Quantum Speedup for Pilot Assignment Problems

We propose a quantum-assisted solution of the pilot assignment problem. In particular, we formulate a pilot assignment problem designed to minimize the interference from co-pilot user terminals as a binary optimization problem which can be solved via a quantum exhaustive search through the Grover adaptive search (GAS) algorithm. The performance of GAS in terms of query complexity is enhanced by introducing a modified initial state and an improved initial threshold using the upper bound for the minimum value of the objective function. Simulation results demonstrate that our proposed method can provide quadratic speedup compared to an exhaustive search performed by a classical computer, concretely demonstrating that quantum computers can be employed to solve optimally and efficiently the pilot assignment problem.