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Precoded Linear Dispersion Codes for Wireless MIMO Channels

Hayes, Robert Lee, Jr.
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1131246446

Abstract Details

2005, PhD, University of Cincinnati, Engineering : Electrical Engineering.
A primary design objective in next generation wireless systems is to make efficient use of available bandwidth while keeping error rates low. Multiple Input, Multiple Output (MIMO) systems have shown promise toward fulfilling this objective. Space-time codes spread data symbols in time and space in order to create redundancy, which improves bit error rates (BER) but does not improve capacity. Spatial multiplexing techniques decompose the matrix channel into subchannels. This improves capacity but the resulting systems are not optimized with respect to BER. Linear Dispersion Codes (LDCs) are linear codes which spread data symbols using dispersion matrices. These codes guarantee high spectral efficiency and have been shown to exhibit good error performance. LDC designs based on frame theory of wavelets explicitly optimize both capacity and error performance. Conventional space-time codes such as Orthogonal Space-Time Block Codes (OSTBC) and spatial multiplexing systems assume that the transmitter has no knowledge of the channel. In some cases, however, feedback from receiver to transmitter can be established to convey channel state information (CSI). Such systems are called precoding systems. In this dissertation, we propose Precoded Linear Dispersion Codes (P-LDCs), a family of precoders which assume that the receiver has perfect channel knowledge while the transmitter has statistical information about the transmit and receive correlation matrices. P-LDCs can be viewed as a unifying design strategy which utilizes the LDC structure to implement an optimal capacity-achieving transmit covariance strategy. Utilizing partial CSI, P-LDCs form a linear space-time precoder using dispersion matrices derived according to capacity optimality criteria. P-LDC dispersion matrices are designed according to a two-fold objective: maximize spectral efficiency, then minimize pairwise codeword error probability for high signal to noise ratio (SNR). Finally, we analyze frame-based LDCs and demonstrate that existing designs are subject to a capacity penalty under certain circumstances heretofore unexplored. We illustrate this capacity penalty and devise a structural constraint for the LDC precoder based on Grassmannian beamforming to reduce the possibility of this capacity penalty.
Dr. James Caffery (Advisor)
217 p.
MIMO; Wireless Communications; Precoding; Space-Time Coding; Linear Dispersion Codes; Equiangular Frames

Recommended Citations

Citations

  • Hayes, Jr., R. L. (2005). Precoded Linear Dispersion Codes for Wireless MIMO Channels [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1131246446

    APA Style (7th edition)

  • Hayes, Jr., Robert. Precoded Linear Dispersion Codes for Wireless MIMO Channels. 2005. University of Cincinnati, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1131246446.

    MLA Style (8th edition)

  • Hayes, Jr., Robert. "Precoded Linear Dispersion Codes for Wireless MIMO Channels." Doctoral dissertation, University of Cincinnati, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1131246446

    Chicago Manual of Style (17th edition)

ucin1131246446
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© 2005, all rights reserved.
This open access ETD is published by University of Cincinnati and OhioLINK.