scholarly journals Low Cost and High Efficiency Hybrid Architecture Massive MIMO Systems Based on DFT Processing

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Weiqiang Tan ◽  
Guixian Xu ◽  
Elisabeth De Carvalho ◽  
Mu Zhou ◽  
Lisheng Fan ◽  
...  

Low cost and high efficiency, defined as energy efficiency (EE) and spectral efficiency (SE), have raised more and more attention in the fifth generation (5G) communication systems due to steadily rising hardware cost, energy consumption, and mobile traffic. This paper studies the hybrid architecture of multiuser massive MIMO systems, where the digital domain utilizes the zero-forcing (ZF) precoding scheme and the analog domain uses discrete Fourier transform (DFT) processing that significantly reduces hardware cost and energy consumption. We derive analytical expressions on the total achievable SE and EE, as well as offering insight into some engineering parameters in the system performance. Our aim is to achieve low cost and high efficiency massive MIMO system, with constraints on the overall transmit power, the number of users, and the number of radio frequency (RF) chains. Results exhibit that the total achievable SE of the hybrid architectures with DFT precessing is inferior to the full digital architectures and hybrid architectures with the ideal phase shifters, but the performance attenuation can be compensated by providing the more input SNR and higher number of RF chains. Moreover, we find that the total achievable EE of hybrid architectures with DFT precessing outperforms other massive MIMO architectures that include a full digital implementation, ideal phase shifters, and a switched network.

2021 ◽  
Vol 11 (09) ◽  
pp. 1696-1700
Author(s):  
Md. Mizanul Hoque ◽  
Md. Masud Karim ◽  
Md. Mustafa Kamal ◽  
Md. Kayesh ◽  
Sawkat Osman

Millimeter-wave (mmWave) communication is most likely to appear as a aspiring technology in the upcoming generation of cellular communication (5G). To confront several challenges (e.g., system complexity, energy consumption etc.), hybrid precoding is largely investigated in mmWave massive MIMO systems due to its low energy consuming nature and reduced system complexity.


Electronics ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 521 ◽  
Author(s):  
Naser Ojaroudi Parchin ◽  
Haleh Jahanbakhsh Basherlou ◽  
Mohammad Alibakhshikenari ◽  
Yasser Ojaroudi Parchin ◽  
Yasir I. A. Al-Yasir ◽  
...  

A design of mobile-phone antenna array with diamond-ring slot elements is proposed for fifth generation (5G) massive multiple-input/multiple-output (MIMO) systems. The configuration of the design consists of four double-fed diamond-ring slot antenna elements placed at different corners of the mobile-phone printed circuit board (PCB). A low-cost FR-4 dielectric with an overall dimension of 75 × 150 mm2 is used as the design substrate. The antenna elements are fed by 50-Ohm L-shaped microstrip-lines. Due to the orthogonal placement of microstrip feed lines, the diamond-ring slot elements can exhibit the polarization and radiation pattern diversity characteristic. A good impedance bandwidth (S11 ≤ −10 dB) of 3.2–4 GHz has been achieved for each antenna radiator. However, for S11 ≤ −6 dB, this value is 3–4.2 GHz. The proposed design provides the required radiation coverage of 5G smartphones. The performance of the proposed MIMO antenna design is examined using both simulation and experiment. High isolation, high efficiency and sufficient gain-level characteristics have been obtained for the proposed MIMO smartphone antenna. In addition, the calculated total active reflection coefficient (TARC) and envelope correlation coefficient (ECC) of the antenna elements are very low over the whole band of interest which verify the capability of the proposed multi-antenna systems for massive MIMO and diversity applications. Furthermore, the properties of the design in Data-mode/Talk-mode are investigated and presented.


Sensors ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 164 ◽  
Author(s):  
Zahra Mokhtari ◽  
Maryam Sabbaghian ◽  
Rui Dinis

Massive multiple input multiple output (MIMO) technology is one of the promising technologies for fifth generation (5G) cellular communications. In this technology, each cell has a base station (BS) with a large number of antennas, allowing the simultaneous use of the same resources (e.g., frequency and/or time slots) by multiple users of a cell. Therefore, massive MIMO systems can bring very high spectral and power efficiencies. However, this technology faces some important issues that need to be addressed. One of these issues is the performance degradation due to hardware impairments, since low-cost RF chains need to be employed. Another issue is the channel estimation and channel aging effects, especially in fast mobility environments. In this paper we will perform a comprehensive study on these two issues considering two of the most promising candidate waveforms for massive MIMO systems: Orthogonal frequency division multiplexing (OFDM) and single-carrier frequency domain processing (SC-FDP). The studies and the results show that hardware impairments and inaccurate channel knowledge can degrade the performance of massive MIMO systems extensively. However, using suitable low complex estimation and compensation techniques and also selecting a suitable waveform can reduce these effects.


2014 ◽  
Vol 563 ◽  
pp. 407-410
Author(s):  
Ching Tien Shih ◽  
Ching Hsiang Shih

In this paper we propose a novel Adjustable Integrating Pointing device Driver (AIPDD) using software technology to redesign mouse driver to integrate the functions of commercial pointing devices to help them to effectively utilize commercial pointing devices to operate computers. In contrast with the latest studies, the software-based AIPDD has the following benefits. (a) It does not require additional hardware cost and circuit preservation. (b) It supports all commercial pointing devices with standard interfaces of a computer, including PS/2, USB and wireless interfaces. (c) It can integrate unlimited devices simultaneously. (d) It is adjustable in real time. In summary, the AIPDD has the benefits of flexibility, low cost, high efficiency and high device compatibility. Keywords: Disabled, Computer pointing device, Mouse Integrate pointing device driver


2021 ◽  
Author(s):  
Cenk M. Yetis ◽  
Emil Björnson ◽  
Pontus Giselsson

<p>Cell-free massive MIMO systems consist of many distributed access points with simple components that jointly serve the users. In millimeter wave bands, only a limited set of predetermined beams can be supported. In a network that consolidates these technologies, downlink analog beam selection stands as a challenging task for the network sum-rate maximization. Low-cost digital filters can improve the network sum-rate further. In this work, we propose low-cost joint designs of analog beam selection and digital filters. The pro-posed joint designs achieve significantly higher sum-rates than the disjoint design benchmark. Supervised machine learning (ML) algorithms can efficiently approximate the input-output mapping functions of the beam selection decisions of the joint designs with low computational complexities. Since the training of ML algorithms is performed off-line, we pro-pose a well-constructed joint design that combines multiple initializations, iterations, and selection features, as well as beam conflict control, i.e., the same beam cannot be used for multiple users. The numerical results indicate that ML algorithms can retain 99-100% of the original sum-rate results achieved by the proposed well-constructed designs.</p>


IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 6650-6660 ◽  
Author(s):  
Seungsik Moon ◽  
In-Soo Kim ◽  
Dongyun Kam ◽  
Dong-Woo Jee ◽  
Junil Choi ◽  
...  

2021 ◽  
Vol 13 (1) ◽  
pp. 1-16
Author(s):  
Prosenjit Paul ◽  
Md Munjure Mowla

Beamspace channel estimation mechanism for massive MIMO (multiple input multiple output) antenna system presents a major process to compensate the 5G spectrum challenges caused by the proliferation of information from mobile devices. However, this estimation is required to ensure the perfect channel state information (CSI) for lower amount of Radio Frequency (RF) chains for each beam. In addition, phase shifter (PS) components used in this estimation need high power to select the beam in the desired direction. To overcome these limitations, in this work, we propose Regular Scanning Support Detection (RSSD) based channel estimation mechanism. Moreover, we utilise a 3D lens antenna array having metallic plate and a switch in our model which compensates the limitation of phase shifters. Simulation results show that the proposed RSSD based channel estimation surpasses traditional technique and SD based channel estimation even in lower SNR area which is highly desirable in the millimeter wave (mmWave) massive MIMO systems.


VLSI Design ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Muhammad Martuza ◽  
Khan A. Wahid

The paper presents a unified hybrid architecture to compute the 8×8 integer inverse discrete cosine transform (IDCT) of multiple modern video codecs—AVS, H.264/AVC, VC-1, and HEVC (under development). Based on the symmetric structure of the matrices and the similarity in matrix operation, we develop a generalized “decompose and share” algorithm to compute the 8×8 IDCT. The algorithm is later applied to four video standards. The hardware-share approach ensures the maximum circuit reuse during the computation. The architecture is designed with only adders and shifters to reduce the hardware cost significantly. The design is implemented on FPGA and later synthesized in CMOS 0.18 um technology. The results meet the requirements of advanced video coding applications.


IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 125225-125239
Author(s):  
Guoqiang Yao ◽  
Guiwu Yang ◽  
Jianhao Hu ◽  
Chao Fei

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