Complementary Coded Scrambling Hopping Multiple Access in the Downlink MIMO Channels

The rapid growth of wireless devices has significantly increased the demand for user capacity in communication systems while exacerbating interference challenges. Existing multiple access techniques often face challenges in user capacity, particularly under unfavorable channel conditions. To tackle this issue, we propose a complementary coded scrambling hopping multiple access (CCSHMA) scheme that is designed to address the high user capacity demands in low signal-to-interference-plusnoise ratio environments. Our scheme utilizes three-dimensional complementary codes to scramble signals across multiple domains to mitigate interference. Furthermore, we implement a grouped code-hopping scheme to improve the user capacity. Simulation results indicate that the CCSHMA scheme effectively improves user capacity and achieves a reduced bit error rate under poor channel conditions compared to multiple-input multiple-output orthogonal frequency division multiple access.