Wideband Hybrid Precoding Techniques for THz Massive MIMO in 6G Indoor Network Deployment

Terahertz (THz) communication is becoming an up-and-coming technology for the future 6G networks as it provides an ultra-wide bandwidth.Appropriate channel models and precoding techniques are essential for supporting the desired coverage and mainly to resolve the severe path loss in THz signals. Initially, the Sub-THz channel (140 GHz) impulse response by using NYUSIM Channel Simulator for 6G indoor office scenario is investigated in this work. The highlight is on Large scale and Small scale parameters like propagation delay and path loss, antenna array gain, etc. The beam split effect is a critical challenge of THz wideband communication.Therefore We have proposed three different THz precoding methodologies like the hybrid precoding, analog beamforming, and the delay-phase precoding to address this challenge. We then extensively investigate its diverse number of time delayers, varying number of antenna elements, and comparison with frequency - mmWave and Sub-THz have been discussed. Finally, the proposed delay-phase precoding techniques outperforms the other precoding techniques with 97% of optimal precoding. So, this an efficient approach for implementing the future indoor communication network deployment for 6G.

A Non-WSSUS Channel Simulator for V2X Communication Systems

This paper presents a simulator of non-wide sense stationary uncorrelated scattering (non-WSSUS) multipath fading channels for the performance analysis of vehicle-to-everything (V2X) communication systems. The proposed simulator is constructed with the combination of the Monte Carlo and sum-of-cisoids (SOC) principles, and it is suitable for multicarrier transmission schemes such as those defined for dedicated short-range communications (DSRC) and cellular-based V2X (C-V2X) communications. The channel simulator provides an accurate and flexible solution to reproduce the time and frequency (TF) correlation properties of non-WSSUS vehicular channels under arbitrary isotropic and non-isotropic scattering conditions. Furthermore, the proposed simulator allows velocity variations and non-linear trajectories of the mobile stations (MSs). To demonstrate the practical value of the presented simulator, we evaluate the bit error rate (BER) performance of two channel estimation techniques that are considered for IEEE 802.11p transceivers, namely the least squares (LS) estimator and the spectral temporal averaging (STA) technique. The BER performance of both channel estimators was analyzed by considering three propagating scenarios for road safety applications. Our results show that the non-stationary characteristics of the vehicular multipath fading channel have nearly no effects on the LS estimator’s BER performance. In contrast, the performance of the STA estimator is significantly affected by the channel’s non-stationary characteristics. A variation of the original STA technique that applies only a temporal averaging is introduced in this work to improve the system’s BER in non-WSSUS channels.