The Switch-based Subcarrier Allocation Policies in Multi-service OFDM Systems

In this paper, we present a switch-based algorithm allocating subchannels and an adaptive modulation in multi-service stream orthogonal frequency division multiplexing (OFDM) systems. Conventional schemes were proposed to optimize the system performance, such as bandwidth efficiency, bit error rate (BER), and etc. However, these schemes could result in the unfairness in resource allocation. Thus, in this work, a new resource allocation algorithm based on weighted round robin (WRR) is proposed to conquer this unfairness, improve the system throughput and maintain the queueing length of each individual stream to a predefined region. Meanwhile, combining the adaptive assignment in diverse subchannels not only augments the bandwidth efficiency but also suboptimizes the entire performance in the environment with the limited resource. The ability of maintaining the queueing length could guarantee the queueing delay according to Little´s law. This feature makes the proposed approach suitable for delay constraint services. The preliminary simulation results demonstrate the aforementioned ability