Extending LTE coverage for machine type communications

In 4G Long-Term Evolution (LTE), numerous features for supporting machine type communications have been introduced. For wide area deployment, ubiquitous coverage is an important requirement. In Rel-13 of LTE specifications, coverage enhancement feature is being introduced. This feature will significantly extend LTE cell coverage to provide services to machines that are installed indoors or in coverage holes. In addition, it can also be used to ensure coverage to low-cost devices with reduced capabilities. In this paper, we provide an overview of this feature including potential enhancement techniques, link and system performance analysis, and impact to battery life. Techniques for future enhancement are also discussed.