A Non-orthogonal Cooperative Transmission Scheme Based on Block-fading Channel

• Main Authors: Chuan-Ling Yeh, 葉娟伶
• Other Authors: Hsueh-Jyh Li
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/17565106141500787419

碩士 === 國立臺灣大學 === 電機工程學研究所 === 96 === In this thesis, we consider a cooperative communication system in a wireless network with three nodes and limited by the half-duplex and total power constrained. We discuss two cooperative strategies which mean the Amplify-and-Forward (AF) relaying and Decode-and-forward (DF) relaying in slot-based block-fading environments. We focus on the non-orthogonal transmission which is defined that the source terminal keeps transmission during the whole cooperative time slots. We assume a classical quasi-static slot-based block-fading channel where the channel keeps constant for one time slot and changes the statement during the second time slot. Under this assumption, we proposed a new protocol that the source terminal retransmits the same data during the second time slot. This proposed protocol based on the selective DF and the AF cooperative modes is superior to the previous non-orthogonal scheme for the low spectral efficiency. By the simulation result, there is a boundary system data rate between the proposed protocol and the classical non-orthogonal protocol. Therefore, we may select a suitable mode between the two protocols based on the boundary rate to improve the system performance. Another issue is the optimal power allocation problem. The power allocation strategy uses the expression of the outage probability to optimize the criterion of the power allocation parameters.