Design multilayer bandpass filter using hairpin resonator for digital broadcasting

This research presents 2.52-2.65 GHz band-pass filter using multilayer hairpin resonator for digital broadcasting applications . Four-pole resonators are centered at 2.58 GHz with bandwidth of 130 MHz .This filter is simulated using Computer Simulation Technology software (CST) and Advance Design System (ADS) . Filter is designed using Chebychev response with passband ripple of 0. 01 dB . Hairpin-line provides compact structures in the filter design . They can conceptually be obtained by folding the resonators of parallel-coupled half wavelength resonator into a “U” shape . This research will contribute towards a small size filter using the latest multilayer stack up model .The proposed microstrip half wavelength coupled line resonator design is employed to design the multilayer band pass filter . For parallel coupled line band pass filter ,the passband insertion loss using FR4 Material is -5.651dB and when using RO3003 Material is -1.79dB .The passband return loss is -30.614dB for the FR4 material type and -18.52 dB for RO3003 material type. For multi layer band pass filter the passband insertion loss using FR4 Material is -2.23dB and when using RO3003 Material is -1.009dB . The passband return loss is 22.706dB using FR4 material type and -18.99 dB when using RO3003 material type. Filter is fabricated on 1.6 mm thickness FR4 for parallel coupled line with dielectric constant of 4.3

Downlink Massive MIMO Systems: Reduction of Pilot Contamination for Channel Estimation with Perfect Knowledge of Large-Scale Fading

Massive multiple-input multiple-output (MIMO) technology is considered crucial for the development of future fifth-generation (5G) systems. However, a limitation of massive MIMO systems arises from the lack of orthogonality in the pilot sequences transmitted by users from a single cell to neighboring cells. To address this constraint, a proposed solution involves utilizing orthogonal pilot reuse sequences (PRS) and zero forced (ZF) pre-coding techniques. The primary objective of these techniques is to eradicate channel interference and improve the experience of end users who are afflicted by low-quality channels. The assessment of the channel involves evaluating its quality through channel assessment, conducting comprehensive evaluations of large-scale shutdowns, and analyzing the maximum transmission efficiency. By assigning PRS to a group of users, the proposed approach establishes lower bounds for the achievable downlink data rate (DR) and signal-to-interference noise ratio (SINR). These bounds are derived by considering the number of antennas approaches infinity which helps mitigate interference. Simulation results demonstrate that the utilization of improved channel evaluation and reduced loss leads to higher DR. When comparing different precoding techniques, the ZF method outperforms maximum ratio transmission (MRT) precoders in achieving a higher DR, particularly when the number of cells reaches . &nbsp

Downlink Massive MIMO Systems: Reduction of Pilot Contamination for Channel Estimation with Perfect Knowledge of Large-Scale Fading

Massive multiple-input multiple-output (MIMO) technology is considered crucial for the development of future fifth-generation (5G) systems. However, a limitation of massive MIMO systems arises from the lack of orthogonality in the pilot sequences transmitted by users from a single cell to neighboring cells. To address this constraint, a proposed solution involves utilizing orthogonal pilot reuse sequences (PRS) and zero forced (ZF) pre-coding techniques. The primary objective of these techniques is to eradicate channel interference and improve the experience of end users who are afflicted by low-quality channels. The assessment of the channel involves evaluating its quality through channel assessment, conducting comprehensive evaluations of large-scale shutdowns, and analyzing the maximum transmission efficiency. By assigning PRS to a group of users, the proposed approach establishes lower bounds for the achievable downlink data rate (DR) and signal-to-interference noise ratio (SINR). These bounds are derived by considering the number of antennas approaches infinity which helps mitigate interference. Simulation results demonstrate that the utilization of improved channel evaluation and reduced loss leads to higher DR. When comparing different precoding techniques, the ZF method outperforms maximum ratio transmission (MRT) precoders in achieving a higher DR, particularly when the number of cells reaches . &nbsp

Energy-Efficient Low-Complexity Algorithm in 5G Massive MIMO Systems

Energy efficiency (EE) is a critical design when taking into account circuit power consumption (CPC) in fifth-generation cellular networks. These problems arise because of the increasing number of antennas in massive multiple-input multiple-output (MIMO) systems, attributable to inter-cell interference for channel state information. Apart from that, a higher number of radio frequency (RF) chains at the base station and active users consume more power due to the processing activities in digital-to-analogue converters and power amplifiers. Therefore, antenna selection, user selection, optimal transmission power, and pilot reuse power are important aspects in improving energy efficiency in massive MIMO systems. This work aims to investigate joint antenna selection, optimal transmit power and joint user selection based on deriving the closed-form of the maximal EE, with complete knowledge of large-scale fading with maximum ratio transmission. It also accounts for channel estimation and eliminating pilot contamination as antennasM→∞. This formulates the optimization problem of joint optimal antenna selection, transmits power allocation and joint user selection to mitigate inter-cellinterference in downlink multi-cell massiveMIMO systems under minimized reuse of pilot sequences based on a novel iterative low-complexity algorithm (LCA) for Newton’s methods and Lagrange multipliers. To analyze the precise power consumption, a novel power consumption scheme is proposed for each individual antenna, based on the transmit power amplifier and CPC. Simulation results demonstrate that the maximal EE was achieved using the iterative LCA based on reasonable maximum transmit power, in the case the noise power is less than the received power pilot. The maximum EE was achieved with the desired maximum transmit power threshold by minimizing pilot reuse, in the case the transmit power allocation ρd = 40 dBm, and the optimal EE=71.232 Mb/j

A compact size microstrip five poles hairpin band-pass filter using three-layers structure for Ku-band satellites application

This paper presents a reduced size microstrip five poles hairpin band-pass filter using three-layers structure for Ku-band satellites application. The three-layers structure shows a substantially reduced filter size and enlarged bandwidth. The filter has been designed based on five-pole resonators at 12.475 GHz and bandwidth of 550 MHz. This filter is designed on Rogers RO3003 substrate having relative permittivity (εr) of 3. The proposed band-pass filter has been designed with the help of Computer Simulation Technology (CST) software. Comparison analyses between the simulated insertion loss and reflection coefficient of RO3003 and FR4 substrates have been carried out in order to show the efficiency of the proposed filter design. Based on the obtained results, the proposed filter design achieves significant filter size reduction compared to other band-pass filters

A compact size microstrip five poles hairpin band-pass filter using three-layers structure for Ku-band satellites application

This paper presents a reduced size microstrip five poles hairpin band-pass filter using three-layers structure for Ku-band satellites application. The three-layers structure shows a substantially reduced filter size and enlarged bandwidth. The filter has been designed based on five-pole resonators at 12.475 GHz and bandwidth of 550 MHz. This filter is designed on Rogers RO3003 substrate having relative permittivity (εr) of 3. The proposed band-pass filter has been designed with the help of Computer Simulation Technology (CST) software. Comparison analyses between the simulated insertion loss and reflection coefficient of RO3003 and FR4 substrates have been carried out in order to show the efficiency of the proposed filter design. Based on the obtained results, the proposed filter design achieves significant filter size reduction compared to other band-pass filters

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

Analysis and investigation of different advanced control strategies for high-performance induction motor drives

Induction motor (IM) drives have received a strong interest from researchers and industry particularly for high-performance AC drives through vector control method. With the advancement in power electronics and digital signal processing(DSP), high capability processors allow the implementation of advanced control techniques for motor drives such as model predictive control (MPC). In this paper, design, analysis and investigation of two different MPC techniques applied to IM drives; themodel predictive torque control (MPTC) and model predictive current control (MPCC) are presented. The two techniques are designed in Matlab/Simulink environment and compared interm of operation in different operating conditions. Moreover, a comparisonof these techniques with field-oriented control (FOC) and direct torque control (DTC) is conducted based on simulation studies with PI speed controller for all control techniques. Based on the analysis, the MPC techniques demonstrates a better result compared with the FOC and DTC in terms of speed, torque and current responses in transient and steady-state conditions