Spectrally efficient code-domain based IRS transmission scheme for 6G communications

The manuscript proposes a novel spectrally efficient code-domain (CD) based intelligent reflecting surface (IRS) transmission scheme intended for sixth-generation (6G) communications. IRS transmission creates a new paradigm for ultra-reliable, high-speed communications even at low signal-to-noise ratio (SNR) through intelligent manipulation of channel phases. The proposed CD-based IRS scheme studies the performance of IRS transmission both in dual-hop (DH) and access point (AP) modes with the presence of the channel phases. The proposed scheme improves the SNR at the receiver, and the simulation results validate the performance improvement. The performance curves analyze the distribution of symbol error probability (SEP) for different SNR values, signal constellations, and the number of reflecting elements. The SEP performance of the proposed scheme is superior to the conventional IRS scheme in all scenarios. Besides, the overall system performance is also tested without the knowledge of the channel phases. The system capacity and throughput performance results manifest the dominance of the proposed scheme under the context of high spectral efficiency.