Information-Theoretic Analysis and Performance Evaluation of Optimal Demappers for Multi-Layer Broadcast Systems

Abstract

Multi-layer broadcast systems distribute services across time and frequency domain by means of power-division multiplexing. Successive interference cancellation is required, in general, in order to extract the content of all services. For a lowcomplexity implementation, the receiver can obtain the strongest (top-layer) signal assuming underlying signals to behave like thermal noise. The thermal noise assumption may not be valid under certain conditions and a more accurate characterization of the interference could bring improved performance. This paper analyzes the validity of the noise-like assumption considering the power ratio between signals and the required Carrier-to-Noise ratio (CNR) for error-free reception. The main contribution of the paper is the proposal of a demapping algorithm that exploits the knowledge of the constellation of underlying signals. Generalized Mutual Information, performance evaluation, and complexity analysis are provided with the AWGN-like assumptions and with the proposed alternative in order to assess the potential performance improvements that can be achieved.

Implementation of a 3-layer LDM Broadcast System Backward-compatible with ISDB-TB

“…Important concepts in the LDM context were also investigated, such as, the error propagation in the cancellation stage [25], more effective channel estimators [26][27][28][29][30], more efficient video encoding techniques [31][32][33], the comparison between LDM and the traditional time-division multiplexing (TDM) or frequency-division multiplexing (FDM) [34], the use of NUCs to improve LDM performance [35], the application of the technique in satellite broadcast system [36], performance analysis using optimized demappers [37] and the use of Multiple-Input Multiple-Output (MIMO) schemes [38].…”

Interference-Managed Local Service Insertion for 5G Broadcast

“…It studies the best reuse distance for cells that employ LDM. In cases where inter-layer interference becomes an issue, [18] suggests using an optimal detector that also models the EL signal in the decoder for the CL signal. Although such joint detectors work well compared to the traditional SIC, the complexity of the receiver is higher and is advised mainly for systems employing robust signals like QPSK.…”

A Novel Spectrally Efficient Local Service Insertion Scheme With Universal Frequency Reuse

“…Such a system, however, usually requires careful planning to minimize the CCI. We propose an interference management scheme for the LSA boundary region of a reuse-1based broadcast system without resorting to joint decoding algorithms such as the one studied in [18]. Instead, different power control algorithms similar to those presented in [20] are devised by us to reduce the CCI-dominated region.…”