Mitigated Pilot Contamination to Achieve Higher Downlink Data Rate in 5G Massive MIMO Systems

Massive multiple-input, multiple-output (M-MIMO) is an important knowledge for fifth-generation (5G) wireless cellular networks. The pilot contamination (PC) is an issue in massive MIMO due to interference between adjacent cells. We proposed that the number of pilot sequence inside a cell could become smaller than or equal to the number of users (UEs), taking into account the different number of UEs that transmitted the same pilot sequence in the same cell. In addition, the pilot sequence became mutually orthogonal for different cells to prevent PC among cells. In this paper, we analyzed a channel estimation for time division duplex (TDD) and improved the achievable data rate by reducing the PC for limiting user capacity and using channel orthogonality for minimum mean square error (MMSE) precoding. From the simulation results, the proposed scheme provided a data rate for two several situations, with and without interference PC for an increased number of antennas. Consequently, increasing the number of coherence intervals made the channel estimation critical and provided a small data rate due to increased noise and interference at increased transmit pilot sequence

Joint Transmit Antennas for Energy Efficiency in Downlink Massive MIMO Systems

Massive multiple-input-multiple-output (MIMO) systems are an exciting area of fifth-generation (5G) technology and very important in maximizing energy efficiency (EE) and saving battery technology.  Obtaining energy efficiency without sacrificing the quality of service (QoS) has become increasingly important for mobile devices. In this paper, we investigate the maximal EE for downlink massive MIMO systems using zero-forcing beamforming (ZFBF), dependent on the number of antenna elements and the optimal number of users inside the cell to optimize the transmit power. The linear precoding ZFBF is able to mitigate interbeam interference, in addition to noise, due to expanding the reception at low  power transmission.  The simulation results reveal that the maximal energy efficiency  can be obtained dependent on increasing the number of antennas M and choosing the  , where the number of antennas is greater than the critical number of antennas   , which minimizes the received interference due to increased transmit power

Reduction Pilot Contamination in Downlink Multi-Cell for Massive MIMO Systems

Massive multiple- input–multiple- output has become an important fifth-generation (5G) wireless communication system because it improves transmitted spectral efficiency. In this paper, we obtained the maximal spectral efficiency by improving transmission performance in cell edges. This was achieved by using pilot reuse sequences from all available pilots in order to mitigate the pilot contamination and to suppress interference between adjacent cells. In addition, we investigated the impacts of pilot contamination on the received signal-to-interference-noise ratios (SINR) of users and employed different pilot reuse. We propose a new method called cell-edge-aware maximum ratio transmission (MRT), zero forcing (ZF), and return zero forcing (R-ZF). These were the precoders that employed less spatial dimensions and were able to suppress adjacent cells interference of the maximally vulnerable active user. We conclude that the large pilot reuse value between neighboring cells increased the gain, avoided interference between adjacent cells, and gave the maximal spectral efficiency. Consequently, the R-ZF was better than ZF and MRT because it was able to suppress the SINR

Circuit Model for Microstrip Array Antenna with Defected Ground Structures for Mutual Coupling Reduction and Beamforming Applications

A microstrip array antenna (MAA) structure incorporated with an orthogonal I-shaped defected ground structure (OI-DGS) was proposed and investigated and its equivalent circuit was created. Reflection losses were simulated and verified with the proposed circuit model using CST Commercial and AWR Microwave Office software. The optimized S11 parameter of the model was obtained by tuning the dimensions of the microstrip patch elements in the MAA and the lengths and widths of the slots of defected ground structure (DGS). The proposed equivalent circuit is expected to be useful as a model for the DGS design and to study its behavior. Finally, two prototypes of MAA, without and with OI-DGS, were fabricated by the milling technology and tested. The simulated results showed that -5.53 dB mutual coupling reduction and the measured around -3 dB. The simulated results demonstrate that main beam shifted 43° while the measured main beam shifted 36°

Configure and Monitor the Networking Using EIGRP Protocol

In this modern internet generation, routing protocol plays an important role. The Enhanced Interior Gateway Routing Protocol (EIGRP) is an advanced protocol for distance-vector routing used on a computer network to simplify routing and configuration decisions. Data packets are transmitted from router to router via internet networks before they reach their destination device on the Internet. The main objective of this paper is to configure and monitor the network by the provider. The protocol implemented, EIGRP is analyzed using the GNS3 software.  In GNS3 software, the setup includes routers and hosts is simulated to display a network that consists of three areas. It analyzed the ping test, display neighbours and topology table, and the number packet received and sent. As a result, the simulated protocol, EIGRP show acceptable performance with hellos sent/received packets are 3544/1766, 144/143 and 6383/2107 of a router; R1, R2, and R3 respectively. In conclusion, EIGRP is the best in routing protocol and provide excellent internetworking

Soil moisture monitoring using field programmable gate array

This paper presents a solution for remote monitoring and sensing of different agricultural parameters that effect the plant growth and productivity. Hardware descriptive language has been used for the implementation of proposed topology on Field Programmable Gate Arrays. The hardware used for this purpose is an Altera board. The simulated results take into consideration the environmental factors such as the humidity, soil moisture content and the temperature. The proposed system continuously monitors the environmental changes for any updates. The system also controls a water motor that is turned on as the system senses the reduction in moisture content. The system implementation on hard wave level show promising results and have been discussed in detailed

Soil moisture monitoring using field programmable gate array

This paper presents a solution for remote monitoring and sensing of different agricultural parameters that effect the plant growth and productivity. Hardware descriptive language has been used for the implementation of proposed topology on Field Programmable Gate Arrays. The hardware used for this purpose is an Altera board. The simulated results take into consideration the environmental factors such as the humidity, soil moisture content and the temperature. The proposed system continuously monitors the environmental changes for any updates. The system also controls a water motor that is turned on as the system senses the reduction in moisture content. The system implementation on hard wave level show promising results and have been discussed in detailed

Maximising system throughput in wireless powered sub-6 GHz and millimetre-wave 5G heterogeneous networks

Millimetre wave (mm-Wave) bands and sub-6 GHz are key technologies in solving the spectrum critical situation in the fifth generation (5G) wireless networks in achieving high throughput with low transmission power. This paper studies the performance of dense small cells that involve a millimetre wave (mm-Wave) band and sub-6 GHz that operate in high frequency to support massive multiple-input-multiple-output systems (MIMO). In this paper, we analyse the propagation path loss and wireless powered transfer for a 5G wireless cellular system from both macro cells and femtocells in the sub-6 GHz (µWave) and mm-Wave tiers. This paper also analyses the tier heterogeneous in downlink for both mm-Wave and sub-6 GHz. It further proposes a novel distributed power to mitigate the inter-beam interference directors and achieve high throughput under game theory-based power constraints across the sub-6 GHz and mm-Wave interfaces. From the simulation results, the proposed distributed powers in femtocell suppresses inter-beam interference by minimising path loss to active users (UEs) and provides substantial power saving by controlling the distributed power algorithm to achieve high throughput

Wide-Band Metamaterial Perfect Absorber Through Double Arrow Shape Printed On A Thin Dielectric

A wide-band metamaterial perfect absorber was introduced. The dual arrow shapes and the ground plane were in between the 0.0035λ TLY-3. Lump element technique was applied to enhance the absorption bandwidth, which was connected between both of the arrow structures. The limitation during fabrication process in using lump element, had seriously restricted its practical applications for microwave absorption. Then, a very thin line was connected between both arrow structures to represent the resistance by lump element which was expected to ease the fabrication process and practical applications as well. Four cases were analyzed: double arrow, double arrow with lump connected, double arrow with lump connected and 9 mm air gap, and thin line connected with 6 mm air gap. The fourth case achieved the highest operational absorbency frequency, which developed about 7.38 GHz (3.87 GHz to 11.25 GHz) approximately to 7.38 GHz. Three resonant frequencies were achieved; 4.17 GHz, 6.09 GHz and 10.30 GHz with perfect absorbency. These properties are expected to be used in practical applications such as satellite and radar communications transmission. These properties of the metamaterial absorber could increase the functionality of the metamaterial absorber to be used in any application especially in reducing radar cross section for stealth applicatio

Symmetrical couple f-shaped notches with high rejection c-band of uwb patch antenna

The ultra-wideband (UWB) antenna is developed to cover a broad bandwidth. ‎The UWB radio systems are interfered ‎by the ‎same ‎spectrum ‎that shared with the local bands. In this paper, two F-shaped slots on a hexagonal patch UWB antenna are demonstrated ‎‎ to realize a high band rejection. The symmetrical couple F-slots is ‎notched on the hexagonal UWB ‎ ‎patch antenna to avoid the interference ‎and ‎‎enhance the notching results at C-band. The demonstrated ‎antenna employs a coplanar waveguide ‎(CPW) technique to meet a fractional bandwidth of 126%. The proposed method validates ‎several ‎‎reconfigurations of the F-slot location on the demonstrated design. Six steps ‎parametric study are considered to test the slots location. The results of the proposed antenna with slots are introduced based on analytical, simulation, and ‎measurement. The total design size ‎‎28 mm × 43 mm × 1.6 ‎mm is simulated by ‎using CST Microwave Studio. The two F-slots are achieved the antenna gain of -6 dB, ‎return loss of -1.2 ‎dB, and ‎VSWR of 15.2 at the rejected band of 4 GHz. The ‎measurement results are compared with the simulation results between the three ‎prototypes. The current ‎distribution on the design is discussed at 2.88 GHz and 4 GHz frequencies. The radiation patterns illustrate ‎omnidirectional of H-plane and bidirectional of E-plane. This paper validates the slots locations to enhance the notches performance and reduce the interference