Improving LTE eMBMS With Extended OFDM Parameters and Layered-Division-Multiplexing.

The evolved multimedia broadcast multicast service (eMBMS) system was developed to achieve higher spectrum efficiency on video traffic delivery over the long term evolution (LTE) networks. As an integrated component of the LTE, eMBMS can be deployed with great flexibility using the existing LTE infrastructure. However, the current eMBMS was designed as a supplementary subsystem, and has limited capability to deliver high-quality broadcast-type video services in a spectrum efficient manner. This paper first studies the capability and limitations of the current LTE eMBMS system to deliver broadcast services when deployed as single-frequency-network (SFN). Next, potential physical-layer enhancements are investigated for future eMBMS systems to achieve enhanced broadcast service delivery capability, higher spectrum efficiency, improved service quality, and more efficient SFN deployment options. These include wideband transmission, non-orthogonal multiplexing, e.g., layered-division-multiplexing technology, and more flexible orthogonal frequency division multiplexing system configurations, such as longer cyclic prefix and smaller subcarrier spacing. Other technologies defined in the latest next generation digital television system are also discussed that might be applicable to the development of a more capable standalone future eMBMS system.