منابع مشابه
Asynchronous code-division random access using convex optimization
Many applications in cellular systems and sensor networks involve a random subset of a large number of users asynchronously reporting activity to a base station. This paper examines the problem of multiuser detection (MUD) in random access channels for such applications. Traditional orthogonal signaling ignores the random nature of user activity in this problem and limits the total number of us...
متن کاملCode Division Multiple Access
1 CDMA Concept 4 1.1 Basic Principles of Spread Spectrum . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1.1 Direct Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.1.2 Frequency Hopping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.1.3 Time Hopper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.1.4 Hybrid Systems . ....
متن کاملNovell Coding Technique for Code Division Multiple Access Communication system
An optical dynamic frequency hopping code division multiple access communication system is proposed. In this system, an electrically controlled tunable optical filter (TOF) is used to encode the modulated broadband light source. The code depends on the function set to the controller. The function defines the dynamic hopping pattern of the central wavelength of the transmitted narrowband optical...
متن کاملOn the Capacity of a Code Division Multiple Access System
We consider multiuser communication on a binary input additive white Gaussian noise channel using Randomly Spread-Code Division Multiple Access. We show concentration of various quantities of the system including the capacity and the free energy. We also obtain a tight upper bound on the capacity of this system in the large user limit which matches with the replica solution. The method is quite...
متن کاملFast frequency modulation optical code division multiple access communication system
An optical fast frequency modulation code division multiple access communication system is proposed. In this system, an electrically controlled tunable optical filter (TOF) is used to encode the modulated broadband light source. The code depends on the function set to the controller. Two-dimensional code named functional code is also proposed based on a shifted sine function. The function defin...
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ژورنال
عنوان ژورنال: Electronics and Control Systems
سال: 2009
ISSN: 1990-5548
DOI: 10.18372/1990-5548.20.681