Digital Emulation of Oscillator Ising Machines

Ising problem is an NP-hard combinatorial optimization problem. Recently, networks of mutually coupled, nonlinear, self-sustaining oscillators known as Oscillator Ising Machines (OIMs) were shown to heuristically solve Ising problems. The phases of the oscillators in OIMs can be modeled as systems of Ordinary Differential Equations (ODEs) known as Generalized Kuramoto (Gen-K) models. In this paper, we solve Gen-K ODE systems efficiently using cleverly designed fixed point operations. To demonstrate this idea, we fabricated a prototype chip containing 33 spins with programmable all-to-all connectivity. We test this design using Multi-Input Multi-Output decoding problems, and show that the OIM emulator achieves near-optimal Symbol Error Rates (SER).