Massive MIMO in cooperative network with multiple relay under imperfect CSI

ABSTRACT

This paper considers a cooperative network, where a base station (BS) has a very large number of antenna and multiple relays assist a large number of the mobile station (MS) in imperfect channel condition. Extending the same scenario for single relay with a very large antenna array and end-to-end (E2E) system performance has been compared to the previous scenario. For analysing the E2E system performance, random matrix theory (RMT) has been used. Since relay acts as a transceiver, so there is a need for proper precoder/detector. By choosing an arbitrarily random matrix for precoder design such that its auto-covariance is an identity matrix and applying zero-forcing (ZF) detection technique, a closed-form expression for end-to-end (E2E) SNR has been formulated. Numerical results verify our derived analytical expression.

KEYWORDS:

• Imperfect CSI
• massive MIMO
• zf

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. Vector $Y_{b_i}$ is independent and orthogonal from $Y_{b_l}$ where $l\ne i,\mathrm{\forall }l=1,2,...j\text{amp}i=1,2,...j$.

2. If we observe the channel condition in this dual hop wireless network then the chance of channel imperfection is more for $MS$ to relay/relays link. Because user terminal are considered to mobile, relay/relays are taken to fixed. Velocity is the main constraints for estimating the channel between $T_x$ and $R_x$ link.