scholarly journals An Investigation of Self-Interference Reduction Strategy in a Spatially Correlated MIMO Channel

2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
Rosdiadee Nordin
Keyword(s):  
Fading Channels ◽  
Multiple Input Multiple Output ◽  
Spatial Multiplexing ◽  
Mimo Channel ◽  
Limiting Factor ◽  
Subcarrier Allocation ◽  
Spatially Correlated ◽  
High Data ◽  
Correlated Channels ◽  
Wide Range

One of the efficient ways to transmit high data rate is by employing a multiple-input multiple-output (MIMO) transmission. One of the MIMO schemes, known as spatial multiplexing (SM), relies on the linear independence data streams from different transmit antennas to exploit the capacity from the fading channels. Consequently, SM suffers from the effect of spatial correlation which is the limiting factor in achieving the capacity benefit that SM can offer. In an attempt to increase the robustness of the SM transmission in a wide range of correlated channels, the use of dynamic subcarrier allocation (DSA) is investigated. The effective signal-to-interference-and-noise ratio (SINR) metric is used as the performance metric to determine the subcarrier quality which can then be utilised in the allocation. Two novel variants of the subcarrier allocation scheme are proposed. It is shown that the DSA-SINR approach improves the BER performance of SM transmission in highly correlated channels environment.

scholarly journals A Family of Hybrid Space-Time Codes for MIMO Wireless Communications

2012 ◽  
Vol 10 (2) ◽  
Author(s):  
M. Bazdresch ◽  
J. Cortez ◽  
O. Longoria-Gándara ◽  
R. Parra-Michel
Keyword(s):  
Low Complexity ◽  
Space Time ◽  
Spatial Multiplexing ◽  
Mimo Channel ◽  
Space Time Coding ◽  
Spatially Correlated ◽  
Correlated Channels ◽  
Space Time Codes ◽  
Receiver Architecture ◽  
High Spectral Efficiency

Hybrid MIMO space-time codes combine the benefits of spatial multiplexing with diversity gain to achieve both high spectral efficiency and link reliability. In this paper, we present a family of hybrid codes, known as LD STBC-VBLASTcodes, along with a receiver architecture suitable for low-complexity hardware implementation. We show that, under Rayleigh fading, the performance of LD STBC-VBLAST codes is superior to other recently proposed hybrid codes. We also present a technique to derive, from a given propagation scenario, spatially correlated MIMO channel models adequate for space-time coding performance analysis. Using this technique, we evaluate the performance of  LD STBC-VBLAST codes under several correlated channels

scholarly journals Massive MIMO channel estimation considering pilot contamination and spatially correlated channels

2020 ◽  
Vol 56 (8) ◽  
pp. 410-413
Author(s):  
F.A. Pereira de Figueiredo ◽  
D.A. Mendes Lemes ◽  
C. Ferreira Dias ◽  
G. Fraidenraich
Keyword(s):  
Channel Estimation ◽  
Massive Mimo ◽  
Mimo Channel ◽  
Pilot Contamination ◽  
Spatially Correlated ◽  
Correlated Channels ◽  
Spatially Correlated Channels

scholarly journals A Flexible FPGA-Based Channel Emulator for Non-Stationary MIMO Fading Channels

2020 ◽  
Vol 10 (12) ◽  
pp. 4161
Author(s):  
Qiuming Zhu ◽  
Wei Huang ◽  
Kai Mao ◽  
Weizhi Zhong ◽  
Boyu Hua ◽  
...  
Keyword(s):  
Fading Channels ◽  
Channel Model ◽  
Multiple Input Multiple Output ◽  
Mimo Channel ◽  
Channel Fading ◽  
Power Delay Profile ◽  
Channel Emulator ◽  
Field Programmable ◽  
Fpga Chip ◽  
Doppler Power

In this paper, a discrete non-stationary multiple-input multiple-output (MIMO) channel model suitable for the fixed-point realization on the field-programmable gate array (FPGA) hardware platform is proposed. On this basis, we develop a flexible hardware architecture with configurable channel parameters and implement it on a non-stationary MIMO channel emulator in a single FPGA chip. In addition, an improved non-stationary channel emulation method is employed to guarantee accurate channel fading and phase, and the schemes of other key modules are also illustrated and implemented in a single FPGA chip. Hardware tests demonstrate that the output statistical properties of proposed channel emulator, i.e., the probability density function (PDF), cross-correlation function (CCF), Doppler power spectrum density (DPSD), and the power delay profile (PDP) agree well with the corresponding theoretical ones.

On the Capacity of MIMO Channels with Outdated Channel State Information

2011 ◽  
Vol 204-210 ◽  
pp. 2053-2056
Author(s):  
Ying Li ◽  
Yi Jun Zhu ◽  
Lan Ma ◽  
Yao Zhu
Keyword(s):  
Fading Channels ◽  
Channel State Information ◽  
Multiple Input Multiple Output ◽  
Ergodic Capacity ◽  
Mimo Channel ◽  
Wide Sense ◽  
Mimo Channels ◽  
Channel State ◽  
State Information ◽  
Input Multiple Output

A Multiple-input multiple-output (MIMO) time-varying flat fading channel is considered. The transmitter obtained the channel state information (CSI) relying on the reciprocity principle or by the feedback from the receiver. Thus, channel state information at the transmitter (CSIT) is outdated due to the delay between the estimation of the channel and the transmission of the data. In order to achieve the maximum channel capacity, the transmitter linearly precoded the signal before transmission based on the outdated CSIT. Under the assumptions of wide-sense stationary uncorrelated scattering Rayleigh fading channels and Jake’s model, the instantaneous mutual information and ergodic capacity is derived for MIMO channels with outdated CSIT. The information outage probability of MIMO channel with outdated CSIT is also presented.

scholarly journals On the Probability of Erasure for MIMO-OFDM

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Kasturi Vasudevan ◽  
A. Phani Kumar Reddy ◽  
Gyanesh Kumar Pathak ◽  
Shivani Singh
Keyword(s):  
Fading Channels ◽  
Communication Systems ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Spatial Multiplexing ◽  
Main Requirement ◽  
Valid Signal ◽  
Input Multiple Output ◽  
Mimo Ofdm ◽  
Wireless Standards

Detecting the presence of a valid signal is an important task of a telecommunication receiver. When the receiver is unable to detect the presence of a valid signal, due to noise and fading, it is referred to as an erasure. This work deals with the probability of erasure computation for orthogonal frequency division multiplexed (OFDM) signals used by multiple input multiple output (MIMO) systems. The theoretical results are validated by computer simulations. OFDM is widely used in present day wireless communication systems due to its ability to mitigate intersymbol interference (ISI) caused by frequency selective fading channels. MIMO systems offer the advantage of spatial multiplexing, resulting in increased bit-rate, which is the main requirement of the recent wireless standards like 5G and beyond.

scholarly journals Conceiving Inferential Prototypes of MIMO Channel Models via Buckingham’s Similitude Principle for 30+ GHz through THz Spectrum

2021 ◽  
Vol 9 (3) ◽  
pp. 1-35
Author(s):  
Perambur Neelakanta ◽  
Dolores De Groff
Keyword(s):  
Multiple Input Multiple Output ◽  
Path Loss ◽  
Spatial Multiplexing ◽  
Mimo Channel ◽  
Channel Models ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Channel Statistics ◽  
Wave Range ◽  
Test Spectrum

Facilitating newer bands of ‘unused’ segments (windows) of RF spectrum falling in the mm-wave range (above 30+ GHz) and seeking usable stretches across unallocated THz spectrum, could viably be considered for Multiple Input Multiple Output (MIMO) communications. This could accommodate the growing needs of multigigabit 3G/4G applications in outdoor-based backhauls in picocellular networks and in indoor-specific multimedia networking. However, in contrast with cellular and Wi-Fi, wireless systems supporting sub-mm wavelength transreceive communications in the outdoor electromagnetic (EM) ambient could face “drastically different propagation geometry”; also, in indoor contexts, envisaging pertinent spatial-multiplexing with directional, MIMO links could pose grossly diverse propagation geometry across a number of multipaths; as such, channel-models based on stochastic features of diverse MIMO-specific links in the desired test spectrum of mm-wave/THz band are sparsely known and almost non-existent. To alleviate this niche, a method is proposed here to infer sub-mm band MIMO channel-models (termed as “prototypes”) by judiciously sharing “similarity” of details available already pertinent to traditional “models” of lower-side EM spectrum, (namely, VLF through micro-/mm-wave). Relevant method proposed here relies on the “principle of similitude” due to Edgar Buckingham. Exemplar set of “model-to-(inferential)-prototype” transformations are derived and prescribed for an exhaustive set of fading channel models as well as, towards estimating path-loss of various channel statistics in the high-end test spectrum.

scholarly journals Performance of WiMAX Physical layer MIMO-OFDM System under Rayleigh Fading Channel

2019 ◽  
Vol 9 (2S3) ◽  
pp. 269-273
Keyword(s):  
Rural Areas ◽  
Orthogonal Frequency Division Multiplexing ◽  
Low Cost ◽  
Multiple Input Multiple Output ◽  
Physical Layer ◽  
Spatial Multiplexing ◽  
System Level ◽  
High Data ◽  
Mimo Ofdm ◽  
Phy Layer

WiMAX infrastructure will meet the needs of multiple consumers at very low cost and without the time required to install a wired network, for those who need quick access to rural areas where cable systems cannot be feasible because of the distances and costs involved. Multi-Input (MIMO) technology in combination with orthogonal frequency-division multiplexing (MIMO-OFDM) is an appealing architecture for wireless systems of the next decade. This system level approach has been used in many WiMAX simulator developments, both public and private. In this paper we are investigating the performance of Wi- MAX PHY layer for PHY-layer modifications of 2×2 MIMO (multiple-input multiple-output), spatial multiplexing, to provide high throughput, bandwidth efficiency and low bit error rate at high data rates. The paper provides necessary description for the simulation process of WiMAX model, addresses the important elements for specific inaccuracies that are existed in the physical layer with the BER for various modulation schemes.

scholarly journals Massive MIMO Channel Estimation Considering Pilot Contamination and Spatially Correlated Channels

2019 ◽  
Author(s):  
Felipe Augusto Pereira de Figueiredo ◽  
Dimas A. M. Lemes ◽  
Claudio Ferreira Dias ◽  
Gustavo Fraidenraich
Keyword(s):  
Channel Estimation ◽  
Mean Square Error ◽  
Massive Mimo ◽  
Mimo Channel ◽  
Mean Square ◽  
Pilot Contamination ◽  
Spatially Correlated ◽  
Correlated Channels ◽  
Spatially Correlated Channels ◽  
The Impact

In this letter, we present a study on linear channel estimators and their respective mean square error (MSE) expressions acknowledging spatially correlated channels and pilot contamination. We also investigate the impact of imperfect channel covariance matrix knowledge.

Analysis and Simulation of Concatenating Orthogonal STBC with TCM in Fading Channels

2013 ◽  
Vol 427-429 ◽  
pp. 2752-2755
Author(s):  
Dong Ming Zhang ◽  
Yong Jun Li ◽  
Li Ding ◽  
Da Wei Zhang
Keyword(s):  
Fading Channels ◽  
Multiple Input Multiple Output ◽  
Block Code ◽  
Coded Modulation ◽  
Mimo Channel ◽  
Performance Simulation ◽  
Trellis Coded ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Better Than

In this paper, we illustrate an orthogonal space-time block code (OSTBC) concatenated with trellis-coded modulation (TCM) model, for information transmission over a multiple-input multiple-output (MIMO) channel with 2 transmit antennas and 1 receive antenna. We establish the model of TCM-OSTBC concatenation using the SIMULINK. Also, the establishment of an independent TCM model and OSTB model are shown in order to compare with the concatenation scheme. Finally, the performance simulation diagram under three schemes is given. As expected, the simulation result clearly shows, the performance of concatenated OSTBC with TCM is better than TCM or OSTBC.

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