A Signal Separation Method for Exceeding the Channel Capacity of BPSK Input

TL;DR

This paper introduces a novel signal separation method using double mapping modulation for parallel transmission, enabling the combined achievable bit rate to surpass the BPSK channel capacity.

Contribution

It proposes a new modulation technique that allows two signals to be transmitted in parallel and separated at the receiver, exceeding traditional channel capacity limits.

Findings

The method achieves higher ABRs than BPSK capacity.

Theoretical analysis confirms the capacity gain.

Simulation results validate the effectiveness of the approach.

Abstract

The field of the coded modulations witnessed its golden era as the simulated achievable bit rates (ABRs) were getting close to the channel capacities of the finite alphabet inputs. However, when working at a single channel, the previous researches are mostly restricted in scope of single input and single output. In contrast, for achieving higher spectral efficiency, the present authors propose a method that builds upon the parallel transmission of two signals that are separated at the receiver. The signal separation is enabled by, so called, the double mapping modulation working through Hamming- to Euclidean space. Consequently, the ABR summation of the two signals is found higher the channel capacity of BPSK input. Both the theoretical- and simulation result confirm this approach.