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Research On Hybrid ARQ Schemes In Wireless Communications

Posted on:2007-12-27Degree:DoctorType:Dissertation
Country:ChinaCandidate:F LiFull Text:PDF
GTID:1118360185451415Subject:Communication and Information System
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With the rapid development of wireless communication systems and the appearance of more and more new services, the requirement of wireless communication systems on data transmission rate and Quality of Service (QoS) is growing higher, which in turn pushes the research on wireless communication technologies. As a result, error control schemes with high efficiency, which will effect both of data transmission rate and QoS of systems, will be a major research field in next generation wireless communication systems. Hybrid ARQ, which utilizes the advantages of two main error control schemes: Forward Error Control (FEC) and Automatic Repeat reQuest (ARQ), has been proved to be an error control scheme with high efficiency and tends to be one of the key technologies in next generation wireless communication systems.In this thesis we extensively analyses all kinds of Hybrid ARQ schemes, including their basic principles, system performances and applications on wireless communication systems. Corresponding research of the author is also introduced in this thesis in detail.1. Basic principles of Hybrid ARQ are introduced first in this thesis, including extensive survey on current research fields of Hybrid ARQ. The thesis introduces all kinds of Hybrid ARQ schemes respectively, and specifically analyses Type-II Hybrid ARQ based on Incremental Redundancy (IR), Type-Ill Hybrid ARQ based on Chase Combining and Reliability-based Hybrid ARQ (RB-HARQ), including their basic principles, system performances and some problems that should be addressed in applications.2. Based on the research on Type-II Hybrid ARQ scheme, this thesis discusses the effect that Hybrid ARQ imposed on other technologies when it is applied in wireless communication systems. In this thesis, PMCAP/CDMA protocol , which is based on Preamble in communication, is set as an example to analyze the influences on the Multiple Access Interference (MAI) control method by "integrating Type-II Hybrid ARQ scheme into PMCAP/CDMA protocol. As a result, an improved MAI control method, Combining Differentiated MAI (CD-MAI) method, is proposed in this thesis. Simulation results show that CD-MAI method can improve the system performance by considering the influence of Type-II Hybrid ARQ scheme.3. This thesis proposed a feedback packet compression algorithm for Reliability-based Hybrdi ARQ scheme. Feedback packet with too large size is always a big problem preventing RB-HARQ from being applied into wireless communication systems, a compress algorithm on feedback packet is proposed in this thesis to mitigate this problem, which utilizes the position relation between adjacent retransmission bits to construct the error bits list. On the other hand, a pre-selection algorithm on retransmission bits in the receiver is also proposed to implement a pre-selection before the selection of retransmission bits, which will lower the complexity of selecting retransmission bits in the receiver. Simulation results show that using the proposed feedback packet compression algorithm, the feedback packet size can be greatly reduced, which in turn will decrease the load of feedback channel and improve the practicability of RB-HARQ scheme.4. A Hybrid ARQ scheme based on subcarrier remapping in OFDM system is also proposed in this thesis. OFDM is deemed to be the mainstream technology in next generation...
Keywords/Search Tags:Error Control, Hybrid ARQ, Combining Differentiated Multiple Access Interference Control, Feedback Packet Compression Algorithm, Pre-selection of Retransmission Bits, Subcarrier Remapping
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