A SDR-Based NR-WLAN Aggregation System towards 5G Indoor Coverage

With the approval of the fifth generation (5G) New Radio (NR) specifications, the anticipated use of higher spectrum brings challenges due to its propagation characteristic. Among them, expanding the range and capacity of indoor scenes gradually attracts worldwide attention. In this paper, a scheme of NR-WLAN aggregation (NWA) is proposed to enhance indoor coverage by offloading NR traffic to the wireless local area network (WLAN). WLAN is considered to be one of the most important radio access techniques, taking full advantage of the unlicensed bands, and has been explored for decades. The state of 5G indoor coverage is concluded first to explain the reason for using WLAN as supplement. Next, the protocol with split link is designed based on the NR system. To improve the performance of the NWA system, a dynamic offloading mechanism is devised and verified in practice. Due to the high flexibility and reconfigurability of open source software defined radio (SDR), we choose general-purpose-processor-based (GPP) SDR to complete our NWA system, which also provides a successful exploration of baseband processing unit (BBU) virtualization. Over-the-air experiments are carried out to evaluate the performance on the designed NWA system. The results demonstrate that the throughput gain of the proposed NWA system is better than that of the 5G network deployment alone.