Capacity analysis of LDM-based DTV system with flexible MIMO configuration

摘要

Layered-Division-Multiplexing (LDM) is a physical-layer non-orthogonal multiplexing (NOM) technology that can efficiently deliver multiple digital TV services with different requirements on throughput and robustness. In literature, channel capacity analysis has been conducted to prove the fundamental advantage of LDM over T/FDM systems when delivering mixed services with different SNR thresholds. Previous analysis only considers wireless systems with single-antenna at both transmitters and receivers. Multiple-input-multiple-output (MIMO) technologies are the key technologies in modern wireless systems to achieve higher spectrum efficiency. As a multiple-layer transmission system, LDM offers an additional freedom to deploy different MIMO technologies in the different signal layers, which results in different channel capacity distribution among the multiple layers. In this paper, we conduct capacity analysis on the achievable transmission capacities in a two-layer LDM system with flexible MIMO configurations, and the capacity distribution among the multiple layers. The analysis will provide insights into the optimization of various MIMO configurations for different application scenarios. Finally, we show that different MIMO technologies can be flexibly incorporated in an LDM system with minimal additional complexity.