Application of Opportunistic Bit to Multilevel Codes

TL;DR

This paper introduces a novel signal organization method using opportunistic bits in multilevel coding, which enhances mutual information and performance over traditional schemes like BPSK and QPSK.

Contribution

It proposes a new signal organization with opportunistic bits in multilevel coding, improving energy efficiency and mutual information compared to conventional methods.

Findings

Higher mutual information than BPSK in one-dimensional case

Better performance over QPSK in two-complex-dimension extension

Numerical results confirm the effectiveness of the proposed method

Abstract

In this paper, we propose a new signal organization method to work in the structure of the multi level coding (MLC). The transmit bits are divided into opportunistic bit (OB) and conventional bit (CB), which are mapped to the lower level- and higher level signal in parallel to the MLC, respectively. Because the OB's mapping does not require signal power explicitly, the energy of the CB modulated symbol can be doubled. As the result, the overall mutual information of the proposed method is found higher than that of the conventional BPSK in one dimensional case. Moreover, the extension of the method to the two-complex-dimension shows the better performance over the QPSK. The numerical results confirm this approach.