Cooperative diversity for the cellular uplink: Sharing strategies, performance analysis, and receiver design

In this thesis, we propose data sharing schemes for the cooperative diversity in a cellular uplink to exploit diversity and enhance throughput performance of the system. Particularly, we consider new two and three-or-more user decode and forward (DF) protocols using space time block codes. We discuss two-user and three-user amplify and forward (AF) protocols and evaluate the performance of the above mentioned data sharing protocols in terms of the bit error rate and the throughput in an asynchronous code division multiple access (CDMA) cellular uplink. We develop a linear receiver for joint space-time decoding and multiuser detection that provides full diversity and near maximum-likelihood performance.;We also focus on a practical situation where inter-user channel is noisy and cooperating users can not successfully estimate other user\u27s data. We further design our system model such that, users decide not to forward anything in case of symbol errors. Channel estimation plays an important role here, since cooperating users make random estimation errors and the base station can not have the knowledge of the errors or the inter-user channels. We consider a training-based approach for channel estimation. We provide an information outage probability analysis for the proposed multi-user sharing schemes. (Abstract shortened by UMI.)

The performance of space-time coded cooperative diversity in an asynchronous cellular uplink

Most of the prior work on cooperative diversity assumes allocation of orthogonal channels to multiple users (inter-user orthogonality) and synchronous communication between the signals transmitted from different cooperating terminals in the network. Both of these assumptions may require an accurate coordination among the cooperating users causing significant overhead in wireless networks. The main purpose of this paper ∗ is to investigate the impact of inter-user non-orthogonality and asynchronous communication on the information-outage probability performance of multi-user space-time coded cooperative diversity in a cellular uplink. We also present a practical system design and we provide bit-error-probability simulations under the practical adaptive receiver design