4.6-Km $D$-Band Photonic-Assisted Terahertz Wireless Communication Employing SIMO and MRC Technology

Photon-assisted generation of terahertz (THz) signals can support larger modulation bandwidths in future ultrahigh-speed wireless communication systems. Single-input–multiple-output (SIMO) or multiple-input–multiple-output (MIMO) technology effectively uses the spatial dimension to improve the quality of the received signal, such as signal-to-noise ratio (SNR) and bit error rate (BER) ratio. Therefore, we experimentally demonstrate $D$ -band photon-assisted THz 1 $\times$ 2 SIMO 4.6-km wireless communication. We use a photon-assisted THz technology to generate a 124.37-GHz $D$ -band signal, which is received according to the maximum ratio combining (MRC) technology after 1 $\times$ 2 SIMO wireless transmission and uses fully blind digital signal processing (DSP) for carrier recovery algorithm without any training sequence. According to the experimental results, the maximum SNR diversity gain between 1 $\times$ 1 and 1 $\times$ 2 SIMO can be up to 2.8 dB. After the MRC algorithm, the BER can be reduced by one order of magnitude, which is less than 15% of soft decision forward error correction (SD-FEC). This is the first experimental demonstration of high gain and long range in a $D$ -band THz 1 $\times$ 2 SIMO system with a line rate of 43.5 Gb/s. These results will provide important assistance to our future efforts in photon-assisted THz wireless communications.