Spatial Multiplexing Using Open-Loop Precoding in Maritime Communication Environment with Channel Correlation and LOS

In mobile communication systems bit-rate reductions while maintaining an acceptable voice quality are necessary to achieve efficiency in channel bandwidth utilization and users satisfaction. As Long-Term Evolution(LTE) converging towards all-IP solutions and supporting VOIP service, the voice signals are converted into coded digital bit-stream and sent over the network. This paper proposes the implementation of codebook excited linear prediction (CELP) voice codec algorithm based on two source-rates of low 9.6Kbps and medium 16Kbps for achieving a perceptible level of voice quality, while efficiently using available bandwidth during the transmission over advanced LTE. The architecture of proposed CELP codec model is implemented to decompose the voice signal into a set of parameters that characterize each particular frame at the encoder part, these parameters are quantized and encoded for transmission to the decoder. The investigation showed that the configuration of the link and the applied CELP codec mode mainly influence on the obtained voice capacity and quality. The quantifying also shows that the voice quality can be traded for the enhanced capacity, since the low rate codec will produce lower voice quality than higher rate codec. Also, this paper is achieved, during theconfiguration of the system with higher channel quality indicator (CQI) index, increasing in the capacity gain to a saturated value of about 500 and 1000 users per cell over 5MHz bandwidth for transmit diversity (TD) and Open-Loop Spatial Multiplexing (OLSM) respectively and up to 1000 and 2000 users per cell over 10MHz channel bandwidth for TD and OLSM respectively.

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Delay analysis and improvement of IEEE 802.11e-based Soft-Real-Time Wireless Industrial Networks: Using an open-loop Spatial Multiplexing scheme

2011 International Symposium on Computer Networks and Distributed Systems (CNDS) ◽

10.1109/cnds.2011.5764568 ◽

2011 ◽

Cited By ~ 5

Author(s):

Mohsen Maadani ◽

Seyed Ahmad Motamedi ◽

Mostafa Mohammadi Noshari

Keyword(s):

Real Time ◽

Open Loop ◽

Spatial Multiplexing ◽

Ieee 802.11E ◽

Delay Analysis ◽

Industrial Networks

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Achievable Capacity with Spatial Channel Correlation in Massive MIMO Multi-Cell Systems

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.b6375.029420 ◽

2020 ◽

Vol 9 (4) ◽

pp. 15-20

Keyword(s):

Large Scale ◽

High Capacity ◽

Antenna System ◽

Base Station ◽

Spatial Multiplexing ◽

Channel Correlation ◽

Mimo Antenna ◽

Linearly Independent ◽

Base Station Antennas ◽

The Impact

Massive Multi-Input and Multi-Output (MIMO) antenna system provides unlimited capacity by the spatial multiplexing and array gain. Since the data rate has been limited by the coherence interference due to pilot contamination (PC). In this paper, we propose transmit combine and precoding schemes to achieve asymptotic capacity in multi-cell scenario, when the number of base station antennas tends to infinity. The impact of spatial channel correlation on channel capacity is explored by considering the co-variance matrices of the user –terminals (UT)s .To do this, we presented linear processing schemes such as MMSE,MRC, and ZF.Where MMSE achieves high capacity in the presence of large-scale fading and PC. Since the diagonals of the channel covariance matrices were designed with non- zero Eigen values and linearly independent. The results outperform and obtain asymptotic limit, when the co-variance of UTs are linearly independent. The results were simulated by using MATLAB 2018b.

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A System View on Iterative MIMO Detection: Dynamic Sphere Detection versus Fixed Effort List Detection

VLSI Design ◽

10.1155/2012/826350 ◽

2012 ◽

Vol 2012 ◽

pp. 1-14 ◽

Cited By ~ 10

Author(s):

Christina Gimmler-Dumont ◽

Frank Kienle ◽

Bin Wu ◽

Guido Masera

Keyword(s):

Communication Systems ◽

Closed Loop ◽

Mimo Systems ◽

Open Loop ◽

Spatial Multiplexing ◽

Loop System ◽

Mimo Detection ◽

Closed Loop System ◽

Closed Loop Systems ◽

Sphere Detection

Multiple-antenna systems are a promising approach to increase the data rate of wireless communication systems. One efficient possibility is spatial multiplexing of the transmitted symbols over several antennas. Many different MIMO detector algorithms exist for this spatial multiplexing. The major difference between different MIMO detectors is the resulting communications performance and implementation complexity, respectively. Particularly closed-loop MIMO systems have attained a lot of attention in the last years. In a closed-loop system, reliability information is fed back from the channel decoder to the MIMO detector. In this paper, we derive a basic framework to compare different soft-input soft-output MIMO detectors in open- and closed-loop systems. Within this framework, we analyze a depth-first sphere detector and a breadth-first fixed effort detector for different application scenarios and their effects on area and energy efficiency on the whole system. We present all system components under open- and closed-loop system aspects and determine the overall implementation cost for changing an open-loop system in a closed-loop system.

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