Performance Optimization for Overloaded MIMO Systems with Virtual Channel Approach

Guide Yang,Wenlong Xia,Yuanping Zhou

doi:10.1155/2018/9651378

Abstract

In this letter, we propose a virtual channel (VC) optimization approach with a closed-loop and adaptive scheme for overloaded MIMO systems. With this approach, each input data stream goes through a VC which is generated at the transmitter; then it is transmitted to a receiver through the actual wireless channels. The VCs are concatenated with the actual wireless channels. Through VC optimization, the values of which can be adjusted to reduce the channel correlation, leading to a much improved system performance. Compared to the conventional overloaded MIMO systems, the overloaded MIMO systems with this approach can achieve significantly better performances in terms of the system capacity and symbol error rate (SER). The method that uses genetic algorithm (GA) for finding the optimal VC vector is described. Simulation results illustrate the effectiveness of the proposed approach.

Highlights

Massive multiple-input multiple-output (MIMO), known as large MIMO, has been considered as one of the most promising candidate technologies for future 5G communications due to its ability to achieve high throughput and spectral efficiency and enhance the energy efficiency of sensor networks [1,2,3,4,5]
Since the number of antennas is limited in a mobile terminal due to its physical size, the overloaded MIMO system in which the number of transmit antennas is larger than the number of receive antennas is considered [8, 9]
Each input data stream goes through a virtual channel (VC) which is generated at the transmitter before it is transmitted to a receiver through the actual wireless channels

Summary

Introduction

Massive multiple-input multiple-output (MIMO), known as large MIMO, has been considered as one of the most promising candidate technologies for future 5G communications due to its ability to achieve high throughput and spectral efficiency and enhance the energy efficiency of sensor networks [1,2,3,4,5]. We propose a virtual channel (VC) approach with the closed-loop and adaptive scheme for a downlink overloaded MIMO system, namely, the VC overloaded MIMO system. With this approach, each input data stream goes through a VC which is generated at the transmitter before it is transmitted to a receiver through the actual wireless channels. (1) Propose a closed-loop and adaptive VC optimization approach that can significantly mitigate the channel correlation effect and improve the system performance for an overloaded MIMO system in terms of the system capacity and the symbol error rate (SER). CN(0, σn2) denotes a circularly symmetric complex Gaussian random variable with mean zero and variance σn

System Model

Performance Optimization for the VC Overloaded MIMO System

Simulation Results

Conclusion