A New MIMO Technique Utilizing Superimposed Auxiliary Signals for Simultaneously Achieving Spatial Multiplexing and Diversity Gains in MIMO-Aided Communication Systems

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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LARGE-SCALE MIMO MC-CDMA SYSTEM USING COMBINED MULTIPLE BEAMFORMING AND SPATIAL MULTIPLEXING

Vietnam Journal of Science and Technology ◽

10.15625/2525-2518/56/1/9204 ◽

2018 ◽

Vol 56 (1) ◽

pp. 102 ◽

Cited By ~ 2

Author(s):

Nguyen Huu Trung ◽

Doan Thanh Binh

Keyword(s):

System Performance ◽

Code Division Multiple Access ◽

Communication Systems ◽

Multiple Access ◽

Large Scale ◽

Spatial Multiplexing ◽

Propagation Loss ◽

Fifth Generation ◽

Simulation Results ◽

Code Division Multiple

This paper proposes a novel Large-scale (massive) Multi-input Multi-output Multi-carrier Code division multiple access (LS MIMO MC-CDMA) model and application to Fifth-Generation Mobile Communication Systems (5G). This system uses combined cylindrical array antenna multiple beamforming architecture with spatial multiplexing. The model is optimized by Min-Max criteria in order to minimize side lobes and maximize compression of propagation loss. The Monte Carlo simulation results unify with the analytical solution for system performance.

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APPLICATION OF MIMO TECHNOLOGY IN MODERN WIRELESS COMMUNICATION SYSTEMS OF DIFFERENT GENERATIONS

T-Comm ◽

10.36724/2072-8735-2021-15-4-4-12 ◽

2021 ◽

Vol 15 (4) ◽

pp. 4-12

Author(s):

Mikhail G. Bakulin ◽

◽

Vitaly B. Kreyndelin ◽

Denis Y. Pankratov ◽

◽

...

Keyword(s):

Wireless Communication ◽

Communication Systems ◽

Technology Development ◽

Multiple Input Multiple Output ◽

Spatial Multiplexing ◽

Wireless Communication Systems ◽

Radio Communication ◽

Radio Access ◽

Radio Frequency Spectrum ◽

Mimo Technology

Multiple Input Multiple Output (MIMO) technology is widely used in modern IEEE radio access systems. There is a tendency to increase the number of antennas, which is also confirmed by the development of MIMO technology in mobile communication systems of 3GPP standards. Requirements for modern radio communication systems are constantly increasing. As the radio frequency spectrum becomes increasingly scarce, it becomes increasingly difficult to transmit large amounts of information by expanding the frequency channel bandwidth. Therefore, the use of MIMO technology to increase the spectral and energy efficiency of communication systems is relevant. In 5G systems, Massive MIMO technology is used, when using which the number of antennas is measured in tens and hundreds. The characteristics of various versions of MIMO technology implemented in the existing standards 802.11n, 802.11ac, 802.11ax, as well as in the promising standard 802.11be (6G systems) are described in detail. Technologies of directional transmission, spatial multiplexing, selection of antennas as particular cases of precoding are considered. Trends of MIMO technology development in wireless communication systems are shown.

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On the Probability of Erasure for MIMO-OFDM

Semiconductor Science and Information Devices ◽

10.30564/ssid.v2i1.1689 ◽

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.

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