Signal Transmission In Channels Research Articles

ოთხგანზომილებიან სიგნალთა არაოპტიმალური კომბინირება

The article discusses the issue of signal transmission in channels where fading takes place along with additive white Gaussian noise. It is commonly supposed that at this time the signal amplitude (envelope) was fluctuated with the Rayleigh distribution. It is accepted that fading is slow and frequency is non-selective. For transmit diversity from antennas, their combination with signals is carried out in a selective scheme. The characteristics of systems based on 2FSK-8PSK and 2FSK 8APSK signals are evaluated with the help of computer simulation.

MIMO relay channel signal transmission in transformed signal subspace

We design a new improved signal space alignment scheme in MIMO Y channel where one of K source nodes sends K−1 independent messages to the other nodes and each message achieves the degrees of freedom (DoF) of d. The key is to let the messages to be exchanged by applying improved signal space alignment for network coding and interference cancellation when antennas configuration extends to N>2M, where N and M denote the number of antennas at the relay and each source respectively. It is not feasible for the traditional signal space alignment to achieve the same DoF under this antenna number configuration. Moreover, we discuss the ill-conditioned channel to improve the system performance for Zero Forcing decoder. The simulations show that our proposed scheme achieves DoF of dK(K−1) and improves system performance reliability.