The Detection Algorithms Based On Fde Theory In Hspa

Because of the popularization of the third generation mobile telecommunication, more and more data service depends on high wireless bandwidth so as to provide high data rate. The HSPA system has high transmission rate in a small delay, it greatly facilitates users experience all kinds of3g data services via mobile terminal. However, wireless channel becomes frequency-selective when data transferred in a high speed, and multi-path interface will damage the orthogonality of the spreading codes, so the performance of HSPA system is degraded. As the traditional anti-multipath techniques, Rake receiver’s performance is less than equalization’s, in addition, the implementation of frequency domain equalization is much easier than that in time domain, so it is necessary to research the frequency domain equalization algorithm in the HSPA system.The article is focus on HSPA system and FDE, in the aspects of system implementation, this paper explains the HSPA system from transmitter and receiver, the key technology of HSPA is elaborated, which contains turbo encoding, rate matching, interleaving, modulating, spreading and rake combing, all of the inverse process of these technology are also elaborated. When comes to FDE, the article gives the detailed analysis of SC-FDE, including its principle and advantage, some typical FDE algorithms are discussed at last.In the aspects of performance analysis, the paper gives the simulation between different equalization, it shows that the FDE’s performance is better than TDE’s. Because the FDE’s channel matrix is diagonal and it employ the efficient FFT algorithm, its complexity is also less than TDE’s. On the other hand, this article gives the performance of three different FDE algorithms, it asserts that the ZF-FDE has the worst performance and the least complexity; the MMSE-FDE has a good performance and it’s implementation is not very complicated; the decision feedback equalizer has the best performance but its complexity is the maximum.The most important part of the paper is the comparison of the performance between SC-FDE and rake receiver in the HSPA system, and discuss how the AMC and HARQ technology have influence on the system throughput. Analysis show that AMC and HARQ both could improve the throughput rate, the rake receiver’s performance has a dramatic drop due to the increase of multipath, however, for HSPA based on FDE, although the transmission efficiency is decline due to the insertion of GI, it hardly influenced by multipath, so it is more appropriate for HSPA system.