In this paper, we propose a reconfigurable optical‐radio wireless network characterized by high flexibility and performance. The hybrid network can be dynamically configured, adapting itself to the changing requirements of users or operating environments, dynamics of the transmission medium, and availability of resources. First, the basic concept, system architecture, and key operating modes are introduced. Possible operating scenarios and their relationship to the operating modes are discussed. Then, a practical implementation of the hybrid network is introduced, describing the network components, architecture, modulation scheme, and implementation technologies. Implementation was carried out using mostly off‐the‐shelf components and universal software radio peripheral blocks. Particular attention has been put in implementing a fast handover mechanism between modes, an essential requirement for seamless network reconfiguration. Network performance is evaluated and different switching approaches are compared. The paper demonstrates practically the proposed concept based on dynamic system reconfiguration. For the implementation, a mode switching algorithm was developed making decisions based on the quality of the wireless channels. The system was tested with live video packets transmitted through the network. System performance was assessed through data throughput and packet loss measured for different modulation parameters. The proposed concept, essentially a software‐defined hybrid network, is flexible and makes efficient use of radio resources. Moreover, the network has the potential to achieve high performance. All these characteristics make reconfigurable optical‐radio networks an attractive candidate for fifth generation and beyond.

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In 2011, we proposed a new receiver structure called Frequency domain linear MMSE filter with sphere detection for single-carrier frequency-division multiple access (SC-FDMA) uplink transmission. Frame error rate simulations and complexity estimations were used to define the most practical sphere detector algorithm for this receiver. High-level Synthesis (HLS) tools were used for comparing different architectures for the sphere detector. After 2011, the HLS design approach has gained more popularity and the tools have evolved. In this paper, HLS tools from different generations were used for implementing the same K-best list sphere detector. The results were compared and the overall experience of the optimization process and the evolution of the HLS tools was discussed. Additionally, the evolution of FPGA technology was discussed. In conclusion, the HLS tools have evolved into practical implementation tools even for high complex wireless communication algorithms. Moreover, 25% increase in throughput and 58% lower resource usage was achieved with the latest generation FPGA.

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