Computationally Efficient Channel Estimation in 5G Massive Multiple-Input Multiple-output Systems

Abstract

Traditional channel estimation algorithms such as minimum mean square error (MMSE) are widely used in massive multiple-input multiple-output (MIMO) systems, but require a matrix inversion operation and an enormous amount of computations, which result in high computational complexity and make them impractical to implement. To overcome the matrix inversion problem, we propose a computationally efficient hybrid steepest descent Gauss–Seidel (SDGS) joint detection, which directly estimates the user’s transmitted symbol vector, and can quickly converge to obtain an ideal estimation value with a few simple iterations. Moreover, signal detection performance was further improved by utilizing the bit log-likelihood ratio (LLR) for soft channel decoding. Simulation results showed that the proposed algorithm had better channel estimation performance, which improved the signal detection by 31.68% while the complexity was reduced by 45.72%, compared with the existing algorithms.

Massive MIMO Systems: Present and Future

“…In the practical viewpoint, limited statistical CSI feedback constraint was considered and machine learning based user grouping aided hybrid beamforming was proposed [18]. Further, CSI estimation elimination approach, which applies a blind adaptive array signal processing, has been proposed and its practical performance was evaluated with considering medium access control (MAC) layer overhead of IEEE802.11ac and frequency division duplex (FDD) based LTE standards [19].…”

Low-Complexity Channel Estimation in 5G Massive MIMO-OFDM Systems

“…Therefore, research on channel estimation for massive MIMO in FDD mode has far-reaching significance. However, in FDD mode, an accurate estimation of the downlink is very difficult [6]. A large number of antennas are distributed on the base station, and these transmissions are simultaneously sent to the user.…”

A Robust Channel Estimation Scheme for 5G Massive MIMO Systems

“…Massive multiple-input multiple-output (MIMO) systems are equipped with a large number of antennas at the base station (BS), which can signi cantly improve the spectrum e ciency and energy e ciency of the system. It is regarded as the most promising technology in the fth-generation (5G) wireless communication system [1][2][3][4][5][6]. In order to obtain the performance gain of a massive MIMO system, the BS side needs to know the channel state information (CSI).…”