Improving spectral efficiency in future 6G mobile communications is a key global challenge. Existing technologies fall short of satisfying future mobile communication requirements. One possible solution is to use chaotic signals in wireless communication networks. Chaotic signals could be a key to future communication tech. This article describes and studies a new communication method. M-ary chaos-shift-keying (M-ary CSK) modes form the basis. This method’s potential matches and even exceeds the spectral efficiency of current technologies. First, we describe a ring generator of chaotic signals. Its main element is a delay line with taps. Then, we describe the principle of a communication system. It uses chaotic synchronization to transmit M-ary information. Below are the results of a mathematical modeling. A communication system based on M-ary CSK was studied and compared with quadrature-amplitude modulation. We acknowledge the positive and negative aspects of the M-ary CSK method. We suggest future research on the M-ary CSK method in promising communication systems.