Location: 2111 Engineering Hall
Date and Time: February 23, 2012, 3:30pm – 5:30pm

Committee:
Professor Ahmed Eltawil (Chair)
Professor Ender Ayanoglu
Professor Fadi Kurdahi

Title: Tree Search Based MIMO Detectors: Algorithms and VLSI Architectures

Abstract:
MIMO communication has been recognized as a promising technology to improve the quality of service and/or to achieve high data rate for wireless communication systems. However, the lucrative features of MIMO communications come along with the costs of significantly increased system complexity. In this thesis, we present efficient design for the spatial multiplexing MIMO receivers at both the algorithm and VLSI architecture levels. We consider that the MIMO detector and the channel decoder are two major blocks and attempt to optimize them in a joint sense. First of all, we will focus on the design of MIMO detector and propose two approaches. The first design presents a novel algorithm and architecture for K-Best detection. The algorithm examines a much smaller subset of points in the tree structure while still achieving near-optimal performance. The VLSI architecture of the detector is based on a pipelined sorter-free scheme such that high throughput is achieved. The second design demonstrates an algorithm and VLSI architecture of combining the features of classical depth-first and breadth-first methods. Techniques to reduce complexity while providing both hard and soft output detection are also presented. Finally we will present an approach to perform joint detection and decoding for MIMO systems using convolutional codes. The BER performance of this approach is significantly better than that of systems which utilize separate detection and decoding blocks. The proof of concept VLSI architecture is provided and a novel way to reduce memory usage is demonstrated.