China
Africa
Explore chapters and articles related to this topic
Introduction
Published in Wen Sun, Qubeijian Wang, Nan Zhao, Haibin Zhang, Chao Shen, Ultra-Dense Heterogeneous Networks, 2023
Wen Sun, Haibin Zhang, Nan Zhao, Chao Shen, Lawrence Wai-Choong Wong
Massive-MIMO is an extension of MIMO that groups antennas together at the transmitter and receiver for improved throughput and spectrum efficiency. In 5G, the 8-antennas MIMO system evolves toward the massive-MIMO system with 256−1024 antennas, which rapidly increase the capacity and spectral efficiency of the system. It is expected that the number of antennas deployed by the MIMO system will exceed 10,000 in 6G systems. A large number of antennas will bring the following advantages: (1) by applying spatial multiplexing technology to transmit hundreds of parallel data streams on the same channel, the system can significantly increase energy efficiency and reduce latency; (2) by utilizing hundreds of available beams, the system can simultaneously serve multiple UEs to significantly increase network throughput; (3) by forming ultra-narrow beams to overcome the propagation loss of mmWave and the terahertz wave, the system can greatly reduce inter-cell interference. Despite the promising advantages, complex algorithms are desired to find the exact location of UEs so as to apply accurate beamforming technology. Beam management and beam steering are key technologies to enable massive-MIMO to be applied in practical scenarios [7].
Key Parameters in 5G for Optimized Performance
Published in Mangesh M. Ghonge, Ramchandra Sharad Mangrulkar, Pradip M. Jawandhiya, Nitin Goje, Future Trends in 5G and 6G, 2021
Dhanashree A. Kulkarni, Anju V. Kulkarni
MIMO is a wireless technology that increases the capacity with multiple transmissions and multiple receptions. The data rate depends on the number of transmit and receive antennas. Many research papers have proposed the highest SE of 145.6 bits/s/Hz based on the channel state information, Shannon capacity calculations, and large number of antennas at the base station. The highest SE can be gained by required number of antennas and decrease the number of users before it reaches the peak value of SE. This is achieved by Error Vector Magnitude (EVM). In MIMO the SE also depends on the number of users decided in one time slot, but practically due to delay violation due to the transmission fluctuations. EC framework is adopted in [86] to determine the relationship between delay violation and transmission rate fluctuation.
Channel Estimation Techniques in the MIMO-OFDM System
Published in Mohammed Usman, Mohd Wajid, Mohd Dilshad Ansari, Enabling Technologies for Next Generation Wireless Communications, 2020
Asif Alam Joy, Mohammed Nasim Faruq, Mohammad Abdul Matin
Massive MIMO is the extension of MIMO, which essentially groups together a huge number of antennas at the transmitter and receiver to offer better throughput and higher spectral efficiency. Moreover, implementation of a massive number of antennas can improve the execution of wireless communication systems by enhancing the data rate (Foschini and Gans, 1998; Amihood et al., 2007), as these large numbers of antennas emphasize energy into ever smaller regions of space to achieve massive improvement in throughput. So, a massive MIMO system is a combination of a large number of transmit antennas at the transmitter in which multiple inputs are provided to the wireless channel and multiple receive antennas at the receiver in which multiple elements or multiple measurements are expected as the output of the wireless communication channel (Stuber et al., 2004; Pun, Koivunen, and Poor, 2010),. The block diagram of NxN massive MIMO is depicted in Figure 6.1.
Performance analysis of downlink massive MIMO system with precoding techniques and pilot reuse factor
Published in Cogent Engineering, 2023
Fikreselam Gared Mengistu, Gebey Admassu Worku
Massive multi-input multi-output (MIMO) is a form of wireless communication technology in which base stations are equipped with a very high number of antenna components in order to improve and boost network performance. Massive MIMO effectively enhances the communication system’s spectrum efficiency and channel capacity while concurrently increasing connection reliability and data transmission rate. Massive MIMO systems, however, experience a bottleneck because of the pilot contamination brought on by users exchanging non-orthogonal pilots. Pilot contamination is therefore a major problem in massive MIMO systems. The strong inter-cell interference caused by this issue consequently limits the performance of the system. In order to reduce the pilot contamination effect, various precoding techniques with a pilot reuse factor are used in this work.
Joint CFO and channel estimation using pilot aided interpolation for high performance MIMO-OFDM
Published in International Journal of Electronics, 2023
S. Chitra, S. Ramesh, Ramya Vijay, G. Jegan, T. Samraj Lawrence
The spectrum and data rate for 4 G and 5 G wireless standards are in high demand to enable for a wide range of applications. Since the wireless channel is impeded by fading and additive noise, transmission of huge amounts of data over such channel is a challenging. Multiple Input Multiple Output (MIMO) is a technology that employs multiple antennas at the transmitter and receiver to exploit multiple independent channels. It utilises the benefits of spatial multiplexing and spatial diversity to achieve high data rates and bandwidth efficiency by simultaneously transmitting data over multiple antennas. The basic principle of MIMO is space-time (SenthilKumar et al., 2020) or space-frequency signal processing which is exploited through the number of spatially distributed antennas at both transmitter and receiver. In comparison to single antenna systems, MIMO offers higher capacity and better service quality.
Neutralizing line based triple-band MIMO antenna with polarization diversity for WLAN/C/X band usage
Published in International Journal of Electronics, 2023
Puspendu Bikash Saha, Dibyendu Ghoshal, Rajib Kumar Dash, Sourav Roy
A low-cost triple-band MIMO antenna is designed with meander slot-loaded elliptical radiators showing wideband resonance with adequate gain and efficiency at WLAN, C and X bands. The MIMO can be used in various applications like WLAN, satellite, ATC, radar, vehicular communication, etc. Neutralising line-embedded ground plane improves all the MIMO parameters including port-isolation to deal with interference in the diversity environment. The proposed MIMO is also enabled with polarisation diversity at different operating bands. It exhibits linearly polarised, RHCP and LHCP radiation at WLAN, C and X bands, respectively. A comparative study of the proposed MIMO has been done with some of the existing works (Table 3). The simple structure with neutralising line-embedded ground avoids the use of complex isolators in-between the radiators, which makes the fabrication easy with compact size.