Analog MIMO Radio-over-Copper: Prototype and Preliminary Experimental Results

TL;DR

This paper presents a prototype and preliminary experimental results demonstrating the feasibility of analog MIMO radio-over-copper using LAN cables for indoor 5G applications, exploiting bandwidth up to 400 MHz with low-cost passive devices.

Contribution

It introduces a fully analog MIMO radio-over-copper system and provides the first experimental validation of its capability to transmit RF signals over LAN cables up to 400 MHz.

Findings

Feasibility of analog relaying of MIMO RF signals over LAN cables.

Experimental demonstration of transmission up to 400 MHz.

Potential for cost-effective indoor 5G deployment.

Abstract

Analog Multiple-Input Multiple-Output Radio-over-Copper (A-MIMO-RoC) is an effective all-analog FrontHaul (FH) architecture that exploits any pre-existing Local Area Network (LAN) cabling infrastructure of buildings to distribute Radio-Frequency (RF) signals indoors. A-MIMO-RoC, by leveraging a fully analog implementation, completely avoids any dedicated digital interface by using a transparent end-to-end system, with consequent latency, bandwidth and cost benefits. Usually, LAN cables are exploited mainly in the low-frequency spectrum portion, mostly due to the moderate cable attenuation and crosstalk among twisted-pairs. Unlike current systems based on LAN cables, the key feature of the proposed platform is to exploit more efficiently the huge bandwidth capability offered by LAN cables, that contain 4 twisted-pairs reaching up to 500 MHz bandwidth/pair when the length is below 100 m. Several works proposed numerical simulations that assert the feasibility of employing LAN cables for indoor FH applications up to several hundreds of MHz, but an A-MIMO-RoC experimental evaluation is still missing. Here, we present some preliminary results obtained with an A-MIMO-RoC prototype made by low-cost all-analog/all-passive devices along the signal path. This setup demonstrates experimentally the feasibility of the proposed analog relaying of MIMO RF signals over LAN cables up to 400 MHz, thus enabling an efficient exploitation of the LAN cables transport capabilities for 5G indoor applications.