Quantum linear system algorithm applied to communication systems

The article discusses the application of quantum linear system algorithms (QLSAs) in communication systems, highlighting their potential to solve large-scale linear equations more efficiently than classical methods. The Harrow-Hassidim-Lloyd (HHL) algorithm is introduced, which can compute solutions to linear systems exponentially faster than the best classical algorithms for sparse matrices. The article then addresses the challenge of extracting classical information from quantum states, a problem known as the read-out problem. The authors propose a method that combines matrix modification and quantum amplitude estimation to extract amplitude and phase information from quantum states. This method is applied to the MIMO detection problem in communication systems, showing how it can be used to recover transmitted signals more efficiently than classical methods. The article also discusses the condition number of the modified matrix and the parameters in the quantum amplitude estimation process, ensuring the efficiency of the proposed algorithm. Finally, the authors summarize their results and discuss the potential applications of their method in communication systems.