A multiple‐input, multiple‐output broadcasting system with space, time, polarization, and labeling diversity

Abstract

Enhancing the reliability of wireless links plays an important role in addressing the digital divide between under-developed and developed nations. Diversity techniques are used in wireless communication to improve link reliability. This article presents a broadcasting system that incorporates space, time, polarization and labeling diversity. The key challenge in incorporating labeling diversity into a system is the design of appropriate bit-to-symbol mappers. The latest technique to designing bit-to-symbol mappers is to use a genetic algorithm approach, which is applicable to any generic modulation scheme. This article presents a modified genetic algorithm mapper design algorithm based on recent advances in labeling diversity evaluation theory. The proposed system is studied under ideal (uncorrelated) conditions, as well as in the presence of inter-beam and inter-antenna inference (correlated conditions). Analytical expressions are presented to model both the correlated and uncorrelated systems, and are verified via Monte Carlo simulations. When compared to the best comparable scheme at a bit-error-rate of 10 −6 , results show that the proposed system improves performance by ≈7 dB for a 2 × 2 16APSK system configuration, and by ≈5 dB for both 2 × 4 32APSK and 2 × 2 64APSK system configurations.Results also show that the proposed system is highly sensitive to correlation at the transmitting node. In particular, transmit-side correlation degrades link reliability by 4 orders of magnitude for the 2 × 3 8APSK configuration studied at 25 dB.