A Study on Cross-Layer Interference of Layered Division Multiplexing

Recently, the next-generation DTTB (Digital Terrestrial Television Broadcasting) for UHDTV (Ultra-High Definition Television) broadcasting is being researched and developed in the world. In Japan, LDM-BST-OFDM (Layered Division Multiplexing Band Segmented Transmission Orthogonal Frequency Division Multiplexing) transmission scheme which combines LDM with BST-OFDM is proposed. LDM is effective to improve the band utilization if the several streams are transmitted in one channel and more flexible band utilization can be achieved by using LDM-BST-OFDM transmission scheme. However, cross-layer interference between the streams multiplexed by LDM is occurred. In this paper, cross-layer interference of LDM is analyzed theoretically and evaluated under AWGN (Additive White Gaussian Noise) by computer simulations. The results of simulations gave good agreement with the value that are obtained by theoretical calculation. In addition, optimized injection level that minimizes the degradation of required CNR by LDM can be obtained by using these theoretical calculations in this paper.