Study On Coded Cooperation In Fading Channels

When mobiles cannot support multiple antennas due to size or other constraints in wireless communications, conventional space-time coding cannot be used to provide uplink transmit diversity. To address this limitation, the concept of coded cooperation has been introduced, where mobiles achieve transmit diversity by relaying each other's messages.This thesis studies the basic principle of coded cooperation diversity with theoretical analysis and simulation. The main results and contents are as follows.1. The principles of diversity are introduced. Based on these, the system model of user cooperation is discussed with theoretical analysis.2. The principle and system of coded-cooperation is discussed. Instead of a simple repetition relay, coded cooperation partitions the code words of each mobile and transmits portions of each codeword through independent fading channels.3. Two extensions to the coded cooperation framework are presented. First, the diversity of coded cooperation is increased in the fast-fading scenario via ideas borrowed from space-time codes, and bounds for the bit-and block-error rates are calculated to demonstrate the resulting gains. Second, since cooperative coding contains two code components, it is natural to apply turbo codes to this framework. The application of turbo codes in coded cooperation is investigated and the performance of BER is demonstrated via error bounds and simulations.