Performance of cooperative relaying systems with co-channel interference

The objectives of this dissertation are to analyze the performance of cooperative decode-and-forward (DF) relaying systems in the presence of multiple interferers and to improve the network throughput for these systems. Since cooperative relaying can gain benefits of spatial diversity and overcome the hardware constraints of existing wireless systems, it is a focus of considerable research. However, from a practical point of view, there are still many unresolved problems of resource allocation in cooperative relaying systems. To get a practical approach for the cooperative relaying system, in this dissertation, we propose and summarize various DF schemes in the view of network topology (multi-branch dual-hop relaying and multi-branch multi-hop relaying), transmission structure (outage-based symbol relaying, outage-based packet relaying, and cyclic-redundancy-check (CRC)-based packet relaying), slot allocation (fixed-slot selection DF, repeated-slot selection DF, and variable-slot selection DF), and network environments (ad-hoc and cellular networks).;We first analyze the outage probability of multi-branch dual-hop DF cooperative relaying systems over Nakagami/Nakagami fading channels, and present an exact closed-form expression for the outage probability with maximum ratio combining considering (MRC) both the effect of co-channel interference and white Gaussian noise. The effect of imbalanced powers of interference received at the relay and the destination is also analyzed to investigate whether the relay or destination is more sensitive to interference. Second, we generalize DF cooperative diversity to multi-branch multi-hop (MBMH) relaying systems over shadowed-Nakagami/shadowed-Nakagami fading channels, and derive closed-form expressions for the outage probability and the average symbol-error-probability of the MBMH DF relaying systems. Against shadowing as well as fading, the effect of the numbers of both branches and hops is considered over the proposed systems. Next, the cooperative relaying system can be extended from ad-hoc to cellular networks. We compare the outage performances of the fixed-gain amplify-and-forward and DF cooperative relaying systems with selective combining over entire cell area. Fourth, we investigate the performance benefits and tradeoffs between outage probability and spectral efficiency for the DF cellular relaying systems with MRC. The optimal-relay location and the effective region are evaluated for omnidirectional and sectorized cells in both the uplink and the downlink with respect to co-channel reuse factor. Fifth, we propose the DF cooperative systems with packet transmission: outage-based packet relaying and CRC-based packet relaying. In the cellular networks, we evaluate average packet-error-probability for various proposed schemes with respect to co-channel reuse factor in both the uplink and the downlink. Finally, we propose a variable-slot selection DF scheme which uses dynamic slot allocation operating on CRC-based packet relaying.;Our research on the performance analysis and throughput improvement of the generalized DF cooperative relaying systems for both ad-hoc and cellular networks can provide other researchers with practical approach to develop future cooperative relaying systems.