Analysis of Optimum Precoding schemes in Millimeter Wave System

2020 ◽  
Vol 13 ◽  
Author(s):  
Divya Singh ◽  
Aasheesh Shukla
Keyword(s):  
Power Consumption ◽  
Millimeter Wave ◽  
Spectral Efficiency ◽  
Phase Shifter ◽  
Phase Shifters ◽  
Achievable Rate ◽  
Wave System ◽  
Digital To Analog Converter ◽  
Hybrid Precoding ◽  
Analog Converter

Background : Millimeter wave technology is the emerging technology in wireless communication due to increased demand for data traffic and its numerous advantages however it suffers from severe attenuation. To mitigate this attenuation, phased antenna arrays are used for unidirectional power distribution. An initial access is needed to make a connection between the base station and users in millimeter wave system. The high complexity and cost can be mitigated by the use of hybrid precoding schemes. Hybrid precoding techniques are developed to reduce the complexity, power consumption and cost by using phase shifters in place of converters. The use of phase shifters also increases the spectral efficiency. Objective: Analysis of Optimum Precoding schemes in Millimeter Wave System. Method: In this paper, the suitability of existing hybrid precoding solutions are explored on the basis of the different algorithms and the architecture to increase the average achievable rate. Previous work done in hybrid precoding is also compared on the basis of the resolution of the phase shifter and digital to analog converter. Results: A comparison of the previous work is done on the basis of different parameters like the resolution of phase shifters, digital to analog converter, amount of power consumption and spectral efficiency. Table 2 shows the average achievable rate of different algorithms at SNR= 0 dB and 5 dB. Table 3 also compares the performance achieved by the hybrid precoder in the fully connected structure with two existing approaches, dynamic subarray structure with and without switch and sub connected or partially connected structure. Table 4 gives the comparative analysis of hybrid precoding with the different resolutions of the phase shifter and DAC. Conclusion: In this paper, some available literature is reviewed and summarized about hybrid precoding in millimeter wave communication. Current solutions of hybrid precoding are also reviewed and compared in terms of their efficiency, power consumption, and effectiveness. The limitations of the existing hybrid precoding algorithms are the selection of group and resolution of phase shifters. The mm wave massive MIMO is only feasible due to hybrid precoding.

scholarly journals Hardware Phase Shift Hybrid Precoding Designs For Multi-User Massive MIMO Systems

2021 ◽  
Vol 2134 (1) ◽  
pp. 012027
Author(s):  
H Ayad ◽  
M Y Bendimerad ◽  
F T Bendimerad
Keyword(s):  
Spectral Efficiency ◽  
Massive Mimo ◽  
Phase Shifter ◽  
Mimo Systems ◽  
Digital Processing ◽  
Hybrid Precoding ◽  
Double Phase ◽  
High Spectral Efficiency ◽  
Fixed Phase ◽  
Configuration Simulation

Abstract Hybrid precoding is a challenging design for massive MIMO systems that involves a combination of analog and digital processing, aiming to maximize the spectral efficiency (SE). Most works on hybrid precoding focus on the single phase shifter (SPS) implementation to adapt the phase from RF chains to antennas. In this paper we propose to develop the double phase shifter (DPS) and the fixed phase shifter (FPS) in both single-path and multi-path configuration. Simulation results certify a significant improvement for both proposed implementations with high hardware efficiency (HE) and high spectral efficiency especially in multi-path environment.

scholarly journals Design and Development of Novel Hybrid Precoder for Millimeter-Wave MIMO System

2021 ◽  
Vol 13 (3) ◽  
Author(s):  
SRINIVAS K ◽  
T Srinivasulu
Keyword(s):  
Millimeter Wave ◽  
Spectral Efficiency ◽  
Large Scale ◽  
Processing Time ◽  
Mimo Systems ◽  
Mimo System ◽  
Phase Shifters ◽  
Additional Element ◽  
Factorization Problem ◽  
Hybrid Beamforming

Power consumption and hardware cost reduction with the use of hybrid beamforming in large-scale millimeter wave MIMO systems. The large dimensional analog precoding integrates with the hybrid beamforming based on the phase shifters including digital precoding with lower dimensionality. The reduction of Euclidean distance between the hybrid precoder and fully digital is the major problem to overcome the minimization of resultant spectral efficiency. The issue formulates as a fully digital precoder’s matrix factorization problem based on the analog RF precoder matrix and the digital baseband precoder matrix. An additional element-wise unit modulus constraint is imposed by the phase shifters on the analog RF precoder matrix. The traditional methods have a problem of performance loss in spectral efficiency. In the processing time and iteration, high complexities result in optimization algorithms. In this paper, a novel low complexity algorithm proposes which maximizes the spectral efficiency and reduces the computational processing time. 

scholarly journals Analog-type millimeter-wave phase shifters based on MEMS tunable high-impedance surface and dielectric rod waveguide

2011 ◽  
Vol 3 (5) ◽  
pp. 533-538 ◽  
Author(s):  
Dmitry Chicherin ◽  
Mikael Sterner ◽  
Dmitri Lioubtchenko ◽  
Joachim Oberhammer ◽  
Antti V. Räisänen
Keyword(s):  
Millimeter Wave ◽  
Phase Shifter ◽  
Phase Shifters ◽  
Impédance Surface ◽  
Impedance Surface ◽  
Wave Phase ◽  
High Impedance ◽  
Type Phase ◽  
W Band ◽  
High Impedance Surface

Millimeter-wave phase shifters are important components for a wide scope of applications. An analog-type phase shifter for W-band has been designed, analyzed, fabricated, and measured. The phase shifter consists of a reconfigurable high-impedance surface (HIS) controlled by micro-electromechanical system (MEMS) varactors and placed adjacent to a silicon dielectric rod waveguide. The analog-type phase shift in the range of 0–32° is observed at 75 GHz whereas applying bias voltage from 0 to 40 V to the MEMS varactors. The insertion loss of the MEMS tunable HIS is between 1.7 and 5 dB, depending on the frequency.

scholarly journals 2x4 Hybrid MZI-MMI Configuration with MMI Phase-shifters as a High-speed Optical Switch with Low Power Consumption

2019 ◽  
Author(s):  
Boris Niraula ◽  
Conrad Rizal
Keyword(s):  
Power Consumption ◽  
High Speed ◽  
Optical Switching ◽  
Phase Shifter ◽  
Optical Switch ◽  
Cmos Technology ◽  
Phase Shifters ◽  
Silicon On Insulator ◽  
Coupling Loss ◽  
Compact Size

This paper reports 2 × 4 hybrid Mach-zehnder interferometer (MZI) - multi-mode interferometers (MMI) based compact thermo-optical switch consisting of slab waveguides on silicon-on-insulator, SOI, platform. The device consists of two identical MMIs, each of 6 μm wide and 140 μm long connected with two phase shifters MMIs each with 2 μm wide and 8 μm long and linear tappers each 4 μm long, connected at both ends of the MMIs to minimize the power coupling loss. The loss for linear taper is found to be below 0.02dB. The footprint of the whole device is six 6 μm × 324 μm. This structure is based on unique multimode region shape, which leads optical switch to have less coupling loss and reduced cross-talk. The average thermo-optical switching power consumption is 1.4 mW, the excess losses are 0.8 dB, and the imbalances are 0.1 dB. Aluminum is used as a heating pad, and a trench is created around this pad to prevent from spreading of heat and reduce power loss almost by a factor of 2 to the adjacent phase shifter. Our new heating method has advantages of compact size and ease of fabrication with the current CMOS technology.

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