Chapter 20
The Radio Propagation Environment
20.1 Introduction
Realistic modelling of propagation characteristics is essential for two main reasons in relation to the LTE system. Firstly, the link- and system-level performance of LTE can be evaluated accurately only when the radio channel models are realistic. In particular, the spatial characteristics of the channel models have a significant effect on the performance of multi-antenna systems. Secondly, the model used for radio propagation plays an important role in the network planning phase of LTE deployment.
Different environments such as rural, suburban, urban, and indoor set different requirements for network planning, antenna configuration, and the preferred spatial transmission mode. Moreover, the actual deployment scenarios for LTE cover numerous special cases ranging from mountainous rural surroundings to dense urban and outdoor-to-indoor situations. As an example of the range of different propagation environments of relevance to high-bandwidth Multiple-Input Multiple-Output (MIMO) systems such as LTE, the IST-WINNER1 project [1] developed wideband radio channel models for 12 propagation environments.
The propagation characteristics are in a large part affected by the carrier frequency. In November 2007 the International Telecommunication Union (ITU) World Radiocommuni- cation Conference (WRC-2007) allocated new frequency bands for International Mobile Telecommunications (IMT) radio access ...