Demonstration of fully functional MIMO wireless LAN transmission over GI-MMF for in-building networks

We propose a low-cost optically-fed architecture capable of increasing the capacity and overall coverage of IEEE 802.11n MIMO WLAN system for in-building networks. A fully functional transmission over GI-MMF was demonstrated employing 2×3 MIMO configuration.

1. Introduction

The multiple-input and multiple-output (MIMO) technology adopted in the IEEE 802.11n standard is widely exploited in wireless communication as it significantly enhances data throughput and link reach without additional bandwidth or transmit power. Traditionally, a large number of wireless access points (APs) in the WLAN have to be deployed inside buildings to guarantee sufficient coverage in every room. However, such an approach is power-hungry and costly especially in large buildings. Nevertheless, the radio-over-fiber (RoF) technique is a promising substitute benefiting from large bandwidth, low loss and immunity to EM interference. Thanks to the optically-fed infrastructure, all the APs connected remotely by fibers from a central station can be positioned wherever the wireless coverage is required. However new challenges to adapt the existing protocol have come up as MIMO radio signals are provided from the central station to remote antennas. Only a few approaches have been discussed recently [1]–[4], but they did not accomplish a full functionality of the MIMO WLAN transmission.