primary user is equipped with MIMO antenna. In this paper, we search for the maximum sum-rate of the cognitive user, limiting the interference to the primary users. Simulation results show that the proposed method can really improve the performance of the cognitive relay networks.

Design of an interlocked four-port MIMO antenna for UWB automotive communications

2021 ◽  
pp. 1-8
Author(s):  
M. Saravanan ◽  
R. Kalidoss ◽  
B. Partibane ◽  
K. S. Vishvaksenan
Keyword(s):  
Multiple Input Multiple Output ◽  
Performance Estimation ◽  
Ultra Wideband ◽  
Antenna Element ◽  
Frequency Range ◽  
Mimo Antenna ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Operating Bandwidth ◽  
Peak Gain

Abstract The design, analysis, fabrication, and testing of a four-port multiple-input multiple-output (MIMO) antenna is reported in this paper for automotive communications. The MIMO antenna is constructed using the basic antenna element exploiting a slot geometry. Two such antennas are developed on the same microwave laminate to develop a two-port MIMO antenna. Two such microwave laminates are interlocked to create the four-port MIMO scheme. The most distinct feature of the proposed architecture is that the inter-port isolation is well-taken care without the need for an external decoupling unit. The four-port MIMO antenna has an overall volume of 32 × 15 × 32 mm3. The prototype MIMO antenna is fabricated and the measurements are carried out to validate the simulation results. The antenna offers ultra-wideband (UWB) characteristics covering the frequency range of 2.8–9.5 GHz. The average boresight gain of the antenna ranges from 3.2 to 5.41 dBi with the peak gain at 8 GHz. The simulated efficiency of the antenna is greater than 73% within the operating bandwidth. The MIMO parameters such as envelope correlation coefficient, diversity gain, and mean effective gain are evaluated and presented. The appropriateness of the proposed antenna for deployment in the shark fin housing of the present-day automobiles is verified using on-car performance estimation.

scholarly journals Mutual Coupling Reduction of DRA for MIMO Applications

2019 ◽  
Vol 8 (1) ◽  
pp. 75-81
Author(s):  
N. Al Shalaby ◽  
S. G. El-Sherbiny
Keyword(s):  
Mutual Coupling ◽  
Dielectric Material ◽  
Ground Plane ◽  
Multiple Input Multiple Output ◽  
Antenna System ◽  
Parasitic Element ◽  
Mimo Antenna ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Element Method

In this paper, A multiple input Multiple Output (MIMO) antenna using two Square Dielectric Resonators (SDRs) is introduced. The mutual coupling between the two SDRAs is reduced using two different methods; the first method is based on splitting a spiral slot in the ground plane, then filling the slot with dielectric material, "E.=2.2". The second method is based on inserting a copper parasitic element, having the same shape of the splitted Spiral, between the two SDRAs.  The effect of replacing the copper parasitic element with Carbon nanotubes (CNTs) parasitic element "SOC12 doped long-MWCNT BP" is also studied. The antenna system is designed to operate at 6 GHz. The analysis and simulations are carried out using finite element method (FEM). The defected ground plane method gives a maximum isolation of l8dB at element spacing of 30mm (0.6λo), whereas the parasitic element method gives a maximum isolation of 42.5dB at the same element spacing.

scholarly journals DESIGN AND ANALYSIS OF COMPACT METAMATERIAL MIMO ANTENNA FOR WLAN APPLICATIONS

2019 ◽  
Vol 57 (2) ◽  
pp. 223
Author(s):  
Hoa Nguyen Thi Quynh ◽  
Sy Tuan Tran ◽  
Huu Lam Phan ◽  
Duy Tung Phan
Keyword(s):  
Ground Plane ◽  
Multiple Input Multiple Output ◽  
Split Ring Resonator ◽  
Antenna Element ◽  
Mimo Antenna ◽  
Complementary Split Ring Resonator ◽  
Antenna Performance ◽  
Multiple Input ◽  
Input Multiple Output ◽  
The Individual

A compact three-port metamaterial multiple-input-multiple-output (MIMO) antenna using complementary split-ring resonator (CSRR) loaded ground have demonstrated in order to miniaturize the size and improve the antenna performance. The antenna is designed on FR4 material and simulated by HFSS software. By loading CSRRs in the ground plane, the size reduction of 77% of the individual patch antenna element is achieved, which appeared to be the major reason for the obtained the compact MIMO antenna. Furthermore, the simulated results show that the proposed MIMO antenna achieves the total gain higher than 5 dB, the isolation less than -11 dB, the envelope correlation coefficient (ECC) value lower than 0.015, and the bandwidth of 100 MHz through the whole WLAN band from 2.4 GHz to 2.484 GHz, indicating promises for WLAN applications.

scholarly journals Deep Scanning—Beam Selection Based on Deep Reinforcement Learning in Massive MIMO Wireless Communication System

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1844
Author(s):  
Minhoe Kim ◽  
Woongsup Lee ◽  
Dong-Ho Cho
Keyword(s):  
Communication Systems ◽  
Large Scale ◽  
Multiple Input Multiple Output ◽  
Base Station ◽  
Q Learning ◽  
Multiple Input ◽  
Beam Selection ◽  
Input Multiple Output ◽  
Optimal Beam ◽  
Resource Allocation Scheme

In this paper, we investigate a deep learning based resource allocation scheme for massive multiple-input-multiple-output (MIMO) communication systems, where a base station (BS) with a large scale antenna array communicates with a user equipment (UE) using beamforming. In particular, we propose Deep Scanning, in which a near-optimal beamforming vector can be found based on deep Q-learning. Through simulations, we confirm that the optimal beam vector can be found with a high probability. We also show that the complexity required to find the optimum beam vector can be reduced significantly in comparison with conventional beam search schemes.

scholarly journals Dual-Band 2 × 2 MIMO Antenna with Compact Size and High Isolation Based on Half-Mode SIW

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Abubaker Ahmed Elobied ◽  
Xue-Xia Yang ◽  
Ningjie Xie ◽  
Steven Gao
Keyword(s):  
Multiple Input Multiple Output ◽  
Dual Band ◽  
Antenna Element ◽  
Mimo Antenna ◽  
High Isolation ◽  
Rectangular Patch ◽  
Compact Size ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Proximity Coupling

This paper presents a close-spaced dual-band 2 × 2 multiple-input multiple-output (MIMO) antenna with high isolation based on half-mode substrate integrated waveguide (HMSIW). The dual-band operation of the antenna element is achieved by loading a rectangular patch outside the radiating aperture of an HMSIW cavity. The HMSIW cavity is excited by a coaxial probe, whereas the rectangular patch is energized through proximity coupling by the radiating aperture of HMSIW. The antenna elements can be closely placed using the rotation and orthogonal arrangement for a 2 × 2 array. Small neutralization lines at the center of the MIMO antenna can increase the isolation among its elements by around 10 dB in the lower band and 5 dB in the higher band. A prototype of the MIMO antenna is fabricated and its performance is measured. The measured results show that the resonant frequencies are centered at 4.43 and 5.39 GHz with bandwidths of 110 and 80 MHz and peak gains of 6 and 6.4 dBi, respectively. The minimum isolation in both bands is greater than 35 dB. The envelope correlation coefficient is lower than 0.005 within two operating bands.

Design of a wearable MIMO antenna deployed with an inverted U-shaped ground stub for diversity performance enhancement

2020 ◽  
pp. 1-11
Author(s):  
Anupma Gupta ◽  
Ankush Kansal ◽  
Paras Chawla
Keyword(s):  
Performance Enhancement ◽  
Multiple Input Multiple Output ◽  
The Body ◽  
Structural Deformation ◽  
Mimo Antenna ◽  
Tissue Phantom ◽  
Capacity Loss ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Broadside Radiation

Abstract A compact multiple input multiple output (MIMO) antenna operating at 2.45 GHz industrial scientific and medical band is presented for wearable devices. Open-end slotting is used to miniaturize the antenna dimensions. Inverted U-shaped ground stub is incorporated to reduce mutual coupling. On-body performance is analyzed on a three-layered equivalent tissue phantom model. The wide bandwidth of 300 MHz and port isolation of 30 dB are obtained from measured results. The antenna shows the efficiency of 40% and directivity of 4.56 dBi when placed at a gap of “s” = 4 mm from the body. Broadside radiation pattern and low specific absorption rate make the antenna suitable for on-body communication. Further, diversity performance is measured in terms of envelope correlation coefficient (ECC), diversity gain (DG), and channel capacity loss (CCL). The value of ECC is 0.025, DG is 9.98 dB, and CCL is 0.12 bits/s/Hz at 2.45 GHz. Antenna robustness is examined by bending the structure at different radii along the x-axis and y-axis. Performance of the proposed structure is reliable with structural deformation.

scholarly journals Modified U-Shaped Resonator as Decoupling Structure in MIMO Antenna

Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1321
Author(s):  
Amjad Iqbal ◽  
Ahsan Altaf ◽  
Mujeeb Abdullah ◽  
Mohammad Alibakhshikenari ◽  
Ernesto Limiti ◽  
...  
Keyword(s):  
Multiple Input Multiple Output ◽  
Equivalent Circuit Model ◽  
Separation Distance ◽  
Antenna System ◽  
Parametric Modelling ◽  
Mimo Antenna ◽  
Antenna Performance ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Simple Assembly

This paper presents an isolation enhancement of two closely packed multiple-input multiple-output (MIMO) antenna system using a modified U-shaped resonator. The modified U-shaped resonator is placed between two closely packed radiating elements resonating at 5.4 GHz with an edge to edge separation distance of 5.82 mm (λ∘/10). Through careful adjustment of parametric modelling, the isolation level of −23 dB among the densely packed elements is achieved. The coupling behaviour of the MIMO elements is analysed by accurately designing the equivalent circuit model in each step. The antenna performance is realized in the presence and absence of decoupling structure, and the results shows negligible effects on the antenna performance apart from mutual coupling. The simple assembly of the proposed modified U-shaped isolating structure makes it useful for several linked applications. The proposed decoupling structure is compact in nature, suppress the undesirable coupling generated by surface wave and nearby fields, and is easy to fabricate.

UWB MIMO antenna with common radiator

2016 ◽  
Vol 9 (3) ◽  
pp. 573-580 ◽  
Author(s):  
Garima Srivastava ◽  
B. K. Kanuijia ◽  
Rajeev Paulus
Keyword(s):  
Low Cost ◽  
Multiple Input Multiple Output ◽  
Impedance Bandwidth ◽  
Rectangular Slot ◽  
Mimo Antenna ◽  
Circular Patch ◽  
Capacity Loss ◽  
Compact Size ◽  
Multiple Input ◽  
Input Multiple Output

A compact printed 2 × 2 ultrawideband (UWB) multiple input multiple output (MIMO) antenna with a single circular patch as a common radiator for both the antenna elements is presented in this paper. A single circular patch is excited by two tapered CPW feeds for dual polarization. To improve the isolation between two ports, a rectangular slot of dimension L1 × W1 is created in the radiator. The UWB MIMO antenna has impedance bandwidth of 3–12 GHz with a isolation better than 17 dB between the two ports. The envelope correlation coefficient and the capacity loss are evaluated to ensure the good diversity performance of UWB MIMO antenna. The antenna has a compact size of 45 × 45 mm2 and is fabricated on low cost FR4 substrate and measured using Agilent VNA. The simulated and measured results show that the proposed UWB antenna is good candidate for UWB MIMO applications.

A Superwideband Monopole Multiple-Input-Multiple-Output (MIMO) Antenna with Dual Notched (Inverted T-Shaped Stub/U-Shaped Slit) Band Characteristics for Wireless Applications

2019 ◽  
Vol 16 (10) ◽  
pp. 4242-4248
Author(s):  
Manoj Kapil ◽  
Manish Sharma
Keyword(s):  
Ground Plane ◽  
Multiple Input Multiple Output ◽  
Impedance Bandwidth ◽  
Mimo Antenna ◽  
Wireless Applications ◽  
Research Article ◽  
Compact Size ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Microstrip Feed

In this research article, a compact MIMO (Multiple-Input-Multiple-Output) antenna with inclusion of two notched bands characteristics is presented. Designed MIMO antenna consist of dual radiating patches printed on one surface of the substrate which covers measured wide impedance bandwidth of 2.88 GHz–19.98 GHz and satisfies bandwidth ratio more than 10:1 for superwideband with compact size of 18 mm × 34 mm. Two radiating patch are placed symmetrically for MIMO configuration and notched bands to eliminate WiMAX/C and WLAN bands are obtained by attaching inverted T-shaped stub on radiating patch and etched inverted U-shape slit in microstrip feed. Isolation between the two radiating patch is maintained by adding two L-shaped stub in slotted rectangular ground plane. Measured radiation pattern are stable in operating band and offers maximum 4.23 dBi and 89% gain and radiation efficiency respectively. Moreover, antenna shows good diversity performance with Envelope-Correlation-Coefficient (ECC) < 0.5, Directive-Gain (DG) > 9.95 dB and Total-Active-Reflection Coefficient (TARC) < -30 dB.

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