LTE-Advanced coverage enhancements

Various technologies in LTE/LTE-Advanced have significantly improved the data throughput of 4G systems. However, the coverage of LTE networks, a very important performance metric to operators, receives relatively less attention. In this article we describe the motivations of LTE coverage enhancements from several aspects. Through link budget analysis, the limiting link and channels are identified. Then potential solutions to LTE coverage enhancements are discussed in a comprehensive manner, with the focus on schemes of specification impact. This article provides insights on how to design practical schemes to improve the coverage of LTE/ LTE-Advanced systems.