Sum-Rate Channel Capacity for Line-of-Sight Models

This work considers a base station equipped with an M-antenna uniform linear array and L users under line-of-sight conditions. As a result, one can derive an exact series expansion necessary to calculate the mean sum-rate channel capacity. This scenario leads to a mathematical problem where the joint probability density function (JPDF) of the eigenvalues of a Vandermonde matrix WWH are necessary, where W is the channel matrix. However, differently from the channel Rayleigh distributed, this joint PDF is not known in the literature. To circumvent this problem, we employ Taylor’s series expansion and present a result where the moments of mn are computed. To calculate this quantity, we resort to the integer partition theory and present an exact expression for mn. Furthermore, we also find an upper bound for the mean sum-rate capacity through Jensen’s inequality. All the results were validated by Monte Carlo numerical simulation.

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Capacity Limits of Base Station Cooperation in Cellular Networks

Cooperative Communications for Improved Wireless Network Transmission ◽

10.4018/978-1-60566-665-5.ch004 ◽

2010 ◽

pp. 102-132

Author(s):

Symeon Chatzinotas ◽

Muhammad Ali Imran ◽

Reza Hoshyar

Keyword(s):

Channel Model ◽

High Capacity ◽

Path Loss ◽

Base Station ◽

Cellular Systems ◽

Current Channel ◽

Capacity Limits ◽

Base Station Cooperation ◽

Rate Capacity ◽

Sum Rate

In the information-theoretic literature, it has been widely shown that multicell processing is able to provide high capacity gains in the context of cellular systems. What is more, it has been proved that the per-cell sum-rate capacity of multicell processing systems grows linearly with the number of base station (BS) receive antennas. However, the majority of results in this area have been produced assuming that the fading coefficients of the MIMO subchannels are completely uncorrelated. In this direction, this chapter investigates the ergodic per-cell sum-rate capacity of the Gaussian MIMO cellular channel under correlated fading and BS cooperation (multicell processing). More specifically, the current channel model considers Rayleigh fading, uniformly distributed user terminals (UTs) over a planar cellular system, and power-law path loss. Furthermore, both BSs and UTs are equipped with correlated multiple antennas, which are modelled according to the Kronecker product correlation model. The per-cell sum-rate capacity is evaluated while varying the cell density of the system, as well as the level of receive and transmit correlation. In this context, it is shown that the capacity performance is compromised by correlation at the BS-side, whereas correlation at the UT-side has a negligible effect on the system’s capacity.

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Investigation into the Impact of Mutual Coupling on the Performance of a Multiuser MIMO System Employing Generalized Channel Inversion Technique

International Journal of Antennas and Propagation ◽

10.1155/2011/965251 ◽

2011 ◽

Vol 2011 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Feng Wang ◽

Konstanty Bialkowski ◽

Marek E. Bialkowski

Keyword(s):

Mutual Coupling ◽

Mimo System ◽

Mobile User ◽

Base Station ◽

Multiuser Mimo ◽

Simulation Experiments ◽

Rate Capacity ◽

Sum Rate ◽

The Impact ◽

System Operating

In this paper, the performance of generalized channel inversion (GCI) technique for a multiuser MIMO system operating under antenna mutual coupling conditions is investigated. The investigation is performed via theoretical derivations and computer simulations. The theoretical derivations show that the presence of mutual coupling may result in an increased performance in terms of sum rate capacity. The simulation experiments confirm the theoretical findings in examples of three groups of numerical results. These results show that the existence of mutual coupling in an array antenna at base station (BS) results in an increased sum rate capacity when antenna interelement spacing at BS is smaller than 0.55 λ. Also it is shown that the presence of mutual coupling at mobile user (MS) terminals results in an increased sum rate capacity when antenna inter-element spacing at MSs is smaller than 0.4 λ. When mutual coupling is considered at both BS and MSs, the system configuration with antenna inter-element spacing equal to 0.45 λat BS and 0.4 λat MSs leads to the highest sum rate capacity.

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Sum-Rate Capacity for Symmetric Gaussian Multiple Access Channels With Feedback

IEEE Transactions on Information Theory ◽

10.1109/tit.2019.2957808 ◽

2020 ◽

Vol 66 (5) ◽

pp. 2860-2871

Author(s):

Erixhen Sula ◽

Michael Gastpar ◽

Gerhard Kramer

Keyword(s):

Multiple Access ◽

Multiple Access Channels ◽

Rate Capacity ◽

Sum Rate

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An Efficient IR-HARQ Power Allocation for Relay-Aided Cellular Networks

Journal of Circuits System and Computers ◽

10.1142/s0218126618501955 ◽

2018 ◽

Vol 27 (12) ◽

pp. 1850195

Author(s):

P. Mangayarkarasi ◽

J. Raja

Keyword(s):

Power Allocation ◽

Cellular Networks ◽

Channel Capacity ◽

Energy Efficient ◽

Base Station ◽

Relay Station ◽

Decode And Forward ◽

Relay Placement ◽

Cell Coverage ◽

The Impact

Energy-efficient and reliable data transmission is a challenging task in wireless relay networks (WRNs). Energy efficiency in cellular networks has received significant attention because of the present need for reduced energy consumption, thereby maintaining the profitability of networks, which in turn makes these networks “greener”. The urban cell topography needs more energy to cover the total area of the cell. The base station does not cover the entire area in a given topography and adding more number of base stations is a cost prohibitive one. Energy-efficient relay placement model which calculates the maximum cell coverage is proposed in this work that covers all sectors and also an energy-efficient incremental redundancy-hybrid automatic repeat request (IR-HARQ) power allocation scheme to improve the reliability of the network by improving the overall network throughput is proposed. An IR-HARQ power allocation method maximizes the average incremental mutual information at each round, and its throughput quickly converges to the ergodic channel capacity as the number of retransmissions increases. Simulation results show that the proposed IR-HARQ power allocation achieves full channel capacity with average transmission delay and maintains good throughput under less power consumption. Also the impact of relaying performance on node distances between relay station and base station as well as between user and relay station and relay height for line of sight conditions are analyzed using full decode and forward (FDF) and partial decode and forward (PDF) relaying schemes. Compared to FDF scheme, PDF scheme provides better performance and allows more freedom in the relay placement for an increase in cell coverage.

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Investigation of DNA denaturation from generalized Morse potential

OAJ Materials and Devices ◽

10.23647/ca.md20180207 ◽

2018 ◽

Vol 3 (2) ◽

Author(s):

R. El Kinani ◽

H. Kaidi ◽

M. Benhamou

Keyword(s):

Morse Potential ◽

Bound States ◽

Analytical Study ◽

Free Energy Density ◽

Exact Expression ◽

Dna Denaturation ◽

Denaturation Temperature ◽

Finite Distance ◽

The Mean ◽

Generalized Morse Potential

In this paper, we present a non-linear model for the study of DNA denaturation transition. To this end, we assume that the double-strands DNA interact via a realistic generalized Morse potential that reproduces well the features of the real interaction. Using the Transfer Matrix Method, based on the resolution of a Schrödinger equation, we first determine exactly their solution, which are found to be bound states. Second, from an exact expression of the ground state, we compute the denaturation temperature and the free energy density, in terms of the parameters of the potential.Then, we calculate the contact probability, which is the probability to find the double-strands at a (finite) distance apart, from which we determine the behaviour of the mean-distance between DNA-strands.The main conclusion is that, the present analytical study reveals that the generalized Morse potential is a good candidate for the study of DNA denaturation

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Doppler Shift of Radio Signals Transmitted between Orbiting Satellites

Australian Journal of Physics ◽

10.1071/ph820155 ◽

1982 ◽

Vol 35 (2) ◽

pp. 155 ◽

Cited By ~ 1

Author(s):

PL Dyson ◽

JA Bennett

Keyword(s):

Electron Concentration ◽

Doppler Shift ◽

Rate Of Change ◽

Line Of Sight ◽

Concentration Gradients ◽

Mean Velocity ◽

Radio Signals ◽

The Mean ◽

The Moment ◽

The Individual

A general expression, applicable at VHF and above, is derived for the Doppler shift of radio signals transmitted between two satellites embedded in the ionosphere. The Doppler shift is made up of several contributions which depend on (a) the rate of change of the free space path between the satellites, (b) the components, perpendicular to the line of sight between the satellites, of both the mean velocity of the satellites and the electron concentration gradients, (c) the moment of the perpendicular electron concentration gradients and the deviations from the mean of the individual satellite perpendicular velocities, (d) the velocity components along the line of sight between the satellites, and the electron concentration values at each satellite, and (e) changes occurring in the ionosphere with time.

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About estimation of base station output power in GSM like systems under real conditions

Yugoslav journal of operations research ◽

10.2298/yjor190415017l ◽

2020 ◽

Vol 30 (1) ◽

pp. 109-119

Author(s):

Aleksandar Lebl ◽

Dragan Mitic ◽

Zarko Markov ◽

Verica Vasiljevic

Keyword(s):

Computer Simulation ◽

Output Power ◽

Mobile User ◽

Base Station ◽

Cumulative Distribution ◽

Real Case ◽

The Real ◽

The Mean

The output power of traffic channels in one cell of GSM like systems is estimated in this paper. We consider the real case: the number of users is much higher than the number of channels, the output power of one channel depends on the cube of the distance between a mobile user and the base station, and the distribution of users in the cell is uniform. We derive the expressions for cumulative distribution of output power of one channel and for the mean output power of the whole base station. Results of the calculation are confirmed by computer simulation.

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