Research On Some Key Technologies In Hspa+Hetnet System

This paper threw an emphasis on the researches in HSPA+Heterogeneous Network (HetNet) system and made some theory analysis and simulation on the uplink distributed coordination in HSPA+HetNet.First of all, the theoretical knowledge of the HSPA+system was introduced, including the development of the third-generation communication techology (3G), the evolution of the system from WCDMA to HSPA+, etc.; Then it began to focus on the HSDPA system, including its key technology, channel, physical layer processing process, etc., and HSUPA system, including its key technology, channel situation, and finally end to HSPA+HetNet.On one hand, to solve the UL-DL imbalance issue in HetNet, we analyze the technology of E-DCH decoupling and make a simulation. And it’s testified that the implementation of E-DCH decoupling can balance the system. Based on it, we propose the CIO combined with E-DCH decoupling scenario and simulate it. E-DCH decoupling combined with3dB CIO would be the best choice. In addition, we make a further discussion of the E-DCH decoupling procedure for R12UEs and LPN UEs and also make a simulation. And the statistics depict a different performance of UL and DL which should be further researched.On the other hand, to solve the interference issue in HetNet, some special things in HSPA+HetNet are put forward. And we propose a distributed uplink interference coordination via pricing (DUIC-P) scheme in which pricing stands for UE’s harm to the uplink co-channel HSPA+HetNet. To mitigate the harm which is brought by interference and to achieve a more reasonable power allocation, we formulate the scheme as efficient non-cooperative power control games with linear pricing (ENPCG-LP) and with exponential pricing (ENPCGEP), both of which are based on an efficient non-cooperative game theoretic approach. A new utility function that includes pricing, UE transmission rate and frame success rate (FSR) is defined. For the two games, firstly we justify the existence and the uniqueness of their Nash equilibriums. Then we consider a feasible implementation for ENPCG-LP through closed-form best response (CBR) and for ENPCG-EP through table look-up scheme (TLS). Finally, Simulation results show the advantages of our proposed schemes. All of the simulations are implemented under a system simulation platform based on C++.