scholarly journals Link budget comparison of different mobile communication systems based on EIRP and EISL

2005 ◽  
Vol 2 ◽  
pp. 127-133 ◽  
Author(s):  
G. Fischer ◽  
F. Pivit ◽  
W. Wiebeck
Keyword(s):  
Mobile Communication ◽  
Communication Systems ◽  
Multiple Access ◽  
Mobile Communication Systems ◽  
Air Interface ◽  
Sensitivity Level ◽  
Link Budget ◽  
Code Division Multiple ◽  
Time Division ◽  
Effective Sensitivity

Abstract. The metric EISL (Equivalent Isotropic Sensitivity Level) describing the effective sensitivity level usable at the air interface of a mobile or a basestation is used to compare mobile communication systems either based on time division or code division multiple access in terms of coverage and emission characteristics. It turns out that systems that organize the multiple access by different codes rather than different timeslots run at less emission and offer greater coverage.

PROSPECTS FOR MOBILE COMMUNICATION SYSTEMS AND KEY TECHNOLOGIES CAPABLE OF SUPPORTING EXPANDING MOBILE MULTIMEDIA SERVICES

2004 ◽  
Vol 13 (02) ◽  
pp. 237-251
Author(s):  
MASAHIRO MINOMO ◽  
TATSURO MASAMURA
Keyword(s):  
Mobile Communication ◽  
Code Division Multiple Access ◽  
Communication Systems ◽  
Base Stations ◽  
Mobile Multimedia ◽  
Multimedia Services ◽  
Mobile Communication Systems ◽  
Research Activities ◽  
Air Interface ◽  
Code Division Multiple

The first commercial service of the 3rd generation (3G) mobile communication system, IMT-2000 (International Mobile Telecommunications), was launched in October 2001 in Japan. This is the first 3G service employing Wideband Code Division Multiple Access (W-CDMA) as its air interface between mobile terminals and base stations. This new system, 3G, is expected to accelerate the deployment of future mobile multimedia services, which substantially got started with the "i-mode" service in February 1999 in Japan. Research activities into future mobile communication systems capable of supporting a vastly expanded market for mobile multimedia services are underway worldwide. This paper describes the vision, service trends, and technical challenges of such future systems. Broadband packet wireless access, Variable Spreading Factor Orthogonal Frequency and Code Division Multiplexing (VSF-OFCDM), are promising candidates for realizing future mobile communication systems that provide higher transmission rates and capacity than 3G systems.

scholarly journals Large deviations for eigenvalues of sample covariance matrices, with applications to mobile communication systems

2008 ◽  
Vol 40 (04) ◽  
pp. 1048-1071
Author(s):  
Anne Fey ◽  
Remco van der Hofstad ◽  
Marten J. Klok
Keyword(s):  
Mobile Communication ◽  
Communication Systems ◽  
Large Deviation ◽  
Covariance Matrices ◽  
Mobile Communication Systems ◽  
Sample Covariance Matrices ◽  
Sample Covariance ◽  
Standard Normal ◽  
Rate Functions ◽  
Code Division Multiple

We study sample covariance matrices of the form W = (1 / n) C C T, where C is a k x n matrix with independent and identically distributed (i.i.d.) mean 0 entries. This is a generalization of the so-called Wishart matrices, where the entries of C are i.i.d. standard normal random variables. Such matrices arise in statistics as sample covariance matrices, and the high-dimensional case, when k is large, arises in the analysis of DNA experiments. We investigate the large deviation properties of the largest and smallest eigenvalues of W when either k is fixed and n → ∞ or k n → ∞ with k n = o(n / log log n), in the case where the squares of the i.i.d. entries have finite exponential moments. Previous results, proving almost sure limits of the eigenvalues, require only finite fourth moments. Our most explicit results for large k are for the case where the entries of C are ∓ 1 with equal probability. We relate the large deviation rate functions of the smallest and largest eigenvalues to the rate functions for i.i.d. standard normal entries of C . This case is of particular interest since it is related to the problem of decoding of a signal in a code-division multiple-access (CDMA) system arising in mobile communication systems. In this example, k is the number of users in the system and n is the length of the coding sequence of each of the users. Each user transmits at the same time and uses the same frequency; the codes are used to distinguish the signals of the separate users. The results imply large deviation bounds for the probability of a bit error due to the interference of the various users.

scholarly journals Large deviations for eigenvalues of sample covariance matrices, with applications to mobile communication systems

2008 ◽  
Vol 40 (4) ◽  
pp. 1048-1071 ◽  
Author(s):  
Anne Fey ◽  
Remco van der Hofstad ◽  
Marten J. Klok
Keyword(s):  
Mobile Communication ◽  
Communication Systems ◽  
Large Deviation ◽  
Covariance Matrices ◽  
Mobile Communication Systems ◽  
Sample Covariance Matrices ◽  
Sample Covariance ◽  
Standard Normal ◽  
Rate Functions ◽  
Code Division Multiple

We study sample covariance matrices of the form W = (1 / n)CCT, where C is a k x n matrix with independent and identically distributed (i.i.d.) mean 0 entries. This is a generalization of the so-called Wishart matrices, where the entries of C are i.i.d. standard normal random variables. Such matrices arise in statistics as sample covariance matrices, and the high-dimensional case, when k is large, arises in the analysis of DNA experiments. We investigate the large deviation properties of the largest and smallest eigenvalues of W when either k is fixed and n → ∞ or kn → ∞ with kn = o(n / log log n), in the case where the squares of the i.i.d. entries have finite exponential moments. Previous results, proving almost sure limits of the eigenvalues, require only finite fourth moments. Our most explicit results for large k are for the case where the entries of C are ∓ 1 with equal probability. We relate the large deviation rate functions of the smallest and largest eigenvalues to the rate functions for i.i.d. standard normal entries of C. This case is of particular interest since it is related to the problem of decoding of a signal in a code-division multiple-access (CDMA) system arising in mobile communication systems. In this example, k is the number of users in the system and n is the length of the coding sequence of each of the users. Each user transmits at the same time and uses the same frequency; the codes are used to distinguish the signals of the separate users. The results imply large deviation bounds for the probability of a bit error due to the interference of the various users.

Radio Channel Modeling and Propagation Prediction for 5G Mobile Communication Systems

2016 ◽  
pp. 1-30
Author(s):  
Charilaos Kourogiorgas ◽  
Nektarios Moraitis ◽  
Athanasios D. Panagopoulos
Keyword(s):  
Communication Networks ◽  
Millimeter Wave ◽  
Mobile Communication ◽  
Communication Systems ◽  
Cellular Systems ◽  
Next Generation ◽  
Mobile Communication Systems ◽  
Air Interface ◽  
Channel Effects ◽  
5G Mobile Communication

5G mobile communication networks are emerging in order to cover the extreme needs for high data rates for delivering multimedia data to mobile communication users. The required bandwidth may be found if millimeter wave bands are fully employed for the establishment of such cellular systems. In this Book Chapter the propagation issues for 5G mobile communication systems are rigorously analyzed and presented. Firstly, the most popular scenarios and architectures of the next generation mobile systems are described and the channel models utilized for the evaluation of physical layer techniques (air interface are given. Secondly, the channel effects are described, i.e. effects due to local environment of the transceivers, atmospheric effects and their combination and the state of the art on the modeling of these effects is analytically presented. Finally, future directions for the propagation and channel model prediction for the next generation mobile communication systems -5G millimeter wave cellular systems are analyzed. Open issues and technical challenges of millimeter wave (mmWave) 5G cellular systems are finally described.

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