Performance Analysis of Scheduling in Decode-and-Forward Broadcast Channel with Limited-Feedback

In wireless dual-hop decode-and-forward (DF) relaying networks, multiple relay stations (RS) and users construct a DF broadcast channel (DFBC). Due to unpredictable decoding failure, scheduling in the DFBC should depend on not only channel qualities but also the availability of error-free data at individual RSs. Based on the reception qualities of RSs and channel quality information (CQI), we propose a new centralized scheduling scheme to maximize the sum rate of the DFBC. An exact closed-form expression for the sum rate is derived to analyze the new scheme. To further facilitate the analysis, the bounds of the sum rate are derived as a computationally effective alternative to the exact expression. Simulations demonstrate that the derived closed-form expression quantifies the proposed scheduling method accurately. It is also revealed that the analytical bounds are able to characterize the performance of the new scheduling method with acceptable accuracy.