Precoding and Detection for Broadband Single Carrier Terahertz Massive MIMO Systems Using LSQR Algorithm

The terahertz (THz) communication utilizes the frequency spectrum above 300 GHz and is widely considered as a promising solution to the future high-speed shortrange wireless communication beyond millimeter wave (mmWave) communication. While providing tens of gigahertz bandwidth, it is subjected to high propagation path loss, intersymbol and inter-user interferences. The massive multiple-input-multiple-output (MIMO) can be applied to address these problems by cooperation between many access point (AP) antennas. As a trade-off, each antenna can be simply built without complicated structure for high antenna gain. However, the channel delay spread due to its large bandwidth is a challenge that the array signal processing have to deal with. In this paper, we define two typical application scenarios of the THz communication, use a ray-launching simulator to generate realistic channel impulse response (CIR) and describe the broadband signal transmission with the block matrices. The least square QR (LSQR) algorithm is applied.