A Soieduling Algorithms For Mac Layer In Lte System

The demand for higher speed of wireless communication has been increaseddramatically during the past decade due to the popularity of smart phones, Wi-Fi, andother applications. To improving the transmission rate and lowing the complexity of thesystem architecture, a long term evolution (LTE) has been launched by3GPP for3Gcommunications. Compare with standard3G technology based on CDMA(TDS-CDMA, WCDMA and CDMA2000), LTE applied OFDM as the maintechnology, and increase the bandwidth to20MHz from5MHz.Under the multiple-carrier scenario, scheduling algorithm in MAC layer of thesystem plays an important role to the system performance: To Guarantee the QoS ofeach Radio Bearer by defining the total data quantity for each Radio Bearer andindicating the package size from RLC layer. For this purpose, the scheduling algorithmin mac layer should allocate resources by taking a comprehensive consideration ofchannel quality, traffic characteristics, priority of Different users.In this study, various downlink scheduling algorithms are proposed and analyzed.Their performances are compared through system level simulation. It is observed thatthe proposed scheduling algorithm shows better performance in terms of QoS andreduced complexity.