Verifying path loss and delay spread predictions of a 3D ray tracing propagation model in urban environment
ABSTRACT In this paper path loss and delay spread predictions of a 3D ray tracing software are compared to wideband radio channel measurements made in Helsinki city center. Measurements were carried out in the 2 GHz band by using a wideband radio channel sounder, which gives out complex channel impulse responses. Reference delay spreads were obtained from power delay profiles, and path losses were available after appropriate cable calibration measurements. Comparisons between measurement and propagation predictions were made in cases where a realistic directional BS antenna was placed (a) slightly below the rooftop level and (b) slightly above the rooftop level. For propagation modeling a fully 3D ray optical model was used.
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ABSTRACT: In this paper, we briefly report on our ongoing work to extend the GNU Radio software suite with a ray tracing based radio channel simulator. Radio channel simulation is an important aspect in the design and evaluation of wireless protocols because noise and inter-ference can have a crucial impact on the performance of a protocol. However, the calculation of radio wave propagation is computatio-nally demanding. Thus, most network simulation frameworks rely on simple statistical radio channel models that do not account for site-specific propagation characteristics. So, these simulators miss important details that might impact a protocol significantly in spe-cific propagation environment. Our radio channel simulator uses ray tracing techniques to over-come this limitation. It precomputes the channel characteristics of a given scene so that it can then efficiently simulate the corre-sponding links. Our implementation seamlessly interfaces with the GNU Radio software defined radio (SDR) framework, replacing its statistical channel simulation component. Furthermore, using GNU Radio's various modulation components, our simulator can provi-de a complete PHY layer simulation interface for other simulators such as ns-3 or OMNeT++. All in all, our simulator enables SDR developers and wireless protocol engineers to quickly assess their design in more realistic simulated environments.SIMUTools March. 01/2011; 2125.
Conference Proceeding: Assessment of urban-scale wireless networks with a small number of measurements.Proceedings of the 14th Annual International Conference on Mobile Computing and Networking, MOBICOM 2008, San Francisco, California, USA, September 14-19, 2008; 01/2008
Conference Proceeding: A Throughput Analysis at the MAC Layer of Mobile WiMAX.2010 IEEE Wireless Communications and Networking Conference, WCNC 2010, Proceedings, Sydney, Australia, 18-21 April 2010; 01/2010