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Title page for ETD etd-07182005-113239


Type of Document Master's Thesis
Author goel, vivek ,
Author's Email Address vivek.goel@gmail.com
URN etd-07182005-113239
Title Semi-blind turbo detection for Multiple-input Multiple-output wireless systems
Degree Master of Science
Graduate Program Electrical Engineering
Advisory Committee
Advisor Name Title
Dr. Huaiyu Dai Committee Chair
Dr. Brian L. Hughes Committee Member
Dr. Winser E. Alexander Committee Member
Keywords
  • Blind detection
  • Multi-cell MIMO
  • Multiuser Kurtosis
Date of Defense 2005-07-13
Availability unrestricted
Abstract
Multiple-input multiple-output (MIMO) techniques constitute the core of future high speed wireless systems. Blind detection in MIMO wireless systems conserves bandwidth and is better suited for use in multiple user scenarios. Since, most of the

modern wireless communication systems employ some form of forward error correction, therefore, we can exploit the turbo principle to further improve the performance of blind detection schemes for MIMO.

In this thesis we propose a new semi-blind turbo multiuser detector (MUD) for signal detection in a MIMO wireless system, operating on a single link with Gaussian noise. This turbo MUD (named as T-MUK) performs a sub-optimal joint detection

and decoding by iteratively exchanging soft information between the detector stage, that optimizes multiuser kurtosis maximization criterion, and the decoder stage, that runs maximum aposteriori probability (MAP) algorithm. It is shown to achieve good performance at the expense of very few training symbols.

This thesis also introduces a successive interference cancellation based semi-blind MUD for multicell MIMO systems. This MUD uses T-BLAST, which is a near optimal detection structure for single link, to detect desired signals and T-MUK to detect interfering signals and improves the estimate for desired signal by using these in an iterative fashion. Numerical results indicate the advantage of using this MUD structure over T-BLAST (which treats inter-cell interference as additional noise). The semi-blind nature of T-MUK in this MUD allows us to avoid a common problem in multicell systems, that of extracting reliable channel information for interferers using training sequences.

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