Research On Hsupa Technology Based On E-Dch

With the rapid development of broadband data and multimedia services, the2Mbit/s transfer rate defined by the original target of the3rd generation mobile communication hasn’t been able to meet the demand of UEs. So it is needed for the3G communication technology to be in the direction of higher and wider development. HSUPA/HSDPA is better to solve the problem of mobile broadband.The key main technical characteristic of HSUPA is increasing a new uplink transmission channel-enhanced dedicated channel (E-DCH) for the UE.E-DCH is a dedicated channel. Every UE only has one E-DCH transport channel, independent to other DCH and E-DCH users. At the same time, HSUPA increase a new MAC-e entity in Node B which is responsible for the execution of fast scheduling and re-transmission. This reduces the transmission delay and increases the speed of the retransmission.This article studies the E-DCH associated technology in WCDMA. The research has focused on the physical layer and MAC layer, relating to the physical layer structure, the MAC-layer structure, Node B fast scheduling, Hybrid automatic repeat request (HARQ), transmission of the short frame, the soft handover, E-TFC selection. The research projects focus on the associated technology of physical layer and MAC layer. First, analyze the related content of the E-DCH in physical layer of the HSUPA, such as its difference with DCH and its three main technologies:the short frame transmission(2msTTI), the fast scheduling based on the Node B and fast hybrid automatic retransmission (Hybrid Automatic Repeat Request, HARQ). The fourth chapter is the focus of this topic, focusing on the calculation algorithm of RSEPS (Received Scheduled E-DCH Power Share), which equals the ratio of scheduled E-DCH power and the total power of the uplink data. It.can be used for various scheduling in communication transmission. For the HSUPA system, its purpose is to allocate the power as much as possible to the uplink E-DCH data within the allowable range, so as to achieve the maximum transmission rate. However, if the allocated power is too large, more than system capacity limit, so that the noise and the interference between different users are so large that causing deterioration of the transmission performance and reducing the system capacity. Therefore, according to the calculated value, the upper levels of the system can get the power distribution ratio in the current system. Then decide whether to continue to allocate more power to HSUPA user or inhibit the transmission.