| Cooperative relay technologies are currently being researched to address the ever-increasing demand for higher data rates, extended coverage, greater mobility, and enhanced reliability. This thesis thus focuses on (1) developing new physical-layer wireless technologies for cooperative relay networks and (2) ascertaining their viability through performance analysis. Specifically, (i) new system and channel models, (ii) signaling and relay-processing algorithms, (iii) joint relay-antenna selection strategies, (iv) joint transmit-receive beamforming techniques, and (v) comprehensive performance analysis frameworks are developed for one-way, two-way, and multi-way cooperative relay networks.;Our first research focuses on developing a comprehensive analytical framework for deriving closed-form performance bounds of multi-hop amplify-and-forward (AF) relay networks. Specifically, mathematically-tractable, asymptotically-exact end-to-end signal-to-noise ratio bounds are first formulated, and thereby, the outage probability and average bit error rate bounds are derived. In our second work, adaptive multiple-relay selection strategies are designed and analyzed for multi-relay AF networks to optimize the trade-offs among the system performance, complexity, and wireless resource usage. Our third research investigates joint antenna and relay selection strategies, which are optimal in the sense of the achievable diversity gains, for multiple-input multiple-output (MIMO) one-way relay networks and MIMO two-way relay networks. Finally, joint transmit/receive zero forcing transmission strategies are developed for MIMO multi-way relay networks for optimizing the achievable diversity-multiplexing trade-off.;The key design criterion of the aforementioned transmission designs is to leverage spatial diversity and/or spatial multiplexing gains available among distributed single-antenna and/or multiple-antenna wireless terminals through distributed transmission and efficient signal processing. Moreover, the fundamental relationships among the data rate, coverage, and reliability metrics are characterized, and thereby, the detrimental impact of practical wireless transmission impairments on the performance of the aforementioned transmission strategies are quantified. The insights obtained through these analyses are then used to refine our physical-layer designs to achieve desirable trade-offs between the system performance, resource usage and implementation complexity. |
