EFFECTIVE CAPACITY EVALUATION MODEL FOR COGNITIVE RADIO NETWORKS USING OFDM
Journal Title: Вісник Національного університету "Львівська політехніка", серія "Радіоелектроніка та телекомунікації" - Year 2014, Vol 796, Issue 2014
Abstract
In this paper considered the cognitive radio (CR) networks with the GSM network like primary network cooperation possibility. The cognitive radio system meant radio with a selfmanagement mechanism with different levels of ability to adapt to the changing radio environment. The self-management mechanism is based on the principles of learning and artificial intelligence. In world practice, the frequency assigned to a particular entity in a certain area on a long term basis. However, most commonly frequency for this designated area not always used, and as necessary. In other words, many frequency bands are irregularly loaded in the space and time domains. Because of the shortage of frequency resources are limited to the cellular network to the data rate. The data rate of modern communication systems is also increasing due to the use high-level types of signal modulation, requiring more signal/noise ratio at the receiver input. Existing GSM network is almost completely satisfy the needs of users for voice services, but the data rate cannot compete with cellular networks based on UMTS and LTE technologies. Here proposed high speed data transmitting method in GSM based on the principles of cognitive radio. On the existing GSM network topology (primary/licensed network) complementary superimposed secondary/unlicensed network operating in the same frequency bands. CR system must have ability to measure, sense, learn, and be aware of important operating conditions. It should be able to find and exploit the unused parts of the spectrum at the fastest and efficient way. The popular spectrum sensing algorithms such as matched filtering, energy detection, spectral correlation (cyclostationarity), radio identification based105 sensing, waveform based sensing can provide awareness of CR system. Moreover, cooperation spectrum sensing can reduce the detection time and increase the agility, but also facilitate the problem of hidden terminal, shadowing or severe multipath fading. Here proposed to use OFDM for the CR system and discussed OFDM’s advantages to allow better sensing and spectrum shaping capabilities, considered OFDM-symbol formation method in CR system and determined the data structure organization. The mathematical simulation model of CR network with one primary system and one secondary cell created for accurate capacity evaluation of selected system. Model simulates GSM primary users’ activity and CR network operation scheme that taking into account the radio environment conditions, CR users location and their quality requirement for different type of services.
Authors and Affiliations
Maryan Kyryk, Volodymyr Yanyshyn, Ihor Strykhaliuk
STAGES OF THE MODERN IT SERVICES DEVELOPMENT AND ENERGY EFFECTIVENESS OF NETWORK TECHNOLOGIES
The article reviews the architectural transformation of modern networks and their (mobile) services and applications. Periods of network services, Internet and cloud computing are posted. We describe the requirements for...
SURFACE PLASMON-POLARITONS NANOSCALE WAVEGUIDES OBTAINED BY OPTICAL PHOTOLITHOGRAPHY
The paper presents a method of phased optical lithography using as source, lightemitting diodes (LED) with wavelengths of 410 nm and 365 nm to form inhomogeneous dielectric waveguides. Distribution of surface plasmon pol...
MODERNIZATION OF FLUX-GATE MAGNETOMETER
Various types of magnetic field sensors, their advantages and disadvantages are considered. Classic flux-gate magnetometer, the block diagram of which is driven, contains dualcore sensor with counter switching of primary...
POWER SPECTRAL DENSITY EVALUATION BASED ON WELCH’S PERIODOGRAM FOR COGNITIVE RADIO
In this paper considered spectrum sensing methods for cognitive radio that based on energy detection. The periodogram method is a DFT based method to estimate power spectral density (PSD). The name of the periodogram com...
VERTICAL HANDOVER ACCESS SELECTION IN MOBILE SDR SYSTEM
In order to satisfy emerging user requirements in advanced services/applications, provided seamlessly, operators have to deploy complex network topologies of heterogeneous nature, where different Radio Access Technologie...