Analog Radio-Over-Fiber Supported Increased RAU Spacing for 60 GHz Distributed MIMO Employing Spatial Diversity and Multiplexing

Abstract

The improvements in coverage through spatial diversity and increased data rates through spatial multiplexing using a distributed Multiple-Input Multiple-Output (MIMO) system are important targets for future wireless communications. Here, the appropriate separation of Remote Antenna Units (RAUs) at several user locations in a millimeter-wave system is demonstrated. An analog Radio over Fiber (RoF) fronthaul is used to achieve flexible spacing of distributed RAUs and transports two Gb/s data streams over 2.2km of fiber and up to 8m of 60 GHz wireless transmission distance. A performance comparison is performed between Single-Input Single-Output (SISO) and MIMO operation using different antenna spacing and transmission distance. Results show that the wider RAU spacing enabled by the RoF distribution provides improved results at longer distances, for both spatial diversity and for spatial multiplexing. Verification of a method for measuring each channel coefficient individually and using subsequent MIMO processing on these coefficients, enables an extension to the results showing the feasibility of 30m indoor transmission. Index Terms-Radio-over-Fiber (RoF), Millimeter Wave (mmW), Multiple-input Multiple-output (MIMO)

Single Radio-Over-Fiber Link and RF Chain-Based 60 GHz Multi-Beam Transmission

“…RAUs might operate for separate base stations, in which case the usual mobile system handover procedures would apply. They could also operate as part of the same base station, and, here, cooperative (joint) transmission and reception techniques for distributed MIMO [35] can be applied. Such an application would be particularly useful in dense user environments to be served by multiple RAUs delivering high-speed data (e.g.…”

A Joint Scheduling and Beamforming Scheme for RoF-Aided MC-SSN

“…Among the existing technologies, RoF is very suitable for MC-SSN applications, since they have the advantages of wide coverage, low deployment cost, and high technical maturity [6], [9], [12]- [15]. MIMO and mmWave technologies are capable for such system, achieving high capacity gain and limited resource assumption [8], [11], [16]. Moreover, some adaptive and intelligent frameworks are introduced, such as cloud/edge [10], [17], [18] or fog/edge computing, software defined network (SDN), multihop/multilayer network [19]- [22], integrated wireless sensor network (WSN) and hybrid LiFi/WiFi [23], etc.…”

“…Radio resource management (RRM) mainly focuses on PHY layer, which is also the key point of this paper. Since the advantage of time and space multiplexing, MIMO technology is promising for high demand networks [3], [5], [11]. DoF of the circular multirelay MIMO interference channel is analyzed, while full duplex MIMO is deployed in [24].…”

“…It is a system with the following advantages [8]: Low attenuation, simplicity and cost-effectiveness, low cost expandability, high capacity, flexibility and dynamic resource allocation. RoF system is also capable for supporting MIMO transmission with the deployment of multi-mode fiber [10], [11].…”

The Fronthaul Infrastructure of 5G Mobile Networks

“…Traditional D-RoF approaches, where common public radio interface (CPRI) processing at the RRH imposes a bottleneck in network performance, will be eventually replaced by new open source standards. On the other hand, A-RoF has also been proposed as a promising alternative solution [10], [38] to completely eliminate the digital processing at the RRH.…”