Scalable Video Coding-based MIMO Broadcasting System With Optimal Power Control

Abstract

This paper presents a scalable video coding (SVC)-based open-loop multi-input multioutput (MIMO) scheme for broadcast services such as LTE broadcast/evolved multimedia broadcast multicast service and terrestrial broadcast TV/ATSC 3.0. It intends to guarantee the minimum essential information (as a base layer) and obtain additional information for improving the video quality (as enhancement layers) when multiple transmit and receive antennas are employed. Two types of SVC-based open-loop MIMO broadcasting schemes are considered: 1) SVC-MIMO-time division multiplexing (TDM) and 2) SVC-MIMO-spatial multiplexing (SM). They provide differentiated video quality that depends on the average channel gain of individual users by employing different modulation and coding scheme (MCS) levels for unequal error protection of individual layers, i.e., a lower MCS level for the base layer and a higher MCS level for the enhancement layers. In particular, SVC-MIMO-SM extends the per-layer service coverage by performing a block-wise successive interference cancellation (SIC) from the base layer up to the highest enhancement layer in the receiver. As a result, the base layer can be decoded with the most robust MCS while the enhancement layers can be decoded with an SIC diversity gain. Furthermore, we formulate an optimal power allocation problem for the SVC-MIMO-SM scheme that can maximize the average system utility function while ensuring the target service coverage. Optimal solutions for different cases are derived by identifying the Karush-Kuhn-Tucker conditions for the given problem. Our numerical results demonstrate that the optimal power allocation provides more average system utility gain than SVC-MIMO-TDM and SVC-MIMO-SM without power control schemes, indicating the enhancement in the per-layer service coverage performance.