Statistical mechanics of CDMA multiuser detector implemented in coherent Ising machine
Toru Aonishi, Kazushi Mimura, Masato Okada, Y. Yamamoto · Journal of Applied Physics · 2018
The scalability and computational ability of the coherent Ising machine (CIM) have made it attract attention as one of the most effective Ising computing architectures for solving large-scale optimization problems. However, the theory and techniques of equilibrium classical thermodynamics cannot be directly applied to the CIM because it is an open-dissipative system. In an attempt to adapt the theory and techniques to the CIM, we have used a canonical frustrated model of Ising computation called the CDMA (Code Division Multiple Access) multiuser detector. Here, we derive a macroscopic equation to estimate the critical value of the spreading factor for achieving a low bit error rate as a function of the normalized pump rate in the CIM-implemented CDMA multiuser detector.