Abstract
In the Long Term Evolution (LTE) of UMTS the Interactive Mobile TV scenario is expected to be a popular service. By using multiresolution with hierarchical modulations this service is expected to be broadcasted to larger groups achieving significant reduction in power transmission or increasing the average throughput. Interactivity in the uplink direction will not be affected by multiresolution in the downlink channels, since it will be supported by dedicated uplink channels. The presence of interactivity will allow for a certain amount of link quality feedback for groups or individuals. As a result, an optimization of the achieved throughput will be possible. In this paper system level simulations of multi-cellular networks considering broadcast/multicast transmissions using the OFDM/OFDMA based LTE technology are presented to evaluate the capacity, in terms of number of TV channels with given bit rates or total spectral efficiency and coverage. Multiresolution with hierarchical modulations is presented to evaluate the achievable throughput gain compared to single resolution systems of Multimedia Broadcast/Multicast Service (MBMS) standardised in Release 6.
Highlights
Orthogonal frequency division multiplexing/orthogonal frequency division multiple access OFDM/OFDMA [2], used in the physical layer of Long Term Evolution (LTE), is an attractive choice to meet requirements for high data rates, with correspondingly large transmission bandwidths and flexible spectrum allocation
The system level simulator is needed to model a system with a large number of mobiles and base stations, and algorithms operating in such a system
The information obtained from the link level simulator is inserted in the system level simulator through the utilization of a specific performance parameter (BLER) corresponding to a determined signal to interference plus noise ratio (SNR) estimated in the terminal or base station
Summary
Orthogonal frequency division multiplexing/orthogonal frequency division multiple access OFDM/OFDMA [2], used in the physical layer (downlink connection) of LTE, is an attractive choice to meet requirements for high data rates, with correspondingly large transmission bandwidths and flexible spectrum allocation. A design parameter that determines the constellation layout allows the control of the amount of distortion that the enhancements symbols add to the baseline constellation, and can be used to control the ratio of coverage areas or service data rates Theoretical evaluation of this type of modulations where it is explicitly shown the dependence of the individual bit streams performance on the constellation design parameter has been previously presented. In OFDMA based networks, the transmission of different fractions of the total set of sub-carriers (chunks) depending on the position of the mobiles is another way to offer multiresolution Any of these methods is able to provide unequal bit error protection.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: EURASIP Journal on Wireless Communications and Networking
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
