The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
As the mobile radio communication needs of uniformed and emergency services soared, two way land mobile radio communication systems are evolved from analog to digital. Although digital radios have better communication range, noise performance and provide superior voice quality in most cases compared to analog counterparts, they have hard time to maintain good voice quality in particular conditions...
Diversity techniques for communications among sensors are very effective tool to increase reception quality and battery lifetimes. A well-known method to increase diversity in cooperative communications is sensor (relay) selection. However, sensor selection method may lead to the selection of the same (near) sensor for transmission over a long period. One of the alternative techniques to sensor selection...
In this paper, we propose an equalization algorithm which greatly reduces the convergence problems and the steady-state error rate of the conventional constant modulus algorithm (CMA). The algorithm introduces a buffer and multiple step-size decision layers to the existing variable step size modified constant modulus algorithm (VSS-MCMA). The buffer is employed to combat the convergence issue while...
To incorporate cooperative diversity, Cooperative Extended Balanced Space-Time Block Codes (CEBSTBCs) have been proposed in the literature, providing full rate and full diversity when one or more feedback bits are sent back via feedback channel. Due to construction technique of the CEBSTBC, a relay out of N relays does not contribute the coding gain. To prevent this, the CEBSTBC with relay selection...
Extended balanced space-time block coding (EBSTBC) is able to achieve large coding gain and guarantee full diversity for any number of transmit antennas. Performance of the EBSTBC has been enhanced with improved transmit scheme (ITS) which is combination of the EBSTBC with transmit antenna selection. Performance of the ITS with a limited number of feedback bits approaches to performance of ideal beamforming...
In cognitive radio communication technique, unlicensed users monitor the existence and availability of licensed (primary) user´s spectrum and attempt to exploit it when the primary users don't use their spectrum. In this technique, an effective spectrum sensing is very crucial for not to disturb primary user. One of the most effective spectrum sensing approaches is pilot tone detection. In many licensed...
Multicasting is a spectrally efficient method for supporting multimedia communication by allowing transmission of packets to multiple destinations using fewer resources. To incorporate cooperative (distributed MIMO) diversity, Cooperative Extended Balanced Space-Time Block Codes (CEBSTBCs) have been proposed providing full diversity when one or more feedback bits are sent back via feedback channel...
To incorporate Multi-Input Multi-Output diversity, Extended Balanced Space-Time Block Codes (EBSTBCs) have been proposed in the literature, providing full diversity when one or more feedback bits are sent back via feedback channel. However, the EBSTBCs are designed for unicast communication. Multicasting is a spectrally efficient method for supporting group communication by allowing transmission of...
Cognitive radio is a radio communication technique, where unlicensed or cognitive users monitor the spectrum for the existence of licensed (primary) users and have a communication capability when the primary users don't transmit their data. This technique needs an effective spectrum sensing because of the not disturbing the primary users. In lots of licensed digital cellular communication system pilot...
Relay selection (RS) is the one of the proposed methods in the literature to utilize cooperative diversity. When the source-relay channel information is not available at the destination, the RS technique does not exploit user diversity efficiently. The proposed solution of this problem in the literature is that the relays monitor all channels "end-to-end" and the mobile unit with the highest...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.