Research On A Novel DCA Scheme In TD-SCDMA System With HSPDA

With more and more requirements of wireless Internet traffic in present information society, transmission rate achieve a high level. In this situation various enhanced technologies have gradually adopted by the 3^rd mobile telecommunication systems, which will provide higher rate of packet transmission and spectrum efficiency to asymmetric wireless Internet traffic.TD-SCDMA is one of the 3^rd mobile telecommunication systems criteria. It adopts High Speed Downlink Packet Access (HSDPA) in Release 5 which can transmit downlink packets at the rate of 2．8Mb/s. High speed packet data has the features of asymmetric, high peak rate and short active time. To utilize radio spectrum resource efficiently, a physical channel has been specially added in TD-SCDMA system which is called High Speed Downlink Shared Channel (HS-DSCH). HS-DSCH is used for high speed packet transmission shared by multi-users. HSDPA has several key technologies, which are Adaptive Modulation & Coding (AMC), Hybrid Automatic Repeat reQuest (HARQ), fast scheduling and so on. With these technologies the data throughput will be greatly improved.Firstly, this thesis introduces TD-SCDMA system, HSDPA technologies applied in TD-SCDMA system.Secondly, the application of HSDPA technology in TD-SCDMA system is analyzed and the influence on TD-SCDMA caused by HSDPA technology is evaluated by a simulation platform.Finally, a new dynamic channel allocation algorithm is introduced. In the system of TD-SCDMA with HSDPA, there are some base stations which could support HSDPA technology while others couldn't. What's more, these two kinds of base stations have different slot allocation schemes. So, if HSDPA utilize the same carrier as TD-SCDMA, It will cause the system serious inter-slot interference. In order to solve the problem, this thesis introduces a novel DCA algorithm called divided-area slot scheduling algorithm. The simulation proves that the throughput in hot-point is improved area and the QoS of non-hot-point service area is also improved.